Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ANESTHESIA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

The effect of anesthesia on intraoperative and postoperative bleeding during abdominal prostatectomies: a comparison of neurolept anesthesia, halothane anesthesia and epidural anesthesia.

Intraoperative blood loss was measured during abdominal prostatectomies in 213 patients anesthetized with neurolept anesthesia, halothane anesthesia and epidural anesthesia. In 55 of these patients, postoperative bleeding was also measured. The average intraoperative blood loss with neurolept anesthesia was 8.2 +/- 5 ml/min, with halothane anesthesia 6.6 +/- 6.3 ml/min and with epidural anesthesia 3.8 +/- 2.3 ml/min. The difference of blood loss in the epidural group and in the groups receiving general anesthesia is highly significant. Average systolic and diastolic blood pressures were lower during operation in the epidural group than in the other two groups. Statistical analyses failed, however, to show a significant correlation between blood pressures and blood loss in the individual patient. Thus, the ultimate explanation for the diminished bleeding associated with epidural anesthesia is not definitely ascertained. The average postoperative bleeding was not significantly different among the three anesthetic groups.

Adult↗

Ophthalmic regional anesthesia: medial canthus episcleral (sub-tenon) anesthesia is more efficient than peribulbar anesthesia: A double-blind randomized study.

BACKGROUND: Regional anesthesia and especially peribulbar anesthesia commonly is used for cataract surgery. Failure rates and need for reinjection remains high, however, with peribulbar anesthesia. Single-injection high-volume medial canthus episcleral (sub-Tenon's) anesthesia has proven to be an efficient and safe alternative to peribulbar anesthesia. METHODS: The authors, in a blind study, compared the effectiveness of both techniques in 66 patients randomly assigned to episcleral anesthesia or single-injection peribulbar anesthesia. Motor blockade (akinesia) was used as the main index of anesthesia effectiveness. It was assessed using an 18-point scale (0-3 for each of the four directions of the gaze, lid opening, and lid closing, the total being from 0 = normal mobility to 18 = no movement at all). This score was compared between the groups 1, 5, 10, and 15 min after injection and at the end of the surgical procedures. Time to onset of the blockade also was compared between the two groups, as was the incidence of incomplete blockade with a need for supplemental injection and the satisfaction of the surgeon, patient, and anesthesiologist. RESULTS: Episcleral anesthesia provided a quicker onset of anesthesia, a better akinesia score, and a lower rate of incomplete blockade necessitating reinjection (0 vs. 39%; P < 0.0001) than peribulbar anesthesia. Even after supplemental injection, peribulbar anesthesia had a lower akinesia score than did episcleral anesthesia. Peribulbar anesthesia began to wear off during surgery, whereas episcleral anesthesia did not. CONCLUSION: Medial canthus single-injection episcleral anesthesia is a suitable alternative to peribulbar anesthesia. It provides better akinesia, with a quicker onset and more constancy in effectiveness.

Aged↗

Frequency of hypotension and bradycardia during general anesthesia, epidural anesthesia, or integrated epidural-general anesthesia for total hip replacement.

STUDY OBJECTIVE: To evaluate the frequency of hypotension and bradycardia during integrated epidural-general anesthesia as compared with general anesthesia or epidural anesthesia alone. DESIGN: Prospective, randomized, open, multicenter study. SETTING: Inpatient anesthesia at 7 University or Hospital Departments of anesthesia. PATIENTS: 210 ASA physical status I, II, and III patients undergoing elective total hip replacement. INTERVENTIONS: Using a balanced randomization method, each hospital enrolled 30 consecutive patients who received integrated epidural-general anesthesia, epidural anesthesia, or general anesthesia. MEASUREMENTS AND MAIN RESULTS: Occurrence of clinically relevant hypotension (systolic arterial blood pressure (BP) decrease >30% from baseline), or bradycardia (heart rate (HR) <45 bpm) requiring pharmacologic treatment were recorded, as well as routine cardiovascular parameters. Clinically relevant hypotension during induction of nerve block was reported in 13 patients receiving epidural block (18%) and 16 patients receiving epidural-general anesthesia (22%) (p = 0.67). Subsequently, 22 of the remaining 54 patients in the epidural-general anesthesia group (41%) developed hypotension after the induction of general anesthesia, as compared with 16 patients of the general anesthesia group (23%) (p = 0.049). No differences in HR or in frequency of bradycardia were observed in the three groups. CONCLUSIONS: The induction of general anesthesia in patients with an epidural block up to T10 increased the odds of developing clinically relevant hypotension as compared with those patients who received no epidural block, and was associated with a twofold increase of the odds of hypotension as compared with the use of epidural anesthesia alone.

