Circulating tumor necrosis factor-related biomarkers predict kidney function decline in Japanese patients with diabetes: An observational cohort study

AIMS

Tumor necrosis factor (TNF) receptors (TNFRs: TNFR1 and, TNFR2) are reportedly associated with chronic kidney disease (CKD) progression chiefly in Caucasian patients with diabetes. We assessed the prognostic value of TNF-related biomarkers for CKD progression in Japanese patients with diabetes.

METHODS

We estimated TNF-related biomarkers using an enzyme-linked immunosorbent assay in 640 patients with diabetes. Cox proportional hazards analysis was performed to estimate hazard ratios (HRs) per one standard deviation (SD) increase in a log-transformed biomarker. The kidney and the composite outcome were defined as a 30% reduction in estimated glomerular filtration rate (eGFR) from baseline, and kidney outcome plus death before kidney outcome, respectively.

RESULTS

During the median follow-up of 5.4 years, 75 (11.7%) patients reached the kidney outcome and 37 (5.8%) died before reaching the kidney outcome. Each SD increase in baseline circulating TNFR1, TNFR2, and ephrin type-A receptor 2 (EphA2) was associated with a higher risk of the kidney outcome independently from baseline eGFR and urine albumin-to-creatinine ratio. However, circulating osteoprotegerin was associated with the composite outcome only.

CONCLUSIONS

Elevated TNFR1, TNFR2, and EphA2 were associated with both kidney and composite outcomes in Japanese patients with diabetes.

Two-handed facemask technique effectively causes hyperventilation in electroconvulsive therapy: an observational study

BACKGROUND

Electroconvulsive therapy (ECT) remains the mainstay treatment option for patients with psychiatric diseases, such as severe depression. Although various anesthetic techniques provide adequate therapeutic seizures, hyperventilation is a useful adjunct to augment seizure duration and improve seizure quality. We investigated how to efficiently use a facemask to accomplish protocolized hyperventilation and evaluate its effect on ECT seizure.

METHODS

We studied 60 patients aged ≥18 years who underwent ECT. The patients were divided into two groups according to the technique of facemask ventilation used: the one-handed (n = 30) and two-handed (n = 30) groups. Following anesthesia induction under preoxygenation conditions, hyperventilation induced hypocapnia in the one-handed facemask group with manual bag ventilation was compared to that in the two-handed facemask group with assisted pressure-controlled ventilation. Ictal and peri-ictal electroencephalogram parameters and cardiovascular responses were monitored and compared between the one-handed and two-handed groups.

RESULTS

The two-handed technique demonstrated better electroencephalogram regularity and minimized cardiovascular stress compared to the one-handed technique. These conclusions come from the fact that the one-handed technique induced a substantial volume of leaks around the facemask (201.7 ± 98.6 mL/breath), whereas minimal leaks (25.8 ± 44.6 mL/breath) with stabler and higher ventilation rate led to greater inhaled minute ventilation in the two-handed group (the one-handed group, 9.52 ± 3.94 L/min; the two-handed group, 11.95 ± 2.29 L/min; p <  0.005). At the end of ECT treatment, all parameters of blood pressure and heart rate increased significantly in both groups equally, with lower SpO₂ and more ST-segment depression on the electrocardiogram in the one-handed group. Comparing baseline values before anesthesia, ECT treatment significantly depressed ST-segment in both groups, while the degree of depression in ST-segment increased significantly in the one-handed group compared to that in the two-handed group.

CONCLUSIONS

End-tidal carbon dioxide monitoring for hyperventilation can reliably ensure hypocapnia only in the two-handed group. In ECT, the two-handed technique assisted by pressure-controlled ventilation is an effective and practical method for hyperventilation to induce adequate therapeutic seizures. While, the two-handed group with sufficient preoxygenation did not cause more cardiovascular stress than the one-handed group.

TRIAL REGISTRATION

UMIN Clinical Trials Registry 000046544, Date of registration 05/01/2022.

An outcome study of adult in-hospital cardiac arrests in non-monitored areas with resuscitation attempted using AED

OBJECTIVES

To investigate the outcomes of patients with in-hospital cardiac arrest (IHCA) who underwent cardiopulmonary resuscitation (CPR) using an automated external defibrillator (AED) in non-monitored areas. Additionally, to detect correlated factors associated with rate of return of spontaneous circulation (ROSC) and survival rate, among collected data.

METHODS

This study included 109 patients. After investigating patient characteristics and resuscitation-related factors, the correlated factors associated with ROSC rates and survival rate were analyzed using univariate and multivariate analyses.

RESULTS

The rate of survival to hospital discharge was 21.1%. CPR with AED performed since 2013 was associated with a higher ROSC rate (adjusted odds ratio [AOR] 3.24, 95% confidence interval [CI]: 1.21 to 9.52, p < 0.05), but not with the survival rate after ROSC. Tracheal intubation was significantly associated with a higher ROSC rate (AOR 3.62, 95% CI: 1.27 to 11.7, p < 0.05) and a lower survival rate after ROSC (hazard ratio 6.6, 95% CI: 1.2 to 43.3, p < 0.05). Dysrhythmia as the cause of cardiac arrest and intensive care unit (ICU) admission after ROSC were associated with higher survival rates (hazard ratio 0.056, 95% CI: 0.004 to 0.759, p < 0.05, and hazard ratio 0.072, 95% CI: 0.017 to 0.264, p < 0.0001, respectively).

CONCLUSIONS

The factors associated with ROSC rate and those associated with the survival rate after ROSC were different. Although initial shockable rhythms on AED were not associated with the survival rate, dysrhythmia as the etiology of cardiac arrest, and ICU admission were significantly associated with higher survival rates after ROSC.

Falsely high patient state index during cardiopulmonary bypass with intra-aortic balloon pumping: a case report

Background

The patient state index (PSI) is a parameter of a four-channel electroencephalography (EEG)-derived variable used to assess the depth of anesthesia. A PSI value of 25–50 indicates adequate state of hypnosis, and a value of 100 indicates a fully awake state. Due to reduced interference from electronic devices like electrocautery, falsely high intraoperative PSI values are rarely reported. However, this case report cautions about falsely high PSI during cardiopulmonary bypass (CPB) with intra-aortic balloon pumping (IABP).

Case presentation

A 68-year-old man was scheduled for coronary artery bypass graft surgery with IABP. General anesthesia was maintained using sevoflurane. Initial PSI was between 30 and 50 before CPB. Propofol was administered during CPB, and IABP provided pulsatile flow. IABP was stopped soon after the initiation of CPB, and the ascending aorta was partially clamped to anastomose the saphenous vein graft to the ascending aorta. The PSI value decreased drastically, but with resumption of IABP, the value increased to approximately 80, despite increasing the dose of anesthetics. Meanwhile, the EEG waveform was nearly flat. After discontinuing CPB, the PSI value returned to being extremely low. There was no evidence of intraoperative awareness or instrument trouble.

After reviewing the anesthesia record, the high PSI value was almost consistent with ongoing IABP during CPB. We suspect that the oscillation noise created by IABP during CPB erroneously influences the PSI algorithm, resulting in a falsely high PSI.

Conclusions

Anesthesiologists should note that adherence to pEEG-derived values without discretion may cause errors when monitoring the depth of anesthesia.

