Minitutorial decisionmaking after cardiac arrest

Clinicians know that CPR has a poor outcome in most cases; communication around this point can be difficult. Therefore various investigators have attempted to predict outcome based on physiological observations post-arrest. One paper looked at predictors of death and neurological outcome in 130 out-of-hospital witnessed cardiac arrest survivors presenting to the Emergency Department. The investigators used time to return of spontaneous circulation, systolic blood pressure at the time of presentation, and a simple neurological examination to score patients (Table 9.2):

• return of spontaneous circulation < 25 minutes (score 0) or > 25 minutes (score 1)

• systolic BP at time of presentation > 90 mmHg (score 0) or < 90 mmHg (score 1)

• initial neurological examination: alert and orientated/rousable/ moves extremities (score 0) or unresponsive with only simple reflexes (score 1).

Table 9.2 Score after cardiac arrest and prognosis

Score Mortality (%) Neurological outcome (%)

0 19 85

1 45 58

2 63 29

The authors suggested that a simple scoring system could be used to triage patients and select those who would benefit from early aggressive measures such as urgent cardiac revascularisation. Note that pupil reflexes were not included in neurological examination -this is because the drugs used during CPR affect pupils, and pupillary reflexes should never be used as a prognostic sign immediately following cardiac arrest.

Although the above may be evidence to support decision-making, this is an incredibly difficult area as there is plenty of anecdotal evidence to show that some people survive to discharge against all the odds.

Self-assessment - case histories

1. A 20-year-old man is admitted unresponsive with a suspected heroin overdose. He received 400 micrograms intravenous naloxone in the Emergency Department and was sent up to the ward with a GCS of 15. You find him unresponsive, lying supine, and snoring loudly. He has an oxygen mask on and the pulse oximeter shows his oxygen saturations are 99%. His other vital signs are: blood pressure 110/60 mmHg, pulse 70 per minute, respiratory rate 5 per minute, temperature 37°C. How do you assess and manage him?

2. A 40-year-old man is found collapsed in his room with a bottle of tablets nearby. No history is available. On examination his airway is clear, breathing is normal, blood pressure is 80/40 mmHg, pulse is 130 per minute, sinus tachycardia with a broad QRS complex. He is unresponsive, has globally reduced tone, although he appears to have jerking movements every so often and has bilateral upgoing plantars with dilated pupils. What is your management?

3. A 25-year-old builder was hit on the head by machinery and is brought in unresponsive to the Emergency Department. There is a haematoma to the left side of his head. Airway is clear, breathing is normal, and he is cardiovascularly stable (blood pressure 140/70 mmHg and pulse 90 per minute). His Glasgow Coma Score is calculated as 7 out of 15. What is your management?

4. A 70-year-old man is brought in with a dense left hemiplegia. His blood pressure is 220/100 and pulse is 75, sinus rhythm. A colleague calls you to ask whether this blood pressure should be treated acutely and whether the patient has "malignant hypertension". Discuss your management.

5. A 30-year-old lady describes a sudden severe headache followed by vomiting. She has become drowsy on the way to hospital. You assess her GCS as 12. Outline your management priorities.

6. A 19-year-old man arrives having been found unresponsive by his girlfriend in the morning. He went to bed the evening before complaining of 'flu-like symptoms and a headache. On examination he has a GCS of 8, respiratory rate 30 per minute, pulse 130 per minute, BP 70/40 mmHg, SaO2 98% on 10 litres per minute oxygen. There is some neck stiffness and a faint purpuric rash on his trunk. What is your management?

7. A 70-year-old lady is admitted having fallen off a step-ladder and injured her head. She has been lying on the floor for 4 hours. Her vital signs on admission are: GCS 4, respiratory rate 10 per minute, pulse 30 per minute, BP 60/30 mmHg, and temperature 29°C. Her arterial blood gases show: pH 7-20, PaCO2 6-0 kPA (46 mmHg), PaO2 11-0 kPA (84-6 mmHg), bicarbonate 3.7-2 mmol/l, BE - 12. What is your management? What are your thoughts on the reasons for her abnormal vital signs?

