Intra-operative Awareness (intra-operative + awareness)

Distribution by Scientific Domains


Selected Abstracts


The incidence of intra-operative awareness during general anesthesia in China: a multi-center observational study

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2009
L. XU
Background: The incidence of awareness in patients undergoing general anesthesia is 0.1,0.2% in Western countries. The medical literatures about awareness during general anesthesia are still rare in China, but some previous studies have reported a higher incidence (1.4,6%) of intra-operative awareness. To find out the reason why the incidence reported in China is much higher than that in Western countries, we performed a prospective, multicenter, non-randomized observational study to determine the true incidence of intra-operative awareness in China. Methods: This is a prospective, non-randomized descriptive cohort study that was conducted at 25 academic medical centers in China. Eleven thousand one hundred and eighty-five patients were interviewed by research staff for evaluation of awareness at the first and fourth day after general anesthesia with muscle relaxation. An independent blinded committee evaluated the responses and determined whether awareness occurred. Necessary data were collected for a binary logistic regression analysis. Results: Data from 11,101 patients were presented. Forty-six cases (0.41%) were reported as definite awareness and 47 additional cases (0.41%) as possible awareness. Three hundred and fifty-five patients (3.19%) had dreams during general anesthesia. Awareness was associated with increased American Society of Anesthesiologists (ASA) physical status, a previous anesthesia, and anesthesia methods of total intravenous anesthesia. Conclusion: The incidence of intra-operative awareness in China is approximately 0.41%, two to three times higher than that widely cited in Western countries. Inappropriately light anesthesia, and the population proportion of surgery and general anesthesia in China may account for the difference. (ClinicalTrials.gov Identifier, NCT00693875.) [source]


Comparison of closed loop vs. manual administration of propofol using the Bispectral index in cardiac surgery

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2009
J. AGARWAL
Background: In recent years, electroencephalographic indices of anaesthetic depth have facilitated automated anaesthesia delivery systems. Such closed-loop control of anaesthesia has been described in various surgical settings in ASA I,II patients (1,4), but not in open heart surgery characterized by haemodynamic instability and higher risk of intra-operative awareness. Therefore, a newly developed closed-loop anaesthesia delivery system (CLADS) to regulate propofol infusion by the Bispectral index (BIS) was compared with manual control during open heart surgery. Methods: Forty-four adult ASA II,III patients undergoing elective cardiac surgery under cardiopulmonary bypass were enrolled. The study participants were randomized to two groups: the CLADS group received propofol delivered by the CLADS, while in the manual group, propofol delivery was adjusted manually. The depth of anaesthesia was titrated to a target BIS of 50 in both the groups. Results: During induction, the CLADS group required lower doses of propofol (P<0.001), resulting in lesser overshoots of BIS (P<0.001) and mean arterial blood pressure (P=0.004). Subsequently, BIS was maintained within 10 of the target for a significantly longer time in the CLADS group (P=0.01). The parameters of performance assessment, median absolute performance error (P=0.01), wobble (P=0.04) and divergence (P<0.001), were all significantly better in the CLADS group. Haemodynamic stability was better in the CLADS group and the requirement of phenylephrine in the pre-cardiopulmonary bypass period as well as the cumulative dose of phenylephrine used were significantly higher in the manual group. Conclusion: The automated delivery of propofol using CLADS was safe, efficient and performed better than manual administration in open heart surgery. [source]


Litigation related to inadequate anaesthesia: an analysis of claims against the NHS in England 1995,2007

ANAESTHESIA, Issue 8 2009
R. Mihai
Summary Inadequate anaesthesia may cause distress to the patient and lead to medical litigation. All claims made to the NHS Litigation Authority 1995,2007 were obtained and the data was examined independently by all authors and classified. In a dataset of 1067 claims there were 161 cases of inadequate anaesthesia and data were suitable for analysis in 159: intra-operative awareness (79), brief awake paralysis (20) and inadequate regional anaesthesia (60). The total cost of closed claims was 3.2m. Cost was incurred in 100% of claims of brief awake paralysis, 87% of claims of awareness and 80% of claims of inadequate regional blockade. Mean cost of closed claims was 32 680 for anaesthetic awareness, 29 345 for inadequate regional blockade and 24 364 for brief awake paralysis. Inadequate anaesthesia accounts for 19% of anaesthesia-related claims in the NHS in England. Strategies that reduce anaesthetic awareness, drug errors and inadequate regional blockade are known and their improved implementation is likely to reduce such claims. [source]