[Successful airway management using i-gel in 7 patients undergoing awake craniotomy]

In order to secure airway during awake craniotomy, we used i-gel to perform positive-pressure ventilation in 7 patients for their anesthetic management. During removal of a tumor around the motor speech center, anesthetic management including asleep-awake-asleep technique was applied for speech testing. The technique, insertion and re-insertion of i-gel, was needed and it was easy in all the patients. During positive-pressure ventilation, peak pressure, tidal volume both for inspiration and expiration, and endtidal-CO2 were not markedly altered. Leakage around i-gel, and its differences between inspiration and expiration were negligible, while the tidal volume was adequate. We conclude that i-gel is useful for anesthetic management for awake craniotomy procedure for both securing airway and ventilation.

[Incidence and characteristics of perioperative pulmonary thromboembolism in Japan from 2009 through 2011 -the results of perioperative pulmonary thromboembolism research by the Japanese society of anesthesiologists (JSA-PTE research) --]

BACKGROUND

This study was designed to investigate the annual incidence and characteristics of perioperative pulmonary thromboembolism (PTE) in Japan from 2009 through 2011, and to compare the current trend with that observed in our previous studies conducted since 2002.

METHODS

In the 3-year study period, a questionnaire was annually mailed to all institutions certified as training hospitals for anesthesiologists by the Japanese Society of Anesthesiologists (JSA). The survey included the parameters of age, sex, type of surgery, and the risk factors in patients who were operated upon.

RESULTS

The questionnaire was sent out to total of 3,556 institutions and obtained answers from 2,511 institutions (70.6%) in the 3-year study period. Total 4,432,538 surgeries were conducted and 1,300 cases (0.03%) of perioperative PTE were registered. The incidence of PTE in all the 3 years was significantly lower than that observed in 2002-2003 (P<0.01). In addition, the mortality in 2011 was also significantly lower than that in 2002-2003 (P<0.05). The incidence of PTE in females (0.04%) was twice of the incidence of males (0.02%). The types of surgery with higher incidence of perioperative PTE were "thoracotomy with laparotomy" (0.08%),"hip joint, limbs" (0.07%) and"craniotomy" (0.06%). Compared with the middle age group (19-65 year-old), the incidence of PTE was twice in the elderly's (66-85 year-old) and in the super-elderly (over 86 year-old) it was thrice. In this survey, most approved risk factors were obesity (44%), malignancy (35%) and long term bed-rest (26%), and the ratio of long term bed-rest was decreasing compared with 2008. In the PTE cases, the ratio of the patients who received anticoagulant drugs (29-30%) or IVC filters placement (4-5%) increased compared with the results of JSA-PTE research in 2008 (P<0.01).

CONCLUSIONS

The incidence and mortality of perioperative PTE decreased;although the factor of decrease in an incidence was considered to be the result of preventive method, as in the decrease in the mortality, the survey should be continued.

[Recent changes in the incidence of life-threatening events in the operating room: JSA surveys between 2001 and 2005]

BACKGROUND

In Japan, the number of medical staff charged with criminal liability has been increasing since 2000, and this medico-legal trend seems to be promoting topics of medical risk management in government, academic meetings and individual hospital. A survey conducted by the Japanese Society of Anesthesiologists (JSA) has been widely accepted among JSA-certified training hospitals, and its denominator has exceeded one million since 2001. The purpose of this investigation is to examine changes in the incidence of life-threatening events in the operating theater between 2001 and 2005 based on the data of the surveys.

METHODS

JSA has conducted annual surveys of life-threatening and neurological events in the operating theater by sending and collecting confidential questionnaires to all JSA certified training hospitals. Cases of life-threatening events between 2001 and 2005 were analyzed. The recovery rates ranged from 76.2% (in 2005) to 91.6% (in 2002), and the annual patient numbers available for analysis ranged from 1,051,245 (in 2005) to 1,367,790 (in 2003) during the study period. The patients with ASA PS 1 or 2 were classified as having good physical status, and those with ASA PS 3 or 4 were classified as having poor physical status. Because mortalities (within 7 postoperative days) are more common in patients with poor physical status, in emergency patients, in neonate, in the elderly, and in patients undergoing cardiovascular surgery, the mortality rate in these patients were investigated. The recovery rate from cardiac arrest without any sequelae was also investigated. The causes of events were classified as follows: totally attributable to anesthetic management (AM), mainly to intraoperative pathological events (IP), to preoperative co-morbidity (PC), and to surgical management (SM). IP consists of pulmonary thromboembolism, acute coronary syndrome, anaphylaxis and so on. The incidence of cardiac arrest and mortality are indicated per 10,000 patients. Odds ratio and 95% confidential interval are shown in comparison with the incidence in 2001 to that in 2005.

RESULTS

The incidences of cardiac arrest were 6.12 in 2001, 5.79 in 2002, 5.89 in 2003, 5.09 in 2004, and 4.24/10,000 patients in 2005, respectively (odds ratio 0.69; CI 0.62-0.78). The incidences of death within 7 postoperative days due to intraoperative life-threatening events were 6.41 in 2001, 6.31 in 2002, 6.61 in 2003, 5.88 in 2004, and 4.91/10,000 patients in 2005, respectively (OR 0.77; CI 0.69-0.85). The incidences of death in patients with poor physical status (from 35.48 to 26.87/10,000 patients; OR 0.76; CI 0.66-0.86), in emergency patients (from 37.25 to 30.55/10,000 patients; OR 0.82; CI 0.72-0.93), in neonates (from 70.09 to 31.70/10,000 patients; OR 0.45; CI 0.22-0.91) and in the elderly (from 11.03 to 8.75/10,000 patients; OR 0.79; CI 0.68 to 0.92) decreased. The incidence of death in patients undergoing cardiovascular surgery ranged between 61.22 and 76.88/10,000 patients, and has not shown any significant decline. The incidences of death due to IP (from 0.65 to 0.42/10,000 patients; OR 0.64; CI 0.44-0.92), PC (from 4.14 to 3.30/10,000 patients; OR 0.80; CI 0.70-0.91) and SM (from 1.49 to 1.02/10,000 patients; OR 0.68; CI 0.54-0.87) decreased. However, the incidence of death due to AM ranged between 0.07 and 0.11/10,000 patients, and has not shown any significant decline partly because of the small number of deaths from this cause. Although recent trends in life-threatening events seemed to be favorable, the recovery rate from cardiac arrest decreased from 40.3% in 2001 to 30.7% in 2005 (OR 0.66; CI 0.51-0.84).

CONCLUSIONS

The incidence of life-threatening events in the operating room and mortality due to these events seemed to have decreased during the recent five years, probably because of progress in risk management in JSA-certified training hospitals. The decrease was obvious in the recent two years. However, the results should be interpreted cautiously, because the response rate to the questionnaire in 2005 was the lowest. To confirm this trend, we should perform a follow-up survey for 2006 and continue the survey. The reasons for the deterioration in the recovery rate from cardiac arrest should also be examined.

[Cerebrovascular accidents developing in the operating theater: a JSA survey for the year 2004]

BACKGROUND

The incidence of cerebrovascular accidents (CVA) developing in the operating theater has not been investigated on a large scale. In 2004, the Japanese Society of Anesthesiologists (JSA) started to survey neurological as well as life-threatening events in the operating theater. The incidence of CVA developing in the operating theater was examined using data obtained by the 2004 survey.

