Factors contributing to delayed extubation after cervical spine surgery in Siriraj Hospital.

Background: Cervical spine surgery brings up great concerns about post operative severe complications and morbidities. Anesthesiologists should know contributing factors for the delayed extubation which includes patient factors, surgical factors, and anesthetic factors. Objective: To study the factors related to delayed extubation for the benefit of anesthetists’ future decision making and the patients’ safety. Methods: Case-controlled study in a retrospective fashion. Patients who undertook cervical spine surgery during 2002 - 2007 without previous intubation, tracheostomy, and ones with data available to be collected; were identified for the study. Data included age, sex, BMI, ASA classification, smoking history, pre-operative neurological deficit, history of previous C-spine surgery, steroid administration, number of cervical spine surgeries, upper cervical level including, surgical approach, instruments, intubation technique, duration of the operation, total blood loss, and total fluid replacement. All 16 factors were studied and analyzed for their relationship to extubation difficulty. Results: Of all 140 patients identified in the study, 70 were patients with immediate extubation and 70 were patients with delayed extubation. Factors that are statistically significant in delayed extubation are: advancing age >60 years, ASA classification > class 2, preoperative neurological deficit, surgery >2 levels of spines, duration of the operation >180 minutes, fiberoptic intubation technique, total fluid administration >4,000 ml during surgery and total blood loss >250 ml. When analyzed with multivariate analysis, factors that related to delayed extubation are advancing age >60 years (odds ratio 4.077, 95% CI 1.562-10.641), neurological deficit (odds ratio 5.719, 95% CI 1.312-24.927), surgery >2 levels of spines (odds ratio 4.108, 95% CI 1.672-10.095), duration of operation >180 minutes (odds ratio 4.538, 95% CI 1.687-12.205), and fiberoptic intubation technique (odds ratio 4.131, 95% CI 1.636-10.433). Conclusion: There are 5 contributively factors that are related to delayed extubation in patients receiving cervical spine surgery at Siriraj Hospital: advancing age > 60 years, neurological deficit, surgery >2 levels of cervical spines, duration of the operation >180 minutes, and fiberoptic intubation technique.

The Thai Anesthesia Incident Monitoring Study (Thai AIMS) of post anesthetic reintubation: an analysis of 184 incident reports.

OBJECTIVE: The present study was a part of the Multi-centered Study of Model of Anesthesia related Adverse Events in Thailand by Incident Report (The Thai Anesthesia Incident Monitoring Study or Thai AIMS). The objective of the present study was to determine the outcomes, contributory factors and factor minimizing incident. MATERIAL AND METHOD: The present study was a descriptive research design. The authors extracted relevant data from the incident reports on reintubation after planned extubation after general anesthesia with endotracheal intubation from the Thai AIMS database during the study period January to June 2007. The cases were extensively reviewed by 3 reviewers for conclusion of anesthesia directly and indirectly related reintubation. Comparative analysis between two groups was done. RESULTS: A total 184 incidents of extubation failure according to the definition were extracted in which 129 cases (70.1%) were classified as directly related to anesthesia and 55 cases (29.9%) were indirectly related to anesthesia. Oxygen desaturation occurred in 85.9% of cases while 90.2% of patients was reintubated within 2 hours after extubation. Hypoventilation (58.1%) was the commonest cause which led to reintubation directly related to anesthesia while upper airway obstruction (39.6%) was the commonest cause in the indirectly related anesthesia group. The proportion of preventable incident was 99.2% and 54.5% in directly and indirectly related anesthesia groups, respectively. Human factors particularly including lack of experience and inappropriate decision-making were considered in 99.2%, are directly related to anesthesia reintubation group. CONCLUSION: Extubation failure and reintubation was mostly related to anesthesia. Most of directly related to anesthesia group were considered as preventable. Human factors were also claimed as contributing factors. Quality assurance activity and improvement of supervision to improve experience and competency of decision making were suggested corrective strategies.

Prospective study of hypotension after spinal anesthesia for cesarean section at Siriraj Hospital: incidence and risk factors, Part 2.

