Effectiveness of isobaric 0.5% bupivacaine and 5% lidocaine in continuous subarachnoid anesthesia with microcatheters

OBJECTIVES: To study the clinical effect of two isobaric local anesthetics infused through microcatheters for continuous subarachnoid anesthesia. MATERIAL AND METHODS: Patients undergoing surgery under continuous subarachnoid anesthesia were enrolled prospectively over 12 months. Twenty-seven-gage catheters were inserted through 22 G Sprotte (Intralong) needles. The two isobaric anesthetics (0.5% bupivacaine and 5% lidocaine) were studied in two successive six-month periods. One milliliter of local anesthetic was administered, followed by incremental doses of 0.5 ml until the required anesthetic level was reached. Hemodynamic variables were recorded, as were levels of anesthetic and motor blockade and complications developing during the surgical and postoperative periods. RESULTS: Thirty-one patients were anesthetized with isobaric 0.5% bupivacaine and 40 with isobaric 5% lidocaine. A high blockade was observed in three patients in the bupivacaine group and in 15 in the bupivacaine group (p < 0.05). The highest anesthetic level reached was T4. Hypotension occurred in one patient in the bupivacaine group and in 10 in the lidocaine group (p < 0.05). Blockade was difficult to increase to the appropriate level in 11 lidocaine patients and in one bupivacaine patient, whereas blockade of distal roots was difficult in 13 bupivacaine patients and in 7 lidocaine patients (p < 0.005). The total doses infused were 11.0 +/- 3.0 mg of 0.5% bupivacaine and 95.6 +/- 24.6 mg of 5% lidocaine. CONCLUSIONS: Isobaric 0.5% bupivacaine provides a more predictable anesthetic blockade with greater hemodynamic stability and a lower rate of difficulty in raising the level of blockade than does 5% lidocaine when administered through microcatheters for continuous subarachnoid anesthesia.     

Onset of spinal block is more rapid with isobaric than hyperbaric bupivacaine

PURPOSE: To compare isobaric with hyperbaric 9.75 mg bupivacaine injected intrathecally, and to evaluate the effects of subsequent injection of lidocaine 2% into the epidural space. METHODS: Patients in group 1 (n = 30) received isobaric 9.75 mg bupivacaine and in group 2 (n = 30) hyperbaric 9.75 mg bupivacaine injected into the subarachnoid space in a combined spinal-epidural technique. They were undergoing urological, gynecological, orthopedic, gastro-intestinal or vascular surgery. Using a double blind technique, the followings parameters were measured: cutaneous analgesia to pinprick, motor blockade, time for two segment regression, time for complete regression of the motor block, quality of anesthesia. In 12 patients the effect of epidural injections of 3 ml lidocaine 2% was observed. RESULTS: Motor and sensory block developed more rapidly (five minutes) in the isobaric group (P<0.05). Maximum upper level (T7+/-2), two-segment regression (52 min in both groups), motor recovery (160 vs. 157 min), and quality of anesthesia did not differ between the two groups. Thirty nine epidural injections of 3 ml lidocaine 2% were given in 12 patients 10 min after spinal injection, 28 were in the hyperbaric group (P<0.05). Twenty six of the epidural injections produced an increase in sensory block of 0 or 1 dermatome, and 13, of 2 or more. CONCLUSION: The block developed more rapidly in the isobaric group, but both isobaric and hyperbaric 9.75 mg bupivacaine produced adequate upper levels of analgesia for surgery. The effect of epidural injections of 3 ml lidocaine 2% was usually minimal.     