METHODS

JSA has conducted annual surveys of life-threatening and neurological events in the operating theater by sending and collecting confidential questionnaires to all JSA certified training hospitals. The recovery rate was 91% (874/960 hospitals) in 2004. Seven hundred fourteen hospitals sent valid responses, and 1,218,371 anesthesias were registered. Among these cases, 123 patients were reported to have developed CVA in the operating theater. Incidences according to age class, ASA PS and surgical sites, causes, and their outcome were investigated. The patients with ASA PS 1 or 2 were classified as having good physical status, and those with ASA PS 3-5 were classified as having poor physical status. The causes of events were classified as follows: totally attributable to anesthetic management (AM), mainly to intraoperative pathological events (IP), to preoperative co-morbidity (PC), and to surgical management (SM).

RESULTS

Overall incidence of CVA was 1.01/10,000 anesthesias. The incidence in patients aged 66 years or above was 2.00/10,000 anesthesias, which was 3.83-(95% confidential interval 2.57-5.71) fold higher than that in patients aged between 19 and 65 years. The incidences in elective and emergency patients with poor physical status were 3.27 and 7.91/10,000 anesthesias, respectively, which was 7.04- (4.56-10.87) and 17.06-(10.90-26.69) fold higher than that in elective patients with good physical status, respectively. The incidences in patients undergoing thoracotomy combined with laparotomy, craniotomy, or cardiovascular surgery were 2.76, 5.96 and 11.65/10,000 anesthesias, respectively, which were 7.22- (1.64-31.76), 15.59- (8.14-29.86), and 30.52- (16.80-55.44) fold higher than that in patients undergoing laparotomy alone. Among cardiovascular surgery, thoracic aortic surgery showed the highest number of incidents (57.98/10,000 anesthesias), followed by on-pump coronary artery bypass (11.07/10,000 anesthesias). Only one patient undergoing off-pump coronary artery bypass developed CVA, resulting in an 8.14- (1.00-66.18) fold lower incidence of CVA compared to that of on-pump coronary artery bypass. AM, IP, PC and SM were responsible for 4.1%, 24.4%, 27.6% and 35.0% of CVA. The incidence of CVA caused by AM or IP was calculated to be 0.29/ 10,000 anesthesias. If patients undergoing cardiovascular surgery or craniotomy were excluded, the incidence of CVA caused by AM or IP was calculated to be 0.13/ 10,000 anesthesias (15/ 1,134,398 anesthesias). The overall outcome of CVA was as follows: uneventful recovery 9.8%, death within 30 post-operative days 26.0%, vegetative state 6.5%, and sequelae involving deficits in the central nervous system 52.0%. The outcome of CVA caused by AM or IP was as follows: uneventful recovery 20.0%, death within 30 post-operative days 22.9%, vegetative state 8.6%, or sequelae involving deficits in central nervous system 45.7%. Twenty-seven point six percent of reported CVA were considered to have been preventable.

CONCLUSIONS

The overall incidence of CVA developing in the operating theater in Japan was reported to be 123 among 1.2 million anesthesias. The incidence was high in elderly patients, in patients with poor physical status, and in patients undergoing cardiovascular surgery. Because the prognosis of CVA developing in the operating theater was poor, clinical strategies for prevention, early detection, prompt diagnosis, and appropriate treatment of CVA should be established.

[Perioperative management for cesarean section in a patient with pulmonary thromboembolism due to deep venous thrombosis]

It has been estimated in Japan that Western-life style increases maternal mortality because of pulmonary thromboembolism (PTE). We report a 29-year-old primipara who suffered PTE due to deep venous thrombosis (DVT) in her 29th weeks' gestation. Except for slight tachypnea, she was relatively stable. Anticoagulation with heparin was started immediately. The retrievable inferior vena cava filter (IVC-F) was inserted. Four hours before surgery with discontinuation of heparin, the cesarean section was performed under general anesthesia. We used transesophageal echocardiography, a pulmonary artery catheter and end tidal CO2 monitoring for early detection and rapid management of recurrent PTE. She had no trouble during operation and her baby was born without serious symptoms. After recovery from anesthesia, she was admitted to the intensive care unit. Heparin was restarted after confirmation of hemostasis. On the 3rd postoperative day, we started thrombolytic therapy with urokinase which was tapered off during a week. Heparin was switched to warfarine gradually. On the 10th postoperative day, IVC-F could not be removed because of remaining DVT. She was discharged on daily warfarine. We experienced the perioperative management for cesarean section at 29 weeks' gestation following PTE due to DVT.

[Survey of nerve injury associated with epidural/spinal anesthesia in Japan which occurred in the year 2004]

BACKGROUND

The incidence of nerve injury associated with epidural/spinal anesthesia has not been sufficiently investigated in Japan.

PURPOSE

The incidence of nerve injury caused by inappropriate epidural/spinal puncture or catheter placement was examined using data obtained by a survey conducted by the Japanese Society of Anesthesiologists for the year 2004.

METHODS

In a survey for the year 2004, 1,218,371 anesthetic procedures were registered, among which 548,819 patients were estimated to be anesthetized under epidural/spinal procedures with or without general anesthesia. Twenty nine patients were reported to have incurred nerve injury due to inappropriate epidural/spinal puncture or catheter placement.

RESULTS

Seven cases of spinal cord and 22 cases of peripheral nerve injury were reported, with estimated incidences of 1/78,000 and 1/25,000 procedures, respectively. Spinal cord injury developed before the start of surgery in 4 cases, intraoperatively in 1 case, and after the end of surgery in 2 cases. Permanent nerve damage developed in 4 patients with spinal cord injury and 7 patients with peripheral nerve injury. Eighty three percent of these events were reported to be preventable.

CONCLUSIONS

The incidence of nerve injury caused by regional anesthesia in Japan seems to be comparable to those reported in the developed countries. To reduce the incidence of this complication, cautious evaluation of the risk/benefit balance in performing regional anesthesia, improving education and supervision of the procedures, and establishing better communication between anesthesiologists and surgeons concerning the timing of catheter removal and the postoperative coagulation state seem to be important.

[The state of pediatric anesthesia in Japan: an analysis of the Japanese society of anesthesiologists survey of critical incidents in the operating room]

BACKGROUND

The Japanese Society of Anesthesiologists (JSA) survey of critical incidents in the operating room and other reports have shown that pediatric patients undergoing anesthesia are at an increased risk. Purpose was to examine the state of pediatric anesthesia in Japan. This might clarify the role of children's hospitals for pediatric anesthesia, and the relationship between critical incidents and volume of pediatric anesthetic procedures.

METHODS

The JSA has conducted annual surveys of critical incidents in the operating room by sending to and collecting confidential questionnaires from all JSA Certified Training Hospitals. From 1999 to 2003, 342,840 pediatric (0-5 yr) anesthetic procedures were registered. During this period, only 15 cardiac arrests and 3 deaths within 7 postoperative days totally attributable to anesthetic management were reported. Therefore, we analyzed cardiac arrests and deaths due to all etiologies. The hospitals were classified as children's hospitals, university hospitals, and other hospitals, and the incidence of cardiac arrest, the recovery rate from cardiac arrest without any sequelae, and the mortality rate were compared according to types of the hospitals. The relationship between death due to intraoperative critical incidents and the volume of pediatric anesthetic procedures was examined using data from the 2003 survey, the recovery rate of which was 85.7%. In 2003, 739 JSA Certified Training Hospitals responded to the survey: 7 children's hospitals, 109 university hospitals, and 623 other hospitals. Among these hospitals, 707 and 270 hospitals conducted pediatric and newborn (<1 mo) anesthesia, respectively. In 2003, 4,630 newborn, 17,890 infant (<1 yr), and 60,524 child (1-5 yr) anesthetic procedures were registered. Odds ratios were determined to compare the risks among the hospital groups, and the 95% confidential interval (CI) was shown. The Chi square test was used to compare the background of patients with cardiac arrest. P values less than 0.05 were considered significant.

