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ABC of Transfer and Retrieval Medicine provides the key information required to help health care professionals involved in the movement of critically ill patients to do so safely, correctly and with confidence. Beginning with the practical and clinical considerations to be taken into account during patient transfer and an overview of transfer equipment, it then addresses pharmacological aspects of patient transfer, the roles and responsibilities of the transfer team, and the requirements of neonatal, paediatric and specialist transfers. Mapped against the syllabus for the Diploma of Retrieval and Transfer Medicine (Royal College of Surgeons of Edinburgh), it has been developed as a core resource for the diploma whilst providing an invaluable resource for any healthcare professional involved in the transfer of critically ill patients including anaesthetists, intensivists, nurses from ICU/ED and paramedics. It also includes frameworks for radiology and arterial blood gas interpretation, guidance on patient triage, transfer checklists and equipment checklists, and a summary of the relevant national guidelines. From a multidisciplinary international author team, this new addition to the ABC series is a useful resource for all health care professionals involved in the transfer of patients. It is relevant to anaesthetists, intensivists, paramedics, critical care and emergency department nursing staff who are required to take part in intra and inter hospital transfers.

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Table of Contents

Series Page

Title Page

Copyright

Contributors

Preface

List of Abbreviations

Chapter 1: Introduction

Further reading

Section 1: Physiology of Transfer Medicine

Chapter 2: Acceleration, Deceleration and Vibration

Introduction

Acceleration

Limiting the effects of acceleration

Vibration

Further reading

Chapter 3: Environmental Exposure and Noise

Introduction

Equipment

Noise

Spatial disorientation

Harsh environmental conditions

Weather

Further reading

Chapter 4: Altitude Physiology

Introduction

The atmosphere

Decompression

Decompression sickness

Air transport at low altitude

Further reading

Section 2: Clinical Considerations

Chapter 5: Resuscitation and Stabilisation

Introduction

Handover

Planning ahead

Human factors

Limiting resuscitation

Further reading

Chapter 6: Patient Packaging and Nursing Care

Introduction

Nursing care

Air transfers

Further reading

Chapter 7: Mode of Transport

Introduction

Ground transport

Air transport

Other modes of transport

Summary

Further reading

Chapter 8: International Repatriations

Introduction

Definition

Selecting the mode of transport

Repatriation on commercial airline

Repatriation by air ambulance

Ground transport

Immigration and other formalities

Professional standards

Arranging international repatriation

Further reading

Chapter 9: Critical Incidents

Introduction

Physiological deteriorations (Table 9.1)

Primary equipment failure (Table 9.2)

Road traffic collision

Prevention

Debriefing and incident reporting

Conclusion

Further reading

Section 3: Transfer Equipment

Chapter 10: Electrical Supply and Batteries

Introduction

Internal rechargeable batteries

External power supply

Power supply on board

Monitor/defibrillator units

Ventilators

Further reading

Chapter 11: Transport Ventilators and Medical Gas Supply

Introduction

Types of portable ventilator

Relevant physics

Medical gases in practice

Further reading

Chapter 12: Monitoring

Equipment

How and when to monitor patients

Specific issues with monitoring in the transfer and retrieval environment

Further reading

Chapter 13: Drug Delivery

Introduction

Oxygen and inhaled delivery devices

Intravenous delivery

Drug administration

Further reading

Chapter 14: Near Patient Testing and Imaging

Introduction

POCT devices

Non-blood-based tests

Future developments

Imaging

Further reading

Chapter 15: Haemorrhage Control and Splinting

Temperature control

Minimising movement

External haemorrhage control

Splinting

Fluid resuscitation and permissive hypotension

Blood and clotting agents

Further reading

Chapter 16: Stretchers, Incubators and Vacuum Mattresses

Stretchers utilised in transfer

Mattresses

Scoops

Vacuum mattress and splints

Incubators

Further reading

Chapter 17: Personal Protective Equipment

Introduction

Legislation

Identifying risks

Managing risks

PPE

Use, storage and checking of PPE

Conclusion

Further reading

Chapter 18: Communication and Navigation

Communication

Equipment

Navigation

Further reading

Section 4: Pharmacology of Transfer Medicine

Chapter 19: Routes of Administration

Routes of administration

Safe medication

Central venous catheters

Mucosal atomisation device (MAD)

Intraosseous

Fluid warming devices

Further reading

Chapter 20: Pre-hospital Sedation and Analgesia

Introduction

Analgesia

Principles of management of acute pain

Non-opioids

Opioids

Inhalational agents

Local anaesthesia

Sedation

Further reading

Chapter 21: Sedation and Neuromuscular Blockers

Induction agents

Neuromuscular blockers

Sedation in the pre-hospital setting

Maintenance of sedation

Further reading

Chapter 22: Inotropes and Vasopressors

Introduction

Cardiovascular physiology

Classification of vasoactive drugs

Mechanism of action

Commonly used drugs

Practicalities

Conclusion

Further reading

Chapter 23: Specialist Pharmacology: Haemostatics and Uterotonics

Specialist haemostatic dressings for pre-hospital use

Tranexamic acid

Mannitol and hypertonic saline

Uterotonics

Uterine relaxants

Antiemetics

Anti-arrhythmics

Further reading

Section 5: The Transfer Team

Chapter 24: Managing and Leading a Transfer

Clinical coordination

The operational (retrieval) team

Leadership

Further reading

Chapter 25: Teamwork and Communication

Introduction

Team resource management

Effective teamwork

Leadership/followership and authority gradients

Communication

The organisational level

Conclusion

Further reading

Chapter 26: Non-technical Skills and Sources of Error

Introduction

Non-technical skills

Human factors

Training in non-technical skills and human factors

Conclusion

Further reading

Chapter 27: Standard Operating Procedures, Checklists and Documentation

Documentation

Standard operating procedures

Checklists

Further reading

Chapter 28: Audit, Medicolegal and Ethical Aspects of Transfer Medicine

Introduction

Legal considerations and regulatory bodies

Voluntary organisations

Cross-border patient transport

Medication during transportation

Clinical governance frameworks

Equipment regulation

Audit

Ethical considerations

Further reading

Chapter 29: Training for Transfers

Introduction

Composition of the medical team

The role of regulatory bodies for retrieval personnel

Initial training

The challenge of continuing professional development

Fitness to practice

Further reading

Section 6: Neonatal and Paediatric Transfers

Chapter 30: Anatomical and Physiological Considerations

Introduction

Airway

Breathing

Circulation

Vascular access

Neurology

Psychological considerations

Other important differences

Additional special considerations in neonates

Changes in the circulation at birth

Further reading

Chapter 31: Neonatal Medical Transfers

Introduction

Prematurity

Term infants with respiratory failure

Hypoxic ischaemic encephalopathy

Congenital anomalies

Surgical

In utero

transfers

Repatriation or ‘back to base’ transfers

Elective transfers

Neonatal transport-specific issues to consider

Further reading

Chapter 32: Paediatric Medical Retrievals

Introduction

Preparing for transport

Common paediatric problems needing transport

Further reading

Chapter 33: Paediatric Trauma Retrievals

Introduction

Paediatric injury patterns

Equipment considerations

Initial triage/assessment (5–10 seconds)

Primary survey (allow <2 minutes)