Aged↗

Effects of low-flow sevoflurane anesthesia on renal function: comparison with high-flow sevoflurane anesthesia and low-flow isoflurane anesthesia.

BACKGROUND: The safety of low-flow sevoflurane anesthesia, during which CF2=C(CF3)-O-CH2F (compound A) is formed by sevoflurane degradation, in humans has been questioned because compound A is nephrotoxic in rats. Several reports have evaluated renal function after closed-circuit or low-flow sevoflurane anesthesia, using blood urea nitrogen (BUN) and serum creatinine as markers. However, these are not the more sensitive tests for detecting renal damage. This study assessed the effects of low-flow sevoflurane anesthesia on renal function using not only BUN and serum creatinine but also creatinine clearance and urinary excretion of kidney-specific enzymes, and it compared these values with those obtained in high-flow sevoflurane anesthesia and low-flow isoflurane anesthesia. METHODS: Forty-eight patients with gastric cancer undergoing gastrectomy were studied. Patients were randomized to receive sevoflurane anesthesia with fresh gas flow of 1 l/min (low-flow sevoflurane group; n = 16) or 6-10 l/min (high-flow sevoflurane group; n = 16) or isoflurane anesthesia with a fresh gas flow of 1 l/min (low-flow isoflurane group; n = 16). In all groups, the carrier gas was oxygen/nitrous oxide in the ratio adjusted to ensure a fractional concentration of oxygen in inspired gas (FiO2) of more than 0.3. Fresh Baralyme was used in the low-flow sevoflurane and low-flow isoflurane groups. Glass balls were used instead in the high-flow sevoflurane group, with the fresh gas flow rate adjusted to eliminate rebreathing. The compound A concentration was measured by gas chromatography. Gas samples taken from the inspiratory limb of the circle system at 1-h intervals were analyzed. Blood samples were obtained before and on days 1, 2, and 3 after anesthesia to measure BUN and serum creatinine. Twenty-four-hour urine samples were collected before anesthesia and for each 24-h period from 0 to 72 h after anesthesia to measure creatinine, N-acetyl-beta-D-glucosaminidase, and alanine aminopeptidase. RESULTS: The average inspired concentration of compound A was 20 +/- 7.8 ppm (mean +/- SD), and the average duration of exposure to this concentration was 6.11 +/- 1.77 h in the low-flow sevoflurane group. Postanesthesia BUN and serum creatinine concentrations decreased, creatinine clearance increased, and urinary N-acetyl-beta-D-glucosaminidase and alanine aminopeptidase excretion increased in all groups compared with preanesthesia values, but there were no significant differences between the low-flow sevoflurane, high-flow sevoflurane, and low-flow isoflurane groups for any renal function parameter at any time after anesthesia. CONCLUSIONS: The only difference between the low-flow and high-flow sevoflurane groups was compound A formation, and postanesthesia laboratory data showed no significant effects of compound A formation during sevoflurane anesthesia on renal function. No significant effects on renal function were observed in either the low-flow or high-flow sevoflurane groups compared with the low-flow isoflurane group.

Aged↗

[Continuous spinal anesthesia vs. combined spinal-epidural anesthesia in emergency surgery. The combined spinal-epidural anesthesia technique does not offer an advantage of spinal anesthesia with a microcatheter].