8. A 23-year-old man arrives in the Emergency Department unconscious. He was the passenger in a car involved in a highspeed accident and was found by the paramedics, having been ejected from the car. He has extensive contusions on his head with a fixed and dilated right pupil. He groans and withdraws his limbs from painful stimuli on the right, but does not move his left side. He will not open his eyes. What is his GCS? What is his prognosis? Outline your management plan.

9. A 62-year-old man is resuscitated from a cardiac arrest. He had a pancreatoduodenectomy 3 days before for cancer. Twenty-four hours after the arrest he has a heart rate of 100 per minute, BP 118/75 mmHg, and a good urine output. Neurological examination reveals no pupillary light reflexes, no spontaneous or roving eye movements and absent motor reflexes. Discuss the neurological prognosis for this patient.

Self-assessment - discussion

1. In this case, the partially obstructed airway (snoring) should be relieved. The respiratory rate in this patient is 5 per minute. Oxygen saturation measurements do not assess ventilation. Arterial blood gas analysis will reveal a respiratory acidosis. Naloxone has a short half-life. This patient is unresponsive and requires either a naloxone infusion or intubation because of the risk of aspiration.

2. This case describes the characteristic cluster of signs seen in tricyclic poisoning and the label on the bottle of tablets found nearby will confirm this. The management starts with A (intubation), B, C (fluid), and D - including bedside glucose measurement and arterial blood gases as first line tests. Sinus tachycardia with a broad QRS complex and hypotension is common in serious tricyclic poisoning and can be difficult to distinguish from ventricular tachycardia. A 12-lead ECG may help to distinguish the two; 50 ml boluses of 8-4% sodium bicarbonate is given, even with a normal arterial pH, when the QRS duration is greater than 120 ms, if there are malignant arrhythmias or persistent hypotension (after securing the airway, and giving a high concentration of oxygen and intravenous fluid). CT scanning of the brain is not necessarily indicated when there is a clear history and signs consistent with poisoning.

3. The builder with a head injury should be managed by a team experienced in major trauma and ATLS (Advanced Trauma and Life Support) - this will ensure that other injuries are not missed. A (with cervical spine control), B, and C are still the immediate management in this case. Tracheal intubation is indicated and the anaesthetist will pay attention to preventing secondary brain injury by the following means:

• Even though the patient is unconscious, he will be given a general anaesthetic and paralysed before intubation to avoid any rise in intracranial pressure (tracheal intubation is extremely stimulating causing a rise in blood pressure and tachycardia in people not fully sedated).

• PaCO2 will be kept within normal range and constantly monitored; hypoxaemia will be avoided.

• MAP will be maintained at around 90 mmHg (blood pressure not too high and not too low).

• The patient will be catheterised to avoid the stimulation of a full bladder, which may lead to a rise in ICP as well as increasing anaesthetic requirements.

• He will need an urgent CT scan of the head and neck, which may indicate the need for urgent neurosurgical intervention.

4. Hypertension following stroke is a common response to brain ischaemia. Blood pressure should not be lowered as blood supply to the potentially viable ischaemic penumbra could be compromised. Many stroke patients are normally hypertensive so a "normal" blood pressure may in fact be too low. The use of sublingual nifedipine gives an unpredictable response and may end up extending the stroke. If the stroke is caused by haemorrhage (in 15% cases), some neurologists would consider lowering an excessively high blood pressure in a controlled way, but not to "normal" levels - seek expert advice. In this patient, attention must be paid to the following: airway, oxygen saturations, hydration, treatment of fever, lowering of high glucose levels, and good nursing care. "Malignant" hypertension is rare and the term "hypertensive crisis" is better. It occurs either on a background of hypertensive disease or as part of other conditions - eclampsia, phaeochromocytoma, and postoperatively (cardiac surgery). There is progressive severe hypertension with encephalopathy (confusion, headache, visual disturbances, fitting, reduced conscious level) and other endorgan damage: renal impairment and heart failure. If this occurs on a background of hypertensive disease, oral therapy is preferred as sudden dramatic falls in blood pressure may cause organ damage through hypoperfusion.

5. The history is consistent with subarachnoid haemorrhage. Management priorities here are to ensure a patent, protected airway and to administer oxygen. Assess and treat any breathing or circulation problems. This patient is drowsy. A formal GCS and neurological examination should be performed. This will provide an objective assessment of subarachnoid haemorrhage according to the World Federation of Neurological Surgeons scale (Table 9.3). A bedside glucose measurement is required. If A, B, C, and D are stable, there is time for a full history and examination. Arterial blood gas analysis would be helpful in assessing oxygenation, ventilation, and perfusion, all important in the prevention of secondary brain injury. The patient should be transferred for an urgent CT scan and neurosurgical opinion as soon as possible.