Secondary survey

Packaging for primary transport

Secondary transfer

Non-accidental injury

Acknowledgements

Further reading

Chapter 34: Additional Considerations

Introduction

Environmental considerations

Specialized paediatric scenarios

Vascular access

Psychological aspects

Further reading

Section 7: Specialist Transfers

Chapter 35: Head & Spinal Injuries

Introduction

The need for transfer

Preparation

Further reading

Chapter 36: Burns

Classification of burns by agent, size and depth

Guidelines for referral to a burn centre

Pulmonary inhalation injury

Carbon monoxide poisoning

Cyanide poisoning

Other irritants

Problems experienced during retrieval of the patient with major burns

Further reading

Chapter 37: Polytrauma and Military Retrievals

Polytrauma

Retrieval

UK Defence Medical Services retrieval systems

Comparison with civilian air ambulance services

Secondary retrieval services

Clinical governance

Disclaimer

Further reading

Chapter 38: Obstetric Transfers

Introduction

Reasons for transfer

Principles of obstetric emergencies

Management of specific obstetric emergencies

Monitoring before and during transfer

Resuscitation of maternal cardiac arrest

‘How to’ advice

Further reading

Chapter 39: Cardiac Transfers

Introduction

Extracorporeal life support techniques

ECMO support for adult patients

Mobile ECMO

ECMO retrieval services

Equipment

Vehicles

Intra-aortic balloon pumps and assist devices

Conclusions

Further reading

Chapter 40: Contagious Patients

Introduction

Commonly encountered disease conditions

Routine precautions

Problems encountered during transfer

Further reading

Chapter 41: Bariatric Patients

Introduction

Physiological effects

Inter-hospital transfer

Intra-hospital transfer

Conclusion

Further reading

Chapter 42: Acute Behavioural Disturbances

Medicolegal, aviation and ethical considerations

Decision-making and risk assessment for the disturbed patient retrieval

Preparing the disturbed patient for transport

Retrieval sedation

Physical restraints

Further reading

Chapter 43: Considerations Regarding Organ Donation

Circulation

Respiration

Electrolytes, metabolism and hormones (Box 43.3)

Further reading

Appendix 1: Framework for Radiology Interpretation

Appendix 2: Framework for Interpretation of Arterial Blood Gases

Is the patient hypoxic?

Is the pCO

2

normal?

What is the acid base status?

What is the lactate?

Additional useful information on arterial blood gas analysers

Appendix 3: Example of a Triage Sieve

Appendix 4: Example of a Transfer Checklist

Appendix 5: Example of Equipment Inventory

Appendix 6: Summary of useful National Guidelines

AAGBI: Inter Hospital Transfer (2009)

Recommendations for the Safe Transfer of patients with brain injury (AAGBI 2006)

AAGBI Infection Control in Anaesthesia (2008)

ANZCA Minimum Standards for Intrahospital Transport of Critically Ill Patients

Initial Care and Transfer of Patients with spinal cord injuries. British Orthopaedic Association 2006.

Index

Advertisement

End User License Agreement

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Guide

Cover

Table of Contents

Preface

Section 1: Physiology of Transfer Medicine

Begin Reading

List of Illustrations

Figure 1.1

Figure 2.1

Figure 2.2

Figure 2.3

Figure 2.4

Figure 3.1

Figure 3.2

Figure 3.3

Figure 3.4

Figure 4.1

Figure 4.2

Figure 4.3

Figure 5.1

Figure 5.2

Figure 5.3

Figure 5.4

Figure 5.5

Figure 5.6

Figure 6.1

Figure 6.2

Figure 6.3

Figure 7.1

Figure 7.2

Figure 7.3

Figure 7.4

Figure 7.5

Figure 8.1

Figure 8.2

Figure 9.1

Figure 9.2

Figure 11.1

Figure 11.2

Figure 11.3

Figure 12.1

Figure 12.2

Figure 13.1

Figure 13.2

Figure 14.1

Figure 14.2

Figure 14.3

Figure 15.1

Figure 15.2

Figure 15.3

Figure 15.4

Figure 15.5

Figure 15.6

Figure 15.7

Figure 15.8

Figure 15.9

Figure 16.1

Figure 16.2

Figure 17.1

Figure 17.2

Figure 19.1

Figure 19.2

Figure 19.3

Figure 19.4

Figure 20.1

Figure 20.2

Figure 20.3

Figure 21.1

Figure 21.2

Figure 22.1

Figure 23.1

Figure 23.2

Figure 24.1

Figure 25.1

Figure 25.2

Figure 26.1

Figure 27.1

Figure 28.1

Figure 29.1

Figure 29.2

Figure 30.1

Figure 31.1

Figure 31.2

Figure 31.3

Figure 31.4

Figure 32.1

Figure 33.1

Figure 33.2

Figure 34.1

Figure 36.1

Figure 36.3

Figure 37.1

Figure 38.1

Figure 38.2

Figure 38.3

Figure 38.4

Figure 39.1

Figure 39.2

Figure 39.3

Figure 39.4

Figure 41.1

Figure 41.2

Figure 42.1

List of Tables

Table 2.1

Table 3.1

Table 3.2

Table 3.3

Table 4.1

Table 4.2

Table 7.1

Table 9.1

Table 9.2

Table 11.1

Table 11.2

Table 11.3

Table 13.1

Table 13.2

Table 14.1

Table 15.1

Table 15.2

Table 15.3

Table 15.4

Table 15.5

Table 15.6

Table 15.8

Table 15.7

Table 16.1

Table 16.2

Table 16.3

Table 17.1

Table 17.2

Table 19.1

Table 19.2

Table 19.3

Table 20.1

Table 21.1

Table 21.2

Table 22.1

Table 22.2

Table 22.3

Table 23.1

Table 23.2

Table 26.1

Table 29.1

Table 30.1

Table 30.2

Table 30.3

Table 30.4

Table 39.1

Table 33.1

Table 35.1

Table 36.1

Table 37.1

Table 37.2

Table 37.3

Table 37.4

Table 38.1

Table 39.1

Table 40.1

Table 40.2

Table 40.3

Table 40.4

ABC of Transfer and Retrieval Medicine

EDITED BY

Adam Low

Specialist Registrar in Anaesthetics

West Midlands Deanery

West Midlands Central Accident Resuscitation & Emergency (CARE) Team

West Midlands Ambulance Service NHS Foundation Trust Medical Emergency Response Incident Team (MERIT), UK

AMREF Flying Doctors, Kenya

Jonathan Hulme

Consultant in Intensive Care Medicine and Anaesthesia, Sandwell and West Birmingham Hospitals NHS Trust

Honorary Senior Clinical Lecturer, University of Birmingham, Birmingham

West Midlands Ambulance Service NHS Foundation Trust Medical Emergency Response Incident Team (MERIT)

Medical Director, West Midlands Central Accident Resuscitation & Emergency (CARE) Team

Mercia Accident Rescue Service (MARS) BASICS, UK

This edition first published 2015, © 2015 by John Wiley & Sons Ltd.

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Library of Congress Cataloging-in-Publication Data

ABC of transfer and retrieval medicine / edited by Adam Low, Jonathan Hulme.

p. ; cm.

Includes bibliographical references and index.

ISBN 978-1-118-71975-6 (pbk.)

