6 resolved citations behind this deck; every point above traces to one of them.
WHERE THE GUIDANCE SITS
What the guidelines and pooled evidence say
3 findings, each on the slide that follows.
Anesthesiology 2025
High PEEP with recruitment maneuvers may reduce postoperative pulmonary
High PEEP with recruitment maneuvers may reduce postoperative pulmonary complications, especially in laparoscopic surgery (OR 0.67 [0.50 to 0.87]).
British journal of anaesthesia 2019
Set the ventilator initially to a tidal volume of 6-8 mL/kg predicted body weight
Set the ventilator initially to a tidal volume of 6-8 mL/kg predicted body weight with PEEP 5 cmH2O, then individualise the PEEP; when recruiting,…
Anesthesiology 2015
The dose-response for postoperative pulmonary complications tracks tidal volume, not
The dose-response for postoperative pulmonary complications tracks tidal volume, not PEEP: adding high PEEP to an already low tidal volume gave no…
WHERE THE GUIDANCE SITS
High PEEP with recruitment maneuvers may reduce postoperative pulmonary
Meta-analysis · Anesthesiology
High PEEP with recruitment maneuvers may reduce postoperative pulmonary complications, especially in laparoscopic surgery (OR 0.67 [0.50 to 0.87]).
High Positive End-Expiratory Pressure (PEEP) With Recruitment Maneuvers Versus Low PEEP During General Anesthesia for Surgery: A Bayesian Individual Patient Data Meta-Analysis of Three Randomized Clinical Trials, Anesthesiology 2025 · PMID 39042027
WHERE THE GUIDANCE SITS
Set the ventilator initially to a tidal volume of 6-8 mL/kg predicted body weight
Guideline · British journal of anaesthesia
Set the ventilator initially to a tidal volume of 6-8 mL/kg predicted body weight with PEEP 5 cmH2O, then individualise the PEEP; when recruiting, use the lowest effective pressure for the shortest effective time.
Lung-Protective Ventilation for the Surgical Patient: International Expert Panel-Based Consensus Recommendations, British journal of anaesthesia 2019 · PMID 31587835
WHERE THE GUIDANCE SITS
The dose-response for postoperative pulmonary complications tracks tidal volume, not
Meta-analysis · Anesthesiology
The dose-response for postoperative pulmonary complications tracks tidal volume, not PEEP: adding high PEEP to an already low tidal volume gave no further reduction.
Protective Versus Conventional Ventilation for Surgery: A Systematic Review and Individual Patient Data Meta-Analysis, Anesthesiology 2015 · PMID 25978326
WHAT THE TRIALS FOUND
Lung-protective ventilation cut major pulmonary and extrapulmonary complications
Randomised trial · The New England journal of medicin
Lung-protective ventilation cut major pulmonary and extrapulmonary complications after major abdominal surgery from 27.5% to 10.5%, and the need for postoperative ventilation or reintubation from 17% to 5%.
A Trial of Intraoperative Low-Tidal-Volume Ventilation in Abdominal Surgery, The New England journal of medicine 2013 · PMID 23902482
Individualized intraoperative open-lung approach involves recruiting collapsed lung areas and personalizing PEEP to potentially reduce postoperative…
IN PRACTICE
In a 69,265-patient registry, a PEEP of 5 cmH2O and a plateau pressure of 16 cmH2O
Cohort · BMJ (Clinical research ed.)
In a 69,265-patient registry, a PEEP of 5 cmH2O and a plateau pressure of 16 cmH2O or less were the settings associated with the lowest risk of postoperative respiratory complications.
Intraoperative Protective Mechanical Ventilation and Risk of Postoperative Respiratory Complications: Hospital Based Registry Study, BMJ (Clinical research ed.) 2015 · PMID 26174419
Individualized intraoperative open-lung approach involves recruiting collapsed lung areas and personalizing PEEP to potentially reduce postoperative pulmonary complications compared to strategies tolerating lung collapse.
Improving Lung Protective Mechanical Ventilation: The Individualised Intraoperative Open-Lung Approach, British journal of anaesthesia 2025 · PMID 39880492
THE NUMBERS
High PEEP did not reduce complications, and cost blood pressure
Patient-level meta-analysis of three trials, 3,837 patients.
High PEEP buys fewer desaturations and pays in hypotension, without changing the outcome that matters.
THE NUMBERS
One fixed PEEP does not fit
Individually titrated PEEP by electrical impedance tomography, 40 patients.
Titrated PEEP ranged from 6 to 16 cmH2O with a median of 12 — a fixed 4 left atelectasis behind.
IN THE ROOM
What this changes about the next case
Colour is the strength of the evidence behind each step, not the urgency.
1
1
Set the ventilator initially to a tidal volume of 6-8 mL/kg predicted body weight with PEEP 5 cmH2O, then individualise the PEEP; when recruiting, use the lowest effective pressure for the shortest effective time.
2
2
High PEEP with recruitment maneuvers may reduce postoperative pulmonary complications, especially in laparoscopic surgery (OR 0.67 [0.50 to 0.87]).
3
3
The dose-response for postoperative pulmonary complications tracks tidal volume, not PEEP: adding high PEEP to an already low tidal volume gave no further reduction.
4
4
Lung-protective ventilation cut major pulmonary and extrapulmonary complications after major abdominal surgery from 27.5% to 10.5%, and the need for postoperative ventilation or reintubation from 17% to 5%.
