Anesthesia and analgesia
-
Anesthesia and analgesia · May 2003
Differing incidences of relevant hypotension with combined spinal-epidural anesthesia and spinal anesthesia.
In this investigation we assessed whether patients receiving spinal anesthesia (SPA) as part of combined spinal-epidural anesthesia (CSE) more often experience relevant hypotension than patients receiving SPA alone. From January 1, 1997, until August 5, 2000, electronic anesthesia records from 1596 patients having received SPA and 1023 patients having received CSE for elective surgery were collected by using a computerized anesthesia record-keeping system. Relevant hypotension was defined as a decrease of mean arterial blood pressure of more than 30% within a 10-min interval and a therapeutic action of the attending anesthesiologist within 20 min after onset. Electronic patient charts were reviewed by using logistic regression with a forward stepwise algorithm to identify independent risk factors that were associated with an increased incidence of hypotension after CSE. Univariate analysis was performed to assess differences in biometric data and relevant risk factors for hypotension between the two procedures. The incidence of relevant hypotension was more frequent with CSE than with SPA alone (10.9% versus 5.0%; P < 0.001). In the multivariate analysis, arterial hypertension (odds ratio, 1.83; 95% confidence interval, 1.21-2.78) and sensory block height >T6 (odds ratio, 2.81; 95% confidence interval, 1.88-4.22) were found to be factors associated with hypotension in the CSE group. Compared with patients receiving SPA alone, patients undergoing CSE had a significantly more frequent prevalence of arterial hypertension and higher sensory block levels (P < 0.01) despite smaller amounts of local anesthetics. In this study, patients receiving CSE had an increased risk for relevant hypotension as compared with patients with SPA alone. Part of this effect seems to be due to the procedure alone and not only because this population is at higher risk. ⋯ This study, based on a large number of patients with a retrospective design by using on-line recorded data, suggests that spinal anesthesia as part of combined spinal-epidural anesthesia may more often lead to relevant hypotension than spinal anesthesia alone. Preexisting arterial hypertension and a sensory block height exceeding T6 are major risk factors for the development of this complication.
-
Anesthesia and analgesia · May 2003
The influence of hemorrhagic shock on etomidate: a pharmacokinetic and pharmacodynamic analysis.
We studied the influence of hemorrhagic shock on the pharmacology of etomidate in swine. Sixteen swine were randomly assigned to control and shock groups. The shock group was bled to a mean arterial blood pressure of 50 mm Hg and held there until 30 mL/kg blood was removed. Etomidate 300 micro g x kg(-1) x min(-1) was infused for 10 min to both groups. Fifteen arterial samples were collected until 180 min after the infusion began to determine drug concentration. Pharmacokinetic variables for each group were estimated by using a three-compartment model. The bispectral index scale was used as a measure of drug effect. The pharmacodynamics were characterized by using a sigmoid inhibitory maximal effect model. The raw data revealed a 25% increase in the plasma etomidate concentration at the end of the 10-min infusion which resolved after termination of the infusion in the shock group. The pharmacokinetic analysis revealed subtle changes in the variable estimates between groups. The etomidate infusion produced a similar Bispectral Index Scale change in both groups. These results demonstrated that, unlike the influence of hemorrhagic shock on other sedative hypnotics and opioids, moderate hemorrhagic shock produced minimal changes in the pharmacokinetics and no change in the pharmacodynamics of etomidate. ⋯ Hemorrhagic shock produced minimal changes in the pharmacokinetics and no change in the pharmacodynamics of etomidate in swine. These results suggest that, unlike other sedative hypnotics and opioids, minimal adjustment in the dose of etomidate is required to achieve the same drug effect during hemorrhagic shock.
-
Anesthesia and analgesia · May 2003
A demographic, service, and financial survey of anesthesia training programs in the United States.
In February 2000, a demographic, service, and finance survey was sent to the directors of anesthesiology training programs in the United States under the auspices of the Society of Academic Anesthesia Chairs/Association of Academic Program Directors. In August of 2000, 2001, and 2002, shorter follow-up surveys were sent to the same program directors requesting the numbers of vacancies in faculty positions and certified registered nurse anesthetists (CRNA) positions. The August 2001 survey also inquired if departments had positive or negative financial margins for the fiscal year ending June 2001. The August 2002 survey included the questions of the 2001 survey and additionally asked if the departments had had an increase or decrease in institutional support and the amount of that current support. The survey results revealed that the average program had 36 anesthetizing locations and 36 faculty. Those faculty spent 69% of their time providing clinical service. Approximately one-half of the departments paid for some of their residents, whereas the other 50% paid for none. Eighty-five percent of the departments employed CRNAs who were funded by the hospital in one third of the departments. In 2000, departments received $34,319/yr in support per faculty full-time equivalent (FTE) from their institutions and had a mean revenue of $407,000/yr/faculty FTE. In 2002, the department's institutional support per FTE increased to $59,680 (a 74% increase since 2000). The departments in academic medical centers paid 20% in overhead expenses, whereas departments in nonacademic medical centers paid 10%. In 2000, 2001, and 2002, the percentage of departments with positive margins was 53%, 53%, and 65%, respectively, whereas the departments with a negative margin decreased from 44% in the year 2000 to 38% in 2001 and 33% in 2002. For the departments with a positive margin, the amount of margin per FTE over this 3-yr period was approximately $50,000, $15,000, and $30,000, respectively. Although the percentage of departments with a negative margin has been decreasing, the negative margin per FTE seems to be increasing from approximately $24,000 to $43,000. The number of departments with open faculty positions has decreased from 91.5% in the year 2000 to 83.5% in 2001 and 78.4% in 2002; in these departments, the number of open faculty positions has also decreased from 3.8 in 2000 to 3.9 in 2001 to 3.4 in 2002. The number of open CRNA positions seems to have been relatively constant with approximately two thirds of the departments requiring an average of approximately four CRNAs each. Overall, academic anesthesiology departments fiscal security seems to have eroded with an increased dependence on institutional support. Departments pay larger overhead rates relative to private practice, and there seems to be a continued, but possibly decreasing, shortage of faculty. ⋯ A survey was conducted of anesthesia training program directors that demonstrated that their departments' financial conditions have been eroding over the years 2000 to 2002. During this same period of time, departments were receiving an increase in institutional support from $34,319/full-time equivalent (FTE) faculty in the year 2000 to $59,680/FTE in the year 2002. Although there seems to be an approximate 10% shortage in academic faculty, the number of departments with open positions has progressively decreased from 91% to 73% over the past 3 yr. On average, the financial condition of the training departments has deteriorated over the past 3 yr despite a significant increase in institutional support to enable departments to recruit and retain faculty in an era of an apparent national shortage of anesthesiologists.
