Command-related distribution of regional cerebral blood flow during attempted handgrip.
To localize a central nervous feed-forward mechanism involved in cardiovascular regulation during exercise, brain activation patterns were measured in eight subjects by employing positron emission tomography and oxygen-15-labeled water. Scans were performed at rest and during rhythmic handgrip before and after axillary blockade with bupivacaine. After the blockade, handgrip strength was reduced to 25% (range 0-50%) of control values, whereas handgrip-induced heart rate and blood pressure increases were unaffected (13 +/- 3 beats/min and 12 +/- 5 mmHg, respectively; means +/- SE). Before regional anesthesia, handgrip caused increased activation in the contralateral sensory motor area, the supplementary motor area, and the ipsilateral cerebellum. We found no evidence for changes in the activation pattern due to an interaction between handgrip and regional anesthesia. This was true for both the blocked and unblocked arm. It remains unclear whether the activated areas are responsible for the increase in cardiovascular variables, but neural feedback from the contracting muscles was not necessary for the activation in the mentioned areas during rhythmic handgrip. (+info)
Carotid endarterectomy under regional anesthesia.
Regional anesthesia for carotid endarterectomy is a simple, reliable, and virtually complication-free technique. We began to perform a series of carotid endarterectomy under regional anesthesia at our institution in May 1990. This report describes our experience with 180 operated patients from May 1990 till December 1995, with regional anesthesia. All patients were operated with microsurgery and we utilized the deeply cervical plexus block at the C-4 level associated with superficial block, along the posterior border of the externocleidomastoid muscle. The main advantage of this technique of anesthesia is that it is the only exact method of assessing the need of a shunt by using the neurological status of the awaken patient during trial carotid cross-clamping. The regional anesthesia allows carotid endarterectomy to be safely performed on patients with advanced cardiac disease or severe chronic obstructive pulmonary disease who were not good candidates for general anesthesia. In this 180 patients we performed 198 consecutive endarterectomies (10% bilateral) with a total morbidity-mortality rate of 2.0%. (+info)
Intravenous regional anesthesia (Bier block) in a dog.
Intravenous regional anesthesia was used in an adult dog as part of a balanced approach to general anesthesia for amputation of the 4th digit of its right hind limb. It allowed the concentration of isoflurane to be reduced to 0.5%. (+info)
Effects of general and locoregional anesthesia on reproductive outcome for in vitro fertilization: a meta-analysis.
The objective of this meta-analysis was to evaluate prospective trials of general or locoregional anesthesia on reproductive outcomes (cleavage and pregnancy rate) for in vitro fertilization (IVF). Of 115 published studies retrieved from a search of articles indexed on MEDLINE from 1966 to February 1999, four studies with distinct general and locoregional anesthesia were deemed eligible for meta- analysis. The pooled relative risk and odds ratios were calculated. A test for homogeneity was also performed. The pooled log odds ratio was 1.03 (95% CI 0.90-1.18) in cleavage rate and 0.71 (95% CI 0.47-1.08) in pregnancy rate. Heterogeneity was negative. Cleavage and pregnancy rates were not significantly different in both the general anesthesia and locoregional anesthesia groups. Both anesthetic techniques were favorable to IVF procedure by available published evidence when anesthesia was needed. (+info)
Severe vasovagal attack during regional anaesthesia for caesarean section.
A patient experienced a severe vasovagal attack during regional anaesthesia for elective Caesarean section. The combination of vagal over-activity and sympathetic block produced profound hypotension that threatened the life of the mother and infant. The vasovagal syndrome is described, and its prevention and management discussed. (+info)
The effect of anesthetic technique on postoperative outcomes in hip fracture repair.
BACKGROUND: The impact of anesthetic choice on postoperative mortality and morbidity has not been determined with certainty. METHODS: The authors evaluated the effect of type of anesthesia on postoperative mortality and morbidity in a retrospective cohort study of consecutive hip fracture patients, aged 60 yr or older, who underwent surgical repair at 20 US hospitals between 1983 and 1993. The primary outcome was defined as death within 30 days of the operative procedure. The secondary outcomes were postoperative 7-day mortality, postoperative myocardial infarction, postoperative pneumonia, postoperative congestive heart failure, and postoperative change in mental status. Numerous comorbid conditions were controlled for individually and by several comorbidity indices using logistic regression. RESULTS: General anesthesia was used in 6,206 patients (65.8%) and regional anesthesia in 3,219 patients (3,078 spinal anesthesia and 141 epidural anesthesia). The 30-day mortality rate in the general anesthesia group was 4.4%, compared with 5.4% in the regional anesthesia group (unadjusted odds ratio = 0.80; 95% confidence interval = 0.66-0.97). However, the adjusted odds ratio for general anesthesia increased to 1.08 (0.84-1.38). The adjusted odds ratios for general anesthesia versus regional anesthesia for the 7-day mortality was 0.90 (0.59-1.39) and for postoperative morbidity outcomes were as follows: myocardial infarction: adjusted odds ratio = 1.17 (0.80-1.70); congestive heart failure: adjusted odds ratio = 1.04 (0.80-1.36); pneumonia: adjusted odds ratio = 1.21 (0.87-1.68); postoperative change in mental status: adjusted odds ratio = 1.08 (0.95-1.22). CONCLUSIONS: The authors were unable to demonstrate that regional anesthesia was associated with better outcome than was general anesthesia in this large observational study of elderly patients with hip fracture. These results suggest that the type of anesthesia used should depend on factors other than any associated risks of mortality or morbidity. (+info)
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. (+info)
General versus regional anaesthesia for hip fracture surgery: a meta-analysis of randomized trials.
Hip fracture surgery is common and the population at risk is generally elderly. There is no consensus of opinion regarding the safest form of anaesthesia for these patients. We performed a meta-analysis of 15 randomized trials that compare morbidity and mortality associated with general or regional anaesthesia for hip fracture patients. There was a reduced 1-month mortality and incidence of deep vein thrombosis in the regional anaesthesia group. Operations performed under general anaesthesia had a reduction in operation time. No other outcome measures reached a statistically significant difference. There was a tendency towards a lower incidence of myocardial infarction, confusion and postoperative hypoxia in the regional anaesthetic group, and cerebrovascular accident and intra-operative hypotension in the general anaesthetic group. We conclude that there are marginal advantages for regional anaesthesia compared to general anaesthesia for hip fracture patients in terms of early mortality and risk of deep vein thrombosis. (+info)