I. Low, Adam, 1982- editor. II. Hulme, Jonathan, 1974- editor.

[DNLM: 1. Critical Care—methods. 2. Transportation of Patients. 3. Monitoring, Physiologic. 4. Patient Care Team. 5. Patient Transfer. WX 218]

RT87.T72

616.02′8—dc23

2014020562

A catalogue record for this book is available from the British Library.

Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books.

Cover image: 12-03-13 © Paolo Cipriani. Medical emergency team arrives at street accident. Stock Photo: 31074458

Contributors

Anders Aneman

Senior Staff Specialist, Intensive Care Unit, Liverpool Hospital, South Western Sydney Local Health District

Conjoint Associate Professor, University of New South Wales, NSW, Australia

Oliver Bartells

Lieutenant Colonel Royal Army Medical Corps, Consultant Anaesthetist, Ministry of Defence Hospital Unit Northallerton, UK

Hannah Bawdon

Anaesthetic registrar, West Midlands Deanery

West Midlands Central Accident Resuscitation & Emergency (CARE) Team

West Midlands Ambulance Service NHS Foundation Trust Medical Emergency Response Incident Team (MERIT), UK

Jon Bingham

Consultant in Trauma, Resuscitation and Anaesthesia, Department of Anaesthesia, University Hospital of North Staffordshire, Stoke-on-Trent

Midlands Air Ambulance, Cosford

West Midlands Ambulance Service Medical Emergency Response Incident Team (MERIT)

North Staffordshire BASICs

West Midlands Central Accident Resuscitation & Emergency (CARE) Team, UK

Clare Bosanko

Specialty Doctor, Emergency Medicine, University Hospital North Staffordshire, Stoke-On-Trent; West Midlands Ambulance Service NHS Foundation Trust Medical Emergency Response Incident Team (MERIT), UK

Michael Büeschges

Resident, Universitätsklinikum Schleswig Holstein Campus Lübeck, Abteilung für Plastische Chirurgie, Intensiveinheit für Schwerbrandverletzte, Lübeck, Germany

Andrew Cadamy

Consultant in Intensive Care Medicine and Anaesthetics, NHS Greater Glasgow and Clyde, Glasgow, UK

Felicity Clarke

Specialist Registrar Intensive Care & Anaesthetics, University Hospital of North Staffordshire, NHS Trust, Stoke on Trent

PHEM Doctor, West Midlands Ambulance Service NHS Foundation Trust Medical Emergency Response Incident Team (MERIT), UK

Alasdair Corfield

Consultant, Emergency Medicine & Emergency Medical Retrieval Service

Honorary Clinical Associate Professor, University of Glasgow, Glasgow, UK

Stuart J Cox,

Senior Nurse, Critical Care and Aeromedical Transfer CEGA Air Ambulance, Dorset

Senior Charge Nurse, General Intensive Care Unit, University Hospital Southampton NHS Foundation Trust, Southampton, UK

James Cuell

Anaesthetic Registrar, West Midlands Deanery, Birmingham School of Anaesthesia, Birmingham, UK

Zoey Dempsey

Consultant Anaesthetist, Department of Anaesthesia and Pain Medicine, Royal Infirmary of Edinburgh, UK

Joep M. Droogh

Consultant in Intensive Care Medicine

Medical Coordinator Mobile Intensive Care Unit, Department of Critical Care, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands

Catriona Duncan

Consultant in Anaesthesia, Timaru District Hospital, Timaru, New Zealand

Daniel Ellis

Director, MedSTAR Emergency Medical Retrieval Service, South Australian Ambulance Service, Australia

Deputy Director of Trauma and Senior Consultant in Emergency Medicine, Royal Adelaide Hospital, Australia

Associate Professor, School of Public Health and Tropical Medicine, James Cook University, Queensland, Australia

George Evetts

Specialist Registrar Intensive Care & Anaesthesia, Royal Air Force, Imperial College School of Anaesthesia, UK

Rob Fenwick

Charge Nurse, Emergency Department, Shrewsbury and Telford Hospitals NHS Trust, UK.

Anna Fergusson

Anaesthetic Registrar, Peninsula Deanery, South West School of Anaesthesia, Plymouth, UK

Karel Habig

Position

Greater Sydney Area Helicopter, Emergency Medical Service, Ambulance Service NSW Rescue, Helicopter Base, Bankstown Airport, NSW, Australia

Tim Harris

Professor Emergency Medicine, QMUL and Barts Health NHS Trust London, UK

Chris Harvey

Adult and Paediatric ECMO Consultant, ECMO Department, University Hospitals of Leicester, Leicester, UK

Stephen Hearns

Consultant in Emergency Medicine, Royal Alexandra Hospital, Paisley

Lead consultant Emergency Medical Retrieval Service, Scotland, UK

Jo Hegarty

Consultant Neonatologist, Newborn Services, National Women's Health, Auckland City Hospital, Auckland, New Zealand

Matthias Helm

Assistant Professor, Head Section Emergency Medicine, Department of Anaesthesiology and Intensive Care Medicine, Federal Armed Forces Medical Centre, Ulm, Germany

Scott Hepburn

Consultant in Emergency Medicine and EMRS

EMRS Lead for Risk Management, Department of Emergency Medicine, Western Infirmary, Glasgow, UK

Craig Hore

ICU Staff Specialist, Liverpool Hospital ICU/ Retrieval Staff Specialist, Ambulance Service of New South Wales, Sydney, Australia

Martin Horton

Immediate Care Practitioner-nurse, Royal Air Force Emergency and pre hospital specialist MERT practitioner, Emergency Department, Heartlands Hospital, Birmingham, UK

Amy Hughes

Clinical Academic Lecturer in Emergency Response, Humanitarian and Conflict Response Institute, University of Manchester

Emergency Medicine Registrar, Derriford Hospital

Honorary Physician in Pre Hospital Care, London's Air Ambulance, Barts and The Royal London NHS Trust, UK

Jonathan Hulme

Consultant in Intensive Care Medicine and Anaesthesia, Sandwell and West Birmingham Hospitals NHS Trust

Honorary Senior Clinical Lecturer, University of Birmingham, Birmingham

West Midlands Ambulance Service NHS Foundation Trust Medical Emergency Response Incident Team (MERIT), UK

Medical Director, West Midlands Central Accident Resuscitation & Emergency (CARE) Team, UK

Mercia Accident Rescue Service (MARS) BASICS, UK

Midlands Air Ambulance, UK

Lesley Jackson

Consultant Neonatal Medicine and Regional Director, West of Scotland Neonatal Transport Service, Yorkhill Hospital, Glasgow, UK

Emma L. Joynes

Retrieval registrar, Careflight Darwin, NT, Australia

Damian D. Keene

Major, Specialist trainee Anaesthesia and Pre-Hospital Emergency Medicine, Department of Military Anaesthesia and Critical Care

Minh Le Cong

Assistant Professor in Retrieval Medicine, Royal Flying Doctor Service Queensland Section, Australia

Fiona Lecky

Clinical Professor and Honorary Consultant in Emergency Medicine, University of Sheffield and Salford Royal NHS Foundation Trust, Greater Manchester, UK

Ian Locke

Critical Care Paramedic, West Midland Ambulance Service, NHS Trust, Midlands Air Ambulance, UK

