A practical guide to the management of medical emergencies - part 1 ppt

Preface, ixAcknowledgments, x Section 1: Common presentations 1 The critically ill patient: assessment and stabilization, 3 2 Cardiac arrest, 13 3 Cardiac arrhythmias: general approac

Acute Medicine

A practical guide to the management of medical emergencies

Reader and Consultant Cardiologist

Guy’s and St Thomas’ Hospitals

London UK

F O U R T H E D I T I O N

Blackwell Publishing, Inc., 350 Main Street, Malden, Massachusetts 02148-5020, USA

Blackwell Publishing Ltd, 9600 Garsington Road, Oxford OX4 2DQ, UK

Blackwell Publishing Asia Pty Ltd, 550 Swanston Street, Carlton, Victoria 3053, Australia

The right of the Authors to be identifi ed as the Authors of this Work has been asserted in accordance with the Copyright, Designs and Patents Act 1988.

All rights reserved No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher.

Acute medicine : a practical guide to the management of medical emergencies / David

Sprigings, John B Chambers – 4th ed.

p ; cm.

Includes bibliographical references and index.

ISBN 978-1-4051-2962-6

1 Medical emergencies–Handbooks, manuals, etc I Chambers, John, MD II Title.

[DNLM: 1 Emergency Treatment–methods–Handbooks 2 Emergencies–

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Blackwell Publishing makes no representation, express or implied, that the drug dosages in this book are correct Readers must therefore always check that any product mentioned in this publication is used in accordance with the prescribing information prepared by the manufacturers The author and the publishers do not accept responsibility or legal liability for any errors in the text or for the misuse

or misapplication of material in this book.

Preface, ix

Acknowledgments, x

Section 1: Common presentations

1 The critically ill patient: assessment and stabilization, 3

2 Cardiac arrest, 13

3 Cardiac arrhythmias: general approach, 18

4 Broad complex regular tachycardia, 21

5 Broad complex irregular tachycardia, 27

6 Narrow complex tachycardia, 33

7 Atrial fi brillation and fl utter, 42

8 Bradycardia and atrioventricular block, 47

9 Hypotension, 53

10 Sepsis and septic shock, 59

11 Poisoning: general approach, 66

12 Poisoning with aspirin, paracetamol and carbon monoxide, 75

13 Acute chest pain, 82

14 Acute breathlessness, 91

15 Arterial blood gases, oxygen saturation and oxygen therapy, 98

16 Respiratory failure, 104

17 Acid–base disorders, 110

18 The unconscious patient, 117

19 Transient loss of consciousness, 124

20 Acute confusional state, 133

21 Falls and ‘off legs’, 137

22 Acute headache, 140

23 Acute vomiting, 147

24 Acute abdominal pain, 151

Section 2: Specifi c problems

29 Acute pulmonary edema, 185

30 Cardiac valve disease and prosthetic heart valves, 194

40 Acute exacerbation of chronic obstructive pulmonary disease, 261

41 Pneumonia (1): community-acquired pneumonia, 268

42 Pneumonia (2): hospital-acquired pneumonia, 277

48 Transient ischemic attack, 315

54 Epilepsy (1): generalized convulsive status epileticus, 349

55 Epilepsy (2): management after a generalized fi t, 355

56 Raised intracranial pressure, 360

64 Biliary tract disorders and acute pancreatitis, 406

65 Acute renal failure, 410

77 Interpretation of full blood count, 489

78 Bleeding disorders and thrombocytopenia, 500

79 Management of anticoagulation, 507

80 Sickle cell crisis, 514

81 Anaphylaxis and anaphylactic shock, 519

82 Complications of cancer, 523

Miscellaneous

83 Acute medical problems in the HIV-positive patient, 535

84 Fever on return from abroad, 542

85 Acute medical problems in pregnancy and peripartum, 551

86 Psychiatric problems in acute medicine, 555

87 Alchohol-related problems in acute medicine, 561

88 Hypothermia, 566

89 Drowning and electrical injury, 571

90 Palliative care, 578

Section 3: Procedures in acute medicine

91 Arterial blood gas sampling, 587

92 Central vein cannulation, 589

93 Temporary cardiac pacing, 600

94 Pericardial aspiration, 609

95 DC cardioversion, 614

96 Insertion of a chest drain, 619

97 Lumbar puncture, 627

98 Aspiration of a knee joint, 635

99 Insertion of a Sengstaken–Blakemore tube, 638

Index, 643

In the 4th edition we have distilled the text to a set of fl ow diagrams with linked tables Our aim is to provide the doctor caring for an acutely ill patient with rapid access to key information, including a balanced interpretation of current national and international guidelines.