Spinal analgesia with hyperbaric 0.5% bupivacaine: effects of different patient positions

A prospective randomised study of the effect when the patient remained sitting for 2, 10, 15, 20 or 25 min, was evaluated in 50 patients (10 in each group) given a spinal anesthesia, with 4 ml 0.5% bupivacaine in 8% glucose (hyperbaric). The first period of sitting was followed by a second period in the horizontal supine position; this period ended when there was the same level of pin-prick analgesia for 5 min. The patient was then placed in the Trendelenburg position until maximum spread was achieved. There was no difference in the spread of analgesia between the five groups at the end of each of the three periods. Between the five groups, there was no difference as to the duration of time from placing the patient in the supine horizontal position until maximum spread of analgesia (mean +/- s.e. mean 12 +/- 2-13 +/- 2 min) in this position, and from the start of the Trendelenburg position until maximum spread (mean +/- s.e. mean 7.5 +/- 1.2-9.5 +/- 1.7 min). All patients except one in the 25-min group had complete motor blockade of the lower limbs.     

Spinal anesthesia with glucose-free bupivacaine: effects of age on neural blockade and pharmacokinetics

Effects of age on spinal anesthesia using glucose-free 0.5% bupivacaine without epinephrine were studied in two groups of patients, one between 20 and 55 yr old, the other older than 55 yr. All patients received 15 mg bupivacaine. The time to onset of analgesia in caudad segments and the time to maximal motor blockade decreased with age. The upper level of analgesia did not change significantly with increasing age. The times to recovery from analgesia at T12 and for the total disappearance of analgesia were longer in the older patient group. Effects of age on duration of motor blockade could not be demonstrated. Peak plasma concentrations of bupivacaine were significantly greater and the total plasma clearance significantly decreased in older patients. Age had no effect on time to peak concentration or the terminal half-life.     

A double-blind comparison of 0.125% ropivacaine with sufentanil and 0.125% bupivacaine with sufentanil for epidural labor analgesia

BACKGROUND: This study intends to evaluate the benefits of the administration of intermittent bolus doses of ropivacaine (0.125%) compared with bupivacaine (0.125%) after addition of sufentanil for analgesia during labor. METHODS: One hundred thirty American Society of Anesthesiologists physical status 1 or 2 parturients were studied. The 90 initial patients were assigned randomly to receive 10 ml bupivacaine, 0.125%, plus 7.5 microg sufentanil (initial bupivacaine 0.125% group) or ropivacaine, 0.125%, plus 7.5 microg sufentanil (ropivacaine 0.125% group). Forty additional patients were recruited and received 0.125% bupivacaine plus 7.5 microg sufentanil (additional bupivacaine 0.125% group) or 0.100% bupivacaine plus 7.5 microg sufentanil (additional bupivacaine 0.100% group). The duration of analgesia, visual analogue scores for pain, motor blockade (using a six-point modified Bromage scale), patient satisfaction scores, nausea, pruritus, heart rate, and blood pressure were recorded. RESULTS: Bupivacaine 0.125% and ropivacaine 0.125% coadministered with sufentanil provided rapid and complete analgesia. Onset of analgesia occurred after +/-15 min and lasted +/-90 min. After the third epidural injection, patients in the ropivacaine group experienced significantly less severe motor blockade than patients in the initial bupivacaine 0.125% group. At this point, 93% of the patients in the ropivacaine group were free from motor impairment versus 66% in the bupivacaine group (P<0.05). Comparable levels of motor blockade were obtained in both additional groups. Patients' evaluation of their analgesia was worst in the bupivacaine 0.100% group. CONCLUSIONS: Ropivacaine 0.125% with sufentanil affords reliable analgesia with minimal motor blockade.     

Spinal anesthesia with isobaric bupivacaine for percutaneous nephro-ureterolithotomy

The duration of analgesia and the cardiovascular changes during anesthesia of spinal blockade with isobaric bupivacaine were examined in 36 patients between 21 and 75 years old undergoing percutaneous nephro-ureterolithotomy. Injection of 0.25% or 0.5% bupivacaine 3.0-4.0 ml through the L3-4 or L2-3 intervertebral space in the horizontal posture resulted in spread of hypalgesia to T6 in 30 patients and of analgesia to T6 in about a half of the patients. In six patients, another intrathecal injection of 2 ml of bupivacaine was performed because their analgesia level had been under T8. Although the operation took 32-141 min. (mean 77.7 +/- 27.5 min.), there was no case requiring exigent exchanging anesthesia for general anesthesia. The frequencies of the hypotension, bradycardia and nausea in spinal blockade with isobaric bupivacaine were not so different from those of the previous epidural anesthesia in 29 patients undergoing the same operation. Most of the cardiovascular changes in the spinal blockade with isobaric bupivacaine happened within 20-30 min. after intrathecal injection of bupivacaine. Spinal anesthesia with isobaric bupivacaine proved satisfactory for percutaneous nephro-ureterolithotomy.     