David Lockey

Consultant, North Bristol NHS Trust, Bristol, & London's Air Ambulance, UK

Hon. Professor University of Bristol, Bristol, UK

Adam Low

Specialist Registrar in Anaesthetics, West Midlands Deanery

West Midlands Central Accident Resuscitation & Emergency (CARE) Team, UK

West Midlands Ambulance Service NHS Foundation Trust Medical Emergency Response Incident Team (MERIT), UK

AMREF Flying Doctors, Kenya

Stefan Mazur

Chief Medical Officer, South Australian Ambulance Service

Senior Consultant, PreHospital and Retrieval Medicine, MedSTAR Emergency Medical Retrieval Service

Senior Consultant in Emergency Medicine, Royal Adelaide Hospital

Associate Professor, School of Public Health and Tropical Medicine, James Cook University, Australia

Russell D. MacDonald

Attending Staff, Emergency Services, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada

Associate Professor and Co-Director, Emergency Medicine Fellowship Program, Department of Medicine, University of Toronto, Toronto, Ontario, Canada

Medical Director and Chair, Quality Care Committee, Ornge Transport Medicine, Mississauga, Ontario, Canada

Terry Martin

Consultant in Anaesthesia and Intensive Care Medicine, Royal Hampshire County Hospital, Winchester

Medical Director, Capital Air Ambulance, Exeter, UK, Director, CCAT Aeromedical Training, UK

Board Director, AMREF Flying Doctors, Nairobi, Kenya

Board Director, European Aeromedical Institute (EURAMI), Tuebingen, Germany

Heather Mcneilly

Paediatric Registrar, West Midlands Deanery, Birmingham, UK

Michael McCabe

Consultant in Anaesthesia, Anaesthetic Department, Worcester Royal Infirmary, Worcester, UK

Carl McQueen

PHEM Doctor, Midlands Air Ambulance; West Midlands Ambulance Service, Medical Emergency Response Incident Team (MERIT), UK &NIHR Doctoral Research Fellow, University of Warwick, UK

Mary Montgomery

Consultant, Kids Intensive Care & Decision Support, Birmingham Children's Hospital, West Midlands, Birmingham, UK

Patrick Morgan

Specialist Registrar, North Bristol NHS Trust, Bristol

Thomas Muehlberger

Associate Professor, Department of Plastic & Reconstructive Surgery, DRK-Kliniken, Berlin, Germany

Blair Munford

Senior Specialist Anaesthetist, Liverpool Hospital

Senior Retrieval Physician, CareFlight

Conjoint Lecturer in Anaesthetics, UNSW, and Senior Lecturer in Physiology, UWS Medical School

Sydney, Australia

Tim Nutbeam

Consultant in Emergency Medicine, Derriford Hospital, Plymouth Hospitals NHS Trust, Plymouth

West Midlands Ambulance Service NHS Foundation Trust Medical Emergency Response Incident Team (MERIT), UK

William O'Regan

Senior Staff Specialist, Intensive Care Unit, Liverpool Hospital, South Western Sydney Local Health District

Consultant for Careflight International Retrieval Service, Sydney, Australia

Christian Ottomann

Associate Professor, Universitätsklinikum Schleswig, Holstein Campus Lübeck, Sektion für Plastische Chirurgie und Handchirurgie, Intensiveinheit für, Schwerbrandverletzte, Lübeck, Germany

Peter Paal

Associate Professor, Department of Anaesthesiology and Critical Care Medicine, Medical University Innsbruck, Innsbruck, Austria

Helicopter Emergency Medical Service Christophorus 1, Innsbruck, Austria

Eithne Polke

Retrieval coordinator, Children's Acute Transport Service, Great Ormond Street Hospital for Children NHS Trust, London, UK

Richard Protheroe

Consultant in Critical Care Medicine and Neuro-Anaesthesia, Salford Royal NHS Foundation Trust, Salford, Greater Manchester, UK

David Quayle

Chief Flight Nurse, Air Medical Ltd, London Oxford Airport, UK

Samiran Ray

Consultant, Children's Acute Transport Service, Great Ormond Street Hospital for Children NHS Trust, London, UK

Cliff Reid

Senior Staff Specialist and Director of Training, Greater Sydney Area Helicopter Emergency Medical Service, NSW Ambulance, Australia

Clinical Associate Professor in Emergency Medicine, University of Sydney, Australia

Sanjay Revenna

Consultant, Kids Intensive Care & Decision Support, Birmingham Children's Hospital, West Midlands, Birmingham, UK

Gareth Roberts

Department of Anaesthesia, University Hospital of Wales, UK

Mark Ross

Specialist Trainee Registrar in Anaesthesia, Department of Anaesthesia and Pain Medicine, Royal Infirmary Edinburgh, UK

Mark Sheils

Flight Doctor, Careflight NT, Nightcliff, Darwin, Australia

Charlotte Small

Research Fellow, Anaesthesia and Critical Care, University Hospitals Birmingham NHS Foundation Trust (Queen Elizabeth Hospital) Birmingham, UK

Helen Simpson

Consultant Obstetrician, James Cook University Hospital, South Tees Foundation Trust, Middlesbrough, UK

Stephen J. M. Sollid

Dean, Norwegian Air Ambulance Academy, Norwegian Air Ambulance Foundation, Drøbak, Norway;

Consultant Anaesthetist, Air Ambulance Department, Oslo

University Hospital, Oslo, Norway

Associate professor, University of Stavanger, Stavanger, Norway

Karl Thies

Consultant Anaesthetist Birmingham Children's Hospital, Birmingham

West Midlands Ambulance Service NHS Foundation Trust Medical Emergency Response Incident Team (MERIT)

Mercia Accident Rescue Service (MARS) BASICS, UK

Robert Tipping

Consultant Anaesthetist, Queen Elizabeth Hospital, Birmingham, UK,

West Midlands Ambulance Service NHS Foundation Trust Medical Emergency Response Incident Team (MERIT), UK

University Hospitals Birmingham NHS Foundation Trust (Queen Elizabeth Hospital), Birmingham, UK

Oddvar Uleberg

Consultant anaesthetist, Norwegian Air Ambulance Foundation, Drøbak, Norway

Department of aeromedical and clinical emergency services, St Olavs University Hospital, Trondheim, Norway

Bettina Vadera

Chief Executive and Medical Director of AMREF Flying Doctors, Kenya

Vice-President of EURAMI (European Aeromedical Institute)

Member of AMPA (Air Medical Physician Association), USA

Mathew Ward

Head of clinical practice, West Midlands Ambulance Service; Immediate Care Practitioner, West Midlands CARE Team, UK

Jon Warwick

Consultant Anaesthetist, Oxford University Hospitals NHS Trust, UK

Medical Director, Air Medical Ltd, London Oxford Airport, UK

Anne Weaver

Consultant in Emergency Medicine & Pre-Hospital Care, London's Air Ambulance, Royal London Hospital, UK

Claire Westrope

Consultant PICU/ECMO, University Hospital Leicester NHS Trust, Leicester, UK

Yashvi Wimalasena

Consultant in Emergency Medicine, Retrieval/HEMS Fellow, Greater Sydney Area HEMS, Ambulance Service of NSW Rescue Helicopter Base Bankstown, NSW, Australia

Jan G. Zijlstra

Professor in Intensive Care, Department of Critical Care, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands

Preface

The introduction of the Diploma in Transfer and Retrieval Medicine by the Royal College of Surgeons of Edinburgh in 2012 was the catalyst for ABC of Transfer and Retrieval Medicine. Reviewing the recommended reading for the Diploma, it was clear that there was no single revision guide to aid candidates' preparation; by using the Diploma curriculum as a framework, we could provide a useful addition to the highly acclaimed “ABC of…” series. Transfer Medicine is also a recognised component of anaesthetic training in the United Kingdom, with dedicated learning outcomes highlighted in the curriculum from the Royal College of Anaesthetists. On this background, we aim to provide a useful point of reference for all healthcare practitioners involved in the field of transfer and retrieval medicine.

