Assessment of preoperative pressure pain tolerance is significantly correlated with the level of postoperative pain. Pain tolerance assessment after fentanyl was administered and fentanyl sensitivity predicted the dose of analgesics used in the first 24 h after surgery. The algometer is thus a simple, useful tool for predicting postoperative pain and analgesic consumption.

In comparison with remifentanil, dexmedetomidine infusions (1) did not result in clinically significant respiratory depression, (2) decreased rather than increased the apnea/hypopnea index, and (3) exhibited some similarity with natural sleep.

SummaryPulse oximeters may delay displaying the correct oxygen saturation during the onset of hypoxia. We investigated the desaturation response times of pulse oximeter sensors (forehead, ear and finger) during vasoconstriction due to mild hypothermia and vasodilation caused by glyceryl trinitrate. Ten healthy male volunteers were given three hypoxic challenges of 3 min duration under differing experimental conditions. Mild hypothermia increased the mean response time of finger oximeters from 130 to 215 s. Glyceryl trinitrate partly offset this effect by reducing the response time from 215 to 187 s. In contrast, the response times of the forehead and ear oximeters were unaffected by mild hypothermia, but the difference between head and finger oximeters was highly significant (p < 0.0001). The results suggest that the head oximeters provide a better monitoring site for pulse oximeters during mild hypothermia.

Bronchial blocker versus left double-lumen endotracheal tube in video-assisted thoracoscopic surgery: a randomized-controlled trial examining time and quality of lung deflation Comparaison du bloqueur bronchique à la sonde endotrachéale à double lumière gauche en chirurgie thoracoscopique vidéoassistée: une étude randomisée contrôlée examinant le temps et la qualité de l'affaissement du poumon Abstract Introduction Double-lumen endotracheal tubes (DL-ETT) and bronchial blockers (BB) have both been used for lung isolation in video-assisted thoracic surgery (VATS). Though not well studied, it is widely thought that a DL-ETT provides faster and better quality lung collapse. The aim of this study was to compare a BB technique vs a leftsided DL-ETT strategy with regard to the time and quality of lung collapse during one-lung ventilation (OLV) for elective VATS. Methods Forty patients requiring OLV for VATS were randomized to receive a BB (n = 20) or a left-sided DL-ETT (n = 20). The primary endpoint was the time from pleural opening (performed by the surgeon) until complete lung collapse. The time was evaluated offline by reviewing video recorded during the VATS. The quality of lung deflation was also graded offline using a visual scale (1 = no lung collapse; 2 = partial lung collapse; and 3 = total lung collapse) and was recorded at several time points after pleural incision. The surgeon also graded the time to complete lung collapse and quality of lung deflation during the procedure. The surgeon's guess as to which device was used for lung isolation was also recorded. Results Of the 40 patients enrolled in the study, 20 patients in the DL-ETT group and 18 in the BB group were analyzed. There mean (standard deviation) time to complete lung collapse of the operative lung was significantly faster using the BB compared with using the DL-ETT [7.5 (3.8) min vs 36.6 (29.1) min, respectively; mean difference, 29.1 min; 95% confidence interval, 1.8 to 7.2; P\0.001]. Overall, a higher proportion of patients in the BB group than in the DL-ETT group achieved a quality of lung collapse score of 3 at five minutes (57% vs 6%, respectively; P \ 0.004), ten minutes (73% vs 14%, respectively; P = 0.005), and 20 min (100% vs 25%, respectively; P = 0.002) after opening the pleura. The surgeon incorrectly guessed the type of device used in 78% of the BB group and 50% of the DL-ETT group (P = 0.10). Conclusion The time and quality of lung collapse during OLV for VATS was significantly better when using a BB than when using a left-sided DL-ETT. Surgeons could not reliably determine which device was being used based on the time and quality of lung collapse. This trial was registered at ClinicalTrials.gov number, NCT01615263. RésuméIntroduction Les sondes endotrachéales à double lumière (SET-DL) et les bloqueurs bronchiques (BB) ont tous deux été utilisés pour isoler un poumon pendant une chirurgie thoracique vidéo-assistée (CTVA). Bien que peu étudié, on pense communément qu'une SET-DL procure un affaissement du poumon plus rapide et de m...

Despite previous reports of high interindividual variability in midazolam pharmacodynamics in patients in the surgical intensive care unit, these cross-validation results suggest that, when midazolam is administered using a target-controlled infusion device, the level of sedation can be predicted within 1 sedation score in 88% of patients based on the target midazolam concentration and the time since the conclusion of the anesthetic.

As expected, dexmedetomidine is not as effective an analgesic as the opioid remifentanil. The difference in the quality of the analgesia with remifentanil may be a reflection of a different mechanism of action or a consequence of the sedative effect of dexmedetomidine.

Objective The objective of this study was to determine the pharmacokinetics of lidocaine in a 48-hour infusion in patients undergoing cardiac surgery with cardiopulmonary bypass. Design A retrospective substudy of a clinical trial assessing the efficacy of intravenous lidocaine for postoperative cognitive decline. Setting University hospital. Participants 99 patients undergoing cardiac surgery with cardiopulmonary bypass. Interventions After induction of anesthesia, lidocaine was administered as bolus of 1 mg/kg and followed by a continuous infusion at 4 mg/min for the first hour, 2 mg/min for the second hour, and 1 mg/min for the next 46 hours. Measurements and Main Results Blood samples were taken at baseline, end of cardiopulmonary bypass, and 24 and 48 hours after cardiopulmonary bypass for measurement of plasma concentration of lidocaine. Lidocaine levels increased significantly over time despite a constant rate of infusion (p < 0.05). The pharmacokinetics of lidocaine was best described by a two-compartment model and body weight was found to be a significant factor for the volume of the central compartment and clearance. The final pharmacokinetic parameters were V1(L) = 0.0619*weight, V2(L) = 187, CL1(L/min) =0.00419*weight, CL2(L/min) = 8.92. Conclusions A two-compartment pharmacokinetic model best describes the plasma concentrations of 48-hour lidocaine infusion in patients undergoing heart surgery with cardiopulmonary bypass. The inclusion of body weight as a covariate on clearance and central compartment improves the model. Lidocaine infusions should be dosed by body weight and decreased after 24 hours to avoid potential toxicity in long-term infusions.

The intersubject variability and predictability of the three-compartment pharmacokinetic model are similar to those of other intravenous anesthetic drugs. This multicenter study did not confirm previous studies of exceptionally large variability of midazolam pharmacokinetics when used for sedation in intensive care settings.