UNLABELLED: In this prospective study we investigated the efficacy of microcatheter spinal anaesthesia in comparison with a combined spinal-epidural technique in trauma patients. METHODS: After institutional approval 60 patients undergoing urgent lower-limb surgery randomly received either CSA (22 G Sprotte needle, 28 G nylon catheter) in group 1 or CSE (18 G Tuohy needle, 22 G epidural catheter and 25 G pencil-point needle) in group 2. An initial subarachnoid bolus of 2 ml of plain bupivacaine 0.5% was injected in both groups. Difficulties with the lumbar puncture or catheter insertion, the time required for performance of either technique and the onset of analgesia at T12 were documented. If analgesia did not reach T12 within 20 min, supplemental bupivacaine was injected either intrathecally or epidurally up to a maximum of 5 ml in the CSA group or 16 ml in the CSE group. RESULTS: The number of lumbar punctures (CSA: n = 1.8 +/- 1.5; CSE: n = 2.6 +/- 1.8; P = 0.05) and the incidence of technical problems (CSA: 13%, CSE: 47%; P = 0.012) was higher in the CSE group. In contrast to CSA, performance of CSE was more time consuming (CSA: 8 +/- 3 min, CSE: 15 +/- 8 min; P = 0.0003), and the total dose of local anaesthetics was higher in the CSE group (CSA: 3.2 +/- 1 ml, CSE: 9.7 +/- 5 ml; P < 0.0001). CONCLUSIONS: Because of the higher incidence of technical problems, more time was required for the performance of CSE. As a consequence, microcatheter CSA might be preferred over CSE in trauma patients.

Aged↗

[Aortofemoral bifurcation bypass--effect of anesthesia procedure (NLA, thoracic continuous catheter peridural anesthesia) on circulation, respiration and metabolism. Hemodynamic changes caused by peridural anesthesia and anesthesia induction].

UNLABELLED: In 50 patients scheduled for infrarenal aortic bypass surgery the cardiovascular effects of two anaesthetic regimes were investigated prior to surgery. A Swan-Ganz-catheter was used for haemodynamic measurements. These patients, having been randomized into two groups, were optimally volume loaded (PCWP 10 mmHg) before anaesthesia. In 24 patients a thoracic epidural was induced with 12-15 ml 0.25% plain bupivacaine. When segmental anaesthesia had extended from T4/5 to L1/2 general anaesthesia was additionally applied (flunitrazepam 1.5-2 mg, pancuronium bromide 0.1 mg/kg). In 26 patients neuroleptanaesthesia was induced (droperidol 0.1-0.2 mg/kg, fentanyl 0.01 mg/kg, pancuronium bromide 0.1 mg/kg, and thiopentone 100-150 mg. Haemodynamic measurements were made before injection into the epidural catheter, after complete spread of anaesthesia, before commencing general anaesthesia and 10-15 min thereafter. RESULTS: Neither of the two procedures were associated with severe haemodynamic alterations. In the epidural group HR fell slightly during latency of complete spread and increased to the same extend following general anaesthesia. The epidural caused MAP (104 to 88 mmHg), mean PAP (20 to 14 mmHg), PCWP (10 to 7.5 mmHg), and RAP (4.5 to 2.5 mmHg) to decrease moderately but no further changes were effected by the subsequent general anaesthesia. SVR and PVR were not influenced by either epidural or by general anaesthesia. CI (3.6 to 3.41 . min-1 . m-2), LVSWI (67 to 52 p . m-1), and cardiac minute work index (55 to 40 J . min-1 . m-2) decreased during latency of complete spread but were no further influenced by general anaesthesia. The haemodynamic changes of neuroleptanaesthesia were almost identical to those of the combined epidural-general anaesthesia. For the operation which followed, a continuous infusion of 0.125 per cent plain bupivacaine (0.25 ml/kg X h) via epidural catheter (in combination with N2O/O2-anaesthesia) was sufficient for complete analgesia in the epidural group. These findings lead to the conclusion that a small bolus volume and a low concentration of bupivacaine result in good anaesthesia while avoiding serious haemodynamic alterations.

