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 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.

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.

When should we order preoperative chest radiography: A systematic review and clinical practice guidelines.

Routine preoperative investigation consumes much resource while Thailand suffers severe financial crisis. Objectives of the study were to apply a systematic review to answer the question whether routine preoperative investigation affected health outcomes; and to construct clinical practice guidelines for preoperative chest radiography (CXR). The guidelines were prepared for elective, non-cardiothoracic surgery in adult patients. Methods of the study were Medline search (1980-1998) and search from studies published in Thailand. Criteria for high validity and reliability were applied to paper selection. The results of the systematic review were discussed among anesthesiologists and other specialists and the guidelines were drawn by consensus. Results from the systematic review, there were no randomized controlled trials to answer the question and no studies reported health outcomes. Routine preoperative investigations yielded few positive results and were not very useful for patient care. From this review and the consensus, we proposed the guidelines, which consisted of a history questionnaire, physical examination and indication for investigation. For the preoperative CXR the indications were: age > 45 years, history of cardiovascular and respiratory diseases, autoimmune deficiency syndrome (AIDS), heavy smoking, chronic cough or fever, malignancy and findings of abnormal breath sounds on examination. This study recommends and prefers preoperative CXR as indicated by history and physical examination to routine.

When should we order preoperative electrocardiography: A systematic review and clinical practice guidelines.

Routine preoperative investigation consumes many resources at the time when Thailand is suffering a severe financial crisis. The objectives of the study were to apply a systematic review to answer the question if routine preoperative investigation affects health outcomes; and to construct clinical practice guidelines for preoperative electrocardiography (ECG). The guidelines were prepared for elective, non-cardiothoracic surgery in adult patients. Methods of the study were a Medline search (1980-1998) and a search of studies published in Thailand. Criteria for high validity and reliability were applied to paper selection. The results of the systematic review were discussed among anesthesiologists and other specialists and the guidelines were drawn by consensus. Results from systematic review found that there were no randomized controlled trials to answer the question and no studies reported health outcomes. Routine preoperative investigation yielded few positive results and were not very useful for patient care. From this review and consensus, we proposed the following guidelines: a history questionnaire, physical examination, and indication for investigation. For the preoperative ECG, the indications are: age > 45 years, history of hypertension, heart disease, palpitation or frequent syncope, diabetes, chronic cough for > 3 weeks or pulmonary disease, heavy smoking (> 10 pack /days for> 10 years), radiotherapy or chemotherapy. Preoperative ECG carried out according to these guidelines would be more cost-effective and routine preoperative investigation should be abandoned.

When should we order preoperative complete blood count and urinalysis: A systematic review and clinical practice guidelines.

Routine preoperative investigation is expensive especially at this time when Thailand is suffering a severe financial crisis. Objectives of the study were to apply a systematic review to answer the question whether routine preoperative investigation affected health outcomes; and to construct clinical practice guidelines for preoperative complete blood count (CBC) and urinalysis (UA). The guidelines were prepared for elective, non-cardiothoracic surgery in adult patients. Methods of the study were Medline search (1980-1998) and a search of studies published in Thailand. Criteria for high validity and reliability were applied to paper selection. The results of the systematic review were discussed among anesthesiologists and other specialists and the guidelines were drawn by consensus. Results from the systematic review found that there were no randomized controlled trials to answer the question and no studies reported health outcomes. Routine preoperative CBC and urinalysis yielded few clinically significant positive results and was not very useful for patient care. From this review and the consensus, we proposed a guidelines, which consisted of a history questionnaire, physical examination and indication for investigation. For the pre-operative CBC the indication were: age > 60 years, would have an operation that needed blood transfusion, had acute or chronic blood loss, malnutrition, pregnancy, heart disease, cancer, chronic renal failure, liver disease, severe infection, SLE, connective tissue disease, radiotherapy or chemotherapy. The guidelines for preoperative UA were: pregnancy, diabetes, abnormal urination, chronic renal failure, SLE or connective tissue disease. Preoperative CBC and UA requests according to these guidelines should be more cost-effective and routine preoperative investigation should be abandoned.

Fire safety systems in Siriraj Hospital and mahidol university administrative building.

Questionaire survey of fire safety systems was conducted in 230 doctors, nurses and employees working in various buildings in Siriraj Hospital and Mahidol University Administrative Office. The result revealed that most of the buildings were well equiped with basic fire fighting equipments, emergency light and emergency fire exits as required by laws but lack of proper maintenance resulting in malfunction, breakage or wreckage or stolen. Many fire exits were locked or blocked. Fire drill has not been practiced for more than 10 years. This hazardous situation need serious attention and immediate corrective action to prevent disaster and loss of human life and property.