Spinal clonidine prolongs labor analgesia from spinal sufentanil and bupivacaine

We sought to determine whether spinal clonidine 50 microg prolongs the analgesia from the spinal administration of sufentanil 7.5 microg and bupivacaine 2.5 mg early in the first stage of labor. Thirty patients were randomized to receive a 2-mL spinal injection of sufentanil 7.5 microg + bupivacaine 2.5 mg with or without clonidine 50 microg using a combined spinal-epidural (CSE) technique. Pain, nausea, pruritus, sedation, motor block, blood pressure, and heart rate were assessed until the patient requested additional analgesia. Analgesia was significantly prolonged in patients who received spinal sufentanil + bupivacaine + clonidine (197 +/- 70 vs 132 +/- 39 min; P = 0.004). Pain scores and side effects, including motor block, sedation, and hypotension, were similar between groups. Spinal clonidine significantly prolongs labor analgesia from spinal sufentanil and bupivacaine without producing serious adverse side effects. IMPLICATIONS: We studied the effects of spinal clonidine administered with spinal sufentanil and bupivacaine on labor analgesia using a combined spinal-epidural technique and conclude that spinal clonidine significantly prolongs labor analgesia from spinal sufentanil and bupivacaine without producing serious adverse effects.     

Effect of intrathecal bupivacaine on somatosensory evoked potentials following dermatomal stimulation

The effect of spinal anesthesia with 3.6 +/- 0.1 ml (mean +/- SEM) of 0.5% bupivacaine on early (less than 150 msec) somatosensory evoked potentials (SEPs) with electrical stimulation of the L1 and S1 dermatomes was examined in 12 patients. The mean level of sensory analgesia (pinprick) was T8,9 +/- 1.0 (+/- SEM) and the mean degree of motor blockade was 1.3 +/- 0.1 (Bromage scale). Intrathecal bupivacaine significantly (P less than 0.05) decreased the amplitude of all SEP components after stimulation of the L1 dermatome and most components during stimulation of the S1 dermatome. Intrathecal bupivacaine also increased the latency of SEPs (P less than 0.05) of both dermatomes. The L1 SEP disappeared in 7 and the S1 SEPs in 5 of the 12 patients during neural blockade. In three patients the SEPs disappeared at both locations. Sensory thresholds increased significantly during blockade. We found no correlation between decrease of amplitude and degree of motor blockade or level of sensory analgesia. Thus, intrathecal plain bupivacaine has a strong depressant effect on the neural afferent transmission as assessed by SEPs. However, despite clinically effective blockade as assessed by pinprick and motor blockade nerve potentials after nociceptive stimulation within the area of sensory block were often able to pass to the cerebral cortex.     

Hyperbaric spinal ropivacaine for cesarean delivery: a comparison to hyperbaric bupivacaine.