Adult↗

Anesthesia associated depression in lymphocyte traffic: less with regional anesthesia than with general anesthesia in sheep.

In the sheep single peripheral lymph node model of Hall and Morris, it is possible to cannulate efferent and afferent lymphatic vessels for long-term study of cells and substances in lymph and for short- and long-term infusions. By supporting the sheep in sternal recumbency (upright) to avoid positional alterations in lymphocyte traffic in short-term studies and by precise timing and measurement of lymph output and cell counts, it is possible to accumulate data on lymphocyte output into efferent lymph on a consecutive, cumulative basis and to detect long- and short-term alterations in lymphocyte traffic. With this model, studies on the effects of general and regional anesthesia were carried out on 42 unstimulated primary peripheral lymph nodes of sheep in vivo. The lymphocyte traffic depressing effects of general anesthesia were found to be significantly less when regional epidural anesthesia was employed. The duration of depression also was less. In the general anesthesia studies, the depth of depression in lymphocyte traffic appeared related to the dose and length of anesthesia. These alterations may play important roles in the immunologic responses to anesthetic compounds and approaches.

Anesthesia, Epidural↗

[Caudal anesthesia combined with general anesthesia in comparison with general anesthesia in ambulatory circumcision].

In 100 boys (5.9 +/- 3.2 years old) undergoing outpatient circumcision, analgesia was provided with 0.375% bupivacaine 1 ml/year of age by caudal injection (group I), administered after induction of general anesthesia. This group was compared with 100 boys (6.3 +/- 3.4 years old), who received only general anesthesia (group II). The puncture technique described was free of complications and the caudal blocks were 98% successful. There was a great difference with regard to the levels of general anesthesia: the average enflurane concentrations required to block autonomic reactions during surgical intervention was 1.3 vol% in group I and 2.7 vol% in group II. The amount of pethidine needed for perioperative pain relief was 8 mg (+/- 5.7) in 17/100 of group I and 17.3 mg (+/- 6.8) in 91/100 of group II. In addition, paracetamol was given in 10/100 of group I and 30/100 of group II. The boys in group I showed calm postoperative behavior. In both groups there were only slight differences in hemodynamic parameters. Of the parents who answered our questionnaire (50 answers to 60 questionnaires), 68% were amazed at the duration of analgesia. During the late postoperative period, in group I there was an almost total absence of vomiting (4%), with an associated rapid return to normal feeding. In 83% the effect of late postoperative analgesia worked so well that no subsequent analgesic was given. In 15% the pain relief lasted 6.3 +/- 2.5 h. The excellent postoperative pain relief produced by caudal anesthesia justifies its frequent use for children subjected to genital surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetaminophen↗

[Perioperative stress response in elderly patients for elective gastrectomy--the comparison between isoflurane anesthesia and sevoflurane anesthesia both combined with epidural anesthesia].

The difference in stress responses between isoflurane anesthesia (I group) and sevoflurane anesthesia (S group) was studied. Twelve patients for elective gastrectomy were divided into two groups: S group, 7 patients, 78 +/- 4.3 years of age, and I group, 5 patients, 77.4 +/- 6.9 years of age. Anesthesia was induced by fentanyl, midazolam and sevoflurane or isoflurane with 100% oxygen. After laryngeal mask air way was inserted under spontaneous ventilation, anesthesia was maintained with air (3 l.min-1), oxygen (2 l.min-1), sevoflurane or isoflurane and epidural block. Vecuronium bromide was given during surgery when needed. The demographic data were not different between the two groups. During operation, it was confirmed that the responses of sympathetic nervous system (epinephrine, norepinephrine) and pituitary-adrenocortical system (ACTH, cortisol) were maintained in both groups. After operation plasma norepinephrine levels increased in both groups. Although the responses of I group tended to be stronger than that of S group, there was no significant difference between the two groups.