We are indebted to all the individuals who have contributed their expertise to the book. As you will see, we have a distinctly multi-national contributor list from a range of healthcare backgrounds, with the specific aim of producing a text of relevance to all practitioners within the field, irrespective of country of practice. All the contributors have a wealth of experience and we are extremely grateful to them for sharing their expertise.

We would like to thank all the team at Wiley for their invaluable guidance, realistic timelines and patience with this project; our families for their unwavering support and tolerance, and our authors for agreeing to contribute to the book, adhering to timelines and stringent word counts!

Whilst on paper, the aim of “maintaining the same standard of care as the patient would receive in hospital throughout the course of the transfer” may sound straight forward, the reality is that it rarely is. This text is dedicated to all of you who move critically ill or injured patients to, or from, health care facilities at all hours of the day and night in often challenging circumstances.

Adam LowJonathan Hulme

List of Abbreviations

AAGBI

Association of Anaesthetists of Great Britain and Ireland

ACCM

American College of Critical Care Medicine

AC

Alternating current

ACT

Activated clotting time

ALS

Advanced life support

ANZCA

Australian & New Zealand College of Anaesthetists.

ATC

Acute trauma coagulopathy

ATLS

Advanced trauma life support

ARDS

Adult respiratory distress syndrome

BMI

Body mass index

BP

Blood pressure

CAA

Civil Aviation Authority

CAT

Combat application tourniquet

CCF

Congestive cardiac failure

CCNs

Critical care networks

CCP

Critical care paramedic

CBRN

Chemical, biological, radiological or nuclear

CAMTS

Commission on accreditation of medical transport systems

CCAST

Critical Care Air Support Team

CDR

Cognitive dispositions to respond

CDH

Congenital diaphragmatic hernia

CO

Cardiac output

CO (burns)

Carbon monoxide

CO

2

Carbon dioxide

COPD

Chronic obstructive pulmonary disease

CNS

Central nervous system

CPD

Continued professional development

CPR

Cardio-pulmonary resuscitation

CQC

Care Quality Commission

CSF

Cerebrospinal fluid

CVA

Cerebrovascular accident

CVC

Central venous catheter

CVP

Central venous pressure

CVS

Cardiovascular system

CXR

Chest X-ray

DBD

Donation after brain-stem death

DCD

Donation after circulatory death

DC

Direct current

DCR

Damage control resuscitation

ECG

Electrocardiogram

ECLA

Extracorporeal lung assist

ECLS

Extracorporeal life support

ECMO

Extracorporeal membrane oxygenation

ECT

Enhanced care teams

ED

Emergency Department

EMS

Emergency medical services

ETCO

2

End tidal carbon dioxide

ETT

Endotracheal tube

EURAMI

European Aero-Medical Institute

FAST

Focussed assessment with sonography in trauma

FFP

Fresh frozen plasma

FiO

2

Fractional inspired oxygen concentration

FRC

Functional residual capacity

FWAA

Fixed-wing air ambulance

GCS

Glasgow Coma Score

GMC

General Medical Council

GPS

Global positioning system

HAFOE

High air flow oxygen enrichment

HCPC

Health and Care Professionals Council

HDU

High dependency Unit

HEMS

Helicopter emergency medical system

HICAMS

Helicopter intensive care medical services

HIE

Hypoxic ischaemic encephalopathy

HIV

Human immunodeficiency virus

HLS

Helicopter landing site

HME filter

Heat moisture exchange filter

HR

Heart rate

HSE

Health and Safety Executive

IABP

Intra-aortic balloon pump

IBW

Ideal body weight

ICP

Intracranial pressure

ICU

Intensive Care Unit

ICS

Intensive Care Society

IFR

Instrumental flight rules

IM

Intramuscular

IN

Intranasal

iNO

Inhaled nitric oxide

IO

Intraosseus

ISS

Injury Severity Score

IUGR

Intra-uterine growth restriction

IUT

In utero transfer

IV

Intravenous

IVC

Inferior vena cava

IVH

Intra-ventricular haemorrhage

kPa

Kilopascals

km

Kilometres

LA

Left atrium

LCD

Liquid crystal display

LV

Left ventricle

MAD

Mucosal atomising device

MAP

Mean arterial pressure

MAS

Meconium aspiration syndrome

MCN

Managed clinical networks

MHRA

Medical and Healthcare Regulatory Agency

MRSA

Methicillin resistant staphylococcus aureus

MTC

Major trauma centre

MV

Minute volume

NACA

National Advisory Committee for Aeronautics

NAI

Non-accidental Injury

NEC

Necrotising enterocolitis

NIBP

Non-invasive blood pressure

NICE

National Institute for Health and Care Excellence

NICU

Neonatal intensive care unit

NiMH

Nickel metal hydride

NMBD

Neuromuscular blocking drugs

NMC

Nursing and Midwifery Council

NTS

Non-technical skills

NVG

Night vision goggles

O

2

Oxygen

O

3

Ozone

OR

Operating room

PACs

Picture Archiving & Communication system

PDA

Patent ductus arteriosus

PEEP

Positive end expiratory pressure

PHEM

Pre-hospital emergency medicine

PPHN

Persistent pulmonary hypertension of the newborn

POCT

Point of care testing

PPH

Post-partum haemorrhage

PRBC

Packed red blood cells

PRF

Patient record form

PTC

Patient transport compartment

PVR

Pulmonary vascular resistance

RDS

Respiratory distress syndrome

REBOA

Resuscitative endovascular balloon occlusion of the aorta.

