Unconscious Patient
Content
Unconscious Patient
Priorities 1. Clear the airway and give oxygen. If there is no femoral or carotid pulse, start CPR . – Remove the false teeth if loose and aspirate the pharynx, larynx and trachea with a suction catheter. – Insert an airway and give 60% oxygen by mask: if the patient is not breathing, ventilate with an Ambubag. – If there is no reflex response (gagging or coughing) to the suction catheter, a cuffed endotracheal tube should be inserted. – Attach an ECG monitor. – Put in a peripheral IV cannula.
Indications for intubation/ventilation of the unconscious patient Clinical
Arterial gases
Coma due to cardiorespiratory arrest Respiratory rate <8/min* No gag reflex To protect the airway before gastric lavage (if gag/cough reflex severely depressed) Pao2 <8kPa (60 mmHg) breathing 60% oxygen Pao2 > 7.3 (55 mmHg)*
*Give naloxone if narcotic poisoning suspected .
Contd… 2. Check the blood glucose immediately by stick test. If blood glucose is <5mmol/1, give dextrose 25g IV (50 ml of dextrose 50% solution) via a large vein. In chronic alcoholics there is a glucose load; prevent this by giving thiamine 100mg IV before or shortly after the dextrose.
Contd… 3. Check the BP and respiratory rate and listen over both lung bases. – If the respiratory rate is less than 10/min, if the pupils are pinpoint or there is other reason to suspect narcotic poisoning, give naloxone. – If systolic BP is <80mmHg (despite correction arrhythmias) give adrenaline 0.5-1mg IV (5-10 ml of 1 in 10,000). If systolic BP is 80-100 mmHg, and there are no signs of pulmonary oedema, give IV fluid (saline or colloid) 500 ml over 30 min, with further fluid if required guided by measurement of central venous pressure (CVP)
Naloxone: selective opiate antagonist 1. Naloxone should be given if: • respiratory rate is <10/min • pupils are pinpoint • narcotic poisoning is suspected 2. Give up to four doses of 800 µg IV every 2-3 min until the respiratory rate is around 15/min 3. If there is a response, start an IV infusion: add 2 mg to 500 ml dextrose 5% or saline (4 µg/ml) and titrate against the respiratory rate and conscious level. The plasma halflife of naloxone is 1 hour: shorter than that of most narcotics.
4. If there is no response narcotic poisoning is excluded.
Contd… 4. Check arterial blood gases and pH. Monitor oxygen saturation by pulse oximetry. – Increase inspired oxygen concentration if Pao2 is < 8kPa (60 mmHg)- Sao2 <90%. – If Paco2 is >7.3 kPa (55 mmHg), consider intubation and ventilation: discuss this with an anaesthetist. – A low Paco2 is an important clue to several causes of coma (Table 6.3)
Causes of coma plus hyperventilation •Diabetic ketoacidosis * •Liver failure* •Renal failure* •Bacterial meningitis •Cerebral malaria •Poisoning with aspirin, carbon monoxide, ethanol, ethylene glycol, methanol, paracetamol of tricyclics* •Stroke complicated by pneumonia or pulmonary oedema •Brainstem stroke
*Associated with a metabolic acidosis
Contd… 5. If coma is a complication of the therapeutic use of benzodiazepine in hospital, flumazenil (a selective benzodiazepine antagonist) may be given (200 µg IV over 15 s; if needed, further doses of 100 µg can be given at 1-min intervals up to a total dose of 1 mg). Flumazenil should not be given to other patients because of the risk of precipitating fits if there is mixed poisoning with benzodiazepines and tricyclics.
Further management At this stage you should obtain a full history and perform a systematic examination. Your further management depends on the neurological signs (Table 6.4 ) The patient can now be placed in one of four groups 1. Signs of head injury (with or without focal neurological signs) 2. Neck stiffness (with or without focal neurological signs) 3. Focal neurological signs but no head injury or neck stiffness 4. No head injury, neck stiffness or focal neurological signs.
Neurological examination of the unconscious patient 1. 2. 3.
4. 5. 6.
7. 8.
Document the level of consciousness in objective terms Examine for signs of head injury (e.g. scalp laceration, bruising, blood at external auditory meatus or from nose) If there are signs of head injury, assume additional cervical spine injury until proven otherwise: the neck must be immobilized in a collar and Xrayed before you test neck stiffness and the oculocephalic responses Test for neck stiffness Record the size of pupils and their response to bright light Test the oculocephalic response. This is a simple but important test of an intact brainstem. Rotate the head to left and right. In an unconscious patient with an intact brainstem both eyes rotate counter to movement of the head Examine the limbs: tone, response to painful stimuli (nailbed pressure), tendon reflexes and plantar responses Examine the fundi
The patient can now be placed in one of four groups 1. Signs of head injury (with or without focal neurological signs) 2. Neck stiffness (with or without focal neurological signs) 3. Focal neurological signs but no head injury or neck stiffness 4. No head injury, neck stiffness or focal neurological signs.
