Effect of open-lung vs conventional perioperative ventilation strategies on postoperative pulmonary complications after on-pump cardiac surgery: the PROVECS randomized clinical trial.

PURPOSE: To evaluate whether a perioperative open-lung ventilation strategy prevents postoperative pulmonary complications after elective on-pump cardiac surgery. METHODS: In a pragmatic, randomized, multicenter, controlled trial, we assigned patients planned for on-pump cardiac surgery to either a conventional ventilation strategy with no ventilation during cardiopulmonary bypass (CPB) and lower perioperative positive end-expiratory pressure (PEEP) levels (2 cm H2O) or an open-lung ventilation strategy that included maintaining ventilation during CPB along with perioperative recruitment maneuvers and higher PEEP levels (8 cm H2O). All study patients were ventilated with low-tidal volumes before and after CPB (6 to 8 ml/kg of predicted body weight). The primary end point was a composite of pulmonary complications occurring within the first 7 postoperative days. RESULTS: Among 493 randomized patients, 488 completed the study (mean age, 65.7 years; 360 (73.7%) men; 230 (47.1%) underwent isolated valve surgery). Postoperative pulmonary complications occurred in 133 of 243 patients (54.7%) assigned to open-lung ventilation and in 145 of 245 patients (59.2%) assigned to conventional ventilation (p = 0.32). Open-lung ventilation did not significantly reduce the use of high-flow nasal oxygenotherapy (8.6% vs 9.4%; p = 0.77), non-invasive ventilation (13.2% vs 15.5%; p = 0.46) or new invasive mechanical ventilation (0.8% vs 2.4%, p = 0.28). Mean alive ICU-free days at postoperative day 7 was 4.4 ± 1.3 days in the open-lung group vs 4.3 ± 1.3 days in the conventional group (mean difference, 0.1 ± 0.1 day, p = 0.51). Extra-pulmonary complications and adverse events did not significantly differ between groups. CONCLUSIONS: A perioperative open-lung ventilation including ventilation during CPB does not reduce the incidence of postoperative pulmonary complications as compared with usual care. This finding does not support the use of such a strategy in patients undergoing on-pump cardiac surgery. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT02866578. https://clinicaltrials.gov/ct2/show/NCT02866578.

Postoperative pain and subsequent PTSD-related symptoms in patients undergoing lung resection for suspected cancer.

BACKGROUND: Because lung cancer resection is at the crossroad between cancer and high-risk surgery, we hypothesized that the patients undergoing lung resection for cancer are exposed to develop a post-traumatic stress disorder (PTSD) syndrome-related symptoms. METHODS: Forty-seven adult patients were included in the study. Patients were eligible for inclusion if they underwent lung resection for suspected cancer, if they were able to speak and read French, and if they agreed to be reached for a telephone interview. We assessed before, immediately after, and 3 months after surgery the presence of symptoms of anxiety and depression (Hospital Anxiety and Depression Scale) and PTSD-related symptoms (impact of events scale revised [IES-R]). At the 3-month assessment, an IES-R score > 22 was used as criteria for predicting the patients at risk of PTSD-related symptoms. RESULTS: We identified an IES-R score higher than 22 in 24 participants (51%). Patients with a preoperatory Hospital Anxiety and Depression Scale(anxiety) score more than 7 (T0) and a maximal visual analogic scale score more than 40 during the first 24 hours after surgery were more likely to develop PTSD-related symptoms at 3-months with odd ratios at 4.61 [1.20-17.73] (p = 0.03) and 1.34 [1.05-1.75] (p = 0.02). CONCLUSION: The prevalence of PTSD-related symptoms after lung cancer resection is high, showing that lung cancer patients undergoing surgical resection are at high risk of postprocedure burden. The presence of preoperative symptoms of anxiety and acute procedural pain during the early postoperative period are strong predictors for developing PTSD-related symptoms after lung cancer surgery.

