Recent theoretical work suggests that small-scale turbulence enhances encounter rates between larval fish and their prey. This finding has been extended to suggest that feeding rates will increase in turbulent environments. However, this extrapolation assumes that turbulence has no detrimental effects on postencounter behaviors (e.g. pursuit success). We develop an analytical model to estimate the probability that larval fish feeding in turbulent environments successfully pursue encountered prey. We show that the overall probability of feeding is a dome-shaped function of turbulent velocity and that the height and location of the maxima depend on turbulence level and the behavioral characteristics of predator and prey. Highly turbulent conditions (e.g. storms) will reduce feeding rates below those which occur during calmer conditions and will affect the type of prey captured and ingested.

Purpose The transversus abdominal plane (TAP) block has been described as an effective pain control technique after abdominal surgery. We performed a systematic review and meta-analysis of randomized-controlled trials (RCTs) to account for the increasing number of TAP block studies appearing in the literature. The primary outcome we examined was the effect of TAP block on the postoperative pain score at six, 12, and 24 hr. The secondary outcome was 24-hr morphine consumption. Source We searched the United States National Library of Medicine database, the Excerpta Medica database, and the Cochrane Central Register of Controlled Clinical Studies and identified RCTs focusing on the analgesic efficacy of TAP block compared with a control group [i.e., placebo, epidural analgesia, intrathecal morphine (ITM), and ilioinguinal nerve block after abdominal surgery]. Meta-analyses were performed on postoperative pain scores at rest at six, 12, and 24 hr (visual analogue scale, 0-10) and on 24-hr opioid consumption. Principal findings In the 51 trials identified, compared with placebo, TAP block reduced the VAS for pain at six hours by 1.4 (95% confidence interval [CI], -1.9 to -0.8; P\0.001), at 12 hr by 2.0 (95% CI, -2.7 to -1.4; P\0.001), and at 24 hr by 1.2 (95% CI, -1.6 to -0.8; P \ 0.001). Similarly, compared with placebo, TAP block reduced morphine consumption at 24 hr after surgery (mean difference, -14.7 mg; 95% CI, -18.4 to -11.0; P \0.001). We observed this reduction in pain scores and morphine consumption in the TAP block group after gynecological surgery, appendectomy, inguinal surgery, bariatric surgery, and urological surgery. Nevertheless, separate analysis of the studies comparing ITM with TAP block revealed that ITM seemed to have a greater analgesic efficacy. Conclusions The TAP block can play an important role in the management of pain after abdominal surgery by reducing both pain scores and 24-hr morphine consumption. It may have particular utility when neuraxial techniques or opioids are contraindicated. RésuméObjectif Le bloc dans le plan du muscle transverse de l'abdomen (ou TAP bloc) a été décrit comme une technique efficace de contrô le de la douleur après une chirurgie abdominale. Nous avons réalisé une revue systématique et une méta-analyse des études randomisées contrô lées (ERC) pour faire un état des lieux du nombre croissant d'études

Early cognitive dysfunction after thoracic surgery with SLV is positively related to intraoperative decline of S(ct)O(2).

The closed-loop system was better at maintaining BIS and Analgoscore than manual administration.

No abstract

Automated systems can improve the stability of controlled variables and reduce the workload in clinical practice without increasing the risks to patients. We conducted this review and meta-analysis to assess the clinical performance of closed-loop systems compared with manual control. Our primary outcome was the accuracy of closed-loop systems in comparison with manual control to maintain a given variable in a desired target range. The occurrence of overshoot and undershoot episodes was the secondary outcome. We retrieved randomized controlled trials on accuracy and safety of closed-loop systems versus manual control. Our primary outcome was the percentage of time during which the system was able to maintain a given variable (eg, bispectral index or oxygen saturation) in a desired range or the proportion of the target measurements that was within the required range. Our secondary outcome was the percentage of time or the number of episodes that the controlled variable was above or below the target range. The standardized mean difference and 95% confidence interval (CI) were calculated for continuous outcomes, whereas the odds ratio and 95% CI were estimated for dichotomous outcomes. Thirty-six trials were included. Compared with manual control, automated systems allowed better maintenance of the controlled variable in the anesthesia drug delivery setting (95% CI, 11.7%-23.1%; percentage of time, P < 0.0001, number of studies: n = 15), in patients with diabetes mellitus (95% CI, 11.5%-30.9%; percentage of time, P = 0.001, n = 8), and in patients mechanically ventilated (95% CI, 1.5%-23.1%; percentage of time, P = 0.03, n = 8). Heterogeneity among the studies was high (>75%). We observed a significant reduction of episodes of overshooting and undershooting when closed-loop systems were used. The use of automated systems can result in better control of a given target within a selected range. There was a decrease of overshooting or undershooting of a given target with closed-loop systems.

M onitoring cerebral oxygen (O 2 ) saturation is increasingly important because studies in cardiac surgery have found that treating cerebral O 2 desaturations can reduce the likelihood of postoperative cognitive dysfunction (POCD) and other complications. Recent studies have shown that the incidence of cerebral O 2 desaturations in patients undergoing thoracic surgery with single-lung ventilation (SLV) is similar to that seen in cardiac surgery, with the risk of poor postoperative outcomes. This prospective, observational, single-blinded study was undertaken to determine POCD after thoracic surgery with SLV.The 76 patients were having elective thoracic surgery with SLV of an anticipated duration of more than 45 minutes. Monitoring included standard clinical parameters and absolute oximetry (S ct O 2 ). Anesthesia was induced with propofol, fentanyl, and rocuronium and maintained with sevoflurane to a target bispectral index of 45. A continuous infusion of bupivacaine and fentanyl was administered throughout the case via an epidural catheter. Brain O 2 saturation was monitored continuously using the FORE-SIGHT cerebral oximeter (CAS Medical Systems, Branford, Conn), starting before induction of anesthesia and continuing until extubation. Sensors were positioned bilaterally on the patient's forehead and covered to prevent ambient light from affecting the measurements. Values of the cerebral oximetry were hidden, and no anesthetic decision was made based on the absolute S ct O 2 values. Baseline S ct O 2 values were obtained in the awake patient after 2 minutes of breathing 100% O 2 through a face mask and defined as the average saturation value during a period of 1 minute, obtained 5 minutes after the application of the sensors. The average left and right absolute S ct O 2 values were collected every 5 minutes. Standard monitoring variables were recorded every 5 minutes. Arterial blood gas analysis was performed every 15 minutes. The average left and right absolute S ct O 2 and the highest and lowest values were used for analysis. The Mini-Mental State Exam (MMSE) test was used to assess cognitive function before surgery and at 3 and 24 hours postoperatively. Data were analyzed using SPSS (v.15.0; SPSS Inc, Chicago, Ill). The Spearman correlation test was used to test the correlation between POCD (defined as a decrease in MMSE score 92 points from baseline) and age, SLV duration, and selected clinical and S ct O 2 parameters.One patient was excluded from analysis because of unwillingness to redo the MMSE test after surgery. Most of the patients were American Society of Anesthesiologists physical status II and III. Duration of surgery was 175 minutes, and duration of SLV was 135 minutes. No patients needed additional continuous positive airway pressure or O 2 insufflations, and no surgical-site infections, postoperative hemorrhage, or stump leakage was observed. The baseline S ct O 2 value was 79% in the awake state, which decreased to a minimum value of 63% during SLV. This is equivalent to a decrease of S ct O 2 b...

The present risk calculation does not justify not offering epidural analgesia as part of a multimodal analgesia protocol in cardiac surgery.