Relation between fentanyl dose and patient state index during spinal anesthesia for elective cesarean section.

BACKGROUND: In spinal anesthesia for cesarean section, the addition of fentanyl to the local anesthetic has been reported to improve perioperative analgesia. However, there is only limited knowledge on sedative effects of the added fentanyl. We examined whether the patient state index® (PSI) can detect and present the light sedated level with patients undergoing cesarean section. FINDINGS: We measured respiratory rate (RR), SpO2, and PSI values. Between child delivery and the completion of the operation, the proportions of time with the PSI values <90 and 80 were calculated. RR <8 breaths/min or SpO2 <95 % was defined as respiratory depression. Respiratory depression was not observed in any patient. At fentanyl doses of 10, 15, and 20 µg, the proportions of time with the PSI <90 were 14.5 ± 20.8, 49.4 ± 35.3, and 71.1 ± 22.9 %, respectively (P < 0.01). There were significant differences between 10 and 15 µg (P < 0.05), and 10 and 20 µg (P < 0.01). Similarly, the proportions of time with the PSI values <80 were 0.5 ± 1.8, 21.1 ± 24.1, and 31.8 ± 32.2 %, respectively (P < 0.05). There was a significant difference between 10 and 20 µg (P < 0.05). CONCLUSIONS: The PSI values decreased in a dose-dependent manner with increasing dose of fentanyl, but no respiratory depression was observed. The PSI values decreased to less than 90, when fentanyl was administered more than 15 µg. Furthermore, the PSI values decreased to less than 80, when fentanyl was administered 20 µg.

[Anesthetic Management of a Patient Complicated with Marfan Syndrome and Suffering from Stanford Type A Aortic Dissection during Pregnancy].

We report a case of a 36-year-old woman at 34 weeks of gestation complicated with Marfan syndrome who underwent Bentall type aortic replacement surgery due to Stanford type A aortic dissection after undergoing caesarean section. Since this patient exhibited severe hypotension before coming to the operating room, it was very difficult to determine whether the cardiac surgery or caesarean section should be performed first. In this case, the caesarean section was performed first, followed by Bentall's surgery. Although intra-aortic balloon pumping and percutaneous cardiopulmonary support were required after weaning from the cardiopulmonary bypass, she was discharged on post-operative day (POD) 40 and the baby was discharged on POD 60, without signs of cerebral palsy. Unfortunately, this patient died on POD 57, due to heart failure. We discuss how to determine the priority of surgeries for patients who require emergency surgery for cardiovascular disease during pregnancy.

[Changes in Electrolytic Concentration Resulting from Perioperative Amino Acid Fluid Administration].

BACKGROUND: Amino acid infusion is frequently selected to avoid hypothermia during surgery. However, changes in electrolytic concentration resulting from its use are unclear. The aim of this study was to identify the effect of amino acid on body temperature and changes in electrolytic concentrations. METHODS: Thirty women undergoing breast cancer surgery under general anesthesia were divided into the following three groups: no amino acid administration, low-dose administration (2 ml x kg(-1) x hr(-1)), and high-dose administration (4 ml x kg(-1) x hr(-1)). Esophageal temperature was recorded every ten minutes and arterial blood samples were obtained before and after surgery. Body temperatures at each time point and arterial blood gas data, including blood gases, electrodes, serum glucose, and hematocrit were compared between the three groups. RESULTS: Body temperature started to increase significantly 40 minutes after starting general anesthesia in the high-dose group, 90 minutes after starting general anesthesia in the low-dose group compared with the no amino acid group. Body temperature was maintained until surgery was completed. The concentration of sodium ion decreased significantly (2.4 mmol x l(-1)) in the high-dose group compared with the other two groups. The concentration of other electrolytes, including potassium, chloride, and calcium, did not change significantly. CONCLUSIONS: Perioperative amino acid administration was effective in maintaining a stable body temperature during surgery under general anesthesia. However, sodium ion concentration might decrease after amino acid administration of 4 ml x kg(-1) x hr(-1) or greater.

[Anesthesia for nonobstetric surgery during pregnancy: cerebrovascular disease].