We have substantially broadened the scope of the book to cover all lems in general medicine likely to be encountered in the emergency depart-ment Integration of the use of echocardiography, which we believe is as important in acute medicine as ECG interpretation, is a particular feature of the text Our emphasis is on urgent management in the fi rst few hours, but

prob-we also give guidance for continuing care

DCSJBCNorthamptonJanuary 2007

We are indebted to the following colleagues for expert criticism of sections

of the manuscript: Professor John Rees, Professor Tom Treasure, Nicholas Hart, John Klein, Boris Lams, Paul Holmes, Tony Rudd, Mark Wilkinson, David Treacher, Bridget McDonald, Michael Cooklin, Archie Haines, Carole Tallon and Andrew Jeffrey

We also wish to thank our trainees for their comments on the text, in ticular Susie Cary, Richard Haynes and Jim Newton We are very grateful to Jim Newton for providing the ECGs for illustration

par-Common presentations

assessment and stabilization

Suspected critical illness (Table 1.1)

Key observations (Table 1.2)

Oxygen, ECG monitor, IV access

Assess/stabilize airway, breathing

and circulation (Tables 1.3–1.7)

Correct hypoglycemia (Table 1.8)

Focused history: major problems,

context and comorbidities

Systematic examination (Table 1.9)

Urgent investigation (Table 1.10)

Further management directed by

dominant clinical problem or

working diagnosis

You are likely to needhelp, so don’t delaycalling for this

The critically ill patient: assessment and stabilization

The critically ill patient: assessment and stabilization

T A B L E 1 2 Nine key observations in suspected critical illness

Signs of critical

1 Airway Evidence of upper See Table 1.3 and pp 245–

airway obstruction 52 for management

of the airway

2 Respiratory Respiratory rate Give oxygen

rate <8 or >30/min (initially 60–100%)

Check arterial oxygen saturation and blood gases (pp 98–103, 587)See Table 1.5; pp 104–9 for management of respiratory failure

3 Arterial Arterial oxygen Give oxygen (initially

oxygen saturation <90% 60–100% if there are

illness)Check arterial blood gases (pp 587, 98–103)

4 Heart rate Heart rate <40 or Give oxygen 60–100%

>130 bpm Connect an ECG

monitor and obtain

IV accessSee p 18 for management of cardiac arrhythmia

5 Blood pressure Systolic BP <90 mmHg, Give oxygen 60–100%

or fall in systolic Connect an ECG

BP by more than monitor and obtain

40 mmHg with IV access signs of impaired See p 53 for perfusion management of

hypotension/impaired perfusion

Continued

The critically ill patient: assessment and stabilization

Signs of critical

6 Perfusion Signs of reduced Give oxygen 60–100%

organ perfusion: Connect an ECG cool/mottled skin monitor and obtain with capillary refi ll IV access

time >2 s; See p 53 for agitation/reduced management of conscious level; hypotension/

oliguria (urine impaired perfusion output <30 ml/h)

7 Conscious level Reduced conscious Stabilize airway,

level (unresponsive breathing and

to voice) circulation

Endotracheal intubation

if GCS 8 or lessExclude/correct hypoglycemiaGive naloxone if opioid poisoning is possible (respiratory rate

<12/min, pinpoint pupils) (see Table 11.2)See pp 118–25 for management of the unconscious patient

8 Temperature Core temperature See pp 59–65 for

<36 or >38°C, with management of sepsis hypotension,

hypoxemia, oliguria

or confusional state

9 Blood glucose Blood glucose Give 50 ml of 50%

<3.5 mmol/l, with glucose IV via a large signs of vein (or 500 ml of 5% hypoglycemia glucose