1. Signs of head injury (with or without focal neurological signs) – An intracranial haematoma must be excluded. – Check for injury to other bones and organs. – Correct hypotension (systolic BP <100 mmHg) with IV fluid or blood, guided by measurement of central venous pressure (CVP). – Arrange skull, cervical spine and chest X-rays and urgent computed tomography (CT) of the head – Discuss further management with a neurosurgeon.
Contd…
2. Neck stiffness (with or without focal neurological signs) – –
–
If the clinical features suggest bacterial meningitis, take blood for culture and start antibiotic therapy. Malaria must be excluded in patients who have recently travelled to or through an endemic area. Arrange urgent CT scan.
LP safely done in:
Immunocompetent person normal level of consiousness No Papilloedema No focal neurological signs
Causes of coma with neck stiffness •Bacterial meningits •Encephalitis •Subarachnoid haemorrhage •Cerebral or cerebellar haemorrhage with extension into the subarachnoid space
Contd… • Focal neurological signs but no head injury or neck stiffness – Exclude hypoglycaemia. – The likely diagnosis is a stroke. – Arrange urgent CT if the diagnosis is unclear, or there is the possibility of an intracranial haematoma or obstructive hydrocephalus.
Causes of coma with FNS but no head injury or neck stiffness With brain stem signs (deviation of eyes or abnormal pupil) • Brain stem compression from cerebral he or large infarct with oedema • Brain stem stroke • Cerebellar strole • Cerebral malaria. Without brain stem signs • Hypoglycemia • Liver failure • Cerebral malaria.
Contd… • No head injury, neck stiffness or focal neurological signs. - The likely diagnosis is poisioning or other metabolic causes • Urgent investigations.
Urgent investigations in an unconscious patient • • • • • • • • • •
Blood glucose Urea, Na, K Full blood counts PT in suspected in liver failure ABG and Ph Gastric lavage if poisoning suspected Chest X Ray Blood culture ECG If poisoning is suspected: saveserum (10 ml), urine (50 ml) and vomit or gastric aspirate (50 ml) at 4 C for subsequent analysis.
Priorities 1. Clear the airway and give oxygen. If there is no femoral or carotid pulse, start CPR . – Remove the false teeth if loose and aspirate the pharynx, larynx and trachea with a suction catheter. – Insert an airway and give 60% oxygen by mask: if the patient is not breathing, ventilate with an Ambubag. – If there is no reflex response (gagging or coughing) to the suction catheter, a cuffed endotracheal tube should be inserted. – Attach an ECG monitor. – Put in a peripheral IV cannula.
Indications for intubation/ventilation of the unconscious patient Clinical
Arterial gases
Coma due to cardiorespiratory arrest Respiratory rate <8/min* No gag reflex To protect the airway before gastric lavage (if gag/cough reflex severely depressed) Pao2 <8kPa (60 mmHg) breathing 60% oxygen Pao2 > 7.3 (55 mmHg)*
*Give naloxone if narcotic poisoning suspected .
Contd… 2. Check the blood glucose immediately by stick test. If blood glucose is <5mmol/1, give dextrose 25g IV (50 ml of dextrose 50% solution) via a large vein. In chronic alcoholics there is a glucose load; prevent this by giving thiamine 100mg IV before or shortly after the dextrose.
Contd… 3. Check the BP and respiratory rate and listen over both lung bases. – If the respiratory rate is less than 10/min, if the pupils are pinpoint or there is other reason to suspect narcotic poisoning, give naloxone. – If systolic BP is <80mmHg (despite correction arrhythmias) give adrenaline 0.5-1mg IV (5-10 ml of 1 in 10,000). If systolic BP is 80-100 mmHg, and there are no signs of pulmonary oedema, give IV fluid (saline or colloid) 500 ml over 30 min, with further fluid if required guided by measurement of central venous pressure (CVP)
Naloxone: selective opiate antagonist 1. Naloxone should be given if: • respiratory rate is <10/min • pupils are pinpoint • narcotic poisoning is suspected 2. Give up to four doses of 800 µg IV every 2-3 min until the respiratory rate is around 15/min 3. If there is a response, start an IV infusion: add 2 mg to 500 ml dextrose 5% or saline (4 µg/ml) and titrate against the respiratory rate and conscious level. The plasma halflife of naloxone is 1 hour: shorter than that of most narcotics.