Is there any benefit to adding intravenous ketamine to patient-controlled epidural analgesia after thoracic surgery? A randomized double-blind study.

OBJECTIVES: Thoracic surgery is associated with severe acute postoperative pain, leading to pulmonary complications and hyperalgesia-induced chronic pain. Thoracic patient-controlled epidural analgesia is also considered as the gold-standard postoperative analgesia. As previously described in major digestive surgery, combination with low-dose intravenous (i.v.) ketamine could potentiate epidural analgesia and facilitate pulmonary function recovery following thoracotomy. METHODS: In a randomized, double-blind trial, 60 patients scheduled to undergo thoracotomy were included. All patients received a thoracic epidural catheter placed before surgery, and standardized general anaesthesia. They were allocated to two groups to receive either an i.v. bolus of ketamine at induction, followed by a continuous infusion during surgery and the first 48 h postoperatively, or an i.v. placebo (a saline solution under the same infusion modalities). Cumulative epidural ropivacaine consumption, postoperative pain scores (patient self-rated numeric pain intensity scale), analgesic rescue consumption, residual pain, haemodynamics and respiratory recovery function were recorded from 12 h to 3 months. Data were expressed as mean ± standard deviation or median ± interquartile range (25-75%). The comparisons between ketamine and placebo groups were performed using χ(2) or Fisher's exact tests for frequencies, and Mann-Whitney tests for quantitative variables. RESULTS: Epidural ropivacaine consumption was similar between groups during the first 48 postoperative hours. Postoperative pain scores and spirometric parameters were not significantly different between groups. But the incidence of postoperative nausea was significantly increased in patients owning to the ketamine group. Finally, the incidence of residual pain was similar between groups at 1 and 3 months following thoracotomy. CONCLUSIONS: Adding i.v. ketamine did not potentiate epidural analgesia neither to reduce acute and chronic postoperative pain nor to improve pulmonary dysfunction following thoracic surgery. Pain scores were low in both groups, mainly because of an optimized analgesia provided by the patient-controlled epidural mode, and might explain this lack of benefit in adding i.v. ketamine.

Molecular detection of microorganisms in distal airways of patients undergoing lung cancer surgery.

BACKGROUND: Whereas proximal airways of patients undergoing lung cancer surgery are known to present specific microbiota incriminated in the occurrence of postoperative respiratory complications, little attention has been paid to distal airways and lung parenchyma considered to be free from bacteria. We have hypothesized that molecular culture-independent techniques applied to distal airways should allow identification of uncultured bacteria, virus, or emerging pathogens and predict the occurrence of postoperative respiratory complications. METHODS: Microbiological assessments were obtained from the distal airways of resected lung specimens from a prospective cohort of patients undergoing major lung resections for cancer. Microorganisms were detected using real-time polymerase chain reaction (PCR) assays targeting the bacterial 16s ribosomal RNA gene and Herpesviridae, cytomegalovirus (CMV), and herpesvirus simplex. All postoperative microbiological assessments were compared with the PCR results. RESULTS: In all, 240 samples from 87 patients were investigated. Colonizing agents were exclusively Herpesviridae (CMV, n=13, and herpesvirus simplex, n=1). All 16s ribosomal RNA PCR remained negative. Thirteen patients (15%) had a positive CMV PCR (positive-PCR group), whereas the remaining 74 patients constituted the negative-PCR group. Postoperative pneumonia occurred in 24% of the negative-PCR group and in 69% of the positive-PCR group (p=0.003). Upon stepwise logistic regression, performance status, percent of predicted diffusion lung capacity for carbon monoxide, and positive PCR were the risk factors of postoperative respiratory complications. The CMV PCR had a positive predictive value of 0.70 in prediction of respiratory complications. CONCLUSIONS: When tested by molecular techniques, lung parenchyma and distal airways are free of bacteria, but CMV was found in a high proportion of the samples. Molecular CMV detection in distal airways should be seen as a reliable marker to identify patients at risk for postoperative respiratory complications.