We evaluated the clinical efficacy and safety of spinal anesthesia with 0.5% hyperbaric ropivacaine compared with 0.5% hyperbaric bupivacaine for elective cesarean delivery. Sixty healthy, full-term parturients were randomly assigned to receive either 12 mg of 0.5% hyperbaric bupivacaine or 18 mg of 0.5% hyperbaric ropivacaine intrathecally. There were no significant differences in demographic or surgical variables or neonatal outcomes between groups. Onset time of sensory block to T10 or to peak level was later in the Ropivacaine group (P < 0.05). The median (range) peak level of analgesia was T3 (T1-5) in the Bupivacaine group and T3 (T1-4) in the Ropivacaine group. Time for sensory block to recede to T10 did not differ between groups. Duration of sensory block was shorter in the Ropivacaine group (188.5 +/- 28.2 min vs 162.5 +/- 20.2 min; P < 0.05). Complete motor block of the lower extremities was obtained in all patients. Ropivacaine also produced a shorter duration of motor blockade than bupivacaine (113.7 +/- 18.6 min vs 158.7 +/- 31.2 min; P < 0.000). The intraoperative quality of anesthesia was excellent and similar in both groups. Side effects did not differ between groups. Eighteen milligrams of 0.5% hyperbaric ropivacaine provided effective spinal anesthesia with shorter duration of sensory and motor block, compared with 12 mg of 0.5% hyperbaric bupivacaine when administered for cesarean delivery Implications: Eighteen milligrams of 0.5% hyperbaric ropivacaine provided effective spinal anesthesia with shorter duration of sensory and motor block, compared with 12mg of 0.5% hyperbaric bupivacaine when administered for cesarean delivery.     

Intrathecal ropivacaine for ambulatory surgery.

BACKGROUND: The rationale of this study was to evaluate intrathecal ropivacaine for ambulatory surgery. METHODS: One hundred fifty patients with American Society of Anesthesiologists physical status 1 scheduled for knee arthroscopy were studied. Patients were randomly assigned to receive 4 ml of one of five isobaric intrathecal solutions: Patients in group 1 (n = 30) received 8 mg of bupivacaine; patients in group 2 (n = 30) received 8 mg ropivacaine; patients in group 3 (n = 30) received 10 mg ropivacaine; patients in group 4 (n = 30) received 12 mg ropivacaine; and patients in group 5 (n = 30) received 14 mg ropivacaine. The level and duration of sensory anesthesia were recorded along with the intensity and duration of motor block. Patients were interviewed to identify transient neurologic symptoms. RESULTS: Intrathecal ropivacaine 10 mg produced shorter sensory anesthesia and motor blockade than bupivacaine 8mg (152 +/- 44 min and 135 +/- 41 min vs. 181 +/- 44 min and 169 +/- 52 min, mean +/- SD; P < 0.05). However, the quality of intraoperative analgesia was significantly lower in the 10-mg ropivacaine group (P < 0.05). Ropivacaine 12 mg produced sensory and motor block almost comparable to bupivacaine 8 mg. Ropivacaine 14 mg produced sensory and motor block comparable to ropivacaine 12 mg but significantly increased the time to void. No sign of transient radicular irritation were noted. CONCLUSION: Intrathecal ropivacaine 12 mg is approximately equivalent to bupivacaine 8 mg. At this dose, ropivacaine offers no significant advantage compared with bupivacaine.     

Spinal anesthesia in children with isobaric local anesthetics: report on 307 patients under 13 years of age

BACKGROUND: Spinal anesthesia in expert hands is an excellent method for children for appropriate surgery. The aim of this study was to evaluate the effects of spinal anesthesia with isobaric solutions in 307 consecutive cases from May 2001 to August 2002. METHODS: In this prospective study, 307 patients from 0 to 12 years of age were scheduled for spinal anesthesia with enantiomeric mixture of bupivacaine (S75 : 25R) 0.5% or racemic bupivacaine 0.5% or lidocaine 2% without glucose, for surgery compatible with the technique. The following were assessed: latency of analgesia, motor block, maximum length and duration of sensory blockade, cardiovascular changes, incidence of headache or transient neurological symptoms and cost. RESULTS: The onset of sensory block occurred at 2.36 +/- 0.95 min. Duration of surgery was 1.29 +/- 0.83 h and the duration of stay in the postanesthesia care unit was 39.72 +/- 26.84 min. The highest level of analgesia ranged from T(9) to T(4) (mean T(6)). Onset of motor block was <2 min in all children and each had a modified Bromage score of 3 at the beginning of the surgery. At the end of the surgery 9% had score 3, 16%, score 2, 46%, score 1 and 29%, zero. Seventy five percent of all patients recovered from motor block 1 or zero at the end of the surgery. Patients older than 1 year were able to walk in 3.79 +/- 0.73 h. There was no case of oxygen desaturation. Hypotension and bradycardia occurred in one patient. Spinal anesthesia failed in five patients. Three children developed postdural puncture headache (PDPH), the youngest aged 2 years. PDPH in all three was mild or moderate. Transient radicular symptoms were not observed. The final cost of the spinal anesthesia was R dollars 49.00 compared with a mean cost of general anesthesia of R dollars 105.00. CONCLUSIONS: Spinal anesthesia continues to gain acceptance as an alternative to general anesthesia in children. There has also been an increased use of spinal anesthesia for other surgical procedures including lower extremity orthopedic procedures as well as specific surgery procedures above the umbilicus and in patients past the neonatal period. Spinal anesthesia in children is a special method suitable for use only by anesthesiologists, expert in administering spinal anesthesia for adults. It was 54% less than the cost of general anesthesia.     