(sweating, IV over 15–30 min) or tachycardia, glucagon

abnormal behavior, 1 mg IV/IM/SC reduced conscious Recheck blood glucose level or fi ts) after 5 min and again

after 30 min See p 10

GCS, Glasgow Coma Scale score (see p 297)

The critically ill patient: assessment and stabilization

T A B L E 1 3 Assessment and stabilization of the airway

Action if you Signs of acute Causes of acute suspect upper

upper airway upper airway airway

obstruction obstruction obstruction

Conscious Respiratory Foreign body Sit the patient up

patient distress* Anaphylaxis Give high-fl ow

Inspiratory Angioedema oxygen

stridor Call for urgent

Suprasternal help from an

Unconscious Respiratory Above causes Head-tilt/chin-lift

Inspiratory soft tissues of (p 249)

stridor oropharynx Remove denturesGurgling Inhalation of (if loose) and

Grunting/ foreign body, aspirate the

snoring secretions, pharynx, larynx

blood, and trachea vomitus with a suction

catheter Call for urgent help from an anesthetistBefore intubation, ventilate the patient using a bag-mask device with 100% oxygen

* Respiratory distress is shown by dyspnea, tachypnea, ability to speak only in short sentences or single words, agitation and sweating

The critically ill patient: assessment and stabilization

T A B L E 1 4 Assessment of breathing

• Conscious level, mental state and speech

• Respiratory rate and pattern

• Arterial oxygen saturation

• Depth and symmetry of chest expansion

• Accessory muscles of respiration active?

T A B L E 1 5 Management of respiratory failure (impaired oxygenation and/or ventilation): general principles

• Maintain patent airway (pp 245–9)

• Increase inspired oxygen concentration if needed to achieve arterial oxygen saturation >90% (>88% in acute exacerbation of COPD)

• Diagnose and treat underlying cause and contributory factors (see Table 16.3)

• If feasible, sit the patient up to improve diaphragmatic descent and increase tidal volume

• Clear secretions: encourage cough, physiotherapy, aspiration

• Drain large pleural effusion if present

• Drain pneumothorax if present (Table 43.3; p 619)

• Optimize cardiac output: treat hypotension and heart failure (Table 1.7)

• Consider ventilatory support (p 108)

COPD, chronic obstructive pulmonary disease

The critically ill patient: assessment and stabilization

T A B L E 1 6 Assessment of the circulation

• Conscious level and mental state

• Heart rate

• Cardiac rhythm by ECG monitor

• Blood pressure

• Skin color, temperature and sweating

• Capillary refi ll time: squeeze the fi nger pulp, held at the level of the heart, for 5 s and then release: a capillary refi ll time of >2 s is

abnormal

• Jugular venous pressure

• Auscultation: added heart sounds, murmurs or pericardial rub?

• Major pulses: present and symmetrical?

• Signs of pulmonary and/or peripheral edema?

T A B L E 1 7 Management of circulatory failure: general principles

• Stabilize airway and breathing: maintain arterial oxygen saturation

>90%

• Correct major arrhythmia (p 18)

• Fluid resuscitation to correct hypovolemia (e.g from acute blood loss (pp 367–9) or severe sepsis (p 63))

• Consider/exclude tension pneumothorax (p 282) and cardiac

tamponade (p 216)

• Use inotropic vasopressor agent if there is pulmonary edema, or

refractory hypotension despite fl uid resuscitation (see Table 9.5)

• Diagnose and treat underlying cause (pp 53–4, 178–9)

• Correct major metabolic abnormalities (e.g derangements of

electrolytes or blood glucose) (see Table 1.8)

The critically ill patient: assessment and stabilization

T A B L E 1 8 Management of hypoglycemia

1 If the patient is drowsy or fi tting (this may sometimes occur with

mild hypoglycemia, especially in young diabetic patients):

