PRONE POSITION IN ARDS AFTER ABDOMINAL SURGERY, IS IT FEASIBLE?
Acute respiratory distress syndrome (ARDS) represents a common clinical problem in intensive care unit patients and it is characterised by high mortality. Evidence that ventilation in the prone position significantly reduces overall mortality in patients with severe acute respiratory distress syndrome is increasing (1,2). When respiratory failure occurs in the early postoperative period after abdominal surgery, cases of severe hypoxemia may benefit from prone position, but the prevalence of surgical complications that could be a priori induced or worsened by this strategy remains unknown.
Gaudry and colleagues (3) performed a study that attempted to clarify if prone position is associated with a greater rate of surgical complications (primary endpoint) and learn the effects of prone position on oxygenation (secondary endpoint). This study was a multicentre retrospective cohort of patients with ARDS who had recently undergone abdominal surgery (<7 days) and data from the prone group were compared with those from the supine group. The following were defined as postoperative surgical complications: scar dehiscence, abdominal compartment syndrome, stoma leakage, stoma necrosis, scar necrosis, wound infection, displacement of a drainage system, removal of a gastro- or jejunostomy feeding tube and digestive fistula.
Over a five-year period, a total of 98 patients had ARDS and underwent abdominal surgery in the last 7 days. Of these, 37% patients had at least one prone position session and 63% remained supine. Rate of surgical complications did not differ between prone and supine groups (39% vs 44%; p=0.65) even after propensity score application (OR 0.72 [0.26–2.02], p = 0.54). In 52% of the prone position patients only one session was necessary due to the significant improvement of Pa O2/Fi O2 ratio increasing from 95 ± 47 to 189 ± 92 mmHg (p < 0.0001). Duration of MV, ICU length of stay and ICU mortality were also not different.
In large randomised controlled trials (RCTs) of prone position in ARDS (1,2) the precise data about patients undergoing post-abdominal surgery and the rate of surgical complications are not provided, therefore it is difficult to draw specific conclusions regarding this subset of patients. In this study, although it was observed that 40% of the patients presented at least one surgical complication potentially related to the prone position, no significant differences were found with the supine group. In terms of oxygenation, the improvement described was greater than that reported in these RCTs, with an increase of PaO2 / FiO2 of almost 100 mmHg after the first prone session. The retrospective design is a limitation but due to the difficulty of performing a proper RCT given the small number of patients concerned by this condition, the data obtained in this study provided useful information for making decisions about this kind of patients.
These results confirm that positioning prone in patients with postoperative ARDS provides a clear benefit on oxygenation without significant increase in surgical complications and no effect on the need for surgical revisions and it should be considered in case of life-threatening hypoxemia.
This article review was submitted by EJRC member Pablo Concha Martínez, MD (Intensive Care Medicine Service, University Hospital Politécnico la Fe, Valencia, Spain).
1. Guérin C, Reignier J, Richard J-C, et al. Prone Positioning in Severe Acute Respiratory Distress Syndrome. N Engl J Med. 2013 Jun 6;368(23):2159–68.
2. Gattinoni L, Taccone P, Carlesso E, et al. Prone Position in Acute Respiratory Distress Syndrome. Rationale, Indications, and Limits. Am J Respir Crit Care Med. 2013 Dec;188(11):1286–93.
3. Gaudry S, Tuffet S, Lukaszewicz A-C, et al. Prone positioning in acute respiratory distress syndrome after abdominal surgery: a multicenter retrospective study: SAPRONADONF (Study of Ards and PRONe position After abDOmiNal surgery in France). Ann. Intensive Care (2017) 7:21