BACKGROUND: The incidence of hypotension after spinal anesthesia is highest in cesarean section. The authors' first retrospective study identified three risk factors that included two non-modifiable (patient's height and low baseline systolic blood pressure) and one modifiable risk factor (sensory analgesia equal to or higher than TS) associated with hypotension. OBJECTIVE: To create a prospective record of the event in the patients who received successful spinal anesthesia for cesarean section. MATERIAL AND METHOD: A prospective data collection, together with questionnaires that were completed by the responsible anesthetic team at the end of the operation for each consecutive patient. All parameters were coded and recorded in SPSS11.5. To assess the association between two categorical variables in a univariable analysis, chi-square test was used along with odds ratio (OR) and its 95% confidence interval (CI). Mutivariable analysis via multiple logistic regressions was employed to determine the effect of each independent variable. RESULTS: Eight hundred and seven full-term pregnant women received successful spinal anesthesia for cesarean section at Siriraj Hospital from July 1 to December 31, 2004. Hypotension was defined as lowest systolic < 100 mmHg and the pressure was lower to equal to or more than 20% of baseline. Incidence of hypotension was 65.1%. Age > 35 yr BMI > 35 were two non-modifiable risk factors that increased the incidence of hypotension in the crude odds ratio (OR) 1.62 and 2.83 respectively with narrow 95% confidence interval. The level of sensory analgesia equal to or higher than T5 was the only one modifiable risk factor that increased the incidence of hypotension with crude OR 1.55 and narrow 95% CI. CONCLUSION: Limitation of the dose of local anesthetic agent or addition of some opioids could reduce the incidence and severity of hypotension after spinal anesthesia for cesarean section.

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.

Prospective study of hypotension and bradycardia during spinal anesthesia with bupivacaine: incidence and risk factors, part two.

OBJECTIVE: Hypotension and bradycardia during spinal anesthesia are common and may relate to severe adverse events such as cardiac arrest or death. The authors'first retrospective study identified three non-modfiiable factors including females, age more than 40 years, and type of operation. Level of blockage higher than T5 was the only one modifiable factor that could be confirmed That study was strongly limited by the nature of the retrospective anesthetic record reviewed study. MATERIAL AND METHOD: The authors prospectively studied the records of 2, 000 patients who received spinal anesthesia at Sriraj Hospital from 1 July 2004 to 31 December 2004. The collected parameters were patient demographic data (sex, age, body weight, height, ASA status), operative data (type of operation, emergency status, position and duration of operation), anesthetic data (type and dosage of local anesthetic agents used, intravenous fluid, vasoactive and sedative agents, highest sensory level of spinal blockage, usage and doses of spinal opioids). Recording forms of hypotension and bradycardia were completed by the responsible anesthetic team in each consecutive patient. RESULTS: Incidence of hypotension (20% or more decrease in systolic blood pressure) in the present study was 57.9%. The highest incidence was in cesarean section. Four non-modifiable risk factors could be identified which included females, age more than 50, body mass index more than 35 (OR = 2.1, 95% CI 1.01-4.29) and type of operation. Two modifiable risk factors included high dose of heavy bupivacaine (OR 1. 88, 95%CI 1. 3-2.74) and level of sensory blockage equal to or higher than T5 (OR 2.27, 95%CI 1.73-2.97). CONCLUSION: Usage of high dose of heavy bupivacaine and level of blockage higher than T5 were two modifiable risk factors associated with hypotension during spinal anesthesia. Avoidance of high block and lower dose of heavy bupivacaine can reduced the incidence and severity of hypotension after spinal anesthesia.

Incidence and risk factors of hypotension during spinal anesthesia for cesarean section at Siriraj Hospital.

OBJECTIVE: Spinal anesthesia is commonly used for cesarean section. Its major adverse effect is hypotension. The objective of this study is to determine the incidence and risk factors of hypotension during spinal anesthesia for cesarean section. MATERIAL AND METHOD: The authors retrospectively reviewed anesthetic records of 991 patients who received spinal anesthesia for cesarean section at Siriraj Hospital. Exclusion criteria were patients with pregnancy included hypertension, received combination of spinal block with other type of anesthesia. RESULTS: The incidence of hypotension (the lowest systolic blood pressure < or = 100 mm Hg) was 76.%. The parameter with increased incidence of hypotension included patient's height < 155 cm (adjusted odd ratio (OR) 1.93, 95%CI 1.19-3.14), baseline systolic blood pressure < or = 120 mmHg (OR 2.14, 95%CI 1.53-2.99) and analgesic level > or = T5 (OR 1.83, 95%CI 1.18-2.84). CONCLUSION: The risk factors associated with increased incidence of hypotension are the patient 's height, baseline systolic blood pressure and level of blockade.