RESULTS

In 2003, 95.7% and 36.5% of JSA Certified Training Hospitals which responded to the survey had conducted pediatric and newborn anesthesia, respectively. Children's hospitals, university hospitals, and other hospitals were responsible for 10.7%, 31.0%, and 58.3% of pediatric anesthetic procedures, respectively. Seven children's hospitals (100.0%), 54 university hospitals (50.5%), and 54 other hospitals (9.1%) conducted more than 201 annual pediatric anesthetic procedures, respectively, and these 115 hospitals conducted 62.5% of all pediatric anesthetic procedures in Japan. There was no significant difference between the overall mortality rate in hospitals with an annual pediatric anesthetic volume of less than 200 and that in hospitals with an annual pediatric anesthetic volume of more than 201 (5.46 versus 7.12/10,000 anesthetic procedures). However, the overall mortality rate was 4.87 times higher (95% confidential interval: 1.53-15.66) in hospitals with an annual pediatric anesthetic volume of more than 101 (7.91/10,000 anesthetic procedures) than in those with an annual pediatric anesthetic volume of less than 100 (1.62/10,000 anesthetic procedures). The situation was quite different when we focused on newborn anesthetic procedures : the overall mortality was 2.63 times higher (95% confidential interval : 1.19-5.84) in hospitals with an annual newborn anesthetic volume of less than 12 (126.6/ 10,000 anesthetic procedures) than those with an annual newborn anesthetic volume of more than 13 (48.5/10,000 anesthetic procedures). Between 1999 and 2003, the incidences of cardiac arrest in children's hospitals, university hospitals, and other hospitals were 9.54 (1.89 times higher than the other hospitals; CI 1.31-2.67), 10.30, and 5.11/10,000 anesthetic procedures, respectively. Among the children who developed cardiac arrest, the ratio of poor preoperative conditions with an American Society of Anesthesiologists physical status classification of more than 3 was significantly lower in the children's hospitals (68.9%) than the university hospitals (84.3%) and the other hospitals (84.0%). The recovery rate from cardiac arrest was 51.1% (2.49 times higher than the university hospitals; CI 1.23-5.06, and 3.05 times higher than the other hospitals ; CI 1.45-6.43), 29.6%, and 25.5%, respectively. The mortality rate was 9.54 (1.77 times higher than the other hospitals; CI 1.25-2.52), 8.87, and 5.38/10,000 anesthetic procedures in children's hospitals, university hospitals and other hospitals, respectively.

CONCLUSION

Almost all JSA Certified Training Hospitals conducted pediatric anesthesia, although only 15.6% of them had an annual pediatric anesthetic volume of more than 200. It was suggested that general pediatric anesthesia was conduced safely in JSA Certified Training Hospitals, even if they had a low annual pediatric anesthetic volume. The exception was newborn anesthetic procedures : the mortality was high in hospitals with an annual newborn anesthetic volume of less than 12. Analysis of critical incidents in the operating room failed to show the superiority of children's hospitals in comparison with the university hospitals and other hospitals. Collecting and analyzing data including the patients without critical incidents are required for further analysis.

[Critical events in the operating room among 1,440,776 patients with ASA PS 1 for elective surgery]

BACKGROUND

The Japanese Society of Anesthesiologists (JSA) survey of critical incidents in the operating room has shown that preoperative complications are the leading causes of critical incidents, and affect the occurrence, severity and outcome of critical incidents which are due to causes other than preoperative complications. Causes of critical events in the operating room were examind in patients for elective surgery with American Society of Anesthesiologists physical status (ASA PS) 1.

METHODS

JSA has conducted annual surveys of critical incidents in the operating room by sending and collecting confidential questionnaires to all JSA Certified Training Hospitals. From 1999 to 2002, 3,855,384 anesthesia patients were registered. Among these, 1,440,776 patients with ASA PS 1 for elective surgery were analyzed. The causes of critical incidents were classified as follows: totally attributable to anesthetic management (AM), mainly to intraoperative pathological events (IP), to preoperative complications (PC), and to surgical management (SM). IP consists of coronary ischemia mainly due to coronary vasospasm, arrhythmias, pulmonary embolism, and other conditions.

RESULTS

The incidences of cardiac arrest, critical incidents other than cardiac arrest and subsequent death were 9.86, 59.41 and 3.12 per 100,000 anesthesia cases, respectively. IP and SM were responsible for 36.6% and 34.5% of cardiac arrest, respectively. AM and SM were responsible for 46.7% and 26.8% of critical incidents other than cardiac arrest, respectively. SM, IP and AM were responsible for 66.7%, 22.2% and 4.4% of subsequent deaths (within 7 postoperative days), respectively. Coronary ischemia and pulmonary embolism were the main causes of death due to IP. The incidences of cardiac arrest and death totally attributable to AM were 1.87 and 0.14 per 100,000 anesthesia cases, respectively. Medication problems were responsible for 48.1% of arrests, while airway/ventilation problems were for 57.2% of critical incidents other than arrest. Human factors (SM combined with AM) were responsible for 53.5%, 73.5%, and 71.1% of cardiac arrest, critical incidents other than arrest and death, respectively.

CONCLUSIONS

Even in elective patients with good physical status, non-lethal incidents were not rare, and lethal incidents were also reported. We should pay significant attention to the following findings, and take some measures to overcome these problems especially related to human factors. Firstly, SM badly harmed some operative patients. Secondly, coronary vasospasm and pulmonary embolism were the main causes of death due to IP. Thirdly, drug administration and airway/ventilation management were the major causes of critical incidents totally attributable to AM. Human factors were responsible for 70.6% of critical incidents and 71.1% of deaths.

[Critical incidents during regional anesthesia in Japanese Society of Anesthesiologists-Certified Training Hospitals: an analysis of responses to the annual survey conducted between 1999 and 2002 by the Japanese Society of Anesthesiologists]

BACKGROUND

Recently, a national survey in France including 35,439 patients who had received spinal anesthesia showed that the incidences of cardiac arrest and mortality associated with spinal anesthesia were 2.5 and 0.8 per 10,000 anesthetics, respectively. In this study, we investigated these values using data obtained from annual surveys conducted by the Japanese Society of Anesthesiologist (JSA).

METHODS

Since 1994, JSA has conducted annual surveys concerning critical incidents in the operating theater by sending confidential questionnaires to JSA-certified training hospitals, then collecting and analyzing the responses. We investigated critical incidents associated with regional anesthesia using data from annual surveys between 1999 and 2002. The questionnaire was identical in each survey conducted during these years. The total number of anesthetics available for this analysis was 3,855,384, of which spinal anesthesia, combined spinal-epidural anesthesia and epidural anesthesia were performed in 409,338, 146,282, and 69,001 patients, respectively. In patients receiving regional anesthesia, 628 critical incidents including 108 cardiac arrests, and 45 subsequent deaths were reported. The causes of critical incidents were classified as follows: totally attributable to anesthetic management, due mainly to intraoperative pathological events, preoperative complications, and surgical management. IP consists of coronary ischemia including coronary vasospasm not suspected preoperatively, arrhythmias including severe bradycardia, pulmonary thromboembolism, and other conditions. Mortality was determined by postoperative day 7. Statistical analysis was performed by chi-square test and Mann-Whitney test. A p value less than 0.05 was considered significant.