The incidence of intracranial hemorrhage is approximately 1-5 in 10,000 pregnancies. In Japan, it is reported that 184 such cases occurred and 10 of them died in 2006. Neurosurgery during pregnancy is required infrequently however a multidisciplinary approach is mandated and anesthesiologists need to modify neuroanesthetic and obstetric practices to accommodate the safety requirements of the mother and fetus. Following the physiologic changes of pregnancy and fetal considerations in nonobstetric surgery during pregnancy, we present the maternal and fetal considerations in anesthesia for intracranial hemorrhage.

A visual stethoscope to detect the position of the tracheal tube.

BACKGROUND: Advancing a tracheal tube into the bronchus produces unilateral breath sounds. We created a Visual Stethoscope that allows real-time fast Fourier transformation of the sound signal and 3-dimensional (frequency-amplitude-time) color rendering of the results on a personal computer with simultaneous processing of 2 individual sound signals. The aim of this study was to evaluate whether the Visual Stethoscope can detect bronchial intubation in comparison with auscultation. METHODS: After induction of general anesthesia, the trachea was intubated with a tracheal tube. The distance from the incisors to the carina was measured using a fiberoptic bronchoscope. While the anesthesiologist advanced the tracheal tube from the trachea to the bronchus, another anesthesiologist auscultated breath sounds to detect changes of the breath sounds and/or disappearance of bilateral breath sounds for every 1 cm that the tracheal tube was advanced. Two precordial stethoscopes placed at the left and right sides of the chest were used to record breath sounds simultaneously. Subsequently, at a later date, we randomly entered the recorded breath sounds into the Visual Stethoscope. The same anesthesiologist observed the visualized breath sounds on the personal computer screen processed by the Visual Stethoscope to examine changes of breath sounds and/or disappearance of bilateral breath sound. We compared the decision made based on auscultation with that made based on the results of the visualized breath sounds using the Visual Stethoscope. RESULTS: Thirty patients were enrolled in the study. When irregular breath sounds were auscultated, the tip of the tracheal tube was located at 0.6 +/- 1.2 cm on the bronchial side of the carina. Using the Visual Stethoscope, when there were any changes of the shape of the visualized breath sound, the tube was located at 0.4 +/- 0.8 cm on the tracheal side of the carina (P < 0.01). When unilateral breath sounds were auscultated, the tube was located at 2.6 +/- 1.2 cm on the bronchial side of the carina. The tube was also located at 2.3 +/- 1.0 cm on the bronchial side of the carina when a unilateral shape of visualized breath sounds was obtained using the Visual Stethoscope (not significant). CONCLUSIONS: During advancement of the tracheal tube, alterations of the shape of the visualized breath sounds using the Visual Stethoscope appeared before the changes of the breath sounds were detected by auscultation. Bilateral breath sounds disappeared when the tip of the tracheal tube was advanced beyond the carina in both groups.

[The incidence of critical arrhythmia related to epinephrine under halogenated inhalational anesthesia--report of the Subcommittee on Drugs, Committee on Patient Safety and Risk Management, and Committee on Administrative Affairs Japanese Society of Anesthesiologists].

The incidences of intra-operative critical arrhythmia related to epinephrine under halogenated inhalational anesthesia were analysed according to questionnaire to 1108 JSA (Japanese Society of Anesthesiologists) Certified Training Hospital. The survey details included prospective (from July 16th, 2008 to Aug 15th, 2008) and retrospective (from Jan 1st, 2007 to Dec 31th, 2007) incidences of critical arrhythmia due to epinephrine under halogenated inhalational anesthesia. Among the 1108 institutions, effective responses were obtained from 583 institutions. A total of 1.2 case per 100,000 cases of critical arrhythmia were recorded in the retrospective study, and no case was recorded in the prospective study. The use of epinephrine under halogenated inhalational anesthesia was safe, but careful use is recommended.

[Ventricular fibrillation during induction of anesthesia in a patient with polycythemia vera].