Incidence and risk factors of hypotension and bradycardia during spinal anesthesia.

Objective: Hypotension and bradycardia during spinal anesthesia are common and may relate to severe adverse events such as cardiac arrest or death. Knowledge of the incidence and risk factors as well as their patho-physiology processes will improve management, planning for anesthesia, training and practice guidelines for the patients receiving spinal anesthesia. Methods: We retrospectively reviewed anesthetic records of 1,698 patients who received spinal anesthesia at Siriraj Hospital from 1 January 2004 to 30 June 2004. The collected parameters were patient demographic data (sex, age, body weight, height, ASA status),operative data (type of operation, emergency status, position and duration of operation),anesthetic data (type and dosage of local anesthetic agents used, intravenous fluid, vasoactive and sedative agents, sensory level of spinal blockage, usage and doses of spinal opioids as well as oxygen supplementation). The lowest systolic, diastolic blood pressure, heart rate and onset of the incidence were collected and analyzed for correlation by appropriate statistical analysis. Bradycardia was defined when heart rate is 50 beat/min or lower and hypotension when systolic blood pressure decreases to 20% or more of the baseline pressure. Results: Incidence of hypotension in this study was 54.4% at 19.4 min. The correlated parameter with increased incidence of hypotension included female (crude odd ratio = 2.005; 95% CI 1.63-2.48), age more than 40 years (adjusted odd ratio = 3.06-6.88; 95%CI 1.55-15.74 upon age group), level of blockage higher than T5 (adjusted odd ratio =1.23; 95%CI 1.15-1.31) and finally type of operation. Operation of hip and femur and cesarean section had adjusted odd ratio = 2.13; 95%CI 1.04-4.38 and 2.32; 95%CI 1.28-4.21, respectively. Incidence of bradycardia in our study was 0.06% which was too low to analyze for correlated parameter. There was no cardiac arrest nor death reported in this study. Conclusion: Level of blockage higher than T5 was the only one modifiable risk factor associated with hypotension during spinal anesthesia that could be identified from this study. Avoidance of high block is the only factor that can be controlled to decrease the incidence and severity of hypotension.

Unplanned intubation during anesthesia: review of 31 cases from the Thai Anesthesia Incidents Study (THAI study).

OBJECTIVES: To examine the causes, outcomes, and contributing factors associated with patients requiring unplanned emergency intubation for adverse respiratory events. METERIAL AND METHOD: Appropriate unplanned intubation incidents were extracted from the Thai Anesthesia Incidents Study (THAI Study) database conducted between February 1, 2003, and January 31, 2004, and analyzed using descriptive statistics. RESULTS: Thirty-one incidents of unplanned intubation were recorded, 21 of which were due to respiratory problems particularly after bronchoscopy with and without surgery of the upper airway. Six of the 21 cases (28.6%) were children under 10 years of age who suffered from papilloma of the larynx. Sixteen cases of the 31 cases (52%) of the unplanned intubations were due to inadequate ventilation; 13 cases (41%) due to laryngeal edema; 11 cases (36%) due to sedative agents. The other events were the result of unstable hemodynamics, severe metabolic acidosis, muscle relaxants, and intrapulmonary lesions. Eighteen cases of unplanned intubations (18/31) (58%) occurred in the Post-Anesthesia Care Unit, 5 cases (16%) in a ward, and 4 (13%) in the operating room. The reported contributing factors included inadequate experience, lack of supervision and the patient's condition. CONCLUSION: Major incidents of unplanned intubation occurred after bronchoscopy. Common contributing factors related to inadequate ventilation, airway obstruction, sedative agents and unstable hemodynamics. Quality assurance, additional training, and improved supervision tended to minimize the incidents.

The Thai Anesthesia Incidents Study (THAI Study) of perioperative death: analysis of risk factors.

