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.

The Thai Anesthesia Incidents Study (THAI study) of morbidity after spinal anesthesia: a multi-centered registry of 40,271 anesthetics.

BACKGROUND: The present study was part of the Thai Anesthesia Incidents Study (THAI Study) of anesthetic adverse outcomes. OBJECTIVE: Study complications after spinal anesthesia. MATERIAL AND METHOD: During the 12 month period (March 1, 2003 - February 28, 2004), a prospective multicentered descriptive study was conducted in 20 hospitals comprised of seven university, five tertiary, four general and four district hospitals across Thailand Anesthesia personnel filled up patient-related, surgical-related, and anesthesia-related variables and adverse outcomes of all consecutive patients receiving anesthesia on a structured data entry form. The data were collected during pre-anesthetic, intra-operative, and 24 hr post operative period Adverse event specific forms were used to record when these incidents occurred. Data were reviewed by three independent reviewers and analyzed to identify contributing factors by consensus. RESULTS: This was registry of 40,271 spinal anesthetics from 172,697 anesthetics. The incidence of total spinal anesthesia, neurological complications, suspected myocardial ischemia, or infarction and oxygen desaturation per 10000 spinal anesthetics were 3.48 (95% CI 1.66-5.30), 1.49 (95% CI 0.30-2.68), 2.73 (95% CI 1.12-4.35), 0.99 (95% CI 0.39-2.56), and 6.46 (95% CI 3.98-8.94) respectively. This was not different to the incidence in other countries. Risk factors of oxygen desaturation were shorter in height [OR 0.95 (95% CI 0.92-0.97); p < 0.0011, higher ASA physical status [OR 3.37 (95% CI 1.98-5.72); p < 0.001], and use of propofol [OR 5.22 (95% CI 1.78-15.35); p = 0.003]. Other complications such as seizure, anaphylactic or anaphylactoid reaction, drug error, and pulmonary aspiration were scarce. There was no case of mismatched blood transfusion in the present study. CONCLUSION: Incidence of total spinal block, neurological complication, and suspected myocardial ischemia or infarction was uncommon. Risk factors of oxygen destruction were shorter in height, higher ASA physical status, and use of propofol. Some events were considered avoidable and preventable.

The Thai Anesthesia Incidents Study (THAI Study) of pulmonary aspiration: a qualitative analysis.

OBJECTIVES: To examine the risk factors, outcomes, and contributing factors associated with perioperative pulmonary aspiration. MATERIAL AND METHOD: Pulmonary aspiration incidents were extracted from the Thai Anesthesia Incidents Study (THAI Study) database conducted between March 1, 2003, and February 28, 2004, and analyzed using descriptive statistics. RESULTS: Thirty-two incidents of aspiration were reported. Passive regurgitation occurred more frequently than active vomiting. Aspiration occurred more commonly in elective rather than emergency surgery, with 59% of incidents taking place during the induction of anesthesia and intubation period. While a major immediate physiological disturbance was common, long term morbidity was not. Death ensued in 5 cases, most of which had significant co-morbidities. Most cases (62.5%) were appropriately treated. The majority of incidents occurred in ASA class 2 (56.3%), age group 15-64 years (59.4%), non obese (92.9%) and non-difficult intubation (71.9%). Most cases were incomplete fasted or had prolonged gastric emptying time. Nasogastric aspiration and rapid sequence induction with cricoid pressure were infrequently used (12.5, 25%). Factors reported as contributing to the incidents included failure of technique and error of judgement. Additional training, continuing medical education and quality assurance tended to minimize the incidents. CONCLUSION: Aspiration occurred commonly in patients with incomplete fasted or had prolonged gastric emptying time and underwent elective surgery. Additional training, continuing medical education and quality assurance tended to minimize the incidents.

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: II. Anesthetic profiles and adverse events.

BACKGROUND AND RATIONALE: The purposes of the Thai Anesthesia Incidents Study (THAI Study) of anesthetic outcomes were to survey patients, surgical, anesthetic profiles and determine factors related to 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 personnel were required to fill up patient-related, surgical-related, anesthesia-related variables and adverse outcomes on a structured data entry form. The data were collected during the preanesthetic evaluation, intraoperative period and 24 hr postoperative period. Adverse events specific forms were used to record when they occurred. All data were keyed at 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 during first 12 months. MD. anesthesiologists involved with 82%, 89%, 45% and 0.2% of cases in university hospitals, regional hospitals, general hospitals and district hospitals respectively. Nurse anesthetists took a major involvement in hospitals run by the Ministry of Public Health. Two-thirds of cases did not receive any premedication (67%) and midazolam was most frequent premedication administered (20%). Common monitoring were non invasive blood pressure (NIBP) (97%), pulse oximetry (96%), electrocardiography (80%), urine output (33%), airway pressure (27%) and capnometry (19%) respectively. The choices of anesthesia were general anesthesia (62%), spinal anesthesia (23%), total intravenous anesthesia (6%), monitor anesthesia care (4%), brachial plexus block (3%) and epidural anesthesia (1%). The adverse events were oxygen desaturation (31.9:10000), cardiac arrest (30.8:10000), death within 24 hr. (28.3:10000), difficult intubation (22.5:10000),re-intubation (19.4:10000), unplanned ICU admission (7.2:10000), coma/cva/convulsion (4.8:10000), equipment malfunction/failure (3.4:10000), suspected myocardial ischemia or infarction (2.7:10000), awareness during anesthesia (3.8:10000), late detected esophageal intubation (4.1:10000), failed intubation (3.1:10000), anaphylaxis or anaphylactoid reaction (2.1:10000), nerve injury (2:10000), pulmonary aspiration (2.7:10000), drug error (1.3:10000), hazard to anesthesia personnel (1.5:10000), unplanned hospital admission (0.1:10000), total spinal block (1.3:10000) and mismatch blood transfusion (0.18:10000) CONCLUSION: Respiratory adverse events were common anesthesia direct related events. High incidence of cardiac arrest and death within 24 hr highlighted concerns for prevention strategies. Incidents of adverse events can be used for institutional quality improvement, educational quality assurance and further research for patient safety in anesthesia.