A 53-year-old male patient complained of the pain with bilateral hip area and right hip joint and underwent emergency arthroscopy and drainage. Twenty-eight years before, he had suffered from gout and from his abnormal increase of blood cells was diagnosed as polycythemia vera. The laboratory examination at admission showed a marked increase of hemoglobin (17.7 g x dl(-1)) and hematocrit (69.5%). Immediately before induction of anesthesia, 1000 ml of phlebotomy was performed with large fluid infusion. After induction of anesthesia and oro-tracheal intubation, electrocardiogram (ECG) suddenly showed ventricular fibrillation (Vf). Defibrillation was applied and the ECG recovered to sinus rhythm, but 30 min later, ECG showed Vf, again. The increased blood viscosity with polycythemia might have induced coronary ischemia and fatal arrhythmia in the patient. Vigourous hemodilution before surgery should have been performed as prophylactic management of the cardiac episodes in this patient.

[A case report of rapid inhalation induction with sevoflurane in a patient with porphyria].

We experienced anesthetic management for a patient with acute intermittent porphyria. A 52-year-old woman underwent a partial right mastectomy. She was anesthetized with continuous thoracic epidural blockade combined with general anesthesia using nitrous oxide, oxygen and sevoflurane. To avoid porphyric attack, we chose vital capacity breath technique for rapid induction. We could successfully manage the patient during the perioperative period without appearance of porphyric symptoms. We conclude that vital capacity breath technique for rapid induction may be suitable for use in patients with porphyria.

[A case of ventilatory difficulty during the use of the laryngeal mask airway].

A 67-year-old male patient with chronic tympanitis was scheduled for elective tympanoplasty. Propofol and fentanyl were used for induction and the patient was ventilated with sevoflurane, oxygen and nitrous oxide for general anesthesia. After about 10 minutes following anesthetic induction, the lungs suddenly could not be ventilated through the laryngeal mask airway, and then it was impossible to insert an endotracheal tube. The surgery was discontinued for the safety of the patient, in spite of the recovery of ventilation with a facemask. It is suspected that the ventilatory difficulty was caused by the following reasons; first, the laryngeal mask airway was shifted by change of the body position, second, the mask tip was inserted at the inlet of the larynx because the internal cuff pressure had risen with nitrous oxide.

[Annual study of anesthesia-related mortality and morbidity in the year 2000 in Japan: the outlines--report of Japanese Society of Anesthesiologists Committee on Operating Room Safety].

This report contains anesthesia-related mortality and morbidity in Japanese Society of Anesthesiologists Certified Training Hospitals (JSACTH) in the year 2000, as a part of the second series of annual studies started in 1999. JSA Committee on Operating Room Safety (CORS) sent confidential questionnaires to 794 JSACTH and received effective answers from 65.5% of hospitals. A total number of 941,217 anesthetics were documented. The respondents were asked to report all cases of cardiac arrests and other critical incidents (serious hypotension, serious hypoxemia and others), and their outcomes (death in operating room, death within 7 days, transfer to vegetative state and rescue without sequelae) as well as one principal cause for each incident from the list of 52 items. They were also requested to submit the tabulation of patients by ASA physical status, age distribution, surgery sites and anesthetic methods. Analysis was made by total incidents under anesthesia/surgery, and also by incidents totally attributable to anesthetic management (AM), due to preoperative complications (PC), due to intraoperative pathological events (IP) and due to surgery (SG). This paper focused analysis on entire patients, since analyses with special reference to ASA physical status, age distribution, surgery sites and anesthetic methods were reported previously. Total incidence of cardiac arrest under anesthesia/surgery was 6.52 per 10,000 anesthetics. PC, IP and SG occupied 46.4%, 19.1% and 23.0% of principal causes of total cardiac arrest, respectively. AM occupied only 8.1% of the principal causes and the incidence was 0.53 per 10,000. The most frequent cause of cardiac arrest in 52 more detailed classification of principal causes was preoperative hemorrhagic shock that occupied 23.3% of all cardiac arrests. The second was massive hemorrhage and/or hypovolemia due to surgical procedures (10.6%), and the third was surgery itself (9.5%). Prognosis of the cardiac arrest was worst in that due to PC, 73.7% of cardiac arrests died in the operating room or within 7 days after surgery and only 20.4% survived without sequelae. The best prognosis was found in cardiac arrest due to AM, 76.0% survived without sequelae and 12.0% died. The mortality rate after cardiac arrest was 3.52 per 10,000 anesthetics, of them 0.06 was due to AM, 0.39 due to IP, 2.23 due to PC and 0.76 due to SG. The mortality rate after critical incidents other than cardiac arrest such as severe hypotension and severe hypoxemia was 3.48, and of them 0.03 was due to AM, 0.18 due to IP, 2.45 due to PC and 0.81 due to SG. The final mortality rate attributable to anesthesia/surgery including deaths after cardiac arrest and after other critical incidents was 7.00 per 10,000 anesthetics and very close to 7.18 [6.22, 8.13], that of mean [95%C.I.] in 1994-1998, and 7.19 in 1999. The final mortality rate totally attributable to AM was 0.10 per 10,000 anesthetics, which was significantly improved from 0.21 [0.15, 0.27], that of mean [95%C.I.] in 1994-1998, but not different from 0.13 in 1999. IP, PC and SG showed the final mortality rate of 0.56, 4.69 and 1.57, respectively. Five major causes of all critical incidents were massive hemorrhage due to surgical procedures (13.8%), preoperative hemorrhagic shock (13.1%), surgical technique (8.6%), inappropriate airway management (6.2%) and preoperative respiratory complication (5.7%). Drug overdose or wrong choice (2.7%) as a human error occupied the 10th. In conclusion, the obtained incidences as to death, other critical incidents and their outcomes as well as the occurrence of principal causes in 2000 study were remarkably close to those in 1999 study. We expect that this second series of annual studies for five-years should reveal precise and definite direction for us to reduce anesthesia-related mortality and morbidity.