RESULTS

The incidences of cardiac arrest and mortality due to all etiologies were 1.69 and 0.76 with spinal anesthesia, 1.78 and 0.68 with combined spinal-epidural anesthesia, and 1.88 and 0.58/10,000 anesthetics with epidural anesthesia, respectively. The incidences of cardiac arrest and mortality due to anesthetic management were 0.54 and 0.02 with spinal anesthesia, 0.55 and 0.00 with combined spinal-epidural anesthesia, and 0.72 and 0.14/10,000 anesthetics with epidural anesthesia, respectively. These values did not significantly differ among regional anesthesia. Death attributable to anesthetic management was reported in 2 patients: both patients were classified as ASA-PS 3 E, and developed cardiac arrest; one due to inadvertent high spinal anesthesia with spinal anesthesia, and the other due to local anesthetic intoxication with epidural anesthesia. Anesthetic management and intraoperative pathological events comprised 33 and 43% of cardiac arrests, respectively. The distribution of causes of death was as follows: anesthetic management, 5%; intraoperative pathological events, 34%; preoperative complications, 35%; surgical management, 26%. Among the causes of anesthetic management-induced critical incidents, inadvertent high spinal anesthesia was the leading cause of cardiac arrest in spinal and combined spinalepidural anesthesia: 90% of arrests occurred in patients with ASA-PS 1+2; 88% in patients below 65 years of age; 45 and 25% in patients undergoing hip or lower extremities surgery, and cesarean section, respectively. Among the causes of intraoperative pathological event-induced critical incidents, pulmonary thromboembolism was the leading cause of cardiac arrest in spinal and combined spinal-epidural anesthesia: 59% of arrests occurred in patients with ASA-PS 1+2; 81% in patients above 66 years of age; 91% in patients undergoing hip or lower extremity surgery.

CONCLUSIONS

The incidence of cardiac arrest and mortality associated with spinal anesthesia in Japan was shown to be in the same order as in France by analyzing a larger population. In patients with good ASA-PS, critical incidents occurred more often under regional anesthesia than under general anesthesia. Inadvertent high spinal anesthesia should be carefully avoided. We should also pay much attention to subclinical deep vein thrombosis in patients who were scheduled for hip or lower extremity surgery, and tourniquet- or bone cement-associated pulmonary embolism in these patients.

[Supplemental survey in 2003 concerning life-threatening hemorrhagic events in the operating room]

BACKGROUND

We previously showed that pre-operative hemorrhagic shock and surgical hemorrhage were the major causes of life-threatening events in the operating room and subsequent fatality. We investigated the background of these events.

METHODS

The Subcommittee on Surveillance of Anesthesia-Related Critical Incidents, Japanese Society of Anesthesiologist (JSA) sent confidential questionnaires to all JSA-certified training hospitals (n=862). The questionnaires were composed of two parts: one for examining all life-threatening events in the operating room and the other for examining the background of massive hemorrhage in the operating room. The number of patients registered between January 1, 2003 and December 31, 2003 was 1,367,790 from 782 hospitals. Life-threatening hemorrhagic events were reported in 1,011 patients, of whom 876 patients were available for further analysis of the background of the events. Fatality within 7 postoperative days following these events was 45.4%.

RESULTS

In patients who developed life-threatening events due to hemorrhage, 35.2% had blood loss of more than 12 l x 60 kg(-1) of body weight, 44.9% had a maximal hemorrhagic speed of more than 240 ml x min(-1) x 60 kg(-1) of body weight, and 39.1% had a minimal hemoglobin concentration of less than 5 g x dl(-1). The main sources of hemorrhage were as follows: the abdominal aorta, 15.4%; the thoracic aorta, 14.0%; the liver, 12.6%; intra-cranium, 8.2%; the pelvic organs, 8.0%; celiac or mesenteric artery, 7.8%; the lung, 7.1%. Of patients who developed life-threatening events due to preoperative hemorrhagic shock, 18.3% underwent cardiac massage preoperatively, 50.0% lost consciousness, 58.5% were intubated, and 16.4% were retrospectively judged to have had no operative indications. Human factors also affected the life-threatening events due to preoperative hemorrhagic shock: delayed decision making concerning indications for surgical treatment, 15.6%; delayed admission to the operating room, 16.6%; delayed supply of blood products, 25.5%; problems in surgical management, 16.3%; problems in anesthetic management, 28.1%. These problems in anesthetic management included shortage of supportive anesthesiologists. This was partly explained by the time of their admission to the operating room: 67.0% of the patients admitted during the week end or at night. Of the patients who developed life-threatening events due to surgical hemorrhage, 58.0% were predicted preoperatively to develop massive hemorrhage by anesthesiologists, and 66.7% were informed of the risks of massive hemorrhage and associated complications. The main causes of surgical hemorrhage were as follows: adhesion or invasion, 44.7%; and problems in surgical judgments or techniques, 43.7%. Anesthetic management affected the development of life-threatening events in these patients: lack of infusion prior to hemorrhage, shortage of supportive anesthesiologists, delay in ordering additional blood products, delayed judgment to start blood transfusion, and shortage of rapid infusion/transfusion apparatus. Delay for hospitals in obtaining blood supply from blood banks was reported in 13.0% of cases, and delayed supply from inhospital blood transfusion service to the operating room in 16.0%. Despite massive hemorrhage, ABO cross-matching was omitted only in 13.4% of patients, and transfusion of ABO-compatible, instead of ABO-identical red blood cells, was performed only in 1.3%.

CONCLUSIONS

To reduce life-threatening hemorrhagic events in the operating theater, reorganization of emergency medical service and blood supply, improvement of surgical techniques, improved triage of patients with hemorrhagic shock, flexible application of compatible blood products in emergency situations, and improvement of the quality and number of anesthesiologists should be considered.

[Surgical volume and mortality due to intraoperative critical incidents at Japanese Society of Anesthesiologists certified training hospitals: an analysis of the annual survey in 2002]

BACKGROUND

We have previously showed that surgical volume affects mortality due to intraoperative critical incidents among patients undergoing cardiac surgery, the surgery with the highest risk, using data obtained by the annual survey in 2001 conducted by the Japanese Society of Anesthesiologists (JSA). In this study, we investigated whether surgical volume affects mortality due to intraoperative critical incidents independent of the surgical site.

METHODS

We investigated this relationship using data obtained from the 2002 annual survey conducted by the Subcommittee on Surveillance of Anesthesia-related Critical Incidents, JSA. Between January 1, 2002 and December 31, 2002, 1,987,988 patients were registered from 704 training hospitals certified by the JSA. Intraoperative critical incidents occurred in 2,844 patients. Of these, 804 patients died within 7 postoperative days. The overall mortality was 4.61 per 10,000 anesthetics. Hospitals were divided into 5 groups according to their annual surgical cases: Group A, fewer than 1,000 (62 hospitals); Group B, 1,000-1,999 (204 hospitals); Group C, 2,000-3,999 (288 hospitals); Group D, 4,000-5,999 (110 hospitals); Group E, more than 6,000 (40 hospitals). Hospitals were also divided into 2 groups according to mortality: Group 1, under 20.00 per 10,000 anesthetics (672 hospitals); Group 2, equal to or higher than 20.00 per 10,000 anesthetics (32 hospitals). Total number of deaths in Group 2 was 158. Mortality was expressed as the mean (95% confidence interval). Statistical analysis was performed using chi-square test and Fisher test. A p value of <0.05 was considered significant.

