[Comparison between conventional and continuous spinal anesthesia using bupivacaine]

Spinal anesthesia using single injection small-dose bupivacaine versus continuous catheter injection techniques for surgical repair of hip fracture in elderly patients

Aging and disease may make elderly patients particularly susceptible to hypotension during spinal anesthesia. We compared the hemodynamic effect of continuous spinal anesthesia (CSA) and small dose single injection spinal anesthesia (SA) regarding the incidence of hypotension. Seventy-four patients aged >75 yr undergoing surgical repair of hip fracture were randomized into 2 groups of 37 patients each. Group CSA received a continuous spinal anesthetic with a titration of 2.5 mg boluses every 15 min of isobaric bupivacaine, while group SA received a single injection spinal anesthetic with 7.5 mg of isobaric bupivacaine. The overall variations in noninvasive automated arterial blood pressure were not statistically significantly different in the 2 groups at baseline and after CSA or SA (not significant). In the SA group, 68% of patients experienced at least one episode of hypotension (decrease in systolic arterial blood pressure greater than 20% of baseline value) versus 31% of patients in the CSA group (P = 0.005). In the SA group, 51% of patients experienced at least one episode of severe hypotension (decrease in systolic arterial blood pressure more than 30% of baseline value) versus 8% of patients in the CSA group (P < 0.0001). In the CSA group, 4.5 +/- 2 mg of ephedrine was injected versus 11 +/- 2 mg in the SA group (P = 0.005). In the CSA group, 5 mg (2.5-10) of anesthetic solution was required versus 7.5 mg in the SA group (P < 0.0001). We conclude that, in elderly patients undergoing hip fracture repair, CSA provides fewer episodes of hypotension and severe hypotension compared with a single intrathecal injection of 7.5 mg bupivacaine.

Continuous spinal anesthesia for cesarean section in a parturient with severe preeclampsia

Epidural anesthesia is a widely accepted technique for cesarean section in the preeclamptic patient with normal coagulation. Regional anesthetic techniques avoid the hazards associated with tracheal intubation in the preeclamptic or eclamptic patient. To date, continuous spinal anesthesia in the preeclamptic parturient has not been described. We present a case in which continuous spinal anesthesia was administered for cesarean section in a morbidly obese parturient with severe preeclampsia. Continuous spinal anesthesia was successfully administered without significant hemodynamic consequences or maternal or fetal morbidity. This case suggests that continuous spinal anesthesia may be a viable alternative anesthetic technique for operative delivery in the preeclamptic parturient when epidural anesthesia cannot be established.

Hemodynamic effects of spinal anesthesia in the elderly: single dose versus titration through a catheter

Sixty elderly patients (> 70 yr old) undergoing surgery for hip fracture were prospectively studied in order to compare hemodynamic tolerance of titrated doses of hyperbaric bupivacaine using continuous spinal anesthesia (CSA) versus single-dose spinal anesthesia (SDSA). Patients were randomized into two groups (CSA group: n = 30; SDSA group: n = 30). The SDSA patients received 10-15 mg of 0.5% hyperbaric bupivacaine (based on age and height), and the CSA patients received a starting dose of 5 mg of 0.5% hyperbaric bupivacaine, followed after 15 min by optional reinjection of 2.5 mg every 5 min until a T10 level sensory block was reached. Onset of anesthesia, noninvasive hemodynamic variables and the need for ephedrine were studied for 4 h after induction of anesthesia. Spinal anesthesia was successful in all patients. Decreases in mean arterial pressure were significantly less frequent and less pronounced in the CSA group (19.9% +/- 1.6% of the baseline value) than in the SDSA group (40.2% +/- 1.9%, P < 0.0001). The mean dose of ephedrine was significantly less in the CSA group (1.8 +/- 0.7 mg, administered to only 37% of patients) than in the SDSA group (19.4 +/- 3.3 mg administered to all patients, P < 0.0001). No late complications related to the spinal anesthesia technique were observed in either group. We concluded that CSA, using small titrated doses of 0.5% hyperbaric bupivacaine, is safe, efficient, and provides better hemodynamic stability than SDSA in elderly patients.

[Comparative study of conventional spinal anesthesia and combined spinal-epidural anesthesia in gynecological surgery]

A prospective study was carried out to compare the qualities of spinal block with those of combined spinal-epidural anaesthesia (CSEA). It included 63 patients, ranked ASA 1 or 2, aged between 35 and 75 years, scheduled for gynaecological surgery due to last more than 2 hours, and randomly allocated to two groups. In the first group (n = 34), spinal anaesthesia was carried out with the patients sitting, in the L3-4 interspace, using 15 mg of hyperbaric bupivacaine with 0.4 mg of adrenaline. In the second group (n = 29), a catheter was inserted in the epidural space through the L2-3 interspace, and spinal anaesthesia carried out as in the first group, using bupivacaine without adrenaline. Once the highest level of analgesia had been reached, aliquots of 0.5% plain bupivacaine were injected through the epidural catheter, until anaesthesia of T5 was obtained. In the spinal group, general anaesthesia was required in 3 cases, as anaesthesia only reached the T12 level in 2 cases, and as surgery lasted longer than the spinal in the third one. In the CSEA group, excellent analgesia was obtained in all patients. Sensory blockade lasted 308 +/- 48 min at the T12 level, versus 162 +/- 51 min in the spinal group (p < 0.025), and 361 +/- 51 min at the L2 level, versus 210 < 44 min in the other group (p < 0.025). "Topping up" was possible with the epidural catheter only, thus raising the level of sensory blockade, making it deeper, and increasing its duration. It avoids the use of general anaesthesia in case of failed spinal blockade.(ABSTRACT TRUNCATED AT 250 WORDS)

[Analysis of failures of spinal anesthesia as a function of practice development in a university hospital]

This study is a retrospective analysis of 303 consecutive spinal anaesthesia performed in orthopaedic patients of a University Hospital between January and December 1990. Failure of spinal anaesthesia was defined as the requirement for general anaesthesia to perform surgery. The parameters studied as possible risk factors of failure were patients demographics, local anaesthetic agents and solutions and techniques of spinal anaesthesia (single injection versus continuous spinal anaesthesia). Failures were related to inadequate or incomplete extension of sensory blockade or to difficulties to perform spinal injection. Continuous spinal anaesthesia was performed in 209 patients mostly with 0.5% isobaric bupivacaine, while 94 patients received a single injection of either hyperbaric 0.5% tetracaine with adrenaline or 0.5% bupivacaine or 5% lidocaine. Failures occurred in 6.3% of the cases but were significantly less frequent with continuous spinal anaesthesia (4.8%) than with the conventional technique (9.6%). The incidence of failure was higher with hyperbaric tetracaine (11.1%) confirming its poor reliability. Inadequate extension of the anaesthetic block was the main cause of failure whatever the spinal anaesthetic technique. These results point out the reliability of continuous spinal anaesthesia but problems may occasionally occur due to spinal catheter misplacement.