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Case 001 · Airway · Robotic Surgery

The Edema That Arrived Late

Airway Robotic Crisis

A 71-year-old man, posted for robotic-assisted laparoscopic prostatectomy, taught a roomful of people something that no textbook line ever quite lands the same way: a borderline cuff leak test can go either way, and even a reasonably read result doesn't guarantee what happens next at the bedside.

The Patient

71-year-old male, 90 kg, diagnosed with carcinoma of the prostate, posted for robotic-assisted laparoscopic prostatectomy (RALP).

Pre-operative red flags

BuildDouble chin, short thick neck STOP-BANG score4 (intermediate-high risk OSA) Anticipated difficultyDifficult bag-mask ventilation Position plannedSteep Trendelenburg, ~40°

This patient walked into the room already carrying two separate risk profiles that don't talk to each other often enough — an airway that was borderline difficult before anyone even induced him, and a procedure that was about to spend hours quietly working against venous drainage from his head and neck.

Intra-operative Course

Surgery lasted approximately 4.5 hours in steep Trendelenburg position. An intraoperative fluid-restrictive strategy was followed, in line with current recommendations for RALP to limit airway and facial edema. Hemodynamics stayed stable throughout, with blood pressure in the 130–140/90 mmHg range.

No issues were flagged intraoperatively. The case "looked clean" — which is exactly the problem with airway edema in steep Trendelenburg. It doesn't announce itself during the case. It announces itself afterward, when the head goes back down and the fluid that pooled for four and a half hours has nowhere obvious left to hide.

The Extubation Sequence

Return to supine
Patient repositioned supine and observed for 20 minutes before any extubation attempt — allowing time for some redistribution of head and neck edema.
Cuff leak test
Performed prior to extubation. Leak volume measured at approximately 100–150 mL — a borderline result. Most published thresholds place clear risk below ~110 mL and general reassurance above ~130 mL, so this reading straddled the line rather than falling clearly into either zone. On balance it was read as acceptable, and the decision to proceed to trial extubation followed.
Trial extubation
With the leak result read as acceptable, a trial extubation was carried out — consistent with standard practice, since even a passing cuff leak test does not eliminate the need for close post-extubation observation. Nebulisation was started immediately after, and the patient remained closely monitored.
~15 minutes post-extubation
Saturation initially maintained, then the patient developed respiratory distress followed by desaturation — the delayed-onset pattern that makes post-extubation airway edema so dangerous. The window where everyone exhales and turns back to their paperwork is exactly when this shows up.
Re-intubation
Performed promptly. Videolaryngoscopy revealed profound airway edema — the kind of finding a moderate-sensitivity screening test like the cuff leak test can miss even when read carefully.

He was managed on the ventilator afterward, kept head-up, and was extubated later once airway edema had clinically resolved — the same safe pathway described for delayed extubation in the literature on this exact patient population.

What This Case Is Really About

This isn't a case about a missed or ignored warning sign. The surgery was fluid-restricted, the positioning was standard, the supine recovery period was observed, and the cuff leak test was performed and gave a borderline result — not a clear pass, not a clear fail. The team made a defensible call on an ambiguous number. The airway still failed about fifteen minutes later.

That gap is what stayed with me. A leak in the 100–150 mL range sits in a zone where the published literature itself disagrees on interpretation — some thresholds (110 mL, 130 mL) would call parts of that range reassuring, others would call the lower end of it concerning. This is precisely why current evidence describes the cuff leak test as a tool with excellent specificity but only moderate sensitivity: a passing or borderline result is genuinely useful for flagging patients at higher risk, but it cannot, by itself, rule out airway edema that is still actively progressing in the tissue. The guidance that follows from this is not "the team should have read the number differently" — it's that close post-extubation monitoring is required regardless of how the leak test reads, and matters most in exactly this kind of high-risk patient.

What I keep coming back to

When the cuff leak volume falls in a borderline zone (roughly 100–150 mL by commonly cited thresholds), the result should not be treated as clearance to extubate and move on — especially in a patient with baseline difficult-airway features after prolonged steep Trendelenburg. Close observation should continue for at least 15–30 minutes after extubation, with re-intubation equipment immediately at hand, regardless of how the leak test was read at the time.

What the Room Discussed Afterward

The post-case discussion covered four things worth carrying into the next steep-Trendelenburg case:

1. Conjunctival edema as a 15-minute checkpoint

Conjunctival edema (CE) is one of the few signs of upper-body venous congestion you can actually see intraoperatively without any extra equipment. A 2019 retrospective study of 56 RALP patients found CE in 23.21% of cases — and of those who developed CE, 61.54% went on to have delayed extubation, a statistically significant association (p = 0.0008).1 The same study found that prolonged Trendelenburg time trended toward more delayed extubation, though this didn't reach statistical significance (p = 0.0842) — duration matters, but it isn't the whole story.