RESULTS

The mortality rates in Groups A-E were 14.89 (8.48-21.3), 3.86 (3.05-4.67), 3.88 (3.19-4.57), 4.04 (3.20-4.88), and 3.12 (2.19-4.05) per 10,000 anesthetics, respectively. Average surgical cases and mortality in Group 1 were 2,789 (2,775-3,002) and 3.24 (2.90-3.58), respectively, while those in Group 2 were 1,672 (1,243-2,101) and 22.18 (30.58-45.94), respectively. If all patients in Group 2 (n=53,509) had been treated in the hospitals of Group 1, 139-143 deaths might have been avoided.

CONCLUSIONS

Surgical volume was shown to affect mortality independent of the surgical site. Hospitals with low surgical volume should pay significant attention to improving surgical outcomes. These results also suggest that centralization or regionalization should be discussed from the perspective of socio-economical problems as well as patient safety.

[Postoperative nausea and vomiting caused by epidural infusion following gynecological laparoscopic surgery: fentanyl and ropivacaine versus ropivacaine alone]

BACKGROUND

Patients who undergo gynecological laparoscopic surgery often begin to eat and ambulate soon after surgery. However, postoperative nausea and vomiting (PONV) can postpone recovery.

METHODS

We prospectively investigated the incidence of PONV, along with oral intake and ambulation in patients who received an epidural infusion following gynecological laparoscopic surgery with combined epidural and general anesthesia. Forty patients were randomly and equally divided into 2 groups: group R, who received patient-controlled epidural analgesia (PCEA) with 0.2% ropivacaine, and group FR, who received a continuous epidural infusion of 0.2% ropivacaine with fentanyl (CEA). PONV and pain were scored during the early (0-6 hours) and late (6-24 hours) postoperative periods.

RESULTS

PONV incidence and scores were significantly lower in group R (5.3%) than group FR (70.6%) during the late period. Further, patients in group R ate significantly more than group FR at both lunch and dinner, and 2 patients could not ambulate the day after surgery in the FR group. There was no significant difference in analgesia requested between the 2 groups.

CONCLUSIONS

We found that PCEA with ropivacaine alone resulted in a significantly lower incidence of PONV and did not disturb eating and ambulation following gynecological laparoscopic surgery, as compared to patients who received CEA.

[Critical incidents due to drug administration error in the operating room: an analysis of 4,291,925 anesthetics over a 4 year period]

BACKGROUND

Wrong drugs, overdose of drugs, and incorrect administration route remain unsolved problems in anesthetic practice. We determined the incidence and outcome of drug administration error in the operating room of Japanese Society of Anesthesiologists Certified Training Hospitals.

METHODS

Data were obtained from annual surveys conducted by Japanese Society of Anesthesiologists between 1999 and 2002. There were 4,291,925 cases of anesthetic delivery for this analysis.

RESULTS

Incidence of critical incidents due to drug administration error was 18.27/100,000 anesthetics. Cardiac arrest occurred in 2.21 patients per 100,000 anesthetics. Causes of these critical incidents were as follows: overdose or selection error involving non-anesthetic drugs, 42.1%; overdose of anesthetics, 28.7%; inadvertent high spinal anesthesia, 17.9%; local anesthetic intoxication, 6.4%; ampule or syringe swap, 4.3%; blood mismatch, 0.6%. Incidence of death following these incidents was 0.44/100,000. Causes of death were as follows: overdose or selection error involving non-anesthetic drugs, 47.4%; overdose of anesthetics, 26.3%; inadvertent high spinal anesthesia, 15.8%; local anesthetic intoxication, 5.3%. Ampule or syringe swap did not lead to any fatalities. Death following inadvertent high spinal anesthesia and local anesthetic intoxication was reported only in patients who had developed cardiac arrest. It should be noted that 88 percent of ampule or syringe swap occurred in patients with American Society of Anesthesiologists-Physical Status 1 or 2, who did not seem to require complex anesthetic management.

CONCLUSIONS

We should increase awareness that drug administration is generally performed with limited objective monitoring, although "To error is human". Increased vigilance is required to avoid drug administration error in the operating room. Additional anesthesia resident education, adequate supervision, and improved organization are necessary. Bar-coding technology might be useful in preventing drug administration error.

[Accidental severance of epidural catheter used in a patient with postoperative delirium]

A 79-year-old man with an abdominal aortic aneurysm had a lumbar epidural catheter inserted for postoperative pain control of bypass graft surgery with continuous epidural analgesia. Five days after the operation, we noticed that forced traction by the patient with delirium had led to the catheter tip being separated and left behind in his body. The remaining portion of the catheter was detected using a lateral lumbar roentgenogram and CT imaging, and it was later removed surgically. We conclude that it was necessary to change the method of analgesia in this patient, since it was difficult to maintain the epidural catheter.

[Study of nausea and vomiting accompanying intravenous patient-controlled analgesia with fentanyl after cervical spine surgery]

BACKGROUND

Serious side effects of postoperative analgesia with opioid drugs include nausea and vomiting.

METHODS

We investigated the effects of various factors (patient background, anesthesia duration, and intraoperative drug use) on the frequency and degree of postoperative nausea and vomiting (PONV) during the first 24 hours of intravenous patient-controlled analgesia (PCA) with fentanyl.

RESULTS

PONV occurred in 34% of the male patients and 68% of the female, and in 31% and 58% of smokers and non-smokers, respectively.

CONCLUSIONS

Consideration should be given to gender and smoking status prior to starting preventive antiemetic therapy using PCA with fentanyl following cervical spine surgery.

[Optimal application time of lidocaine adhesive tape examined using current perception threshold measurement]

BACKGROUND

We often use lidocaine adhesive tape (Penles, Wyeth Lederle Japan, Ltd., Tokyo, Japan) as a topical anesthetic prior to puncturing a vein with a needle. Since the tape is usually in place for a long time, we often experience problems with creasing and flaring when inserting the needle. We attempted to determine the optimal time for application of the tape as well as for vein puncture after its removal by measuring pain sensation in human subjects.

METHODS

Lidocaine tape was applied to the dorsum of volunteer hands for 2, 4, 6, and 12 hours, and we evaluated changes after removal by determining current perception threshold (CPT), pain score, touch sensation score, diameter of the vein, pruritus, and flare.

RESULTS

CPT levels were found to increase within 1 hour after removal of the lidocaine tape with all 3 electrical stimulus rates used (2000 Hz, 250 Hz, 5 Hz). Further, pain and touch sensation scores were low within 2 hours of removal regardless of application time. Notably, with 4 and 6 hours of application, scores were stable 4 and 6 hours after removal. However, vein diameter and pruritus results did not change regardless of application time, while crease and flare were only observed within 30 minutes after removal.

CONCLUSIONS

We concluded that lidocaine tape provided maximum pain relief when applied 4 to 6 hours prior to vein puncture and up to 1 hour after removal.

[Postoperative continuous epidural analgesia with portable disposable infuser pump: review of 1500 cases]

BACKGROUND

We have been offering active postoperative analgesia service (PAS). In order to further enhance the quality of PAS, we reviewed 1500 cases of postoperative continuous epidural analgesia (PCEA).

METHODS

Postoperative patients received epidural administration of a mixed analgesic solution employing bupivacaine, morphine, or fentanyl using a portable disposable infuser pump (PDIP) for at least 72 hours. Analgesic effects were assessed by using Prince Henry's scoring and the demand for additional analgesics. The frequency and causes of discontinued infusion were also evaluated.

RESULTS

83.9% of cases showed no complications. However, in 4.7% of cases infusion was discontinued because of side effects (nausea, vomiting, pruritus, lower limb motor block, and hypotension, etc.), in 4.1% because of dislodgment of the epidural catheter, in 3.4% because of disconnection, in 2.0% because the patient removing the catheter, and in 0.8% because of the condition of the catheter insertion site.

