A cost-benefit analysis of the ENIGMA trial.

BACKGROUND: The ENIGMA trial was a prospective, randomized, multicenter study that evaluated the clinical consequences of including N2O in general anesthesia. Patients who were given a N2O-free anesthetic when undergoing major surgery for which the expected hospital stay was at least 3 days had lower rates of some postoperative complications. This suggests that, despite a higher consumption of potent inhalational agent, there could be a financial benefit when N2O is avoided in such settings. METHODS: A retrospective cost analysis of the 2,050 patients recruited to the ENIGMA trial was performed. We measured costs from the perspective of an implementing hospital. Direct health care costs include the costs for maintaining anesthesia, daily medications, hospitalization, and complications. The primary outcome was the net financial savings from avoiding N2O in major noncardiac surgery. Comparisons between groups were analyzed using Student t test and bootstrap methods. Sensitivity analyses were also performed. RESULTS: Rates of some serious complications were higher in the N2O group. Total costs in the N2O group were $16,203 and in the N2O-free group $13,837, mean difference of $2,366 (95% CI: 841-3,891); P = 0.002. All sensitivity analyses retained a significant difference in favor of the N2O-free group (all P ≤ 0.005). CONCLUSIONS: Despite N2O reducing the consumption of more expensive potent inhalational agent, there were marked additional costs associated with its use in adult patients undergoing major surgery because of an increased rate of complications. There is no cogent argument to continue using N2O on the basis that it is an inexpensive drug.

Critical incident monitoring in a teaching hospital--the third report 2003-2008.

UNLABELLED: Several factors have been incriminated in the etiologies of critical incidents: shortages in organizing rules, anesthesia technique, patient environment, human factor, team work and communication. This is the third follow up report describing our performance during the last five years (2003-2008). The possible incriminating causes were identified with the objective of avoiding such eventualities and consequently providing a better patient outcome. PATIENTS & METHODS: The computerized database and the medical records of critical incidents reports in our Department during the period of 2003-2008 were reviewed on case-by-case basis. Seventy reported incidents were discussed in the Department's Morbidity & Mortality Meetings (MMM). Incidents were classified as per possible incriminating causes: pulmonary, cardiovascular, central nervous system, metabolic, inadvertent drug injection, communicating failure, equipment failure and miscellaneous causes. RESULTS: Most of the critical incidents reports occurred during maintenance of anesthesia, followed next by during induction and next by same operative day later in the ward. The majority of cases were respiratory events (29 cases), followed by communication failure (12 cases), failure of equipment (9 cases) and inadvertent drug injection (4 cases). CONCLUSIONS: Respiratory events, human errors, team communication and equipment failures, continue to be the leading causes of critical incidents. Critical incidents are apt to occur so long as the human factor is involved. Vigilance in operational efficiency and the scrutiny in drug administration, supervision and training should be closely monitored in order to minimize critical incident reports.

Anesthesia for thoracoscopic thymectomy: modified non-muscle relaxant technique--case reports.

Anesthesia for thymectomy in myasthenia gravis is challenging. The anesthetic experience of that technique is quite large. In involves either muscle relaxant or non-muscle relaxant techniques. However, the literature is deficient of standard anesthetic technique for thoracoscopic thymectomy. Therefore we present in this report a modified non-muscle relaxant technique for thoracoscopic thymectomy (TT). We report two cases who underwent TT under general anesthesia using sufentanil and propofol for induction and local anesthesia spray to the vocal cords to facilitate endobronchial intubation using non-muscle relaxant technique. The intubating, operating and postoperative conditions were excellent. To the best of our knowledge, this is the first report on modified non-muscle relaxant technique for TT in myasthenia gravis. Further cases have to be done to verify our technique.

Perioperative bioelectrical impedence analysis in neurosurgery.

The use of bioelectrical impedence (BI) measurement to assess body composition has recently attracted the attention of anesthesiologists. Analysis of BI provides a non-invasive method to quantify fluid distribution in different body compartments. This study was designed to assess whether BI analysis reflects fluid depletion in neurosurgical patients with moderate blood loss. Six adult male patients scheduled for elective craniotomy under general anesthesia were studied. Exclusion criteria included patients with cardio-respiratory disease. BI analysis was performed at three stages, A, day before operation, B, during surgery and C, on the first postoperative day. Total body resistivity was measured by BI analysis with a four-terminal portable impedence analyzer. At each frequency, impedence was calculated as resistance (Rx)2 + reactance (Rc)2. The mean values of total body water (TBW) at stages A, B and C were 39.8 L (range: 33.1-46.7 L), 43.2 L (range: 33.1-66.2 L) and 36.8 L (range: 22.4-36.3 L) respectively with significant differences (P<0.05). The impedence at the three frequencies during stages A, B and C showed significant differences (P<0.05). In conclusion, we have found that in male neurosurgical patients multiple frequency BI measurements has reflected fluid balance perioperatively. Whether this observation remains true for other surgical procedures with massive blood loss, yet to be further investigated.