• Give 50 ml of 50% glucose IV via a large vein (if not available give

250 ml of 10% glucose over 15–30 min) or glucagon 1 mg IV/IM/SC

• Recheck blood glucose after 5 min and again after 30 min

• In patients with chronic alcohol abuse, there is a remote risk of precipitating Wernicke’s encephalopathy by a glucose load; prevent this by giving thiamine 100 mg IV before or shortly after glucose administration

2 Identify and treat the cause (pp 423–4)

3 If hypoglycemia recurs or is likely to recur (e.g liver disease, sepsis,

excess sulfonylurea):

• Start an IV infusion of glucose 10% at 1 litre 12-hourly via a central or large peripheral vein

• Adjust the rate to keep the blood glucose level at 5–10 mmol/L

• After excess sulfonylurea therapy, maintain the glucose infusion for 24 h

4 If hypoglycemia is only partially responsive to glucose 10% infusion:

• Give glucose 20% IV via a central vein

• If the cause is intentional insulin overdose, consider local excision

of the injection site

The critically ill patient: assessment and stabilization

T A B L E 1 9 Systematic examination of the critically ill patient

Central nervous Conscious level and mental state

system (pp 293–302) Pupils: size, symmetry, response to light

(p 121)FundiLateralized weakness?

Tendon refl exes and plantar responses

Head and neck Neck stiffness?

The critically ill patient: assessment and stabilization

Further reading

Andrews FJ, Nolan JP Critical care in the emergency department: monitoring the critically

ill patient Emerg Med J 2006; 23: 561–4.

Bion JF, Heffner JE Challenges in the care of the acutely ill Lancet 2004; 363:

• Sodium, potassium and creatinine

• Full blood count

Urgent

• Chest X-ray

• Cranial CT if reduced conscious level or focal signs

• Coagulation screen if low platelet count, suspected coagulation disorder, jaundice or purpura

• Biochemical profi le

• Amylase if abdominal pain or tenderness

• C-reactive protein

• Blood culture if suspected sepsis

• Urine stick test

• Toxicology screen (serum 10 ml and urine 50 ml) if suspected

poisoning

Cardiac arrest

Cardiac arrest (Table 2.1)Sudden loss of consciousness with absent femoral or carotid pulses

Call resuscitation team

Clear airway and secure open airway (Table 38.1)

Ventilate with 100% oxygen

Cardiopulmonary resuscitation (CPR) 30 : 2 until

defibrillator/ECG monitor attached

One shock: 200 J biphasic

When to stop

resuscitation (Table 2.3)

After successful resuscitation (Table 2.4)

Cardiac arrest

T A B L E 2 1 Causes of cardiac arrest

With ventricular fi brillation/pulseless ventricular tachycardia

• Acute coronary syndrome

• Ischemic heart disease with previous myocardial infarction

• Other structural heart disease (e.g dilated or hypertrophic

Cardiac arrest

T A B L E 2 2 Adjunctive drug therapy in cardiopulmonary resuscitation (CPR)

Amiodarone Shock-refractory VF/VT 300 mg, diluted in 5%

(persisting after third glucose to a volume shock) of 20 ml, or from a

prefi lled syringe, via

a central vein or large peripheral vein, followed by saline fl ushHemodynamically stable VT See Table 4.2

Atropine PEA with a rate <60/min 3 mg bolus

Sinus or junctional

bradycardia with

unstable hemodynamic

state

Bicarbonate PEA caused by hyperkalemia, 50 ml of 8.4% sodium

tricyclic poisoning or bicarbonate

severe metabolic acidosis (50 mmol)

Calcium PEA caused by hyperkalemia, 10 ml of 10% calcium

hypocalcemia, poisoning chloride (p 450, 456) with calcium-channel

blocker

Epinephrine To augment myocardial and 1 mg, repeated every

cerebral perfusion during 3–5 min until

Cardiac arrest

T A B L E 2 3 When to stop cardiopulmonary resuscitation

• Resuscitation should be stopped if a ‘Do not attempt resuscitation’

(DNAR) order has been written, or the circumstances of the patient indicate that one should have been

• Resuscitation should be stopped if there is refractory asystole for

more than 20 min (except when cardiac arrest is due to hypothermia)