CONCLUSION

These results indicate that to improve our method of PCEA with PDIP, we must re-assess our regimen used for continuous epidural infusion for postoperative pain relief, and develop measures to prevent side effects and complications.

[Transluminal placed endovascular graft (TPEG) for thoracic aortic disease in fifteen patients under general anesthesia]

In 15 transluminal placed endovascular graft (TPEG) operations for thoracic aortic aneurysm either from dissection or injury, we induced general anesthesia with propofol, and maintained with propofol or sevoflurane in nitrous oxide and oxygen. The temporary balloon occlusion technique used for prevention of stent migration caused hypotension (systolic pressure 30-60 mmHg) in all cases. After releasing the occluding balloon, blood pressure in each patient recovered to the prehypotension level without use of catecholamine. We experienced two emergency operations, a thoracotomy and a celiotomy, resulting from graft failure. We had sudden hypotension in two other cases. In the first patient with aortic regurgitation, coronary air embolism was suspected because of ST segment elevation, while in the other, the hypotension was due to unexpected bleeding from the femoral artery sheath. Two additional patients developed vascular injuries occurring during manipulation of the catheter or sheath. In order to manage anesthesia for TPEG, it is necessary to be aware of its complications.

[Assessment of preoperative anxiety in patients entering the operating room on foot using state-trait anxiety inventory]

The purpose of this prospective study was to assess the effect of walking into the operating room on preoperative anxiety level. Sixty non-premedicated patients scheduled for elective surgery were randomly divided into two groups based on how they were transported into the operating room. One group was carried on a stretcher (n = 30) and the other entered on foot under their own power (n = 30). A subjective assessment of anxiety was performed using a state-trait anxiety inventory (STAI) the day before surgery and on arrival at the operating room. STAI values were not increased in the operating room as compared to the day before surgery for either group and did not differ between groups, though they showed a high level of anxiety throughout the preoperative period. We conclude that walking into the operating room has no significant influence on preoperative anxiety level.

[Severe hypotension after removal of pheochromocytoma in a pediatric patient]

An 8-year-old male patient with pheochromocytoma pretreated with prazocin, carteolol, and enarapril received sevoflurane general anesthesia with fentanyl. After removal of the tumor, blood pressure and urine volume decreased and ST segment in ECG was depressed. We administered dopamine and norepinephrine to increase blood pressure, but pulmonary edema became aggravated postoperatively. He was treated with noninvasive pressure support ventilation with face mask for 4 hours which was effective. His postoperative recovery was uneventful thereafter. We hypothesized that his hemodynamic deterioration was caused by sudden decrease in serum level of norepinephrine after the tumor removal, and the responsiveness to catecholamines was depressed by long exposure to norepinephrine. We conclude that we should use norepinephrine for anesthetic care even in pediatric patients as in adults.

[Coronary artery spasm during low flow anesthesia]

A 70-year-old man, without history of angina pectoris, was scheduled for aorto-femoral bypass graft surgery under epidural anesthesia supplemented with nitrous oxide and sevoflurane. At the beginning of operation, twenty minutes after the start of low flow anesthesia (2 l.min-1), ECG showed an elevation of the ST segment during hypotension. Rising blood pressure and bolus injection of nitroglycerin relieved the elevation and his circulation became stable. It was suspected that a coronary spasm attack was induced by hypotension, as well as vagal stimulation from an inadequate amount of anesthesia. For prevention of intraoperative coronary spasm, it is important to maintain anesthesia at sufficient levels using monitors.

[Effect of bolus propofol administration on muscle evoked potential (MsEP) during spine surgery]

Intraoperative monitoring of descending pathways by means of muscle evoked potential (MsEP) is a reliable method to monitor spinal cord motor function, but MsEP is readily affected by anesthetics. We monitored MsEP evoked by repetitive transcranial electrical stimulation of the motor cortex in 30 patients receiving spine surgery. Total intravenous anesthesia was maintained with propofol and fentanyl without any muscle relaxant. Onset latencies and peak to peak amplitudes of MsEP were evaluated before and after the bolus propofol administration. The concentrations of propofol in blood and the effect-site during MsEP monitoring were predicted by computer simulation software. The amplitude of MsEP decreased slightly by bolus propofol administration, but the latencies showed no significant change with propofol under the same condition. We consider that total intravenous anesthesia with propofol and fentanyl without muscle relaxants is compatible with the recording of MsEP evoked by high frequency repetitive electrical transcranial stimulations. When MsEP is monitored during spine surgery, anesthetic condition should be controlled carefully in order to maintain a stable blood concentration of propofol and thus to assure the reliability of MsEP measurements.

[Perforation of the superior vena cava and hemothorax caused by insertion of a pulmonary artery catheter]

A 70-year-old woman with aortic regurgitation was scheduled for aortic valve replacement. After induction of anesthesia resistance was encountered when attempting to remove the guide wire with a sheath dilator prior to insertion of a pulmonary artery (PA) catheter through the right internal jugular vein. Ten hours after catheter insertion, chest X-ray examination in ICU showed poorly delineated right lung field, and hemothorax was suspected, as a large amount of fluid was also seen draining from the chest drain tube. Twenty two hours after catheter insertion, we opened her chest and found that the superior vena cava (SVC) had been perforated. After surgical closure of the hole on the SVC, the hemodynamics because stabilized and active bleeding was controlled. The patient was subsequently discharged from the hospital without any further complications. This perforation was thought to be caused by carelessness during insertion of the PA catheter. To prevent serious complications, such as perforation of the great vessels or heart by a catheter, the results of the present case suggest that careful attention is required during catheterization, especially when resistance is encountered.

[Evaluation of adhesive tape containing lidocaine using current perception threshold measurement]

Lidocaine adhesive tape (Penles; Wyeth Lederle Japan, Ltd, Tokyo, Japan) is placed for pain relief prior to puncturing a vein with a needle. We investigated the optimal time interval from application of Penles to vein puncture by measuring current perception threshold (CPT) levels with a Neurometer, by which it was possible to measure the extent of nerve block in a non-invasive and quantitative manner with 3 electrical stimulus rates (2000 Hz, 250 Hz, and 5 Hz). Penles was applied to the dorsum of volunteers' hands for 1, 2, 4, 6 and 12 hours before measuring CPT levels. With a stimulation rate of 2000 Hz and 250 Hz, CPT, levels were found to increase 4 hours after the Penles application, while peak CPT levels for 5 Hz stimulation were observed from 6 to 12 hours after application. However, CPT levels tended to decrease 12 hours after application, regardless of the stimulus rate. From the result, we conclude that Penles provides maximum benefit when applied 6 hours prior to vein puncture.

Perioperative temporal profile of cognitive function in elderly patients undergoing hip surgery

To test the hypothesis that elderly patients who have surgery for femoral neck fractures may have delirium not only after surgery but before surgery, we prospectively investigated the perioperative temporal profile of cognitive function in such patients. We performed the Abbreviated Mental Test (AMT) six times in each patient (on the day of admission, 3 days after admission, on the day before surgery, 2 days after surgery, 7 days after surgery, and on the day of discharge). Patients were given no premedication and were anesthetized with spinal anesthesia using 0.2% hypobaric tetracaine. Of the 68 patients who were admitted because of a diagnosis of fractured neck of the femur and were scheduled to have surgery, 27 patients were subjected to analysis. Four and three patients showed a significant decrease (3 or more points) in AMT score 2 and 7 days after surgery, respectively. We conclude that surgery may have a stronger impact on cognitive function than environmental change shortly after admission in elderly patients with femoral neck fractures.