A Double-blind Comparison of 0.125% Ropivacaine with Sufentanil and 0.125% Bupivacaine with Sufentanil for Epidural Labor Analgesia

Background: This study intends to evaluate the benefits of the administration of intermittent bolus doses of ropivacaine (0.125%) compared with bupivacaine (0.125%) after addition of sufentanil for analgesia during labor.

Methods: One hundred thirty American Society of Anesthesiologists physical status 1 or 2 parturients were studied. The 90 initial patients were assigned randomly to receive 10 ml bupivacaine, 0.125%, plus 7.5 [micro sign]g sufentanil (initial bupivacaine 0.125% group) or ropivacaine, 0.125%, plus 7.5 [micro sign]g sufentanil (ropivacaine 0.125% group). Forty additional patients were recruited and received 0.125% bupivacaine plus 7.5 [micro sign]g sufentanil (additional bupivacaine 0.125% group) or 0.100% bupivacaine plus 7.5 [micro sign]g sufentanil (additional bupivacaine 0.100% group). The duration of analgesia, visual analogue scores for pain, motor blockade (using a six-point modified Bromage scale), patient satisfaction scores, nausea, pruritus, heart rate, and blood pressure were recorded.

Results: Bupivacaine 0.125% and ropivacaine 0.125% coadministered with sufentanil provided rapid and complete analgesia. Onset of analgesia occurred after +/- 15 min and lasted +/- 90 min. After the third epidural injection, patients in the ropivacaine group experienced significantly less severe motor blockade than patients in the initial bupivacaine 0.125% group. At this point, 93% of the patients in the ropivacaine group were free from motor impairment versus 66% in the bupivacaine group (P < 0.05). Comparable levels of motor blockade were obtained in both additional groups. Patients' evaluation of their analgesia was worst in the bupivacaine 0.100% group.     

Intrathecal Ropivacaine for Ambulatory Surgery: A Comparison between Intrathecal Bupivacaine and Intrathecal Ropivacaine for Knee Arthroscopy

Background: The rationale of this study was to evaluate intrathecal ropivacaine for ambulatory surgery.

Methods: One hundred fifty patients with American Society of Anesthesiologists physical status 1 scheduled for knee arthroscopy were studied. Patients were randomly assigned to receive 4 ml of one of five isobaric intrathecal solutions: Patients in group 1 (n = 30) received 8 mg of bupivacaine; patients in group 2 (n = 30) received 8 mg ropivacaine; patients in group 3 (n = 30) received 10 mg ropivacaine; patients in group 4 (n = 30) received 12 mg ropivacaine; and patients in group 5 (n = 30) received 14 mg ropivacaine. The level and duration of sensory anesthesia were recorded along with the intensity and duration of motor block. Patients were interviewed to identify transient neurologic symptoms.

Results: Intrathecal ropivacaine 10 mg produced shorter sensory anesthesia and motor blockade than bupivacaine 8mg (152 +/- 44 min and 135 +/- 41 min vs. 181 +/- 44 min and 169 +/- 52 min, mean +/- SD;P < 0.05). However, the quality of intraoperative analgesia was significantly lower in the 10-mg ropivacaine group (P < 0.05). Ropivacaine 12 mg produced sensory and motor block almost comparable to bupivacaine 8 mg. Ropivacaine 14 mg produced sensory and motor block comparable to ropivacaine 12 mg but significantly increased the time to void. No sign of transient radicular irritation were noted.     