-
Anesthesia and analgesia · May 2003
The diagnosis of obstructive sleep apnea as a risk factor for unanticipated admissions in outpatient surgery.
The goal of this study was to determine whether the preoperative diagnosis of obstructive sleep apnea (OSA) is an independent risk factor for perioperative complications in patients undergoing nonotorhinolaryngologic outpatient surgical procedures. We used existing databases to identify 234 patients with polysomnography-confirmed OSA who had outpatient surgical procedures in the years 1997 through 2000. Control patients were matched for type of anesthesia, age, sex, body mass index, surgical procedure, and surgical date. Their perioperative medical records were reviewed. There was no significant difference in the intraoperative management of OSA and control patients, except that the laryngeal mask airway was less likely to be used in OSA patients. There was no significant difference in the rate of unplanned hospital admissions (23.9% versus 18.8%; odds ratio, 1.4; 95% confidence interval, 0.8-2.5) or other adverse events (2.1% versus 1.3%; odds ratio, 1.7; 95% confidence interval, 0.4-7.0) between OSA and non-OSA patients. Further, when admission did occur, it was generally unrelated to cardiac or respiratory events. In this retrospective analysis, the preoperative diagnosis of OSA was not a risk factor for either unanticipated hospital admission or for other adverse events among patients undergoing outpatient surgical procedures in a tertiary referral center. ⋯ In patients scheduled for outpatient surgery in a large academic practice, the diagnosis of obstructive sleep apnea confirmed by polysomnography was not an independent risk factor for unanticipated hospital admission or for other adverse perioperative events.
-
Anesthesia and analgesia · May 2003
Randomized Controlled Trial Comparative Study Clinical TrialThe influence of local active warming on pain relief of patients with cholelithiasis during rescue transport.
Upper abdominal pain, a frequent symptom of the presence of gallstone disease, is the cause of 6% of the emergency calls of the Austrian emergency system. Pain resulting from cholelithiasis is characteristically severe. Recent data show that active warming during emergency transport of trauma victims is effective in reducing pain. Therefore, we hypothesized that local active warming of the abdomen would be an effective pain treatment for patients with acute cholelithiasis and could be provided by paramedics. Sixty patients (>19 yr) consented to participate in this study. They were divided into two groups: Group 1, who received active warming of the upper abdomen with a carbon-fiber warming blanket (42 degrees C), and Group 2, who received no warming of the abdomen. Neither group received any drug-based pain care. Patients were asked to rate their pain and anxiety by using visual analog scales (VAS). Statistical evaluation was performed with Student's t-test; P < 0.05 was considered significant. In Group 1, a significant (P < 0.01) pain reduction was recorded in all cases on a visual analog scale (VAS), from 86.8 +/- 5.5 mm to 41.2 +/- 16.2 mm. In Group 2, the patients' pain scores remained comparable, from 88.3 +/- 9.9 mm to 88.1 +/- 10.0 mm on a VAS. In comparing Group 1 with Group 2 on arrival at the hospital, pain scores showed a significant difference (P < 0.01). In Group 1, the VAS score changes for anxiety were significantly reduced (P < 0.01), from 82.7 +/- 10.8 mm before treatment to 39.0 +/- 14.0 mm after treatment. In Group 2, a nonsignificant change of this score was noted, from 84.5 +/- 14.6 mm to 83.5 +/- 8.4 mm. Comparing Group 1 with Group 2 on arrival at the hospital showed a significant difference in anxiety scores (P < 0.01). We conclude that local active warming is an effective and easy-to-learn treatment for pain resulting from acute cholelithiasis in emergency care. ⋯ Active local warming of the upper abdomen is an effective treatment for patients with cholelithiasis being transported to the hospital by paramedics who are not permitted to provide any drug-based pain care. We observed no negative side effects of this treatment.