Epidemiology, ventilation management and outcome in patients receiving intensive care after non-thoracic surgery - Insights from the LAS VEGAS study

Introduction and objectives: Information about epidemiology, ventilation management and outcome in postoperative intensive care unit (ICU) patients remains scarce. The objective was to test whether postoperative ventilation differs from that in the operation room.

Material and methods: This was a substudy of the worldwide observational LAS VEGAS study, including patients undergoing non-thoracic surgeries. Of 146 study sites participating in the LAS VEGAS study, 117 (80%) sites reported on the postoperative ICU course, including ventilation and complications. The coprimary outcomes were two key elements of ventilator management, i.e., tidal volume (V_T) and positive end-expiratory pressure (PEEP). Secondary outcomes included the proportion of patients receiving low V_T ventilation (LTVV, defined as ventilation with a median V_T < 8.0 ml/kg PBW), and the proportion of patients developing postoperative pulmonary complications (PPC), including ARDS, pneumothorax, pneumonia and need for escalation of ventilatory support, ICU and hospital length of stay, and mortality at day 28.

Results: Of 653 patients who were admitted to the ICU after surgery, 274 (42%) patients received invasive postoperative ventilation. Median postoperative V_T was 8.4 [7.3-9.8] ml/kg predicted body weight (PBW), PEEP was 5 [5-5] cm H₂O, statistically significant but not meaningfully different from median intraoperative V_T (8.1 [7.3-8.9] ml/kg PBW; P < 0.001) and PEEP (4 [2-5] cm H₂O; P < 0.001). The proportion of patients receiving LTVV after surgery was 41%. The PPC rate was 10%. Length of stay in ICU and hospital was independent of development of a PPC, but hospital mortality was higher in patients who developed a PPC (24 versus 4%; P < 0.001).

Conclusions: In this observational study of patients undergoing non-thoracic surgeries, postoperative ventilation was not meaningfully different from that in the operating room. Like in the operating room, there is room for improved use of LTVV. Development of PPC is associated with mortality.