5
5
In a 69,265-patient registry, a PEEP of 5 cmH2O and a plateau pressure of 16 cmH2O or less were the settings associated with the lowest risk of postoperative respiratory complications.
The oral-boards stem on the next slide puts these into one scenario.
KEY TAKEAWAYS
What to carry into the next case
High PEEP with recruitment maneuvers may reduce postoperative pulmonary
Anesthesiology 2025
Set the ventilator initially to a tidal volume of 6-8 mL/kg predicted body weight
British journal of anaesthesia 2019
The dose-response for postoperative pulmonary complications tracks tidal volume, not
Anesthesiology 2015
Lung-protective ventilation cut major pulmonary and extrapulmonary complications
The New England journal of medicine 2013
High PEEP with recruitment maneuvers may reduce postoperative pulmonary
Questions I'll ask you in the room
How does your plan change if the patient is not optimised?
What is the physiology behind what we just did?
Talk me through the trade-off you made there.
What would make you abandon this plan and do something else?
Oral boards stem
A 58-year-old with a BMI of 38 is undergoing laparoscopic sleeve gastrectomy in steep reverse Trendelenburg. Peak pressures are 34 cmH2O after insufflation and the saturation has drifted to 93%.
Board questions
1. State the initial ventilator settings recommended by international expert consensus on lung-protective ventilation for a surgical patient - tidal volume with its weight basis, and PEEP - what should be done with PEEP after that, and the principle to follow when performing a recruitment manoeuvre.
Show answer
Set an initial tidal volume of 6-8 mL/kg predicted body weight with PEEP 5 cmH2O, then individualise the PEEP. When recruiting, use the lowest effective pressure for the shortest effective time.
6-8 mL/kg of predicted body weight with PEEP 5 is a starting point, not the final setting - the PEEP gets individualised from there.
Lung-Protective Ventilation for the Surgical Patient: International Expert Panel-Based Consensus Recommendations, British journal of anaesthesia 2019 · PMID 31587835
2. In an individual patient data meta-analysis of protective versus conventional intraoperative ventilation, which ventilator variable did the dose-response for postoperative pulmonary complications track, and what happened when high PEEP was added to an already low tidal volume?
Show answer
The dose-response tracked tidal volume, not PEEP. Adding high PEEP on top of an already low tidal volume gave no further reduction in postoperative pulmonary complications.
In that pooled data the tidal volume was doing the work - piling PEEP on top of an already low tidal volume added nothing.
Protective Versus Conventional Ventilation for Surgery: A Systematic Review and Individual Patient Data Meta-Analysis, Anesthesiology 2015 · PMID 25978326
3. In a randomised trial of intraoperative low-tidal-volume, lung-protective ventilation during major abdominal surgery, give the effect on major pulmonary and extrapulmonary complications and on the need for postoperative ventilation or reintubation, with the event rates for each.
Show answer
Major pulmonary and extrapulmonary complications fell from 27.5% to 10.5%, and the need for postoperative ventilation or reintubation fell from 17% to 5%.
Those are large absolute differences, and they were shown after major abdominal surgery - that is the population the numbers describe.
A Trial of Intraoperative Low-Tidal-Volume Ventilation in Abdominal Surgery, The New England journal of medicine 2013 · PMID 23902482
4. A Bayesian individual patient data meta-analysis of three randomised trials compared high PEEP with recruitment manoeuvres against low PEEP, reporting an odds ratio of 0.67 (0.50 to 0.87) for postoperative pulmonary complications in laparoscopic surgery. Say how strongly you should state this finding to a resident, and for which surgical setting.
Show answer
State it as a possible rather than an established benefit: high PEEP with recruitment manoeuvres may reduce postoperative pulmonary complications, especially in laparoscopic surgery, where the odds ratio was 0.67 (0.50 to 0.87). The finding is hedged as 'may reduce', and laparoscopic surgery is the setting where it is described.
Say 'may reduce' - this is pooled trial data with the clearest signal in laparoscopic surgery, not a settled rule for every case.
High Positive End-Expiratory Pressure (PEEP) With Recruitment Maneuvers Versus Low PEEP During General Anesthesia for Surgery: A Bayesian Individual Patient Data Meta-Analysis of Three Randomized Clinical Trials, Anesthesiology 2025 · PMID 39042027
The bottom lineHigh PEEP with recruitment maneuvers may reduce postoperative pulmonary
Sources
[1] High Positive End-Expiratory Pressure (PEEP) With Recruitment Maneuvers Versus Low PEEP During General Anesthesia for Surgery: A Bayesian Individual Patient Data Meta-Analysis of Three Randomized Clinical Trials, Anesthesiology 2025 · PMID 39042027 open
[2] Lung-Protective Ventilation for the Surgical Patient: International Expert Panel-Based Consensus Recommendations, British journal of anaesthesia 2019 · PMID 31587835 open
[3] Protective Versus Conventional Ventilation for Surgery: A Systematic Review and Individual Patient Data Meta-Analysis, Anesthesiology 2015 · PMID 25978326 open
[4] A Trial of Intraoperative Low-Tidal-Volume Ventilation in Abdominal Surgery, The New England journal of medicine 2013 · PMID 23902482 open
[5] Intraoperative Protective Mechanical Ventilation and Risk of Postoperative Respiratory Complications: Hospital Based Registry Study, BMJ (Clinical research ed.) 2015 · PMID 26174419 open
[6] Improving Lung Protective Mechanical Ventilation: The Individualised Intraoperative Open-Lung Approach, British journal of anaesthesia 2025 · PMID 39880492 open