RR

Respiratory rate

RS

Respiratory system

RTD

Regional trauma desk

RSI

Rapid sequence induction

SAR

Search and rescue

Sats

Saturations

SIRS

Systemic inflammatory response syndrome

SOPs

Standard operating procedures

SV

Stroke volume

SVC

Superior vena cava

SVR

Systemic vascular resistance

TB

Tuberculosis

TBSA

Total body surface area

TETRA

Terrestrial trunked radio

TPN

Total parenteral nutrition

TRM

Team resource management

TU

Trauma unit

TUC

Time of useful consciousness

TV

Tidal volume

UK

United Kingdom

UK-DMS

United Kingdom Defence Medical Services

UPS

Universal power supply

UV

Ultraviolet

V

Volts

VFR

Visual flight rules

VHF

Very high frequency

WHO

World Health Organization

°C

Degrees Celsius

<

Less than

>

Greater than

Chapter 1Introduction

A. Low1,2,3 and J. Hulme1,2,4,5,6,7

1West Midlands Central Accident Resuscitation & Emergency (CARE) Team, UK

2West Midlands Ambulance Service NHS Foundation Trust Medical Emergency Response Incident Team (MERIT), UK

3AMREF Flying Doctors, Kenya

4Intensive Care Medicine and Anaesthesia, Sandwell and West Birmingham Hospitals NHS Trust, UK

5University of Birmingham, UK

6Mercia Accident Rescue Service (MARS) BASICS, UK

7Midlands Air Ambulance, UK

Intensive care beds are a limited and often pressurised resource within any healthcare setting. As the complexity and breadth of surgical interventions increases, alongside longevity and associated co-morbidities, the requirement for critical care is expanding worldwide. In the developed world many healthcare systems are moving towards networked care: with tertiary centres for specialist care, meaning patients presenting to their local hospital may subsequently need to be transferred for definitive intervention (e.g. neuro/cardiothoracic/transplant surgery or an intervention such as hyperbaric oxygen therapy). Neonatal and paediatric intensive care facilities are becoming centralised, increasing the need for ‘Retrieval Teams’ who will travel to the patient, assist local health care professionals in resuscitation and stabilisation before transporting the patient back to base facility. The development of trauma networks may mean patients are transported longer distances from point of injury to Major Trauma Centres (MTCs), or stabilised at Trauma Units before onward transfer to a MTC for definitive multidisciplinary care. Regional Enhanced Care Teams (ECTs) are becoming increasingly common to assist in the primary management and transfer of these polytrauma patients. Figure 1.1 illustrates an example of a critically ill patient undergoing numerous transfers.

Figure 1.1 A 20-year-old male is assaulted and hits his head on the pavement with brief loss of consciousness. He is assessed on scene by paramedics who stabilise him and transfer him to the nearest Emergency Department. Green arrow, intra-hospital transfer; red arrow, secondary retrieval; blue arrow, repatriation.

The increase in worldwide travel and business networks means people risk ill health while abroad. They may want or require repatriation for healthcare, family support or financial reasons. This request may be instigated by their medical insurance company, resulting in international transportation.

It is inevitable that critically ill patients will need to be moved at some point in their illness. This may be from point of injury or small healthcare facility to specialist care, or from one area of a healthcare facility to another. Pressures on critical care beds may necessitate movement of patients in order to manage local resources. In the UK, the NHS has created Critical Care Networks on a regional basis to facilitate this aspect of resource management. The principles and risks associated with moving any critically ill patient are discussed in depth in this book.

The following definitions and concepts are important to understand:

Retrieval

: deployment of a specialist team of appropriately trained health care professionals to the patient's location to resuscitate and stabilise prior to transfer to definitive care.

Transfer

: the movement of a patient (not necessarily critically ill), from one location (or healthcare facility) to another.

Primary retrieval

: from a pre-hospital location to hospital.

Secondary retrieval

: movement from a healthcare facility with limited resources/expertise to a specialist care facility.

Tertiary retrieval

: movement from one specialist care facility to another, or for bed availability.

Repatriation

: retrieval from distant or international health care facility to patient's local hospital or specialist care unit.

Inter-hospital transfer

: movement of a patient from one hospital facility to another.

Intra-hospital transfer

: movement of a patient from one department to another within the same hospital buildings.

Movement of critically ill patients can be achieved via a variety of transport modalities, selection of which requires clinical, financial and logistical consideration.

The movement of critically ill patients is not without risks to patient and team (summarised in Box 1.1). Historical data have suggested that retrievals and transfers may be associated with increased mortality and length of hospital stay, with increased incidence of hypoxaemia and hypotension, persisting upon arrival at the receiving facility (see Further reading).

Box 1.1 Potential risks encountered during patient transfers

Environmental exposureRoad traffic collisionEquipment failurePhysiological instability hypoxaemiaarrhythmiashypotensionhypertensionraised intracranial pressuredeath during transfer

Acknowledgement of these factors has resulted in the development of dedicated transfer and retrieval teams with associated clinical governance/training schemes, standardised equipment and standardised operating procedures to optimise patient safety (Box 1.2). All these factors will help to ensure ‘the rule of RIGHT’:

The RIGHT patient is taken at the RIGHT time, by the RIGHT people to the RIGHT place, using the RIGHT transport modality and receiving the RIGHT clinical care throughout.

Box 1.2 Key components to being a part of an effective retrieval team

Understanding of the physiological consequences of moving critically ill patientsGood clinical acumen and skill to assess and stabilise critically ill patientsFamiliarity and understanding of equipment utilisedFamiliarity and understanding of commonly used drugsGood communication between the team, base hospital and receiving hospitalGood management and leadership skillsAppreciation of ethical and legal issues surrounding patient transfers and retrievalsWorking within ones scope of practice and clinical governance scheme

This book aims to introduce the reader to all these different aspects of transfer and retrieval medicine. It is no substitute for hands-on clinical experience, but we hope it will provide a useful reference for any practitioner (paramedic, nurse or doctor) involved in the transfer and retrieval of critically ill patients.

Further reading

Flabouris A, Hart GK, George C. Outcomes of patients admitted to tertiary intensive care units after interhospital transfer: comparison with patients admitted from emergency departments.

Crit Care Resusc

2008;

10

(2):97–105.

Flabouris A, Hart GK, George C. Observational study of patients admitted to intensive care units in Australia and New Zealand after interhospital transfer.

Crit Care Resusc

2008;

10

(2):90–6.

Section 1

Physiology of Transfer Medicine

Chapter 2Acceleration, Deceleration and Vibration

M. Sheils1 and C. Hore2

1Careflight NT, Australia

2Ambulance Service of New South Wales, Austalia

Overview

This chapter will enable the reader to:

discuss gravity in relation to the flight environmentlist the origins of negative, positive, linear accelerations and radial accelerationsunderstand the value of appropriate positioning and orientation of patients for transfersdiscuss the key fundamentals of crashworthiness in road and air modes of patient transportdiscuss the physics of vibration, harmonics and resonance and the physiological/physical consequenceslist the sources of mechanical vibration in road and air modes of patient transport.

Introduction

Any patient being moved will experience acceleration and vibration, irrespective of mode of transport. In the critically ill, these can have significant physiological impact that the transferring team must be aware of. This chapter will discuss the physics, sources and physiological consequences of acceleration and vibration. The importance of crashworthiness in reducing exposure to short-duration acceleration and protective strategies in limiting the effects of long-duration accelerations and vibration will also be considered.

Acceleration

Physics of acceleration

Speed

: The distance travelled in a given unit of time regardless of direction, usually measured as miles/kilometres per hour or metres per second. Air travel is measured as nautical miles per hour (knots).

Velocity

: Speed applied to a given direction, e.g. 300 knots West.

Force

: Newton's first law states that an object will remain at a constant velocity or state of rest unless a force is applied to it. Force therefore causes acceleration. The standard international (SI) unit for force is a newton (N): a force that will accelerate a mass of 1 kg × 1 m/s

2

. The gravitational pull of the earth exerts 9.81 N on any mass. That is, if an object with a mass of 1 kg is dropped from a height, gravity would cause it to accelerate at 9.81 m/s

2

until terminal velocity is reached. The 9.81 N force of gravity is better known as 1 G. Inhabitants of this planet have evolved so that our physiological performance is optimised under the gravitational force of 1 G.