BACKGROUND: National statistical data of mortality and morbidity related to anesthesia have not been reported. The need to comprehensively examine the cause of death as well as other adverse events prompted the first national study in Thailand. MATERIAL AND METHOD: In the Thai Anesthesia Incidents Study (THAI Study), a prospectively defined cohort of patients who underwent anesthesia from February 1, 2003 to January 31, 2004 (n=163,403) was studied. All consecutive patients who died intraoperatively or within the period of 24 hr after anesthesia were classified to determine a relationship with anesthesia by 3 independent reviewers. These data were further analysed to identify contributing factors. RESULTS: The incidence of 24-hr perioperative death, anesthesia directly related and anesthesia partially related death per 10,000 anesthetics was 28.2 (95% CI 25.7-30.8), 1.7 (95% CI 1.1-2.3) and 4.0 (95% CI 3.1-5.0) respectively. Of 462 deaths, 28 cases (6.5%), 66 cases (14.3%), 61 cases (3.3%), 399 cases (86.7%) and 104 cases (22.6%) were anesthesia directly related, anesthesia partially related, surgical related, patient disease related and system or management related to perioperative death. The common main causes of death were exangination (42.4%), traumatic brain injury (14.3%), sepsis (13.6%), heart failure (5.0%) and hypoxia (5.0%). CONCLUSION: This study shows incidence of 24-hr perioperative death of 1:354 which is comparable with other studies. Quality assurance activity, prevention of human failure and equipment failure, system improvement of perioperative care, availability of recovery room, intensive care unit, efficient blood bank and adequate number of MD. anesthesiologists are suggestive corrective strategies.

The Thai Anesthesia Incidents Study (THAI Study) of oxygen desaturation.

OBJECTIVES: To examine incidents, contributory factors, treatment and outcomes associated with oxygen desaturation during anesthesia practice in Thailand. MATERIAL AND METHOD: Relevant data were extracted from the Thai Anesthesia Incidents Study (THAI Study) database between February 1, 2003 and January 31, 2004 and analyzed by using mainly descriptive statistics. RESULTS: Four hundred and ninety seven incidents of oxygen desaturation (SpO2 <90 for at least 3min or < or = 85%) were reported. The incidents were widely distributed throughout anesthesia phases. Most of the incidents (92.2%) occurred during general anesthesia, while 23 (4.6%) occurred after regional anesthesia. Anesthesia was the sole contributory factor in 280 patients (56.8%) and a combination of that with other factors in 126 (25.4%). The majority of the incidents (88.4%) was related to respiratory adverse events, whereas, 8% was related to circulatory ones. Sixteen incidents (3.2%) were related to anesthetic machine and equipment failure. Most of the incidents (60.0%) caused minor physiologic changes and were correctable. The management was considered adequate in the majority of patients. As a result, 77.5 % of the patients recovered completely, whereas, death ensued in 5.8%. The cases of death were associated with co-morbidity (ASA class 4 and 5) with an Odds ratio of 12.9 (95% CI:5.4,31.0). The common contributory factors were inexperience, wrong decision, inadequate knowledge and lack ofsupervision. The proposed corrective strategies included improvement in supervision, care improvement, additional training, clinical practice guideline and quality assurance activity. CONCLUSION: Incidents associated with oxygen desaturation were distributed throughout all phases of anesthesia. Most of them were preventable and correctable. Therefore, anesthesia care providers should be alert in looking for incidents, and manage them promptly before they were in serious adverse events.

Perioperative myocardial ischemia/infarction: study of incidents from Thai Anesthesia Incidence Study (THAI Study) of 163,403 cases.

OBJECTIVES: To analyze incidence, risk factors, clinical course, outcomes of PMI. Degree of anesthesia related to PMI, management, precipitating factors and corrective strategies. MATERIAL AND METHOD: PMI cases were extracted from the Thai Anesthesia Incidents Study (THAI Study) database conducted between February 1, 2003 and January 31, 2004, and analyzed using descriptive statistics. RESULTS: Forty-five cases were recorded as PMI (Suspected myocardial ischemia/infarction) from 20 hospital study centers. The incidence was 2.7:10,000 of all anesthetic services (163,403 cases). PMI occurred more frequently in male, underlying disease of hypertension, diabetes mellitus, ischemic heart disease, ASA class >2, under general anesthesia and during operation. EKG change and hypotension were primary clinical symptoms. PMI caused high mortality (5 cases), high morbidity (6 cases of brain death), high medical cost and change of management plan. CONCLUSION: PMI was strongly impact to both anesthetic and surgical outcomes. Improve quality of anesthetic care for patient at risk and surgical risk reflected the whole anesthetic quality of care.

