Anesthesiology, Resuscitation and Intensive Care
This domain tests airway assessment, the anaesthetic complications you must recognise in the recovery room, and ICU management of the surgical patient: sepsis, ARDS and shock.
Airway and anaesthesia
- Assess Mallampati class, mouth opening, thyromental distance and cervical mobility; predict difficulty and have a failed-intubation plan including a supraglottic device and front-of-neck access.
- Rapid sequence induction with cricoid pressure for a full stomach; ketamine is useful in shock because it preserves blood pressure.
- Spinal anaesthesia is contraindicated in hypovolaemia, coagulopathy, raised intracranial pressure and infection at the puncture site; complications include hypotension, post-dural puncture headache and spinal haematoma.
- Malignant hyperthermia: masseter spasm, rising end-tidal CO2, hyperthermia and rigidity. Stop the trigger, give dantrolene 2.5 mg/kg, cool the patient, treat hyperkalaemia and acidosis.
- Local anaesthetic systemic toxicity: perioral tingling, seizures, arrhythmia. Stop injection, secure the airway and give 20% lipid emulsion.
Resuscitation and intensive care
- Sepsis Hour-1 bundle: cultures, lactate, broad-spectrum antibiotics, 30 mL/kg crystalloid for hypotension or lactate ≥4 mmol/L, vasopressors to mean arterial pressure ≥65 mmHg.
- ARDS (Berlin definition): acute onset, bilateral opacities, PaO2/FiO2 ≤300 on PEEP ≥5. Ventilate at 6 mL/kg predicted body weight, keep plateau <30 cmH2O, and prone if the ratio is <150.
- Shock: distinguish hypovolaemic, cardiogenic, distributive and obstructive using clinical signs, lactate, echocardiography and central venous oxygen saturation.
- Sedation and analgesia: multimodal analgesia, daily sedation interruption, delirium screening, early enteral nutrition.
Worked example
Six hours after laparotomy a patient has BP 85/50, heart rate 125, lactate 4.5, warm peripheries and a normal central venous pressure. Reasoning: this is distributive shock, septic until proven otherwise. Take cultures, start antibiotics within the hour, give a 30 mL/kg fluid challenge, add noradrenaline if the mean arterial pressure stays below 65 mmHg, and search for the source - anastomotic leak, wound, chest or line.
Traps
- Giving a fluid bolus to cardiogenic pulmonary oedema.
- Waiting for a temperature rise to diagnose malignant hyperthermia; rising CO2 and masseter spasm come first.
- Ventilating an ARDS patient at 10 mL/kg.
- Attributing postoperative tachycardia to pain when it is bleeding or sepsis.