Predictors of intra-operative recall of awareness: Thai Anesthesia Incidents Study (THAI Study): a case-control study.

BACKGROUND: The authors determined predictors of intra-operative recall of awareness in the Thai Anesthesia Incidents Study (THAI Study). OBJECTIVE: To study a multi-centered registry of anesthesia in 20 hospitals across Thailand. MATERIAL AND METHOD: Structured data collection forms of patients who underwent general anesthesia and experienced intra-operative recall of awareness between March 1, 2003 and February 28, 2004, were reviewed by three independent anesthesiologists. One case of awareness was matched to four controls by age, gender, and level of hospitals. Univariate analysis (p < 0.1) and logistic regression (p < 0.05) identified characteristics associated with intra-operative recall of awareness. RESULTS: Eighty-one cases were matched with 324 controls in the nested case control study. From univariate analysis, risk factors were cardiac surgery, cesarean delivery, upper abdominal surgery, i.v. anesthetics, depolarizing muscle relaxant, non-depolarizing muscle relaxant, and nitrous oxide (p < 0.1). The predictors from multivariable logistic regression were cesarean delivery p < 0.001, OR 6.48 (95% CI 2.03, 20.71), and cardiac surgery p < 0.001, OR 10.37 (95% CI 3.37, 31.89). Decreased risk was associated with intra-operative use of nitrous oxide p = 0.02, OR 0.42 (95% CI 0.20, 0.88). CONCLUSION: In the THAI Study, predictors of intra-operative recall of awareness were cesarean delivery and cardiac surgery. Use of nitrous oxide attenuates the risk of awareness.

Perioperative stroke and coma in Thai Anesthesia Incidents Study (THAI Study).

OBJECTIVES: To analyze perioperative stroke and coma using database of Thai Anesthesia Incidents Study (THAI Study) with regard to frequency, contributing factors, preventive and corrective strategies. MATERIAL AND METHOD: Details of perioperative neurological complications comprising stroke and coma in one year were recorded prospectively by attending anesthesiologists or nurse anesthetists in standardized record forms. All data were analyzed to identify contributing factors and preventive strategies. RESULTS: Among 172,592 anesthetics, there were 24 cases of coma, and 28 cases of stroke. Most cases of coma that eventually died (12/16 cases, 75%) had ASA physical status (ASA PS) ranging from 2E to 5E. Perioperative stroke was found mainly in patients with ASA PS 3 and most of the incidence (74%) occurred in patients who had no previous history of stroke. These patients already had pre-existing cardiovascular diseases and underwent high risk procedures. There were 54% of perioperative stroke cases that could be due to improper cardiovascular management and 42% due to improper emergency neurological management. CONCLUSION: The incidence of perioperative stroke and coma in this study was approximately 0.03%. The majority of cases had no prior stroke or coma, which suggested that a problem during perioperative period itself might predispose patients to these complications. Preventive strategies included quality assurance activity, improved communication, and practice guideline.

An analysis of intraoperative recall of awareness in Thai Anesthesia Incidents Study (THAI Study).

OBJECTIVES: This study aimed to analyze intraoperative awareness using database of Thai Anesthesia Incidents Study (THAI Study) with regard to frequency, contributing factors, preventive and corrective strategies. MATERIAL AND METHOD: Details of intraoperative recall of awareness were recorded prospectively by attending anesthesiologists or nurse anesthetists in standardized record forms during February 1, 2003 to July 31, 2004. Participating hospitals included 7 university hospitals, 5 tertiary care hospitals, 4 secondary care hospitals, and 4 primary care hospitals. All data were analyzed to identify contributing factors, preventive and corrective strategies. RESULTS: Among 126078 general anesthetized cases, there were 99 cases of intraoperative recall of awareness. Awareness was found in female patients more than male patients (63% versus 37%). The majority of patients had ASA PS 1 and 2. Cardiac, obstetric, and lower abdominal surgery were involved in anesthesia awareness more than other type of surgery. Patients experiencing awareness reported sound (62%), pain (51%), feeling operated without pain (33%), and paralysis (25%). There was slight impact of anesthesia awareness in Thai patients (only 13% had temporary emotional stress and 13% had mild anxiety) despite small percentage of proper management by reassurance and psychiatric consultation (15%). The contributing factors included inadequate knowledge (67%), inadequate medication dosage (44%), and inadequate care from inexperience (11%). Awareness incidents were documented to be preventable in 36% of patients and partially preventable in 38% of patients. The corrective strategies included guideline practice (30%), additional training (28%), quality assurance activity (19%), and improved supervision (16%). CONCLUSION: The incidence of intraoperative recall of awareness in this study was 0.08%. Patients reported sound, pain, feeling operated without pain, and paralysis. Corrective strategies included guideline practice, additional training, quality assurance activity, and improved supervision.