Subarachnoid sufentanil as sole agent vs standard spinal bupivacaine in transurethral resection of the bladder

AIM: The aim of the study was to determine whether intrathecal sufentanil alone provides an adequate analgesia for patients undergoing transurethral resection of the bladder (TURB) and to compare it to standard spinal bupivacaine anesthesia in terms of motor and sensory blockade, discharge time and side effects. METHODS: Sixty-two patients were blindly and randomly assigned to receive either intrathecal bupivacaine (10 mg of 0.5% hyperbaric bupivacaine) or intrathecal sufentanil (15 microg). Motor and sensory blockade was evaluated using a modified Bromage scale as well as cold and pinprick tests. Severity of pain was assessed by means of a 10-point verbal analog scale. RESULTS: We found that the mean duration of sensory blockade was similar for both sufentanil and bupivacaine patients but the quality of analgesia induced by sufentanil alone was poor as compared with spinal bupivacaine anesthesia. CONCLUSION: The subarachnoid administration of sufentanil 15 mg seems to be inadequate for TURB surgery. In addition, the advantage of a faster recovery we observed in sufentanil patients is minimized by the occurrence of a troublesome symptom such as pruritus. On the other hand, spinal bupivacaine produces an undesirable motor blockade exceeding, in our opinion, the requirement for TURB procedure.     

Comparison between spinal anaesthesia and sciatic-femoral block for arthroscopic knee surgery

AIM: We compared spinal anesthesia and sciatic-femoral block for arthroscopic knee surgery in terms of hemodynamic changes, intraoperative anesthesia, postoperative analgesia, postoperative motor block and bladder function, side effects, and patient satisfaction. METHODS: Thirty-two patients were randomised into 2 groups: Group B (sciatic-femoral block with mepivacaine 1% 15 + 25 mL, 120 mm/35 mm 22-gauge needles and ElectroNerve Stimulator) and Group S (unilateral spinal anesthesia with 7 mg of hyperbaric bupivacaine 0.5% and 25-gauge Sprotte needle in L2-L3 space). We recorded pain, together with hemodynamic parameters (baseline, 5, 10, 15, 30 min), utilising Numerical Rating Scale (NRS) during the tourniquet application and during the surgical procedures, anesthesia quality, orthopedic evaluation for intraoperative liberty of knee movement. During the postoperative period we recorded at 2, 4 and 6 h: postoperative analgesia, motor block, first urine output, side effects, first requirement for analgesic drug, patient satisfaction and costs. RESULTS: The only significant differences between the 2 groups (P<0.05) were the heart rate changes at 10, 15, 30 min with an increase in Group B and a decrease in Group S, and the first urine output at 200+/-69 min in Group B versus 269+/-66 min in Group S. CONCLUSION: In conclusion the sciatic-femoral nerve block is a valid alternative to spinal anesthesia for arthroscopic knee surgery, leading to a faster discharging from the hospital.     

Prolongation of lidocaine spinal anesthesia with phenylephrine

The effect of added phenylephrine on the duration of sensory analgesia during lidocaine spinal anesthesia was determined in 65 ASA class I-III patients randomly divided into three groups. Group 1 (n = 25) received 62.5 mg lidocaine in 7.5% glucose; group 2 (n = 21) received lidocaine with 2 mg phenylephrine; and group 3 (n = 19) received lidocaine with 5 mg phenylephrine. The level of analgesia to pin prick was assessed by an anesthesiologist unaware of the drug combination used. The mean +/- SD cephalad level of analgesia did not differ among the groups. In group 1, the times for two- and for four-segment regression of the level of analgesia, and the time for regression of analgesia to the T-12 dermatome, were 77 +/- 19 (1 SD), 99 +/- 24, and 109 +/- 26 min, respectively. The corresponding values were 98 +/- 25, 118 +/- 27, and 130 +/- 36 min in group 2 and 124 +/- 32, 142 +/- 31, and 162 +/- 35 min in group 3. All the regression times in group 2 were significantly longer than those in group 1 (P less than 0.05). All the regression times in group 3 were significantly longer than those in group 2 (P less than 0.02). It is concluded that clinically useful prolongation of sensory analgesia may be obtained by addition of phenylephrine to lidocaine during spinal anesthesia.     