Aged↗

Effects of halothane anesthesia compared with fentanyl anesthesia and no anesthesia during coronary ligation in rats.

The effects of halothane and fentanyl anesthesia on responses to ligation of a coronary artery in chronically prepared rats were compared with responses in conscious animals. A total of 86 rats were used; 24 were ligated under halothane anesthesia, 18 under fentanyl, and 23 were left conscious. Three other groups (each of seven rats) were identically prepared but not ligated. Non-ligated rats were left conscious or anesthetized with halothane or fentanyl. Ligation was performed with the aid of a permanently implanted snare around the left anterior descending coronary artery. The responses to ligation that were measured were: arrhythmias, blood pressure changes, heart rate changes, ECG changes, mortality rate, occluded zone, and infarcted cardiac tissue mass. It was found that 1% halothane anesthesia starting 30 min before and continuing for 4 h after permanent ligation, had an overall beneficial effect, when compared with controls. Fentanyl (200-1,000 micrograms/kg, iv) had no overall beneficial effect, compared with conscious controls. Halothane reduced arrhythmias and mortality rates, when compared with controls, while fentanyl did not. Halothane produced lower blood pressures, fewer ECG changes, and lower heart rates than those seen in conscious or fentanyl anesthetized rats. The occluded and infarcted zones produced by ligation were not influenced by the two anesthetics.

Anesthesia, General↗

Federal legislative and regulatory impact on funding of nurse anesthesia educational programs: Medicare reimbursement for nurse anesthesia education. Report of the National Commission on Nurse Anesthesia Education.

The negative effects of Medicare's inconsistent and detrimental payment policies for anesthesia services are dealt with in relation to institutions where nursing anesthesia programs exist. Such policies burden CRNAs and nurse anesthesia students with financial disincentives and payment exclusions that could lead to a long-term worsening of the shortage of trained practitioners.

Humans↗

[Loco-regional anesthesia in remote medical units. III. Anesthesia of upper-limb: the intravenous loco-regional anesthesia (author's transl)].

The loco-regional intravenous anesthesia has the great advantage of its simplicity. It is a good complement of the plexic blocks for anesthesia of the upper limb, but it must be discarded in case of lasting interventions because of the tourniquet, or in case of large damages through which the anesthesic fluid leak out, or if a long hemostatic checking may be foreseen.

Anesthesia, Conduction↗

The differential cost of anesthesia and recovery with propofol-nitrous oxide anesthesia versus thiopental sodium-isoflurane-nitrous oxide anesthesia.

STUDY OBJECTIVE: To assess the recovery room profile of propofol in outpatient anesthesia and to compare it to the profile of a standard technique. DESIGN: A comparative, randomized, double-blind, third-party open study. SETTING: Ambulatory Surgery Center at The Emory Clinic. PATIENTS: Ninety-nine ASA physical status I, II, or III nonpregnant female patients who had been diagnosed as needing breast biopsies. INTERVENTIONS: All patients were given 1 microgram/kg of fentanyl prior to induction. Those in the propofol group were induced with 2.0 to 2.5 mg/kg of propofol and maintained with a 100 to 200 microgram/kg/min infusion of propofol with nitrous oxide (N2O) in oxygen (O2). In the thiopental sodium-isoflurane group, patients were induced with 4.0 to 5.0 mg/kg of thiopental sodium and maintained with isoflurane and N2O in O2. MEASUREMENTS AND MAIN RESULTS: Recovery from anesthesia was assessed by an evaluator who was unaware of the anesthetic technique used for each patient. Immediate recovery time was measured in terms of awakening, response to verbal command, and orientation to time and place. A brief postoperative follow-up questionnaire was completed to assess the patients' subjective feelings regarding their ability to eat, concentrate, and resume normal activities. In the thiopental sodium-isoflurane group, 15 of 50 patients (30%) had nausea and vomiting, but in the propofol group, only 4 of 49 patients (8.1%) had nausea and vomiting (p less than 0.01). The latter group resumed normal activity (i.e., reading and watching television) 7.93 +/- 0.76 hours postanesthesia, whereas the thiopental sodium-isoflurane group resumed normal activity 17.02 +/- 1.21 hours postanesthesia (p less than 0.001). Patients in the propofol group returned to work in an average of 1.5 +/- 0.09 days, compared with 2.0 +/- 0.09 days for the thiopental sodium-isoflurane group (p less than 0.001). CONCLUSIONS: The propofol group needed less nursing care and returned to more productive activity earlier than did the thiopental sodium-isoflurane group.