Weight

: When the force of gravity is applied to a mass it gives rise to the force we sense as weight. If an 80-kg patient is subjected to an accelerative force of 2 G they would weigh 160 kg.

Acceleration

: A rate of change of velocity measured in metres per second squared. Acceleration can be a positive number or a negative number (deceleration). Newton's second law states that acceleration is directly related to the force applied to it and inversely proportional to the mass of the object.

Newton's third law states that for every action or force, there is an equal and opposite reaction. Therefore when we are accelerated by one force in one direction, we will be exposed to a force in the opposite direction, known as the reactive or inertial force. The reactive force felt during acceleration is known as G force and is labelled according to the magnitude (in multiples of Gs) and the direction it is applied in relation to the body (Figure 2.1).

Figure 2.1 G force nomenclature.

G force along the vertical axis of the body is labelled Gz, with a positive vertical G force (+Gz) when the body is accelerated upwards and the reactive force pushes down. This is felt as an increased weight. A negative vertical G force (–Gz) occurs when the body is accelerated downwards with the reactive force pushing upwards. G force along the anteroposterior axis is labelled Gx. Positive anteroposterior G force (+Gx) occurs when the body is accelerated forward and the reactive force pushes the body backwards. Negative anteroposterior G force (–Gx) occurs as the body decelerates or accelerates in a backwards direction with the reactive force pushing the body forward. G force applied laterally is labelled Gy. Positive lateral G force (+Gy) occurs when the body is accelerated to the right and negative lateral G force (–Gy) when the body is accelerated to the left.

Sources of acceleration

Broadly speaking acceleration can be defined as long-duration accelerations, lasting greater than 2 seconds in excess of 1 G, or short duration accelerations, lasting less than 1 second. Long-duration accelerations can be due to a change of rate of movement (linear acceleration) or change of direction (radial acceleration) or a combination of both (angular acceleration).

Linear accelerations include the increase in forward velocity as a fixed wing aircraft prepares for take-off or a land ambulance leaves the scene of retrieval (Figure 2.2). Negative linear acceleration occurs as a fixed wing aircraft decelerates following a landing or a land-based ambulance decelerates on arrival. In a seated patient the reactive G forces will be applied along the anteroposterior axis (Gx) with little physiological effects. However if supine, the linear acceleration will act along the vertical axis with greater displacement of organs and fluid volumes in response to the vertical G force (Gz). In rotary wing aircraft, lift off will cause the linear acceleration along the vertical axis (Gz) in the seated patient and anteroposterior axis in (Gx) in the supine patient.

Figure 2.2 An Aeromedical King Air fixed-wing accelerating in a straight line down the runway prior to take-off. The linear accelerative force will be felt along the anterior-posterior aspect of the craft.

Radial accelerations occur when an aircraft is turning at a constant speed (Figure 2.3). The reactive force is applied from the point around which the turn is occurring. As the plane tilts into the turn the G force is applied in the positive vertical axis (+Gz) of the seated occupant, felt as an increase in weight as the occupant is pushed into their seat.

Figure 2.3 Mid-flight the craft changes course. The radial accelerative forces will be applied from the point at which the plane is turning. This would push a seated patient into their seat, sensed as an increase in weight.

Examples of short-duration accelerations include the impact of a crash, an extremely heavy landing or the deployment of a parachute, resulting typically in linear accelerations.

Physiological effects of acceleration

Long-duration acceleration

During transportation, patients are exposed to forces greater than 1 G. If acceleration is sustained, the reactive forces can lead to significant shifts in fluid volumes and organs leading to physiological changes.

Hypoxia, hypoglycaemia, hypovolaemia and acidosis all affect the efficiency of compensatory mechanisms, reducing tolerance to sustained G force. Other factors determining tolerance are rate of onset, magnitude, duration and direction of acceleration.

Acceleration is tolerated least, when applied to the vertical axis of the body (Gz). In this axis there is more space for the organs to shift, and greater hydrostatic pressures are produced as the G force is applied across a longer column. Physiological effects of acceleration along the vertical axis depend on whether it is applied as a positive (+Gz) or negative G force (–Gz).

Effects of sustained high positive vertical G force (+Gz)

As +Gz increases, hydrostatic forces causes the blood pressure to fall in the head and increase in the feet. The capacitance vessels of the lower extremities are dilated and blood pools reducing venous return. At +5Gz blood flow to the brain ceases, resulting in loss of consciousness.

After 6 seconds of exposure to +Gz, baroreceptors in the carotid artery initiate compensatory mechanisms in response to the drop in carotid blood pressure. Heart rate, contractility and peripheral vasoconstriction can increase blood pressure; however, it rarely returns to pre-exposure levels. In hypovolaemic and septic patients, these mechanisms are quickly overwhelmed.

During high +Gz the abdominal viscera and diaphragm are pulled down. This results in an increase in residual capacity of the lung. The descent of lung tissue causes distension of apical alveoli and compression of basal alveoli leading to preferential ventilation of the lung apices. Simultaneously perfusion to the apical alveoli is reduced, with resultant ventilation perfusion (V/Q) mismatch (exaggerated in hypovolaemic patients).

Effects of sustained high negative vertical G force (–Gz)

Gz is poorly tolerated. Hydrostatic pressures will increase venous return leading to a reflex bradycardia. After sustained exposure peripheral vessels in the lower body dilate reducing blood pressure. Pooling of blood in the cerebral circulation will lead to raised intracranial pressure and reduced cerebral perfusion pressure.

Gz forces the abdominal organs and diaphragm to be pushed up reducing the residual capacity and causing a V/Q mismatch equal and opposite to that described in +Gz.

Short-duration accelerations

Short duration accelerations are usually unplanned and have the potential to cause serious injury or even death dependant on multiple factors (Box 2.1).

Box 2.1 Factors that predict injury in short-duration accelerations

Magnitude and duration: The greater the magnitude and the longer this is applied the higher the incidence of injury.Rate of onset: If the rate of onset of the deceleration can be buffered, survivability is increased.Direction of force: Forces along the Gz axis cause the greatest organ displacement and hydrostatic effects. These are applied to a smaller surface area to spread the force.Site of application: A site with a larger surface area (buttocks) or stronger bony structure (skull) will provide greater protection from injury.

Limiting the effects of acceleration

Long-duration accelerations

In hypovolaemic patients it may be beneficial to position the supine patient feet first during the acceleration at the start of the retrieval in a fixed wing or land-based ambulance. This will increase venous return. In patients with fluid overload, high ventilation pressures, suspected head injury or penetrating eye injury it may be advantageous to position the supine patient head first at the start of the journey to prevent the physiological changes described when exposed to –Gz.

When considering patient positioning, it is important to note that due to the limited space of retrieval vehicles, the patient's position cannot be changed during the retrieval. Therefore during deceleration the patient will be exposed to the force, which was risk managed at the start of the journey. For this reason the best strategy for protecting patients from long-duration accelerations is to request a smooth transit. When transporting a head injury patient by fixed wing aircraft, request the pilot use the full length of the runway on landing rather than rapidly decelerate to make the shortest taxi route.