The practical takeaway raised in discussion: check the conjunctivae roughly every 15 minutes during a long Trendelenburg case, and treat visible CE as a trigger to consider a diuretic rather than a finding to simply note in the chart.

2. The cuff leak test reassures less than it sounds like it should

Worth flagging directly: clinicians use "positive" and "negative" inconsistently for this test. In most of the quantitative literature (Miller & Cole 1996; Jaber et al. 2003), a "positive" cuff leak test actually refers to a low leak volume (<110 mL) — positive for risk — while a "negative" test means an adequate leak and lower risk. This patient's leak, at 100–150 mL, straddled the commonly cited 110–130 mL threshold zone — a genuinely borderline number rather than a clearly reassuring one. The practical lesson isn't to distrust the test outright; it's to recognise that a borderline or even a clearly "good" volume doesn't override the rest of a patient's risk profile, and shouldn't be the only thing the extubation decision rests on.

3. Central line site selection in this position

For patients requiring central venous access who are also going into steep Trendelenburg, the discussion favored avoiding internal jugular cannulation where feasible and preferring the subclavian route — partly to avoid adding to head-and-neck venous congestion that the position is already creating, and partly to keep the access route undisturbed by the same swelling you're trying to monitor for.

4. Don't forget the eyes — and don't forget to ask about them beforehand

Steep Trendelenburg raises intraocular pressure (IOP) and intracranial pressure (ICP), and in patients with a history suggestive of glaucoma or raised ICP, this carries a real risk of postoperative visual loss. A relevant ocular and neurological history should be taken before any pelvic surgery planned in steep Trendelenburg, and a modified, less steep ("Z") Trendelenburg position should be considered for patients identified as high-risk.

Conjunctival edema and prolonged Trendelenburg position alert the anaesthesiologist to underlying airway edema, so extubation should be done cautiously to prevent airway-related complications. — Bodkhe et al., Int J Med Sci Innov Res, 2019

Where the Evidence Stands Today

Current perioperative airway guidance continues to support extubation caution after prolonged steep Trendelenburg and pneumoperitoneum, particularly in patients with baseline difficult-airway features. Practical measures with reasonable supporting evidence include:

None of this is exotic. All of it was, in fact, already present in this case — the fluid restriction was followed, the position change before extubation was observed, the cuff leak test was performed and gave a borderline number that was read as acceptable. The lesson here isn't "do more" or "distrust every test." It's "an equivocal result deserves the same vigilance as a worrying one." The 15–30 minutes after extubation are not a formality to get through — they're the window where this kind of edema actually declares itself.

References

  1. Bodkhe A, Upadhye S, Nadkarni M, Pitale C, Purohit A. Robotic Assisted Laparoscopic Prostatectomy: Conjunctival Edema and Trendelenburg Time as Predictors for Delayed Extubation. Int J Med Sci Innov Res. 2019;4(5):229–239.
  2. Miller RL, Cole RP. Association between reduced cuff leak volume and postextubation stridor. Chest. 1996;110(4):1035–1040.
  3. Jaber S, Chanques G, Matecki S, et al. Post-extubation stridor in intensive care unit patients: risk factor evaluation and importance of the cuff-leak test. Intensive Care Med. 2003;29:69–74.
  4. Kilic OF, Borgers A, Köhne W, et al. Effects of steep Trendelenburg position for robotic-assisted prostatectomies on intra- and extrathoracic airways. Br J Anaesth. 2015;114(1):70–76.
  5. Awad H, Walker C, Shaikh M, et al. Anesthetic considerations for robotic prostatectomy: a review of the literature. J Clin Anesth. 2012;24:494–504.
  6. Taketani Y, Mayama C, Suzuki N, et al. Transient but significant visual field defects after robot-assisted laparoscopic radical prostatectomy in deep Trendelenburg position. PLoS One. 2015.
June 2026 Airway · Robotic · Crisis

This case has been fully de-identified. No institutional or departmental identifiers are included. Details have been generalised where necessary to protect patient and staff confidentiality, consistent with HIPAA principles, India's Digital Personal Data Protection (DPDP) Act 2023, and NMC ethical guidelines. This content is for educational reflection only and does not represent the views of any institution, employer, or training program, and is not a substitute for independent clinical judgment.