Ambulatory Surgical Procedures↗

Anesthesia for craniotomy: total intravenous anesthesia with propofol and alfentanil compared to anesthesia with thiopental sodium, isoflurane, fentanyl, and nitrous oxide.

STUDY OBJECTIVE: To compare a total intravenous (IV) anesthetic technique based on propofol and alfentanil with a commonly used anesthetic technique for craniotomy. DESIGN: Open-label, randomized, clinical study. SETTING: Neurosurgical clinic at a university hospital. PATIENTS: Forty patients, aged 18 to 55 years, scheduled for brain tumor surgery. INTERVENTIONS: In 20 patients, anesthesia was induced with fentanyl and thiopental sodium and maintained with fentanyl, dehydrobenzperidol, isoflurane, nitrous oxide (N2O), and a thiopental sodium infusion. Twenty patients were anesthetized with a propofol loading infusion followed by a maintenance infusion at a fixed rate. In addition, alfentanil was administered as a loading bolus, followed by a variable-rate infusion, with additional doses as necessary to maintain hemodynamic stability. MEASUREMENTS AND MAIN RESULTS: A decrease in blood pressure (BP) after induction with thiopental sodium was followed by a significant increase in BP and heart rate (HR) during intubation. BP and HR did not change during the propofol loading infusion. However, the administration of alfentanil was followed by a similar decrease in BP with a return to baseline values during the intubation period. Return of normal orientation (7 +/- 5 minutes vs 27 +/- 23 minutes) and concentration (12 +/- 12 minutes vs 35 +/- 37 minutes) was shorter and more predictable for the propofol-alfentanil-treated patients than for the thiopental sodium patients. Maintenance propofol concentration (nine patients) was between 3 +/- 0.69 micrograms/ml and 3.36 +/- 1.17 micrograms/ml, while the concentration at awakening was 1.09 microgram/ml. Alfentanil concentration at extubation (nine patients) was 79 +/- 34 ng/ml. CONCLUSION: A total IV anesthetic technique with propofol and alfentanil is a valuable alternative to a more commonly used technique based on thiopental sodium, N2O, fentanyl, and isoflurane.

Adult↗

Epidural anesthesia impairs both central and peripheral thermoregulatory control during general anesthesia.