[Perioperative mortality and morbidity for the year 2000 in 532 Japanese Society of Anesthesiologists certified training hospitals: with a special reference to surgical sites--report of the Japan Society of Anesthesiologists Committee on Operating Room Safety].

Perioperative mortality and morbidity in Japan for the year 2000 were analyzed with special reference to operative regions. The total number of analyzed cases was 903,086. The percentages for each operative region were as follows, CRANIOTOMY 4.5%, THORACOTOMY 3.5%, HEART and GREAT-VESSELS 3.7%, THORACOTOMY with LAPAROTOMY 0.7%, LAPAROTOMY 30.4%, CESARIAN SECTION 3.3%, HEAD-NECK-ENT 14.7%, CHEST-ABDOMEN-PERINEUM 14.0%, SUPINE 3.6%, EXTREMITY including PERIPHERAL-VESSEL 17.2%, OTHERS 4.4%. The incidence of serious events, including cardiac arrest and severe hypotension and hypoxemia developing to cardiac arrest, was 26.74 per 10,000 anesthetics in all operative regions. The events were observed more frequently in HEART and GREAT-VESSELS 170.39, THORACOTOMY with LAPAROTOMY 85.84 and THORACOTOMY 63.63, and less frequently in CHEST-ABDOMEN-PERINEUM 10.49, CESARIAN SECTION 10.95 and EXTREMITY including PERIPHERAL-VESSEL 13.42. Regarding the prognosis of events, the cases with no sequelae were 63.4% in all operative regions. While there were fewer cases with no sequelae in CRANIOTOMY 49.0%, THORACOTOMY with LAPAROTOMY 43.4% and HEART and GREAT-VESSELS 44.4%, there were more cases in HEAD-NECK-ENT 86.9% and CHEST-ABDOMEN-PERINEUM 89.5%. The incidence of serious events totally attributable to anesthetic management was 5.24 per 10,000 anesthetics in all operative regions. The events were observed more frequently in THORACOTOMY 12.91 and SPINE 8.02, and less frequently in LAPAROTOMY except CESARIAN SECTION 4.11 and EXTREMITY including PERIPHERAL-VESSEL 4.65. The main cause of events in THORACOTOMY was inadequate airway management and in SPINE was inadequate airway management and the overdose or miss selection for drugs. Regarding the prognosis of events totally attributable to anesthetic management, the cases with no sequelae were 91.8% in all operative regions. There were fewer cases with no sequelae in HEART and GREAT-VESSELS 82.6%. The incidence of serious events totally attributable to anesthetic management was one fifth of all serious events in all operative regions. While the total deaths from 903,086 cases, including deaths in the operating room or within 7 postoperative days, were 641 cases (7.10 per 10,000 cases), the deaths totally attributable to anesthesia were 9 cases (0.10 per 10,000 cases).