Anesthetic implications for video assisted thoracoscopic thymectomy in myasthenia gravis.

Thymectomy is an established therapy in the management of generalized myasthenia gravis (MG). However, the optimal surgical approach to thymectomy has remained controversial. There are advocates for transternal, transcervical approaches for "maximal" thymectomy. Video-assisted thoracoscopic thymectomy (VATT) presents new approach to thymectomy. By minimizing chest wall trauma, VATT not only causes less postoperative pain, shortens hospital stay, gives better cosmetic results but also leads to wider acceptance by patients for earlier surgery. Anesthesia for thymectomy in MG is challenging. Currently we are using non-muscle relaxant technique (NMRT) which we adopted in 1994, for maximal thymectomy. In this paper, we present our limited experience with two cases of VATT using two different NMRTs. Two cases of MG underwent VATT under general anesthesia (GA) and one lung ventilation (OLV) using double lumen tube (DLT). In both cases NMRT was used which encompass, light GA plus thoracic epidural analgesia (TEA) in one case and without TEA in the other case. We believe that the use of NMRT provides good operative and postoperative conditions. In this report we have described two different NMRTs, one with TEA and the other without. Further studies are needed on large number of cases to establish an anesthetic protocol for VATT.

Critical incident reports in adults: an analytical study in a teaching hospital.

UNLABELLED: Self-auditing is important to improve the standard of care. In a previous study (1991--1997), we reported human error and equipment factor as the two major causes leading to critical incidents. This study analyzes the computerized database and the medical records of 71 critical incidents reported in the Department morbidity and mortality meeting between 1998--2002, in an attempt to identify factors that have led to critical incidents and compare them with our previous report. PATIENTS & METHODS: We use a standard form where factors which lead to critical incidents are identified such as: anesthesia providers, patient's characteristics, type of anesthesia and others. The form includes a section for the reporter to narrate the whole incident. RESULTS: Seventy-one incident reports in adult patients were studied. In 35.3% consultants reported the incidents, while 64.7% were reported by residents. Most of the incidents were reported in patients undergoing emergency surgery (P = 0.0034) and with physical status III-IV (P = 0.008). Incidents due to circulatory events were 33.8%, while respiratory incidents were 35.2%. The majority of incidents were due to human error (38%), lack of team communication (23.9%), patient condition (10%) and technical problems, (19.7%). Suggestions for prevention of incidents were, better training 29.2%, better communication 20.3%, developing of algorithms 12.6%, checklists 10.2%, better supervision 15.2%, improved equipment 6.3%, improved arrangement of drugs 5.2% and for additional monitoring 1%. CONCLUSIONS: Emergency surgery and patient ASA physical status III-IV were significant predictors of critical incident reports. Analysis of anesthesia related problems may contribute to improved preventive strategies.

Sevoflurane vs isoflurane anaesthesia: a study of postoperative mental concentration and fine motor movements.

Ambulatory anaesthesia is a challenging specialty. Often locoregional techniques are preferred due to the speedy recovery and short hospital stay. However a reasonable number of day-case surgery are performed under general anaesthesia where the recovery of cognitive functions are delayed. Therefore we conducted this study in order to assess the postoperative mental concentration and fine motor movements following isoflurane versus sevoflurane anaesthesia. Twenty adult patients were enrolled in the study. They were ASA 1, age 33 +/- 10 yr and weight 68 +/- 7 kg. They were divided into two groups A and B for isoflurane and sevoflurane respectively. After routine monitoring, induction for both groups was achieved with propofol, endotracheal intubation was facilitated with atracurium and maintenance with either isoflurane or sevoflurane 1 MAC with 50% nitrous oxide in oxygen. During the recovery period the cognitive functions were assessed using the tracing test equipment where the time error product (TEP) was used as a test score. In both groups 30 min after anaesthesia the TEP was 10,000 sec. Thirty minutes later the median TEP was 6,316 sec and 10,000 sec in groups A and B respectively. Another thirty minutes later, the TEP median was 4,052 sec and 1,209 sec for groups A and B respectively. Five hours after anaesthesia the TEP in both groups became identical but still significantly higher compared with the preoperative values. In the present study the TEP was reduced in the sevoflurane group 2 hr after anaesthesia from 10,000 sec to nearly 1,000 sec where in the isoflurane group it was reduced from 10,000 sec to 4,000 sec. In conclusion, sevoflurane anaesthesia resulted in superior recovery of the early TEP scores compared to isoflurane but in both groups the late TEP scores were identical. We believe that following general anaesthesia in day-case set up the patients should refrain from any kind of work that necessitates fine motor movement and mental concentration for at least 24 hr postoperatively.