BACKGROUND: The authors tested the hypotheses that: (1) the vasoconstriction threshold during combined epidural/general anesthesia is less than that during general anesthesia alone; and (2) after vasoconstriction, core cooling rates during combined epidural/general anesthesia are greater than those during general anesthesia alone. Vasoconstriction thresholds and heat balance were evaluated under controlled circumstances in volunteers, whereas the clinical importance of intraoperative thermoregulatory vasoconstriction was evaluated in patients. METHODS: Five volunteers were each evaluated twice. On one of the randomly ordered days, epidural anesthesia (approximately T9 dermatomal level) was induced and maintained with 2-chloroprocaine. On both study days, general anesthesia was induced and maintained with isoflurane (0.7% end-tidal concentration), and core hypothermia was induced by surface cooling and continued for at least 1 h after fingertip vasoconstriction was observed. Patients undergoing colorectal surgery were randomly assigned to combined epidural/enflurane anesthesia (n = 13) or enflurane alone (n = 13). In appropriate patients, epidural anesthesia was maintained by an infusion of bupivacaine. The core temperature that triggered fingertip vasoconstriction identified the threshold. RESULTS: In the volunteers, the vasoconstriction threshold was 36.0 +/- 0.2 degrees C during isoflurane anesthesia alone, but significantly less, 35.1 +/- 0.7 degrees C, during combined epidural/isoflurane anesthesia. Cutaneous heat loss and the rates of core cooling were similar 30 min before vasoconstriction with and without epidural anesthesia. In the 30 min after vasoconstriction, heat loss decreased 33 +/- 13 W when the volunteers were given isoflurane alone, but only 8 +/- 16 W during combined epidural/isoflurane anesthesia. Similarly, the core cooling rates in the 30 min after vasoconstriction were significantly greater during combined epidural/isoflurane anesthesia (0.8 +/- 0.2 degrees C/h) than during isoflurane alone (0.2 +/- 0.1 degrees C/h). In the patients, end-tidal enflurane concentrations were slightly, but significantly, less in the patients given combined epidural/enflurane anesthesia (0.6 +/- 0.2% vs. 0.8 +/- 0.2%). Nonetheless, the vasoconstriction threshold was 34.5 +/- 0.6 degrees C in the epidural/enflurane group, which was significantly less than that in the other patients, 35.6 +/- 0.8 degrees C. When the study ended after 3 h of anesthesia, patients given combined epidural/enflurane anesthesia were 1.2 degrees C more hypothermic than those given general anesthesia alone. The rate of core cooling during the last hour of the study was 0.4 +/- 0.2 degrees C/h during combined epidural/enflurane anesthesia, but only 0.1 +/- 0.3 degrees C/h during enflurane alone. CONCLUSIONS: These data indicate that epidural anesthesia reduces the vasoconstriction threshold during general anesthesia. Furthermore, the markedly reduced rate of core cooling during general anesthesia alone illustrates the importance of leg vasoconstriction in maintaining core temperature.

Adolescent↗

Converting from general anesthesia to cervical block anesthesia for carotid endarterectomy.

Between January 1, 1992 and June 30, 1998, vascular and general surgery residents performed 401 carotid endarterectomies (185 cervical block, 216 general anesthesia) under supervision of vascular attending surgeons. In January 1995, cervical block anesthesia was newly instituted. Initially anesthesiologists were randomly assigned to these cases and anesthetic technique was not standardized. At the surgeons' insistence later in the series, three specially trained anesthesiologists routinely administered cervical block anesthesia. As experience grew, surgeons realized that operating time greater than 2 hours and high neck dissections requiring mandibular retraction were poorly tolerated by cervical block anesthesia patients but that repeat carotid endarterectomies could be safely performed. Shunts were selectively inserted if significant electroencephalographic changes occurred or carotid stump pressures were less than 50 mm Hg systolic when general anesthesia was used; neurologic changes occurred when cervical block anesthesia was used; or there was a history of ipsilateral stroke for either anesthetic method. Despite an initial learning curve with cervical block anesthesia, the stroke-mortality rate was similar between the two groups (general anesthesia: 1.9% [four cerebrovascular accidents, two deaths]; cervical block anesthesia: 1.6% [two cerebrovascular accidents, two deaths]). Eight (12%) of the first 66 cervical block anesthesia patients were converted to general anesthesia compared to 2 (1.7%) of the most recent 119 patients with cervical block anesthesia (p = 0.03). After cervical block anesthesia was initiated, seven of the first eight repeat carotid endarterectomies were performed using general anesthesia compared to one of the most recent six repeat cases (p = 0.02). As surgeons' comfort with cervical block anesthesia increased, 94% (100) of the most recent consecutive 106 carotid endarterectomies were performed using this technique. These results suggest that carotid endarterectomy can be performed as safely using cervical block anesthesia as general anesthesia, specialized anesthesiologists are essential to achieve a successful outcome, selected repeat carotid endarterectomies can be performed using cervical block anesthesia, very cephalad lesions are best treated using general anesthesia, and surgical trainees can safely perform carotid endarterectomy under attending surgeon supervision if the operation is carried out expeditiously.

Anesthesia, General↗