Postoperative reintubation after planned extubation in Thai Anesthesia Incidents Study (THAI Study).

OBJECTIVE: To analyze precipitating causes, outcomes and corrective strategies especially anesthetic related factors associated with reintubation after planned extubation in anesthetic technique of general anesthesia with endotracheal intubation. DESIGN: Prospective observational study. MATERIAL AND METHOD: Incidents of reintubation after planned extubation were extracted from the Thai Anesthesia Incidents Study (THAI Study) database conducted between February 1, 2003, and January 31, 2004, and analyzed using descriptive statistics. RESULTS: The total of two hundred and thirty four patients of reintubation after planned extubation (RAP) at the end of general anesthesia was reviewed in this study. The incidence of RAP was 27:10,000 and the incidence in the university hospital was similar to the tertiary and secondary care hospital. The incidence was increased in extreme age group (age < 1 and > 70 year). One hundred and fifty eight cases of RAP (67.5%) occurred in operating theater and recovery room which included 83 cases occurring within 10 minutes after extubation. The two most common primary diagnoses were upper airway obstruction and hypoventilation. Three main precipitating factors were residual effect of neuromuscular blocking and anesthetic agents (53-57%), upper airway obstruction (31%) and unstable hemodynamics (26.3%). Nearly half of RAP incidents occurring in the operating theater and recovery room were successful reextubation within six hours and 58-72 % of these two subgroups were complete recovery. The chance for prevention was more than 80% by additional training and supervision. CONCLUSION: More than 90% of RAP occurred in operating theater and recovery room were completely or partially related to anesthetic process. Incidence of RAP could be decreased by quality assurance process of recording, reporting and modeling care process together with increase individual experience.

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.

Delayed detection of esophageal intubation: Thai Anesthesia Incidents Study (THAI Study) database of 163,403 cases.

INTRODUCTION: Even though esophageal intubation is a common event in anesthesia practice, frequently it is easily detected and resolved. However delayed detection of esophageal intubation (DDEI) can lead to many serious adverse events such as severe hypoxemia, cardiac arrhythmia, cardiac arrest and brain death. OBJECTIVES: To analyze the incidence of DDEI during general anesthesia with endotracheal intubation and to identify its risk factors, especially patients factors and anesthetic techniques, as well as suggested strategies to prevent it. DESIGN: Prospective observational study. MATERIAL AND METHOD: All reported DDEI incidents were identified from the Thai Anesthesia Incidents Study (THAI Study) database conducted between February 1, 2003, and January 31, 2004. Data were analyzed by using descriptive statistics. RESULTS: Forty four cases of DDEI were reported from total of 85,021 cases underwent general anesthesia with endotracheal intubation (5.2: 10,000). The incidence was highest in tertiary care hospital (11.6:10,000). Infant patients (< or = 1 year of age), emergency operation and technique of rapid sequence induction with cricoid pressure were identified as risk factors of DDEI. Detection of DDEI was mainly based on clinical examination. The incidents with extremely low SpO2 level were reported but most of them were adequately managed without long term consequences and only one patient suffered from severe permanent brain damage. CONCLUSION: The overall incidence of DDEI in Thailand was 5.2:10,000. Contributing factors included infant patients, emergency operation, and rapid sequence induction with cricoid pressure. Increased awareness and additional training are suggested as preventive strategies.

An experience with intubating laryngeal mask airway for difficult airway management: report on 38 cases.