The Thai Anesthesia Incidents Study (THAI Study) of perioperative convulsion.

OBJECTIVES: To identify the incidence of perioperative convulsion within 24 hours, outcome, predisposing risk factors, contributing factors related to anesthesia and corrective strategies. MATERIAL AND METHOD: The prospective cohort study enrolled all anesthetics from twenty eligible hospitals in Thailand between March 1, 2003, and February 28, 2004. Postoperative convulsion incidents were extracted from the Thai Anesthesia Incidents Study (THAI Study) database in terms of demographic data, details of events, outcome, contributing factors related to anesthesia and corrective strategies. RESULTS: The incidence of perioperative convulsion was 3.1 per 10,000 from all 172,592 anesthetics. Most patients (73.59%) recovered in 24 hours. The majority of risk factors were related to surgery (67.92%) and patient factors (54.72%) while anesthesia was the minor factor (30.19%). The contributing factors related to anesthesia were medication error (route, type, time) 43.75% and human error (inadequate care, inadequate knowledge, inadequate communication) 43.75%. The important corrective strategies included improved supervision and clinical practice guideline. CONCLUSION: The incidence of postoperative convulsion was 3.1 per 10000. Anesthesia was the minor contributing factor. The most important risk factors included medication error and human error.

The Thai Anesthesia Incidents Study (THAI Study) of anesthetic outcomes: I. Description of methods and populations.

BACKGROUND AND RATIONALE: Since anesthesia, unlike medical or surgical specialties, does not constitute treatment, The Royal College of Anesthesiologists of Thailand host the Thai Anesthesia Incidents Study (THAI Study) of anesthetic outcomes to determine factors related to anesthesia related adverse events. MATERIAL AND METHOD: A prospective descriptive study of occurrence screening was conducted in 20 hospitals comprised of 7 university, 4 general and 4 district hospitals across Thailand. Anesthesia personnels were required to fill up patient-related, surgical-related, anesthesia-related variables and adverse outcomes on a strutured data entry form. The data included preanesthetic evaluation intraoperative period and 24 hr postoperative period. Adverse events specific form was recorded when adverse events occurred. All data were keyed in data management unit with double entry technique and descriptive statistics was used in the first phase of this study. RESULTS: A total of 163403 consecutive cases were recorded in one year. The mean (S.D.) of age, weight and height of patients were 38.6(2.3) yrs, 53.9(17.7) kgs and 153.4(22.7) cm respectively. There were more female (52.9%) than male (47. 1%) patients with ASA PS 1, 2, 3, 4, 5 = 50.8%, 36.3%, 10.7%, 2.0%, 0.2% respectively. Hypertension (11.6%), anemia (7.7%) and diabetes melitus (6.8%) were the three most common abnormalities in preanesthetic history taking. Mallampati score of 111870 patients grade 1, 2, 3, 4 were 54.0%, 39.7%, 5.6%, 0.7% and laryngoscopic grade 1, 2, 3, 4 of 74888 patients were 81.0%, 15.5%, 3.0% and 0.5% respectively. CONCLUSION: The first phase of THAI study epidemiological project can represent both the anesthesia and surgical profiles in Thailand. The collected data available should be useful for the improvement of the quality of anesthesia, guidelines for clinical practices, medical education and for further research.