[Perioperative mortality and morbidity in the year 2000 in 502 Japanese certified anesthesia-training hospitals: with a special reference to ASA-physical status--report of the Japan Society of Anesthesiologists Committee on Operating Room Safety].

Perioperative mortality and morbidity in Japan from Jan. 1 to Dec. 31, 2000 were studied retrospectively. Committee on Operating Room Safety in Japanese Society of Anesthesiologists (JSA) sent confidential questionnaires to 794 certified training hospitals of JSA and received answers from 67.6% of the hospitals. We analyzed their answers with a special reference to ASA physical status (ASA-PS). The total number of anesthesia available for this analysis was 897,733. The percentages of patients with ASA-PS of I, II, III, IV, I E, II E, III E, and IV E are 38.0, 40.3, 8.5, 0.4, 4.3, 5.3, 2.5, and 0.7%, respectively. Mortality and morbidity from all kinds of causes including anesthetic management, intraoperative events, co-existing diseases, and surgical problems were as follows. The incidences of cardiac arrest (per 10,000 cases of anesthesia) were 1.11, 3.26, 12.25, 54.60, 0.77, 4.46, 21.08 and 217.75 in patients with ASA-PS of I, II, III, IV, I E, II E, III E, and IV E, respectively. The incidences of critical events including cardiac arrest, severe hypotension, and severe hypoxemia were 6.89, 20.22, 62.18, 148.21, 6.71, 20.38, 106.72 and 592.21 in patients with ASA-PS of I, II, III, IV, I E, II E, III E, and IV E, respectively. The mortality rates (death during anesthesia and within 7 postoperative days) after cardiac arrest were 0.26, 0.77, 3.69, 41.60, 0.00, 1.06, 9.42 and 163.31 per 10,000 cases of anesthesia in patients with ASA-PS of I, II, III, IV, I E, II E, III E, and IV E, respectively. The overall mortality rates were 0.32, 1.38, 9.75, 70.20, 0.26, 2.12, 29.15 and 353.02 in patients with ASA-PS of I, II, III, IV, I E, II E, III E, and IV E, respectively. Overall mortality and morbidity were higher in emergency anesthesia than in elective anesthesia. ASA-PS correlated well with overall mortality and morbidity, regardless of etiology. The incidences of cardiac arrest totally attributable to anesthesia were 0.23, 0.50, 1.32, 0.00, 0.00, 0.85, 2.69 and 4.95 in patients with ASA-PS of I, II, III, IV, I E, II E, III E, and IV E, respectively. The incidences of all critical events totally attributable to anesthesia were 3.13, 5.56, 11.46, 5.20, 3.87, 5.94, 13.90 and 14.85 in patients with ASA-PS of I, II, III, IV, I E, II E, III E, and IV E, respectively. The mortality rates after cardiac arrest totally attributable to anesthesia were 0.03, 0.03, 0.00, 0.00, 0.00, 0.21, 0.45 and 3.30 in patients with ASA-PS of I, II, III, IV, I E, II E, III E, and IV E, respectively. The overall mortality rates totally attributable to anesthesia were 0.03, 0.06, 0.00, 0.00, 0.00, 0.21, 0.45 and 6.60 in patients with ASA-PS of I, II, III, IV, I E, II E, III E, and IV E, respectively. The overall mortality rate totally attributable to anesthesia among patients with good physical status (ASA-PS of I, II, I E, II E) was 0.05. Anesthetic management was mainly responsible for critical events in patients with good physical status, while coexisting diseases were in those with poor physical status. Surgical problems including procedures and massive hemorrhage were the leading causes of mortality in patients with good physical status. We reconfirmed that ASA-PS is useful to predict perioperative mortality and morbidity. It also seems likely that we should make much more efforts to reduce anesthetic morbidity in patients with good physical status, and to improve preanesthetic assessment and preparation in those with poor physical status. Reducing mortality and morbidity from surgical problems is also required for improving perioperative mortality.