A.K. Staehr-Rye

Differential Effects of Intraoperative Positive End-expiratory Pressure (PEEP) on Respiratory Outcome in Major Abdominal Surgery Versus Craniotomy.

Objectives: In this study, we examined whether (1) positive end-expiratory pressure (PEEP) has a protective effect on the risk of major postoperative respiratory complications in a cohort of patients undergoing major abdominal surgeries and craniotomies, and (2) the effect of PEEP is differed by surgery type. Background: Protective mechanical ventilation with lower tidal volumes and PEEP reduces compounded postoperative complications after abdominal surgery. However, data regarding the use of intraoperative PEEP is conflicting. Methods: In this observational study, we included 5915 major abdominal surgery patients and 5063 craniotomy patients. Analysis was performed using multivariable logistic regression. The primary outcome was a composite of major postoperative respiratory complications (respiratory failure, reintubation, pulmonary edema, and pneumonia) within 3 days of surgery. Results: Within the entire study population (major abdominal surgeries and craniotomies), we found an association between application of PEEP ≥5 cmH2O and a decreased risk of postoperative respiratory complications compared with PEEP <5 cmH2O. Application of PEEP >5 cmH2O was associated with a significant lower odds of respiratory complications in patients undergoing major abdominal surgery (odds ratio 0.53, 95% confidence interval 0.39 – 0.72), effects that translated to deceased hospital length of stay [median hospital length of stay : 6 days (4–9 days), incidence rate ratios for each additional day: 0.91 (0.84 – 0.98)], whereas PEEP >5 cmH2O was not significantly associated with reduced odds of respiratory complications or hospital length of stay in patients undergoing craniotomy. Conclusions: The protective effects of PEEP are procedure specific with meaningful effects observed in patients undergoing major abdominal surgery. Our data suggest that default mechanical ventilator settings should include PEEP of 5–10 cmH2O during major abdominal surgery.

Postoperative shoulder pain after laparoscopic hysterectomy with deep neuromuscular blockade and low-pressure pneumoperitoneum: A randomised controlled trial.

BACKGROUND Postoperative shoulder pain remains a significant problem after laparoscopy. Pneumoperitoneum with insufflation of carbon dioxide (CO2) is thought to be the most important cause. Reduction of pneumoperitoneum pressure may, however, compromise surgical visualisation. Recent studies indicate that the use of deep neuromuscular blockade (NMB) improves surgical conditions during a low-pressure pneumoperitoneum (8 mmHg). OBJECTIVE The aim of this study was to investigate whether low-pressure pneumoperitoneum (8 mmHg) and deep NMB (posttetanic count 0 to 1) compared with standard-pressure pneumoperitoneum (12 mmHg) and moderate NMB (single bolus of rocuronium 0.3 mg kg−1 with spontaneous recovery) would reduce the incidence of shoulder pain and improve recovery after laparoscopic hysterectomy. DESIGN A randomised, controlled, double-blinded study. SETTING Private hospital in Denmark. PARTICIPANTS Ninety-nine patients. INTERVENTIONS Randomisation to either deep NMB and 8 mmHg pneumoperitoneum (Group 8-Deep) or moderate NMB and 12 mmHg pneumoperitoneum (Group 12-Mod). Pain was assessed on a visual analogue scale (VAS) for 14 postoperative days. MAIN OUTCOME MEASURES The primary endpoint was the incidence of shoulder pain during 14 postoperative days. Secondary endpoints included area under curve VAS scores for shoulder, abdominal, incisional and overall pain during 4 and 14 postoperative days; opioid consumption; incidence of nausea and vomiting; antiemetic consumption; time to recovery of activities of daily living; length of hospital stay; and duration of surgery. RESULTS Shoulder pain occurred in 14 of 49 patients (28.6%) in Group 8-Deep compared with 30 of 50 (60%) patients in Group 12-Mod. Absolute risk reduction was 0.31 (95% confidence interval 0.12 to 0.48; P = 0.002). There were no differences in any secondary endpoints including area under the curve for VAS scores. CONCLUSION Deep NMB and low-pressure pneumoperitoneum (8 mmHg) reduced the incidence of shoulder pain after laparoscopic hysterectomy in comparison to moderate NMB and standard-pressure pneumoperitoneum (12 mmHg). TRIAL REGISTRATION Clinicaltrials.gov identifier: NCT01722097.

