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AS7.1-5 | Intensive Care Management — PBL Case

CLINICAL SETTING

Mr. Ramesh Kumar, a 65-year-old retired schoolteacher, is brought to the recovery room following an emergency exploratory laparotomy for a perforated duodenal ulcer. The surgery lasted 3.5 hours; he received 3.5 litres of crystalloid intraoperatively and lost an estimated 600 mL of blood. His past medical history includes hypertension on amlodipine 5 mg daily, Type 2 diabetes mellitus on metformin, and a 25 pack-year smoking history. He was extubated at the end of surgery and initially appeared alert, with an SpO2 of 96% on 4 L/min nasal cannula. Forty-five minutes after arrival in the recovery room, the recovery nurse calls you urgently: Mr. Kumar is confused (GCS now 12 — E3V3M6), his respiratory rate is 32/min, SpO2 has dropped to 88% despite increasing oxygen to 10 L/min via non-rebreather mask, and his blood pressure is 82/46 mmHg with heart rate 128/min and temperature 38.8°C. He has a urinary catheter draining 15 mL over the past 45 minutes. His abdomen is distended and he is moaning in apparent pain.

Trigger 1: Immediate Assessment — Identifying the Crisis

You arrive at the bedside. A rapid assessment reveals: GCS 12 (E3V3M6), RR 32/min, SpO2 88% on 10 L/min oxygen via non-rebreather mask, BP 82/46 mmHg (MAP approximately 58 mmHg), HR 128/min, temperature 38.8°C, and urine output 15 mL/45 min (= 0.2 mL/kg/hour for a 75 kg patient). He is confused, cannot follow complex commands, and is groaning. His abdomen is distended and board-like. The recovery nurse informs you that the surgical team has identified intraoperative contamination of the peritoneal cavity with gastric contents.

DISCUSSION POINTS

  • Which organ systems are failing or threatened in Mr. Kumar, and what specific clinical evidence supports each organ failure? Apply the framework used in ICU admission decision-making.
  • Does this patient meet criteria for ICU admission? If yes, on what specific grounds? If you had only one ICU bed available and another patient in the hospital also needed it, how would you think about the triage decision?
Click to reveal Trigger 2: Airway and Ventilator Management — Deterioration Requiring Intubation (discuss previous trigger first!)

Trigger 2: Airway and Ventilator Management — Deterioration Requiring Intubation

You make the decision to call the ICU team and transfer Mr. Kumar urgently. While awaiting the team, his GCS drops to 9 (E2V2M5). He vomits approximately 50 mL of bilious fluid and his SpO2 falls to 82% transiently. The ICU fellow performs rapid sequence intubation with propofol 1.5 mg/kg and suxamethonium 1.5 mg/kg IV. Mr. Kumar is successfully intubated and connected to a ventilator. His ideal body weight is 70 kg. The ICU fellow asks you to suggest initial ventilator settings. The fellow also notes that after intubation, the ventilator alarmed a high peak airway pressure of 36 cmH2O; plateau pressure measured at 30 cmH2O.

DISCUSSION POINTS

  • Calculate and specify the initial ventilator settings for Mr. Kumar: tidal volume (with calculation), respiratory rate, FiO2, PEEP, and mode of ventilation. What are your oxygenation and ventilation targets? Explain the physiological rationale for each setting choice.
  • The ventilator shows a peak pressure of 36 cmH2O and plateau pressure of 30 cmH2O. How do you interpret this pressure pattern, and what does it tell you about where the problem lies — in airway resistance or lung compliance? Is the plateau pressure acceptable, and what is the maximum safe value?
Click to reveal Trigger 3: ICU Monitoring and 24-Hour Review — Complications and Goals (discuss previous trigger first!)

Trigger 3: ICU Monitoring and 24-Hour Review — Complications and Goals

Mr. Kumar is now settled in the ICU. He is on volume-controlled ventilation with the settings your team agreed on. Monitoring is established: continuous ECG, SpO2, arterial line (right radial), central venous catheter (right internal jugular, triple lumen), and urinary catheter. His 4-hour ABG on current settings shows: pH 7.31, PaO2 72 mmHg, PaCO2 44 mmHg, HCO3 21 mEq/L, lactate 3.8 mmol/L (down from 5.2 at admission). MAP is 65 mmHg on norepinephrine 0.12 mcg/kg/min. Urine output has improved to 35 mL/hour. His ScvO2 is 62%. The ICU nurse reports that over the last 30 minutes the ventilator has been alarming a high peak pressure (now 44 cmH2O) with plateau pressure 32 cmH2O, and the SpO2 has fallen from 96% to 88%. Auscultation reveals absent breath sounds on the right side.

DISCUSSION POINTS

  • Interpret the pattern of high peak pressure (44 cmH2O) with a corresponding rise in plateau pressure (32 cmH2O) in Mr. Kumar. What is the most likely cause of the acute deterioration with absent right-sided breath sounds? Describe your immediate bedside management steps using the DOPE mnemonic.
  • Reviewing the 4-hour data: his lactate has fallen from 5.2 to 3.8 mmol/L, MAP is now 65 mmHg, and urine output has recovered to 35 mL/hour, but ScvO2 is 62% (normal >65%). What does the ScvO2 of 62% tell you about oxygen delivery and consumption in Mr. Kumar? What further interventions would you consider to improve this parameter, and at what point would you consider ICU discharge criteria to be met?

Group Task Assignments

Group 1: Collaborative Task

  • Create a one-page structured ICU handover document for Mr. Kumar that a junior doctor could use at the 6-hour mark, incorporating: admission diagnosis, reason for ICU, current ventilator settings, monitoring targets, vasopressor dosing, resuscitation endpoints (MAP, lactate, urine output, ScvO2), and two anticipated complications with their monitoring signs.

Group 2: Collaborative Task

  • Role-play the ICU morning ward round for Mr. Kumar at 24 hours: one student takes the role of the night junior doctor handing over, one takes the role of the ICU consultant receiving the handover, and one takes the role of the primary surgeon (asking about surgical wound, drain output, and antibiotic choice for peritonitis). Identify the key communication priorities and clinical decisions that need to be made in the round.

Learning Issues

Research these questions and bring your findings to the discussion.

  1. [AS7.1] What is the structure of a multidisciplinary ICU team? What are the specific roles of the intensivist, ICU nurses, physiotherapist, and pharmacist in the daily management of a ventilated post-operative patient?
  2. [AS7.2] What are the published criteria for ICU admission and discharge? How do you apply these criteria to a post-operative surgical patient with septic shock, and at what point would this patient meet step-down criteria for transfer to a high-dependency unit?
  3. [AS7.3] What is the systematic ABCDE approach to managing an unconscious patient in the ICU? What daily nursing and medical care routines (ventilator care bundle) are required to prevent complications in a ventilated, sedated patient?
  4. [AS7.4] What are the principles of lung-protective ventilation and the ARDSNet protocol? How do you select ventilator mode, tidal volume (using IBW), PEEP, and FiO2 for a patient with post-operative ARDS? How do you interpret peak versus plateau airway pressure to diagnose compliance versus resistance problems?
  5. [AS7.5] What parameters are monitored in an ICU and what is the physiological basis for each? How do you interpret ScvO2, serum lactate, urine output, and invasive haemodynamic measurements as integrated markers of tissue perfusion rather than isolated values?