No abstract

SummaryRespiratory depression, a potentially serious complication after general anaesthesia, can be detected promptly by close monitoring of both oxygen saturation and respiratory rate. Obese patients have morphological changes that may impair the reliability of monitoring devices. In this study, respiration rate was simultaneously recorded every second for up to 60 min using a computer in 30 adult obese patients (body mass index ≥ 35 kg.m À2 ), by three methods: acoustic; thoracic impedance; and capnometry via a facemask (Capnomask â , reference method). Of the 99 771 data triplets collected, only 85 520 (86%) were included; 12 021 (84%) were not studied due to failure of capnometry and 2240 (16%) due to failure of the acoustic method. Compared with capnometry, bias was similar using both the acoustic method and impedance (À0.3 bpm vs À0.6 bpm, respectively, p = 0.09), but limits of agreement were narrower for the acoustic method (AE3.5 bpm vs AE5.3 bpm, respectively, p = 0.0008). The proportion of respiration rate values obtained with the acoustic method and impedance that differed by at least 10% or 20% for more than 15 s were 11% vs 23% and 2% vs 6%, respectively (p = 0.0009 for both comparisons). The acoustic sensor was well tolerated, while the facemask was pulled off on several occasions by four (13%) agitated patients. In obese patients requiring close monitoring of respiration rate, the acoustic method may be more precise than thoracic impedance and better tolerated than capnometry with a facemask.

No abstract

Several surveys showed that cardiopulmonary bypass (CPB) is associated with incidents that negatively affect outcome and suggested that improved monitoring and safety could be associated with a decreased rate of incidents. In 2004, the French “Haute Autorité de Santé”(an independent French government advisory agency) and the French College of Perfusion issued recommendations concerning safety and monitoring devices for CPB. The aims of this study were to investigate the difference between the recommendations and the clinical practice of CPB shortly after publication of the recommendations and compare the 2005 situation with the results of a previous survey performed in France and to investigate the rate of perfusion incidents and their outcome. A 62-item questionnaire was sent in January 2006 to all 66 centers performing cardiac surgery and CPB in France. The survey investigated the use of safety and monitoring devices as well as perfusion incidents for 2005. Fifty-seven centers (response rate, 86%) returned the questionnaire, totaling 34,496 CPB procedures. There was a wide difference between the recommendations and the reported use of safety and monitoring devices with no clinically relevant change from the previous French survey concerning 2001. An incident was reported for every 198 CPB procedures with death at a frequency of 1:4864 and permanent sequelae of 1:11,349, respectively (a permanent injury or death in 1:3220 procedures). The three most frequent perfusion incidents were adverse effects to protamine (1:1702), dissection at the arterial cannulation site (1:1792), and coagulation of the circuit (1:4864). In conclusion, this survey showed that an important effort must be made in France to implement into clinical practice the recommendations concerning CPB monitoring and safety devices. The analysis of CPB-related incidents suggest that, with the exception of protamine adverse effects, the majority of deaths and severe permanent injuries in this survey could probably be avoided by improved use of the monitoring and safety devices.

We prospectively studied spontaneous recovery from cisatracurium-induced neuromuscular block in 18 patients scheduled for cardiac surgery, and its suitability for fast-track cardiac surgery. Neuromuscular block was induced by an i.v. bolus (range 0.15-0.3 mg kg(-1)) and maintained by a continuous infusion (range 1.1-3.2 microg kg(-1) min(-1)) of cisatracurium until sternal closure. In the intensive care unit (ICU), spontaneous recovery was evaluated by the train-of-four (TOF) ratio measured at the adductor pollicis muscle. The ICU medical staff were unaware of the TOF ratios until sedation was stopped. At that time, if the TOF ratio was less than 0.9, sedation was recommenced. On arrival in ICU, all patients had residual paralysis. The mean time to reaching a TOF ratio of at least 0.9 was 102 min (range 74-144 min) after discontinuation of the cisatracurium infusion. Fifteen patients (83%) were successfully extubated during the first 8 h after stopping the cisatracurium infusion. Only one patient showed residual paralysis when sedation was discontinued. These results support the use of cisatracurium as a suitable neuromuscular blocking agent for fast-track cardiac surgery.