A retrospective study was performed on 38 patients (23 males and 15 females) in whom the intubating laryngeal mask airway (ILMA) was used for airway management at Srinagarind and Siriraj Hospital in 2003. The patients 'age and weight ranged between 12 and 75 years and 40 and 94 kg, respectively. Difficult tracheal intubation was suspected before starting general anesthesia in 17 patients, whereas it was found difficult after induction of general anesthesia in 21. The ILMA was successfully placed in all patients with airway patency classified as 'good' and 'acceptable' in 36 patients (94.7%), and 'poor' in two. Oxygen saturation during intubation was maintained above 95 percent in all patients. Tracheal intubation through the ILMA was successful in 34 patients (89.5%), which was described as 'easy' in 27 of 34 patients (79.4%). In the remaining 7, 2-5 attempts were required for successful tracheal intubation. The types of endotracheal tubes used were: 1) the pre-formed silicone tube in 55.9 percent, 2) the pre-formed flexible tube in 41.2 percent; and, 3) the standard polyvinyl tube in 2.9 percent. In the four patients with failed tracheal intubation through the ILMA, three were successfully intubated with conventional laryngoscopy and one with gum elastic bougie. There were no serious complications following the use of the ILMA in these patients. The ILMA proved a safe, very useful and easy to use device with a high success rate for difficult airway management.

Quality assessment of anesthesia service at Siriraj Hospital.

As part of a quality assurance program, the quality of the anesthesia service at Siriraj Hospital was assessed by using a newly developed data collecting system to find the incidence of clinical indicators. During a 7-month period (June-December 2001), 14,036 anesthetics were included for evaluation. The mortality rate within 24 hours and CPR rate during anesthesia were equal at 20.6/ 10,000. Other clinical indicators were major anesthetic complications (mainly airway, respiratory and cardiovascular system) 144.8/10,000, drug mishaps and adverse drug reactions 6.4/10,000, anesthetic equipment related complications 3.5/10,000 and patient's dissatisfaction 30.6/10,000. Patterns of some complications were also reported. The implications of the results; comparison to international standard, prioritization of the problems, baseline information before intervention, recognition of complication patterns and guidance to future system management and research projects; were discussed. In conclusion, we demonstrated the effective data collecting system and its results and implication for quality assurance program.

Perioperative desaturation: incidence, causes, management and outcome.

OBJECTIVE: To determine the incidence, causes, management and outcome of desaturation occurring in the perioperative peroids (induction, maintence, emergence and recovery room) at Siriraj Hospital from June 2001-December 2001. METHOD: Perioperative incident reports were collected and analyzed. Patients were catergorized as having desaturation if the SPO2 was below 90 per cent for more than 3 minutes. The incidence, causes, management, and outcomes of these patients were examined in detail. RESULTS: 62 out of 16,716 cases (0.37%) experienced desaturation. Elective patients (0.41%) experienced desaturation more frequently than emergency patients (0.14%). The causes were airway obstruction, hypoventilation, endotracheal tube problems, aspiration, atelectasis, and pulmonary edema. These patients were treated with higher FiO2, airway management, and ventilatory support which led to unplanned ICU admission. 4 patients developed cardiac arrest with successful resuscitation although 2 patients had cerebral infarction. CONCLUSION: Perioperative desaturation is an important sign of respiratory complications that should be recognized and treated immediately to prevent mortality and serious morbidity.

A double-blind, randomized study comparing postoperative pain management using epidural ropivacaine with intravenous ketorolac or intravenous ketorolac alone following transabdominal hysterectomy.

OBJECTIVE: The aim of this study is to compare the effect on postoperative pain of epidural ropivacaine in combination with intravenous ketorolac with intravenous ketorolac alone following transabdominal hysterectomy. DESIGN: A multi-center, randomized, double-blind study was conducted in Thailand and the Philippines to assess postoperative pain management in 107 patients given ketorolac alone or in combination with epidural ropivacaine following transabdominal hysterectomy. Pain score was assessed using a 100-mm visual analogue pain scale (VAS). RESULTS: The VAS scores for pain on coughing and at rest were significantly better in the ropivacaine group. The number of patients who asked for morphine in addition was higher in the ketorolac group compared to the ropivacaine + ketorolac group. The time taken to carry out the first three ambulatory steps was similar for both the two treatment groups. A higher degree of motor block was observed in the ropivacaine group over time. The adverse events observed were similar in both groups. CONCLUSION: We demonstrated that epidural infusion of ropivacaine in addition with intravenous ketorolac gave superior pain relief at rest and on coughing in patients undergoing transabdominal hysterectomy when compared to the group receiving intravenous ketorolac alone.