Critical Care·CA-3 / Fellow

Post-Op Septic Shock & ARDS

Critical care mastery involving lung-protective ventilation, pressor selection, and surgical source control timing.

The stem

A 72 y.o. male is 3 days post-op from an incarcerated hernia repair. He develops acute shortness of breath and hypotension. CXR shows bilateral patchy opacities. BP is 75/40, HR 135, and he is requiring 80% FiO2 on HFNC. Surgical team wants to re-explore for possible anastomotic leak...

Focus

Management of septic shock, lung-protective ventilation (6cc/kg), and the timing of surgical source control in the unstable patient.

Examination relevance

Examiners look for 'The ICU Perspective': Are you treating a number or the pathology? Defend your resuscitative goals (MAP > 65, Lactate clearance). ARDS and sepsis logic are evergreen topics.

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Expert sample response

I will manage this patient using early, goal-directed therapy for septic shock while initiating a lung-protective ventilation strategy. My first priority is stabilizing the MAP to >65 mmHg using titrated norepinephrine as my first-line pressor. Simultaneously, I'll address his respiratory failure by setting the tidal volume to 6 mL/kg of predicted body weight and applying sufficient PEEP to maintain SpO2 >88%, while keeping plateau pressures below 30 cmH2O.

I will clearly communicate to the surgical team that while he is hemodynamically fragile, definitive 'source control' is required to reverse the septic state. I will resuscitate with balanced crystalloids rather than albumin or starch. I'll maintain broad-spectrum antibiotic coverage and track lactate clearance as a marker of resuscitative success. For the induction of anesthesia, I will use a hemodynamically stable agent like ketamine or etomidate, assuming he is a 'full stomach' due to his ileus.

Full walkthrough

What the Examiner Is Testing

This case tests whether you treat the numbers or the pathology. The core principle: source control is required to reverse septic physiology, and you have to be willing to take a hemodynamically fragile patient to the OR when that's what will save them. The examiner also wants precise lung-protective ventilation targets — not vague references to "low tidal volumes."

The Board Trap

The trap is refusing to take the patient to the OR because "he's too unstable." Untreated surgical source — an anastomotic leak — will kill this patient faster than the anesthetic. The flip side trap is agreeing to go to the OR without stabilizing him first and then crashing on induction from a poorly planned resuscitation.

Walk-Through: How This Case Plays Out

Examiner: The patient is on 80% FiO2 on HFNC and his BP is 75/40. The surgeon wants to re-explore. How do you approach this?

Me: I would agree with surgical source control — the anastomotic leak is driving the sepsis and won't resolve without it. But I'm not going to the OR yet. I need to establish adequate IV access, start norepinephrine as my first-line pressor to get the MAP above 65, and plan my induction carefully. I'd estimate 15-20 minutes of resuscitation before induction, not hours.

Examiner: What are your ventilator settings in the OR?

Me: I'd set tidal volume at 6 mL/kg of predicted body weight — not actual body weight. For a 72-year-old male, that's probably around 400 mL. PEEP titrated to maintain SpO2 above 88 to 92%, plateau pressure below 30 cmH2O. FiO2 as low as I can get away with to hit the saturation target. I'm driving rate up to maintain CO2 clearance at the lower tidal volumes — probably RR of 20 to 24.

Examiner: What induction agent do you use?

Me: I would use ketamine — 1 to 2 mg/kg. He's in septic shock with a full stomach from his ileus. Ketamine maintains sympathetic tone, preserves the BP better than propofol or even etomidate in a vasoplegic patient. It also provides good analgesia. I'd follow with a low-dose benzodiazepine for amnesia. Etomidate is a reasonable alternative but the cortisol suppression concerns me in a patient who's already immunocompromised.

Examiner: His lactate is 6.2 on arrival. What does that tell you and how do you follow it?

Me: A lactate of 6.2 means severe tissue hypoperfusion — this patient is in distributive shock with end-organ ischemia. I want to track lactate clearance as my resuscitation marker. A 10% decrease per 2 hours is the minimum acceptable response. If the lactate is not clearing despite MAP above 65 and adequate volume, I'd add vasopressin as a second pressor. I'm following arterial blood gases every 30 to 60 minutes intraoperatively.

Key Phrases That Score Points

"Source control first — you cannot resuscitate your way out of an untreated anastomotic leak."
"6 mL/kg of predicted body weight — not actual body weight. Plateau pressure below 30."
"Ketamine for induction in vasoplegic septic shock — it maintains sympathetic tone better than alternatives."
"Lactate clearance is my resuscitation target — not just MAP and urine output."
"Norepinephrine first-line, vasopressin second — I'm following the Surviving Sepsis algorithm."

Why This Case Appears on the Boards

Examiners use the unstable septic patient to test whether you have an ICU perspective — treating the pathology rather than optimizing numbers. The ability to commit to surgical source control in a fragile patient while simultaneously managing ventilation and hemodynamics is the exact decision-making they're evaluating.