• Resuscitation should not be stopped while the rhythm is ventricular

fi brillation

T A B L E 2 4 What to do after successful resuscitation

Aim Action

Stabilize airway Maintain clear airway, with placement of

and breathing endotracheal tube if indicated (pp 245–52)

Give oxygen 100%

Check arterial blood gases and pHConsider mechanical ventilation if there is coma (GCS 8 or below) or pulmonary edemaInsert a nasogastric tube to decompress the stomach (gastric distension causes splinting of diaphragm) if there is coma

Obtain a chest X-ray to check position of endotracheal tube and central venous cannula, and exclude pneumothorax

Stabilize the Continuous ECG monitoring and 12-lead ECG

circulation If there is evidence of ST elevation acute coronary

syndrome, consider revascularization by thrombolysis or PCI (Table 25.2)

If cardiac arrest was due to primary asystole, put in a temporary pacing lead (p 600)Postresuscitation myocardial dysfunction (lasting 24–48 h) may result in hypotension and low cardiac output, requiring inotropic vasopressor support (p 58)

brady-Continued

Cardiac arrest Aim Action

Protect the Control seizures (p 350)

brain Treat hyperthermia by fanning, tepid sponging or

paracetamolControl blood glucose (p 10; Table 67.5)

If there is coma, consider induced hypothermia (32–34°C for at least 12–24 h, using chilled saline infusion)

Establish cause Establish cause of arrest by clinical assessment,

of arrest ECG, echocardiography, blood tests

Seek expert advice on management to prevent recurrence

Maintain normal Correct hypokalemia and hyperkalemia (aim for

plasma potassium plasma potassium 4–4.5 mmol/L) (pp 447, 450) Prevent sepsis IV lines inserted without sterile technique during

the resuscitation should be changed

GCS, Glasgow Coma Scale; PCI, percutaneous coronary intervention

Further reading

American Heart Association Guidelines for cardiopulmonary resuscitation and

emer-gency cardiovascular care (2005) Circulation website (http://circ.ahajournals.org/

Cardiac arrhythmias: general approach

general approach

NoYes

Cardiac arrhythmia

Cardiac arrest or BP unrecordable? Yes Call resuscitation team

ALS algorithm (p.13)No

Patient unstable?

Bradyarrhythmia

(<40 bpm)

Tachyarrhythmia (>150 bpm)

Atropine/pacing

(Tables 8.2, 8.5)

DC cardioversion (Table 95.3)

Urgent investigation (Table 3.2)

Refer to cardiologist

Key observations (Table 1.2)

Oxygen, ECG monitor, IV access

Focused assessment (Table 3.1)

Stabilize airway and

breathing (Tables 1.3, 1.4)

Call resuscitation team

If time, record 12-lead

ECG and rhythm strip

Record 12-lead ECG and rhythm strip

Make a diagnosis Urgent investigation (Table 3.2)Correct systemic factors (e.g hypokalemia)Plan management (Chapters 4–8)

Cardiac arrhythmias: general approach

T A B L E 3 1 Focused assessment of the patient with an arrhythmia

Symptoms?

• Of arrhythmia (palpitation, presyncope, syncope)

• Of underlying cardiac disease (chest pain, breathlessness)

Hemodynamically stable? Signs of instability are:

• Heart rate <40/min or >200/min

• Pauses >3 s

• Systolic BP <90 mmHg

• Syncope

• Reduced conscious level

• Anginal chest pain

• Pulmonary edema

Known arrhythmia?

• Previous management?

• Current therapy?

Underlying cardiac disease?

• Evidence of ischemic heart disease (e.g history, Q waves on ECG)?

– This makes ventricular tachycardia almost certainly the diagnosis if there is a regular broad complex tachycardia

– Flecainide should be avoided for cardioversion or prevention of

atrial fi brillation because of the risk of precipitating ventricular

arrhythmias

• Could LV systolic function be signifi cantly impaired (e.g exertional

breathlessness, large cardiac shadow on chest X-ray, previous

echocardiography)?