High intraoperative inspiratory oxygen fraction and risk of major respiratory complications

Background High inspiratory oxygen fraction ( FIO2 ) may improve tissue oxygenation but also impair pulmonary function. We aimed to assess whether the use of high intraoperative FIO2 increases the risk of major respiratory complications. Methods We studied patients undergoing non-cardiothoracic surgery involving mechanical ventilation in this hospital-based registry study. The cases were divided into five groups based on the median FIO2 between intubation and extubation. The primary outcome was a composite of major respiratory complications (re-intubation, respiratory failure, pulmonary oedema, and pneumonia) developed within 7 days after surgery. Secondary outcomes included 30-day mortality. Several predefined covariates were included in a multivariate logistic regression model. Results The primary analysis included 73 922 cases, of whom 3035 (4.1%) developed a major respiratory complication within 7 days of surgery. For patients in the high- and low-oxygen groups, the median FIO2 was 0.79 [range 0.64-1.00] and 0.31 [0.16-0.34], respectively. Multivariate logistic regression analysis revealed that the median FIO2 was associated in a dose-dependent manner with increased risk of respiratory complications (adjusted odds ratio for high vs low FIO2 1.99, 95% confidence interval [1.72-2.31], P -value for trend <0.001). This finding was robust in a series of sensitivity analyses including adjustment for intraoperative oxygenation. High median FIO2 was also associated with 30-day mortality (odds ratio for high vs low FIO2 1.97, 95% confidence interval [1.30-2.99], P -value for trend <0.001). Conclusions In this analysis of administrative data on file, high intraoperative FIO2 was associated in a dose-dependent manner with major respiratory complications and with 30-day mortality. The effect remained stable in a sensitivity analysis controlled for oxygenation. Clinical trial registration NCT02399878.

Dose-dependent Protective Effect of Inhalational Anesthetics Against Postoperative Respiratory Complications: A Prospective Analysis of Data on File From Three Hospitals in New England

Objectives: Inhalational anesthetics are bronchodilators with immunomodulatory effects. We sought to determine the effect of inhalational anesthetic dose on risk of severe postoperative respiratory complications. Design: Prospective analysis of data on file in surgical cases between January 2007 and December 2015. Setting: Massachusetts General Hospital (tertiary referral center) and two affiliated community hospitals. Patients: A total of 124,497 adult patients (105,267 in the study cohort and 19,230 in the validation cohort) undergoing noncardiac surgical procedures and requiring general anesthesia with endotracheal intubation. Interventions: Median effective dose equivalent of inhalational anesthetics during surgery (derived from mean end-tidal inhalational anesthetic concentrations). Measurements and Main Results: Postoperative respiratory complications occurred in 6,979 of 124,497 cases (5.61%). High inhalational anesthetic dose of 1.20 (1.13–1.30) (median [interquartile range])-fold median effective dose equivalent versus 0.57 (0.45–0.64)-fold median effective dose equivalent was associated with lower odds of postoperative respiratory complications (odds ratio, 0.59; 95% CI, 0.53–0.65; p < 0.001). Additionally, high inhalational anesthetic dose was associated with lower 30-day mortality and lower cost. Inhalational anesthetic dose increase and reduced risk of postoperative respiratory complications remained significant in sensitivity analyses stratified by preoperative and intraoperative risk factors. Conclusions: Intraoperative use of higher inhalational anesthetic doses is strongly associated with lower odds of postoperative respiratory complications, lower 30-day mortality, and lower cost of hospital care. The authors speculate based on these data that sedation with inhalational anesthetics outside of the operating room may likewise have protective effects that decrease the risk of respiratory complications in vulnerable patients.

Eliminate postoperative respiratory complications: preoperative screening opens the door to clinical pathways that individualise perioperative treatment.

Pulmonary complications, including postoperative respiratory failure, represent the second most frequent form of postoperative complications after surgical site infections, with an incidence estimated to range from 2.0 to 7.9%, depending on the definitions and patients studied. Postoperative respiratory failure is a severe complication, which leads to a longer hospital stay, higher financial cost and increases the in-hospital death rate by as much as 90-fold.