Mental state change after general and regional anesthesia in adults and elderly patients, a randomized clinical trial.

BACKGROUND: Mental state changes after anesthesia seemed to be more frequent in older patients, but the results were still unclear. OBJECTIVE: To compare the mental scores between adults and elderly patients after general and regional anesthesia. METHODS: This was a stratified randomized trial with factorial design. Sixty patients > or = 60 years old and sixty patients < 60 years old were randomly assigned to receive general or regional anesthesia. Their mental states were assessed blind by investigators, using the Thai Mental State Examination score. RESULTS: The two anesthetic groups showed no difference in the mental scores, but the two age groups showed significantly different scores. The components of mental states that were significantly different were orientation and recall. There were no significant differences in registration, attention, calculation and language. The model for predicting the score included age, education level and narcotics given within six hours before assessment. Sex, weight, intraoperative hypotension, blood loss and duration of anesthesia could not explain the change in the scores. CONCLUSION: Age, but not anesthetic technique, affected the mental scores after anesthesia.

A survey of the anesthesia scavenging systems in a teaching hospital.

Pollution by anesthetic gases can be a problem in operating theaters. More than 90 per cent of this pollution can be reduced by using a scavenging system. Such systems increase the complexity, and thus the hazards of administering anesthesia. A case of pneumothorax prompted an investigation of the active scavenging systems currently used in a teaching hospital by using a pre-use check up protocol. Thirty-eight closed-reservoir active scavenging systems were included. Ten systems (26.3%) were assembled incorrectly. All systems passed a negative pressure relief valve test. Seventeen systems (44.7%) failed to pass a positive pressure relief valve test because high pressure (over 10 cmH2O) developed during an O2 flush, but direct measurement of the pressure at the scavenging interface revealed that these defects were caused by a problem with the adjustable pressure limiting (APL) valves, not with the positive pressure relief valves of the system. We suggest that routine pre-use check up together with regular maintenance of equipment should be emphasized and all personnel should be encouraged to learn more about safety precautions.

Professor Salard Tupavong, key contributor to the development of anesthesia in Thailand.

The practice of Anesthesiology by a qualified Thai national was introduced to the Kingdom of Thailand 50 years ago, when Professor Salard Tupavong graduated from the United States of America and returned to Siriraj Hospital. She made a tremendous contribution to the birth of anesthesia as a specialty, as a pioneer of modern anesthesia and pain therapy in Thailand. She initiated a Residency Training Program and an Inter-hospital Lecture Program in Thai Anesthesiology. She has also helped promote the academic advance of the specialty as well as served as a source of communication and distribution of knowledge for Thai and Asian anesthesiologists. She was regularly invited as an honorary speaker by the committees of both national and international congresses. We are most appreciative of everything that she has done and wish her happy and healthy days ahead.

Siriraj’s oxygen system: Document for reference and maintenance.

This cross-sectional study was done during January to March 1999 by anesthesiolo-gists, engineers and technicians to investigate the whole oxygen system in Siriraj hospital. Four liquid oxygen containers supplied 15 buildings, were connected by main pipelines whose diameter were 1 1/4 to 2 1/2 inches. There were 2,511 oxygen outlets in the wards, operating suites, emergency rooms and intensive care units (ICU). The oxygen manifolds were installed in 10 buildings as reserved supply. The inappropriateness of oxygen source, piping systems, pressure gauges, manifolds, valves, alarm systems and outlets was found and recorded. These were potentialy hazardous to the patients, personnel and related equipment such as sophisticated ventilators in ICU. Lack of qualified personnel, emergency plan, proper knowledge and maintenance were contributing factors. All inappropriateness was correctable and could be prevented. We recommend the correction and maintenance plans together with acquisition of qualified engineer to improve the safety of medical oxygen service as well as the utility of equipment. The result could be used as reference and for maintenance purpose.

When should we order preoperative blood glucose, BUN, creatinine, or electrolytes: A systematic review and clinical practice guidelines.

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 checking of blood glucose, BUN, creatinine and electrolytes. 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 suggested there were no randomized controlled trials to answer the question and no studies reported health outcomes. From this review and the consensus, we proposed guidelines which consisted of a history questionnaire, physical examination and indications for investigation. For the preoperative checking of blood glucose, the indications were: age > 60 years, obesity, diabetes, hypoglycemia, liver disease, alcoholism, severe infection, alteration of consciousness, hypothalamic, pituitary, pancreatic and adrenal disease, and steroid therapy. The common indications for both BUN/creatinine and electrolytes checking were: age > 60 years, undergoing TURP, TUR-BT and major KUB surgery, obesity, diabetes, hypertension, chronic renal failure, renal disease, liver disease, alcoholism, severe infection, severe vomiting or diarrhea, history of fluid, acid base or electrolyte disturbance, alteration of consciousness, hypothalamic, pituitary, pancreatic and adrenal disease, ADH abnormality and diuretic or digoxin therapy. The additional indications for electrolyte checking were: convulsion or muscle weakness, CNS disease with increased ICP and steroid therapy.

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.

Direct medical costs of anaesthesia in Siriraj Hospital.

The direct medical cost of anaesthesia in 1995 at Siriraj Hospital, which is a government tertiary care and teaching hospital was studied from the hospital’s perspective. The costs of anaesthesia were divided into labour cost, equipment cost, and drug and consumable item cost. For labour cost, different personnel were costed separately. In the care of equipment costs depreciation was applied. The costs of drugs and consumable items were calculated at 1995 prices. Four operative procedures: paediatric inguinal herniorrhaphy, caesarean section, laparoscopic cholecystectomy and correction of scoliosis were used as models to show different costs of an anaesthetist (salary plus fringe benefits) was 136.80 baht per hour. The cost of equipment varied from 4.04 to 38.42 baht per hour. The percentage of the labour cost, equipment cost, and drug and consumable item cost, were 40, 12 and 48 percent respectively in anaesthesia for scoliosis correction and 29, 6 and 65 percent respectively in caesaream section under general anaesthesia. The cost of monitoring equipment was lower than the amount that the hospital previously charged. We did not include non-medical costs and indirect medical costs in this study. The direct medical cost was low because of low personnel salary in the government sector. This study lay the toundations for further economic analysis in anaesthesia.