Effects of pneumoperitoneum on cardiac autonomic nervous activity evaluated by heart rate variability analysis during sevoflurane, isoflurane, or propofol anesthesia

BACKGROUND

The effects of pneumoperitoneum on the activity of the cardiac autonomic nervous system have not been completely understood.

METHODS

In this study, 45 unpremedicated adult patients who underwent laparoscopic cholecystectomy were anesthetized with either 3.5% sevoflurane, 2% isoflurane, or 8 mg/kg/h propofol (15 patients in each group). The status of cardiac autonomic nervous activity was evaluated by heart rate variability analysis three times: once when the patient was awake, once after induction of general anesthesia, and once after insufflation for pneumoperitoneum. Intra-abdominal pressure was maintained automatically at 10 mm Hg by a carbon dioxide (CO(2)) insufflator. For each measurement, electrocardiogram was recorded for 256 s and played back offline to detect R-R intervals. Power spectral analysis of heart rate variability was applied, and the low-frequency (LF, 0.04-0.15 Hz) and high-frequency (HF, 0.15-0. 40 Hz) bands of the spectral density of the heart rate variability were obtained from a power spectra of R-R intervals using the fast-Fourier transform algorithm. The HF/LF ratio also was analyzed.

RESULTS

Measurements of heart rate variability in the three groups showed similar change. Although the power of HF, which represents parasympathetic nervous activity, did not change, the power of LF, which represents both sympathetic and parasympathetic nervous activity, decreased during the anesthetized stage and increased during the insufflated stage. The HF/LF ratio, which represents the balance of parasympathetic and sympathetic activity, increased after induction of general anesthesia, and decreased after insufflation.

CONCLUSIONS

Our results suggest that pneumoperitoneum increases sympathetic cardiac activity. The choice of general anesthetic did not seem to have a major influence on the change in the cardiac autonomic nervous system after induction of pneumoperitoneum for laparoscopic cholecystectomy.

Effects of one-lung ventilation on cardiac autonomic nervous activity as evaluated by power spectral analysis of heart rate variability

The purpose of this prospective study was to evaluate the effects of one-lung ventilation on the activity of the cardiac autonomic nervous system. Ten adult patients who underwent thoracotomy were endotracheally intubated with a double-lumen tube under general anesthesia using isoflurane. After induction of anesthesia, a continuous, 256-sec electrocardiogram (ECG) was obtained during bilateral lung ventilation (control) followed by recordings during one-lung ventilation of each side. Using the R-R interval tachograms obtained for the 256-sec ECGs, low frequency (LF: 0.04-0.15 Hz) and high frequency (HF: 0.15-0.40 Hz) bands of the spectral density of the heart rate variability and the HF/LF ratio were analyzed using the fast Fourier transform algorithm. Log(HF), which indicates parasympathetic activity, increased during one-lung ventilation on each side, but did not differ between ventilated sides. Log(LF), which represents sympathetic and parasympathetic activity, increased similarly to log(HF) on both sides. Log(HF/LF), the balance of the sympathetic and parasympathetic activity, did not change during one-lung ventilation. We suggest that one-lung ventilation alone does not substantially affect the cardiac autonomic nervous system.

Sevoflurane inhibited beta-adrenoceptor-G protein bindings in myocardial membrane in rats

The effects of sevoflurane on the beta-adrenoceptor (beta AR) system, consisting of the receptor, stimulatory guanosine triphosphate (GTP) binding protein (Gs), and adenylate cyclase (AC), were studied in rat myocardial membrane. Cyclic adenosine monophosphate (cAMP) production rate was measured as cAMP generation stimulated by l-isoproterenol, guanosine 5"-O-(3-thiotriphosphate) (GTP gamma S), and forskolin, respectively. The receptor studies were performed by using the dihydroalprenolol ([3H]DHA) binding method. Nonspecific binding was determined in the presence of l-propranolol. beta AR binding capacity determined by the maximum number of binding sites (Bmax) and the dissociation constant (Kd) for [3H]DHA were calculated. beta AR affinity for agonists was assessed by an inhibition constant (Ki), calculated from the concentration of l-isoproterenol to produce half-maximum inhibition of [3H]DHA binding (IC50). At 2.0 mM sevoflurane, cAMP production rate was significantly depressed by 87.1% +/- 4.8% with l-isoproterenol and by 79.4% +/- 7.0% with GTP gamma S, but not significantly depressed by forskolin. In the presence of 0-2.0 mM sevoflurane, Kd for [3H]DHA and Ki for l-isoproterenol increased in a concentration-dependent manner, whereas Bmax remained unchanged. The ratio of high affinity state against the high and low affinity state of the adrenoceptor decreased significantly from 0.60 +/- 0.15 to 0.35 +/- 0.12. We conclude that sevoflurane might depress the beta AR signal transduction system by reducing ligand-receptor bindings and disrupting the relationship between the receptor and Gs.

[Usefulness of the interchangeable medical bibliography: introduction of "reference transform utility" program for Macintosh]

We made a text file format exchange program on HyperCard 2.0 for medical bibliography. Some database applications on Macintosh to manage the medical bibliography were available. FileMaker ProJ, EndNotePlus and Microsoft Excel were well known as popular databases and spread sheet application for Macintosh. The data format among the applications is not uniform. We need to translate a data format into another format to share the same data among these database applications. But it requires a lot of time and labor to make this conversion by manual operation. We have developed a file conversion utility program with HyperCard as a user friendly software.

[Anesthetic management of patients with pheochromocytoma for adrenalectomy using balanced anesthesia with continuous infusion of nicardipine and nitroglycerin]

Four patients underwent surgical removal of pheochromocytoma under balanced anesthesia with fentanyl, sevoflurane and epidural anesthesia combined with continuous infusion of nicardipine and nitroglycerin. Circulation was stable during the operation in all the patients. There were no serious hypertension and hypotension, arrhythmia and pulmonary edema during the postoperative period. We conclude that the anesthetic management of patients with pheochromocytoma for adrenalectomy using balanced anesthesia with continuous infusion of nicardipine and nitroglycerin is one of the most useful anesthetic methods.

[Anesthesia for venoplasty of right hepatic vein and liver portion of inferior vena cava using veno-venous bypass]

A patient with Budd-Chiari syndrome who underwent a new surgical technique; venoplasty of right hepatic vein and liver portion of inferior vena cava using veno-venous bypass, was reported. The patient was 31 year-old man whose weight and height were 55 kg and 157 cm, respectively. During the anesthetic management of this patient, we encountered following problems; continuous massive bleeding, profound hypothermia and hemodynamic derangement. These problems were similar to those of liver surgery using veno-venous bypass such as extracorporeal liver surgery and liver transplantation.

[A program for continuous infusion of cardiovascular agents (CIRCULATION)--how to derive the algorithm and how to use the mathematical formula in this program]

Recently, many cardiovascular agents came to be administered to serious or perioperative cases continuously, and difficult calculation became necessary. For continuous infusion of cardiovascular agents, we devised a personal computer program (CIRCULATION) to avoid difficult calculation for PC-9801 series (NEC) by a C language (Turbo-C, Version 2.0). It is easy to use the program, and it calculates the algorithm for many cardiovascular agents in a second. The program is very useful for anesthesiologists and for other doctors when they administer various cardiovascular agents.