Local cerebral blood flow measured by stable xenon CT during fentanyl-diazepam anesthesia

We assessed the local cerebral blood flow (LCBF) in 40 patients under fentanyl-diazepam anesthesia. The measurement of LCBF was made using 50%–70% stable xenon with 20 min of inhalation interval and a shuttle method for computed tomography imaging. All patients were anesthetized with 5.95±1.76 μg·kg⁻¹ fentanyl and 0.22±0.07 mg·kg⁻¹ diazepam under mechanical ventilation during CBF measurement. The values and distribution of LCBF on non-affected hemisphere appeared to be unaltered by fentanyldiazepam anesthesia. We also assessed the cerebral carbon dioxide reactivity in 6 patients. The cerebral carbon dioxide reactivity, expressed as percentage change in LCBF per unit change in arterial carbon dioxide partial pressure, was 5.39±1.07, and there were no significant differences of reactivity among regions studied. In conclusion, we showed reference values of LCBF and carbon dioxide reactivity, measured by stable xenon-enhanced computed tomography, in patients under fentanyl-diazepam anesthesia. Carbon dioxide reactivity was preserved in all regions including gray matter, white matter, and basal ganglia.     

Local anesthesia for inguinal hernia repair in adolescents

Background Many centers use local anesthesia for adult inguinal hernia surgery in the setting of day-case surgery. There are no reports on, or guidelines for, use of anesthesia for inguinal hernia surgery in adolescents. We describe our initial experience with the use of local anesthesia and intravenous sedation for inguinal hernia surgery in adolescents in the setting of a day-surgery facility. Methods The charts of 14 consecutive adolescent patients (aged 12–17) who had inguinal hernia surgery from July 2004 to March 2005 were reviewed retrospectively. Intravenous sedation was administered 1–3 min before injection of local anesthetic. Sedation consisted of midazolam 0.085 mg kg⁻¹ and either fentanyl 0.85 μg kg⁻¹ or ketamine 0.085 mg kg⁻¹, according to the preference of the anesthesiologist. Additional sedation with half the initial dose was administered if required. Local anesthesia using a combination of lignocaine and bupivacaine was administered by the surgeon with infiltration in the skin and deep tissues. Results Fourteen adolescents aged 12–17 years (mean 14.8 ± 1.37), weighing 34–100 kg (mean 61.2 ± 16.5), had 15 inguinal hernia repairs with sedation and local anesthesia. All the patients were male. All completed the surgery with sedation and local anesthesia. None required conversion to general anesthesia. There were no immediate or subsequent complications. Mean time from the end of surgery to discharge home was under 2 h (mean 106 ± 36 min). Examination of patient charts did not reveal any complaints regarding the surgery or the postoperative course at the postoperative follow up visit. Conclusions The use of local anesthesia with intravenous sedation for inguinal hernia repair in the adolescent age group seems feasible and requires further prospective study.     

小儿腹腔镜下疝囊高位结扎术的麻醉处理

目的探讨小儿腹腔镜下疝囊高位结扎术的麻醉处理方法和安全性。方法本组80例腹腔镜下疝囊高位结扎术患儿,ASAⅠ~Ⅱ级,以气管全麻下行术式,入室后连续监测HR、MAP、SpO2、气道峰压(PIP)、PETCO2及体温,并分别记录术前、气腹后5min、气腹后10min、放气后10min的各项监测指标。结果所有患儿麻醉均满意,无一例出现麻醉意外、并发症,CO2气腹后10、20min HR、MAP、PETCO2、PIP显著升高(p<0.05,p<0.01),SpO2无显著变化,放气后10min各项指标与术前相比差异无显著意义。结论面对小儿特殊的解剖、生理和CO2气腹对生理产生的影响,做好术前准备,选择正确的麻醉方法和合适的麻醉药物,维持稳定的循环,小儿可安全实施腹腔镜疝囊高位结扎手术。     

A comparative study on therapeutic method of traumatic epidural hematoma

Objective： To explore the therapeutic methods, surgical indications and clinical practice of minimally invasive surgery on traumatic epidural hematoma （EDH）. Methods： Retrospective study was made on 135 patients with traumatic EDH admitted into our hospital from June 2002 to August 2005. Sixty-five patients were treated with mini-invasive negative pressure drainage （treatment group）, 70 patients with comparable condition used traditional craniotomy （control group ）. The mean time of operation, average days in hospital, expenditure and prognosis of two groups were recorded and analyzed. Results： There was no significant difference in therapeutic efficacy between two groups. Patients in treatment group had a shorter hospital stay and less expenditure than those in control group. Conclusion： Mini-invasive negative pressure drainage is simple, effective, economical and applicable to some traumatic EDH patients.     

Uptake and biotransformation of sevof lurane in humans: A comparative study of sevof lurane with halothane, enflurane, and isoflurane

Study Objective: To compare the volatile anesthetic sevoflurane with halothane, enfurane, and isof urane on the uptake and biotransformation in humans.

Design: Prospective pharmacokinetic study of sevofurane administration in human subjects.

Setting: Inpatient surgery clinic at a university medical center.

Patients: Thirty-two Japanese patients, free of systemic diseases, undergoing minor elective surgery with endotracheal general anesthesia.

Interventions: The patients were assigned randomly to one of four groups: halothane, enflurane, isofurane, or sevofurane. One of the four volatile anesthetics being investigated [equivalent to 1.1 minimum alveolar concentration (MAC): halothane, 0.85%; enfurane, 1.85%; isofurane, 1.27%; and sevofurane, 1.88%; in inspired concentrations throughout the first hour of anesthesia] was administered for 60 minutes.