– If so, avoid high-dose beta-blockers and fl ecainide

• Is there Wolff–Parkinson–White syndrome? This may cause:

– AV re-entrant tachycardia (narrow complex, regular) (conduction

forward through the AV node and back via the accessory pathway)– Fast conduction of atrial fi brillation down the accessory pathway

(broad complex, irregular)

– Rarely, antidromic tachycardia (broad complex, regular) (conduction forward down the accessory pathway and back via the AV node)

Continued

Cardiac arrhythmias: general approach

Further reading

See the Resuscitation Council (UK) website on management of periarrest arrhythmias (http://www.resus.org.uk/pages/periarst.pdf).

Associated acute or chronic illness?

• Atrial fi brillation commonly complicates pneumonia and other

infection

• Electrolyte disorders (especially of potassium) should be excluded/corrected

AV, atrioventricular; LV, left ventricular

T A B L E 3 2 Urgent investigation of the patient with an arrhythmia

• 12-lead ECG and rhythm strip during the arrhythmia and after resolution (Q waves, QT interval, delta wave, evidence of LV

hypertrophy?)

• Electrolytes (especially potassium and, if on diuretic, magnesium) and creatinine

• Blood glucose

• Thyroid function (for later analysis)

• Plasma digoxin level (if taking digoxin)

• Plasma troponin

• Chest X-ray (heart size, evidence of raised left atrial pressure,

coexistent pathology, e.g pneumonia?)

• Echocardiogram (for LV function, RV function, valve disease)

LV, left ventricular; RV, right ventricular

Broad complex regular tachycardia

tachycardia

12-lead ECG and rhythm strip (Table 4.1)

Check electrolytes/creatinine

No

Broad complex regular tachycardia

Key observations (Table 1.2)

Oxygen, ECG monitor, IV access

Focused assessment (Table 3.1)

Patient unstable?

ECG abnormality due to artifact

(pseudoventricular tachycardia)?

(Table 4.1, Fig 4.2)

ECG identical with previously confirmed

supraventricular tachycardia (SVT) with

bundle branch block? (Table 4.1)

Could this be pre-excited atrial flutter

or antidromic tachycardia? (Table 4.1)

Treat as ventricular tachycardia (Table 4.1, Fig 4.1)

DC or chemical cardioversion (Table 4.2) or antitachycardia pacing

No action needed

Treat as SVT (p.33)

DC or chemicalcardioversion (Table 5.3)Refer to cardiologist

Broad complex regular tachycardia

T A B L E 4 1 Broad complex regular tachycardia: differential diagnosis and management

Monomorphic Commonest cause DC cardioversion

ventricular and should be the (p 617) if there

tachycardia default diagnosis is hemodynamic

(Fig 4.1) (especially if there instability or other

is a history of measures are previous myocardial ineffective infarction or In stable patient, other structural DC cardioversion, IV heart disease) antiarrhythmicRestore sinus rhythm therapy (Table 4.2),

as soon as possible, or antitachycardia even in pacing

hemodynamically Refer to a cardiologist stable patients, as

sudden deterioration may occur

Supraventricular Confi rm with DC cardioversion

tachycardia (SVT) adenosine test (p 617) if there

with bundle (Table 6.3) is hemodynamic

measures are ineffective

In stable patient, IV adenosine, verapamil or beta-blocker (Table 6.3)Record 12-lead ECG after sinus rhythm restored to check for pre-excitation (WPW syndrome)

Continued

Broad complex regular tachycardia

Refer to a cardiologist

if episodes are frequent or severe

or if pre-excitation

is found

Antidromic These are rarely seen DC cardioversion

tachycardia or but should be Refer to a cardiologist

atrial fl utter considered in a

WPW syndrome young patient with

syndrome who does

not have structural

heart disease

Pseudoventricular Caused by body No action needed

tachycardia movement and The importance of

(Fig 4.2) intermittent skin– recognition is to

electrode contact prevent misdiagnosis (‘toothbrush as ventricular tachycardia’) tachycardia

No hemodynamic change during apparent ventricular arrhythmia

WPW, Wolff–Parkinson–White

Further reading

American College of Cardiology, American Heart Association and European Society of Cardiology Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death (2006) American College of Cardiology website (http://www.acc.org/qualityandscience/clinical/topic/topic.htm).