4. If there is no response narcotic poisoning is excluded.
Contd… 4. Check arterial blood gases and pH. Monitor oxygen saturation by pulse oximetry. – Increase inspired oxygen concentration if Pao2 is < 8kPa (60 mmHg)- Sao2 <90%. – If Paco2 is >7.3 kPa (55 mmHg), consider intubation and ventilation: discuss this with an anaesthetist. – A low Paco2 is an important clue to several causes of coma (Table 6.3)
Causes of coma plus hyperventilation •Diabetic ketoacidosis * •Liver failure* •Renal failure* •Bacterial meningitis •Cerebral malaria •Poisoning with aspirin, carbon monoxide, ethanol, ethylene glycol, methanol, paracetamol of tricyclics* •Stroke complicated by pneumonia or pulmonary oedema •Brainstem stroke
*Associated with a metabolic acidosis
Contd… 5. If coma is a complication of the therapeutic use of benzodiazepine in hospital, flumazenil (a selective benzodiazepine antagonist) may be given (200 µg IV over 15 s; if needed, further doses of 100 µg can be given at 1-min intervals up to a total dose of 1 mg). Flumazenil should not be given to other patients because of the risk of precipitating fits if there is mixed poisoning with benzodiazepines and tricyclics.
Further management At this stage you should obtain a full history and perform a systematic examination. Your further management depends on the neurological signs (Table 6.4 ) The patient can now be placed in one of four groups 1. Signs of head injury (with or without focal neurological signs) 2. Neck stiffness (with or without focal neurological signs) 3. Focal neurological signs but no head injury or neck stiffness 4. No head injury, neck stiffness or focal neurological signs.
Neurological examination of the unconscious patient 1. 2. 3.
4. 5. 6.
7. 8.
Document the level of consciousness in objective terms Examine for signs of head injury (e.g. scalp laceration, bruising, blood at external auditory meatus or from nose) If there are signs of head injury, assume additional cervical spine injury until proven otherwise: the neck must be immobilized in a collar and Xrayed before you test neck stiffness and the oculocephalic responses Test for neck stiffness Record the size of pupils and their response to bright light Test the oculocephalic response. This is a simple but important test of an intact brainstem. Rotate the head to left and right. In an unconscious patient with an intact brainstem both eyes rotate counter to movement of the head Examine the limbs: tone, response to painful stimuli (nailbed pressure), tendon reflexes and plantar responses Examine the fundi
The patient can now be placed in one of four groups 1. Signs of head injury (with or without focal neurological signs) 2. Neck stiffness (with or without focal neurological signs) 3. Focal neurological signs but no head injury or neck stiffness 4. No head injury, neck stiffness or focal neurological signs.
1. Signs of head injury (with or without focal neurological signs) – An intracranial haematoma must be excluded. – Check for injury to other bones and organs. – Correct hypotension (systolic BP <100 mmHg) with IV fluid or blood, guided by measurement of central venous pressure (CVP). – Arrange skull, cervical spine and chest X-rays and urgent computed tomography (CT) of the head – Discuss further management with a neurosurgeon.
Contd…
2. Neck stiffness (with or without focal neurological signs) – –
–
If the clinical features suggest bacterial meningitis, take blood for culture and start antibiotic therapy. Malaria must be excluded in patients who have recently travelled to or through an endemic area. Arrange urgent CT scan.
LP safely done in:
Immunocompetent person normal level of consiousness No Papilloedema No focal neurological signs
Causes of coma with neck stiffness •Bacterial meningits •Encephalitis •Subarachnoid haemorrhage •Cerebral or cerebellar haemorrhage with extension into the subarachnoid space
Contd… • Focal neurological signs but no head injury or neck stiffness – Exclude hypoglycaemia. – The likely diagnosis is a stroke. – Arrange urgent CT if the diagnosis is unclear, or there is the possibility of an intracranial haematoma or obstructive hydrocephalus.
Causes of coma with FNS but no head injury or neck stiffness With brain stem signs (deviation of eyes or abnormal pupil) • Brain stem compression from cerebral he or large infarct with oedema • Brain stem stroke • Cerebellar strole • Cerebral malaria. Without brain stem signs • Hypoglycemia • Liver failure • Cerebral malaria.
Contd… • No head injury, neck stiffness or focal neurological signs. - The likely diagnosis is poisioning or other metabolic causes • Urgent investigations.
Urgent investigations in an unconscious patient • • • • • • • • • •
Blood glucose Urea, Na, K Full blood counts PT in suspected in liver failure ABG and Ph Gastric lavage if poisoning suspected Chest X Ray Blood culture ECG If poisoning is suspected: saveserum (10 ml), urine (50 ml) and vomit or gastric aspirate (50 ml) at 4 C for subsequent analysis.