In fixed-wing aircraft more consideration should be placed on the effects of tilt as the aircraft climbs at take off and descends for landing. If the flight path of the fixed-wing aircraft is unobstructed by land masses, buildings or flight plan restrictions, it would be sensible to ask for a shallow gradient during take-off and landing to reduce the effect of tilt.

It is important to ensure we prevent any harm which may be caused from equipment subjected to acceleration. High-magnitude accelerations may cause equipment to fall if not securely fastened. Equipment resting on the patient will increase in weight when subjected to +Gz such as during a turn in a fixed-wing aircraft.

Short-duration accelerations

During the rapid deceleration of a crash the severity of injuries may be reduced by the crashworthiness of the vehicle involved. Crashworthiness can be described as vehicle factors that determine the level of exposure to the short duration acceleration suffered by the occupants, this can be summarised by the ‘CREEP’ acronym (Figure 2.4).

Figure 2.4 CREEP acronym of crashworthiness applied to a BK117 rotary-wing craft. Container—the structure must be of sufficient strength to prevent intrusion into the allocated survival area. It must prevent penetration of external objects. Restraint—the 4 point harness provides sufficient strength to maintain the crewman in the allocated survival area. Energy attenuation—crumple zones attenuate energy, reducing exposure to the deceleration forces. The skids and crumple seat provide added protection from +Gz forces in this craft. Escape—failure to escape will cause morbidity and mortality in an otherwise survivable crash. The jettison door to the left of the crewman is designed to fall away with a simple pull of the red handle. Post-crash factors—Life jackets, survival packs, EPOS masks and fire extinguishers are stored on this craft.

Vibration

Physics of vibration

Vibration: any form of movement which is repeatedly alternating in direction. Everything has a ‘natural frequency’ that it will oscillate at dependent on its mass and spring tension. Vibration can be transmitted from one body to another if they come into direct contact. If a source of vibration is oscillating close to the natural frequency of a second body, it will cause maximal oscillation of the second body (its resonant frequency).

Sources of vibration

Vibration during retrieval is unavoidable. The most common source is a turning land-based ambulance at low frequencies (0–2 Hz). In rotary-wing craft, vibration is marked, the main sources being transmitted from the main rotor (12–15 Hz) and tail rotor (23–25 Hz). Vibration in fixed wing aircraft comes from turbulence (0–4 Hz). Engine vibration (20 Hz to 20 kHz) is dampened as a design feature of the aircraft.

Physiological effects of fibration

Vibrations with a frequency of 0.1–100 Hz are likely to have adverse effects. The area of the body affected is dependent on the body part whose resonant frequency is closest to the source of vibration (Table 2.1).

Table 2.1 Effects of vibration according to its frequency.

Frequency (Hz)

Effect

0–2

Motion sickness

3–4

Hyperventilation(caused by resonance of air in trachea)

3–8

Abdominal contents

4–8

Leg muscles

12–15

Differential head/torso movement

15–20

Soft facial muscles

60–90

Eyes

20–100

Muscle contraction

Vibration causes pain and fatigue to muscles as they work to maintain body position and dampen the vibration, consequently increasing metabolic rate. Vibration causes vasoconstriction and impaired sweating, which coupled with the increased muscle activity impairs thermoregulation. Vibrations with a frequency close to the heart rate can potentially cause fluctuations in blood pressure and induce dysrhythmias. Exposure to high levels of vibration has the potential to disrupt clot formation.

Interference with monitoring, malfunctioning of pacemakers and dislodgement of IV access/endotracheal tubes are additional risks.

Limiting the effects of vibration

Most vibration reduction occurs as a design function of the vehicle/aircraft. Further reductions are achieved by avoiding direct contact between the patient and airframe, using padding to dampen the vibration, and ensuring the crew, the patient and the equipment are adequately secured. Route planning is another important tool for protecting patients from vibration forces, e.g. avoiding turbulence in fixed-wing retrieval and excessive turning in road retrieval (Box 2.2 case scenario).

Box 2.2 Case scenario highlighting strategies to protect the patient from acceleration at take-off and the vibrational forces caused by turbulence in fixed wing retrieval

15-year-old male injured in a motor vehicle roll over in a rural locationTransport modality: Fixed wingFlight time: 90 minutesLocation: transferred to airfield for retrieval

Primary survey

A: Patent. B: Sats 95%, RR 17 on 02 via Hudson mask. Reduced air entry to the left base noted, percussion is equivocal. C: HR 95, BP 100/65, warm peripherally. No external haemorrhage. D: GCS 15, crying due to severe left thigh pain. E: deformed left femur, closed.

Resuscitation

Despite the reduced air entry to the left base the patient has been stable since injury. For this reason you decide not to place a chest drain but ensure access by positioning the patient head first as the stretcher is situated on the right side of the aircraft. Two peripheral cannula are sited and 1 L of 0.9% saline is primed to pre-empt a significant drop in blood pressure during take-off. Analgesia is given and the leg splinted.

You request a slow acceleration and shallow gradient at take-off, and a cruising altitude of 16,000 feet, allowing the cabin to be pressurised to sea level.

Progression

Take off occurs without incident or the need to provide a fluid bolus. 45 minutes into the flight your pilot advises that there is an area of storm clouds ahead at this altitude. He provides you with three options:

He advises that he can fly through but there will be at least moderate turbulence.He requests permission to fly above the storm cloud.He advises that he has sufficient fuel to fly around the storm cloud but this will add a further 30 minutes to the journey.Which option do you feel is most appropriate?

Further reading

Glaister DH, Prior ARJ. The effects of long duration acceleration, in Ernsting J, Nicholson AN, Rainford DJ (eds)

Aviation Medicine

(3rd ed.). Arnold: London, 2003.

Harding RM, Mills FJ. Acceleration, in Harding RM, Mills FJ (eds)

Aviation Medicine

(3rd ed.) BMJ: London, 2003.

Stott JRR. Vibration, in Ernsting J, Nicholson AN, Rainford DJ (eds)

Aviation Medicine

(3rd ed.) Arnold: London, 2003.

http://ftp.rta.nato.int/public/PubFullText/RTO/EN/RTO-EN-HFM-113/EN-HFM-113-07.pdf

.

Chapter 3Environmental Exposure and Noise

P. Paal1,2 and M. Helm3

1Department of Anaesthesiology and Critical Care Medicine, Medical University Innsbruck, Austria

2Helicopter Emergency Medical Service Christophorus 1, Austria

3Department of Anaesthesiology and Intensive Care Medicine, Federal Armed Forces Medical Centre, Germany

Overview

Retrieval medicine is practised in environments highly varying in geography, weather conditions, transfer facilities and time frames. Stakeholders of retrieval services should adapt transport modalities to the idiosyncrasies of a given areaNoise may adversely affect a transfer. To overcome problems with hearing loss and communication by both patients and crew during air transport, a proper pre-flight brief should occur, equipment be available (e.g. intercom and headsets) and communication discipline during transport agreed. During transport, adequate monitoring (with acoustic and visual alarms) has to be guaranteed continuouslyDiscrepancies between sensory stimuli can lead to spatial disorientation, with potentially dire consequences. Specifically developed night vision goggles may improve night visionExtreme environmental conditions can negatively impact on the patient, equipment and crew.

Introduction