Table 9.3 World Federation of Neurological Surgeons SAH grading

WFNS grade GCS Major focal neurological deficit

1 15 Absent

2 13-14 Absent

3 13-14 Present

4 7-12 Present or absent

5 3-6 Present or absent

6. The most important diagnosis is meningococcal sepsis. However, immediate management priorities are A, B, C. The low GCS score indicates the need for urgent intubation. The patient requires fluid loading whilst preparations for intubation are made. A bedside glucose measurement and arterial blood gas is required. A full history and formal examination can be done once A, B, and C are stable. Blood cultures should be taken and intravenous antibiotics given whilst arrangements are made for an urgent CT of the head. Lumbar puncture is not necessary in cases of obvious meningococcal meningitis. Clotting abnormalities are a contraindication to LP. The bacteria can be isolated from blood cultures and swabs of the throat and skin lesions. This patient requires further management on the ICU.

7. This lady has a head injury and an unstable cervical spine until proven otherwise. Intubation is indicated, with careful immobilisation of the C-spine. Intravenous atropine and warmed fluids are required to treat the circulation abnormalities. The arterial blood gases show a metabolic acidosis from hypoperfusion. Persistent hypotension may require invasive monitoring and vasoactive drugs. Active rewarming is indicated in severe hypothermia. A bedside glucose measurement and arterial blood gas are required. Differential diagnosis is straightforward hypothermia from lying on the floor or spinal shock. Spinal shock results from spinal cord concussion and gives rise to 24-72 hours of initial paralysis, hypotonicity, and areflexia. Return of activity below the level of the injury, such as the bulbocavernous reflex (anal sphincter contraction in response to tugging on the urinary catheter), signifies the end of spinal shock. Prolonged absence of distal motor function or perirectal sensation indicates complete spinal cord injury. Resuscitation in spinal shock includes raising the legs to reduce peripheral blood pooling, intravenous atropine to block vagal effects, vasopressors to support blood pressure, and high dose intravenous methylprednisolone, which improves outcome by minimising spinal oedema and by its anti-inflammatory actions. Once A, B, and C are stable, urgent CT imaging of the head and neck should be arranged with referral to the neurosurgical team if required.

8. The patient's GCS is 7 (E1, M4, V2). He has signs consistent with an extradural haematoma. These arise from tears in the dural arteries, usually the middle meningeal artery, and are often associated with linear skull fractures over the parietal or temporal areas. Extradural haematomas account for 1% of severe head injuries. The prognosis is generally good as the primary brain injury is usually not serious. However, secondary brain injury occurs rapidly owing to raised intracranial pressure, and is fatal if the clot is not evacuated. Immediate measures to reduce ICP may be required whilst surgery is being prepared. Extradural haematomata classically present as a loss of consciousness immediately after injury, followed by a lucid interval, and then a gradually decreasing conscious level associated with the development of an ipsilateral fixed dilated pupil and contralateral hemiparesis. However, presentation may be atypical or with coma, as in this case. Management in the Emergency Department is directed at stabilising life-threatening problems with A, B, or C, initiating measures to reduce intracranial pressure and transferring the patient safely to theatre. The only procedure to delay craniotomy would be life-threatening haemorrhage. It may be possible to perform a laparotomy and craniotomy simultaneously.

9. The patient has suffered global cerebral ischaemia following cardiac arrest. The best neurological recovery is seen in patients who have a short duration of coma. Patients who remain in a coma 7-14 days after global ischaemia are unlikely to ever become independent. Individual signs suggesting neurological recovery are related to certain brainstem reflexes at the time of the initial examination. Absent light reflexes during the initial examination (allowing for the effects of cardiac arrest drugs to have worn off) place the patient in a very poor prognostic category. The presence of pupillary light reflexes with the return of spontaneous eye opening and conjugate eye movements, accompanied by motor responses, improves the prognosis and chance of independence. Based on this patient's examination at 24 hours, independent function is very unlikely.

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