Effect of high perioperative oxygen fraction on surgical site infection and pulmonary complications after abdominal surgery: the PROXI randomized clinical trial.

CONTEXT: Use of 80% oxygen during surgery has been suggested to reduce the risk of surgical wound infections, but this effect has not been consistently identified. The effect of 80% oxygen on pulmonary complications has not been well defined. OBJECTIVE: To assess whether use of 80% oxygen reduces the frequency of surgical site infection without increasing the frequency of pulmonary complications in patients undergoing abdominal surgery. DESIGN, SETTING, AND PATIENTS: The PROXI trial, a patient- and observer-blinded randomized clinical trial conducted in 14 Danish hospitals between October 2006 and October 2008 among 1400 patients undergoing acute or elective laparotomy. INTERVENTIONS: Patients were randomly assigned to receive either 80% or 30% oxygen during and for 2 hours after surgery. MAIN OUTCOME MEASURES: Surgical site infection within 14 days, defined according to the Centers for Disease Control and Prevention. Secondary outcomes included atelectasis, pneumonia, respiratory failure, and mortality. RESULTS: Surgical site infection occurred in 131 of 685 patients (19.1%) assigned to receive 80% oxygen vs 141 of 701 (20.1%) assigned to receive 30% oxygen (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.72-1.22; P = .64). Atelectasis occurred in 54 of 685 patients (7.9%) assigned to receive 80% oxygen vs 50 of 701 (7.1%) assigned to receive 30% oxygen (OR, 1.11; 95% CI, 0.75-1.66; P = .60), pneumonia in 41 (6.0%) vs 44 (6.3%) (OR, 0.95; 95% CI, 0.61-1.48; P = .82), respiratory failure in 38 (5.5%) vs 31 (4.4%) (OR, 1.27; 95% CI, 0.78-2.07; P = .34), and mortality within 30 days in 30 (4.4%) vs 20 (2.9%) (OR, 1.56; 95% CI, 0.88-2.77; P = .13). CONCLUSION: Administration of 80% oxygen compared with 30% oxygen did not result in a difference in risk of surgical site infection after abdominal surgery. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00364741.

Perioperative oxygen fraction - effect on surgical site infection and pulmonary complications after abdominal surgery: a randomized clinical trial. Rationale and design of the PROXI-Trial.

BACKGROUND: A high perioperative inspiratory oxygen fraction may reduce the risk of surgical site infections, as bacterial eradication by neutrophils depends on wound oxygen tension. Two trials have shown that a high perioperative inspiratory oxygen fraction (FiO(2) = 0.80) significantly reduced risk of surgical site infections after elective colorectal surgery, but a third trial was stopped early because the frequency of surgical site infections was more than doubled in the group receiving FiO(2) = 0.80. It has not been settled if a high inspiratory oxygen fraction increases the risk of pulmonary complications, such as atelectasis, pneumonia and respiratory failure. The aim of our trial is to assess the potential benefits and harms of a high perioperative oxygen fraction in patients undergoing abdominal surgery. METHODS AND DESIGN: The PROXI-Trial is a randomized, patient- and assessor blinded trial of perioperative supplemental oxygen in 1400 patients undergoing acute or elective laparotomy in 14 Danish hospitals. Patients are randomized to receive either 80% oxygen (FiO(2) = 0.80) or 30% oxygen (FiO(2) = 0.30) during surgery and for the first 2 postoperative hours. The primary outcome is surgical site infection within 14 days. The secondary outcomes are: atelectasis, pneumonia, respiratory failure, re-operation, mortality, duration of postoperative hospitalization, and admission to intensive care unit. The sample size allows detection of a 33% relative risk reduction in the primary outcome with 80% power. DISCUSSION: This trial assesses benefits and harms of a high inspiratory oxygen fraction, and the trial may be generalizable to a general surgical population undergoing laparotomy. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00364741.

Thoracic paravertebral block for breast cancer surgery: a randomized double-blind study.

BACKGROUND: We examined in this randomized, double-blind study whether a multilevel paravertebral block performed before general anesthesia with propofol and a laryngeal mask enhances postoperative analgesia after breast cancer surgery. METHODS: Eighty-eight patients were randomized to receive paravertebral injections with either ropivacaine 0.5% (30 mL) or an equivalent amount of isotonic saline. Nine patients were excluded after randomization, thus 79 patients remained for evaluation (ropivacaine, n = 38; placebo, n = 41). Variables of efficacy were the amount of fentanyl delivered by the patient-controlled analgesia device in the postanesthesia care unit (PACU), postoperative pain measured on a numeric rating scale at regular intervals from the day of surgery and until the second postoperative day. RESULTS: The median consumption of fentanyl in the PACU was less in the ropivacaine group compared with the placebo group (0 microg [range: 0-250 microg] versus 100 microg [range: 0-800 microg], P = 0.001). Also, fewer patients in the ropivacaine group reported pain > or =3 on the numbers rating scale in the PACU (13 vs 31, P < 0.0001). No statistical difference in pain scores or consumption of analgesics could be demonstrated after discharge from the PACU. CONCLUSIONS: A multilevel paravertebral block provides good analgesia for breast surgery, but the duration of analgesia is briefer than described in previous studies.

[Measuring of preoperative anxiety by three self-reporting scales: State Trait Anxiety Inventory, Symptoms CheckList 92 and visual analogue scale]. / Måling af praeoperativ angst med tre selvrapporteringsskalaer: State Trait Anxiety Inventory, Symptoms CheckList 92 og visuel analogskala.

INTRODUCTION: Preoperative anxiety is a common phenomenon. It is therefore necessary to investigate whether quantitative self-reporting anxiety scales can be helpful in the anaesthetic clinic and research. The aim of this study was to compare the state trait anxiety inventory (STAI), symptoms checklist 92 (SCL 92), the subscales anxiety and phobic anxiety, and a visual analogue scale for anxiety (VAS). MATERIAL AND METHODS: Thirty-eight women consecutively referred for elective breast surgery filled in the rating scales the day before the operation. RESULTS: A statistically significant correlation was found between STAI, SCL 92, anxiety, and VAS. The patients' STAI and SCL 92 anxiety scores were markedly higher than that of the background population. DISCUSSION: In this study the STAI scale, SCL 92 anxiety, and VAS measure all essential features of the phenomenon. SCL 92 anxiety is nevertheless considered to be the most appropriate rating scale, because it has been validated in a Danish population.