Hypotension and Hypoxia under Anaesthesia

A 58-year-old man with hypertension and type 2 diabetes mellitus undergoes elective laparoscopic cholecystectomy under general anaesthesia. After induction with propofol (2 mg/kg) and intubation with succinylcholine, his blood pressure drops to 85/50 mmHg and SpO₂ falls to 88% on FiO₂ 1.0. Breath sounds are present bilaterally. Heart rate is 110 bpm. The anesthesiologist notes the capnograph shows a normal waveform. What is the most likely cause of hypotension in this patient?

A 72-year-old woman with COPD (FEV₁ 35% predicted) and sleep apnea undergoes emergency repair of a perforated peptic ulcer under general anaesthesia. Induction is achieved with etomidate (0.2 mg/kg). Five minutes after intubation, SpO₂ drops to 85% on FiO₂ 1.0, and blood pressure is 92/58 mmHg. Bilateral breath sounds are present. Peak airway pressure is 28 cm H₂O (baseline 18 cm H₂O). Capnograph shows a normal waveform. What is the most likely cause of hypoxia in this patient?

A 42-year-old woman with severe asthma is undergoing emergency appendicectomy under general anesthesia. Five minutes after induction with thiopental and intubation, the SpO₂ drops from 98% to 82%, peak airway pressure rises to 45 cm H₂O, and the patient develops diffuse wheezing. Blood pressure remains 110/70 mmHg. What is the most appropriate immediate next step?

A 58-year-old male with hypertension and type 2 diabetes mellitus is undergoing elective laparoscopic cholecystectomy under general anesthesia. After induction with propofol and intubation with succinylcholine, the patient's SpO₂ drops to 88% and systolic blood pressure falls to 78 mmHg. Auscultation reveals bilateral air entry. What is the most appropriate immediate next step?

A 52-year-old male with hypertension undergoing elective open cholecystectomy develops sudden hypotension (BP 85/50 mmHg) and hypoxia (SpO₂ 88%) 30 minutes after induction with propofol and succinylcholine. Breath sounds are bilaterally absent. Which is the investigation of choice to confirm the suspected diagnosis?