Measurements and Main Results: In all patients, serum and urinary fluoride concentrations were measured. The concentrations of all gases were measured separately with a mass spectrometer. The cumulative uptake of each anesthetic agent during a certain period was calculated as an integration of the uptake rate per minute. The results for one-hour inhalation of sevofurane (1.1 MAC) showed an uptake (corrected for body surface area and MAC) of 490 ml/m²/MAC and estimated degradation rate of 3.3%. For purposes of comparison, similar studies of halothane (uptake, 653 ml/m²/MAC; degradation rate 15.7%), enfurane (1150 ml/m²/MAC; 1.3%), and isofurane (439 ml/m²/MAC; 0.6%) were also conducted. Sevofurane had a peak serum inorganic fluoride concentration of 19.3 μmol/L, and no abnormality in hepatic or renal functions was observed in any of the subjects during the two weeks postoperatively.

Conclusions: Accurate determinations of uptake and degradation rate for sevoflurane and three other volatile anesthetics in Japanese patients were obtained. These findings have established that, despite its relatively large MAC *1.71%), sevoflurane has a small uptake due to its low solubility. However, the degradation rade was shown to be as high as 3.3%, resulting in a higher serum fluoride concentration than seen after administration of isoflurane, halothane, and (possibly) enflurane.     

Oesophageal atresia: caudo-thoracic epidural anaesthesia reduces the need for post-operative ventilatory support

The mortality of neonates with oesophageal atresia in the Third World remains high because of delays in presentation and diagnosis. Lack of appropriate intensive care facilities is a further contributing factor. Caudothoracic epidural anaesthesia was used during surgical repair of oesophageal atresia in 35 patients in an attempt to minimise the need for post-operative ventionally support. This group was compared with 36 patients whose surgery was performed under general anaesthesia. The age at the time of referral, sex ratio, and weight were comparable in both groups. Using the Waterson classification, a greater number of poorer prognostic patients were seen in the epidural group (P <0.02). In all Waterson risk categories fewer patients required ventionally support post-operatively, which was statistically significant (P <0.01) when all categories were combined. We are encouraged by our results and believe this technique has a rôle in the management of neonates undergoing major surgery, both where neonatal intensive care exist or is deficient as in many parts of the Third World.     

The effects of anesthesia on otoacoustic emissions

We have measured transient-evoked and distortion-product otoacoustic emissions (OAEs) in the chinchilla and compared them in the awake and anesthetized animal (using either ketamine or barbiturate agents). We report a significant increase in OAE amplitudes during anesthesia, particularly using ketamine. These effects are most evident for transient-evoked otoacoustic emissions (TEOAEs) as measured in the non-linear mode. Our data support the hypothesis that tonic activity levels in cochlear efferents may be reduced by anesthetic effects, either directly or indirectly (e.g., by general reductions in descending pathway activity), and that reduced cochlear efferent activity will result in the observed increase of OAE amplitudes.     

Mivacurium chloride for anesthesia in day surgery

Anesthetic techniques for day surgery must foresee a prompt recovery of alertness, ambulation and alimentation. The aim of our study is to evaluate mivacurium chloride in outpatient general anesthesia. Twenty patients, aged 18–55 years, American Society of Anesthesiologists (ASA) class I–II, undergoing surgical procedures were studied. Mivacurium (0.2 mg/kg) was administered to provide neuromuscular relaxation and endotracheal intubation was performed. Additional doses of 0.1 mg/kg mivacurium were given to maintain neuromuscular block, monitored by Relaxograph (Datex). In all patients, mivacurium provided satisfactory conditions for tracheal intubation after a mean time of 120 ± 15 s. Spontaneous recovery after the last dose of mivacurium was obtained in a mean time of 15 min. No side-effects or significant hemodynamic changes were recorded. The incidence of histamine-related side-effects was low. Mivacurium produces spontaneous recovery of neuromuscular block in a short time and shows some ideal properties for anesthesia in day surgery.     

Perioperative respiratory events in smokers and nonsmokers undergoing general anaesthesia

Background: The prevalence of respiratory diseases in smokers and nonsmokers and the incidence of perioperative respiratory events (PREs) were investigated for patients undergoing general anaesthesia. The aim was to quantify well-known problems and to identify possible new associations between smoking and PREs.
Methods: From July 1992 to December 1994, risk factors, demographic data, and PREs were documented by an automatically readable anaesthetic record (ARAR). PREs were used as defined by the German Society of Anaesthesiology and Intensive Care.
Results: Of 26 961 subsequent anaesthesias in adults, 7122 (26.4%) were performed in smokers with a prevalence of chronic bronchitis of 23.3% (4.8% in nonsmokers). 1573 PREs occurred in 1397 (5.2%) of all anaesthetics. 459 events concerned intubation problems and problems in technical airway management. 1114 specific respiratory events (SPREs) like re-intubation, laryngospasm, bronchospasm, aspiration, hy-poventilation/hypoxaemia and others had a total incidence of 5.5% in smokers and 3.1% in nonsmokers. The relative risk (RR) of SPREs was 1.8 in all smokers, 2.3 in young (16–39 years) smokers, and 6.3 in obese young smokers. The RR of perioperative bronchospasm was 25.7 in young smokers with chronic bronchitis.
Conclusion: The impact of smoking on perioperative respiratory problems should make anaesthetists take this widespread preoperative condition seriously, particularly in young adults. The presented method of incident reporting (based on a national classification) could contribute to future research in anaesthetic epidemiology.