椎管内注射利多卡因及舒芬太尼对下尿道功能恢复的影响

背景椎管内阻滞可以扰乱排尿反射,即使感觉阻滞恢复到S3节段,膀胱功能仍未完全恢复。经椎管内给予阿片类药物,呈剂量依赖性抑制膀胱逼尿肌收缩功能。因此,本研究探讨椎管内注射利多卡因及舒芬太尼对下尿道功能的影响。方法10例择期行下肢矫形手术的健康男性青年患者置入充盈性膀胱测压导管。记录基础指标后,给予100mg重比重利多卡因及20μg舒芬太尼行椎管内阻滞。手术后,记录感觉及运动神经阻滞恢复情况,并进行尿流动力学监测至患者可以自主完全排空膀胱。结果椎管内阻滞后,患者出现排尿感觉的时间为240（37）分钟,但此时患者无法自主排尿。膀胱充盈最大容量时,当感觉阻滞恢复到S2节段时,有6例患者有排尿感觉,其余4例患者恢复到S3节段时有排尿感觉,并且此期间未记录到膀胱逼尿肌收缩。椎管内阻滞后,患者可以自主完全排空膀胱的时间为332（52）分钟。具有排尿感觉至可以自主完全排空膀胱的时间间隔为90分钟。结论应用重比重利多卡因及舒芬太尼进行椎管内阻滞后,膀胱收缩功能恢复迟于感觉阻滞恢复到S3节段的时间。     

Spinal tonicaine: potency and differential blockade of sensory and motor functions

BACKGROUND: Long-acting local anesthetics are beneficial for the management of postoperative pain and chronic pain. The authors recently reported that a single injection of N-beta-phenylethyl-lidocaine (tonicaine), a quaternary lidocaine derivative, effectively blocks rat sciatic nerve function four to nine times longer than lidocaine, with a predominance of sensory versusmotor blockade. The purposes of this study were to measure directly the potency of this charged drug by internal perfusion of cultured neuronal cells, and to evaluate the differential blockade of sensory versus motor function via spinal route in rats. METHODS: The tonic and additional use-dependent blockade of Na+ currents by internal tonicaine was assayed in cultured GH3 cells during whole cell voltage-clamp conditions. In addition, tonicaine was injected into the intrathecal space of rats at intervertebral space L4-L5, and the proprioceptive, motor, and sensory functions, and tissue integrity, subsequently were evaluated. RESULTS: Internal application of tonicaine in GH3 cells revealed that it was approximately 80 times more potent in blocking Na+ currents than was externally applied lidocaine. In vivotesting in a rat neuraxial anesthesia model showed that tonicaine at 0.5 mm produced blockade that lasted much longer than that produced by bupivacaine even at approximately a 55 times higher concentration (28.8 mm). Tonicaine spinal block also produced a longer duration of sensory than motor blockade (112.5 +/- 16.3 min vs. 45.8 +/- 7.1 min). Evidence of neurotoxicity was seen at a concentration of 1.0 mm. CONCLUSION: In vitro testing shows that tonicaine displays a higher affinity for the local anesthetic binding site than does lidocaine; in vivotesting indicates that tonicaine elicits sensory blockade of a duration significantly longer than that elicited by bupivacaine. Tonicaine, however, has a narrow therapeutic index, with substantial neurotoxicity at 1 mm in rats, and may have limited clinical value.     

Neostigmine combined with bupivacaine, clonidine, and sufentanil for spinal labor analgesia.

We previously found that spinal clonidine prolongs labor analgesia when combined with spinal bupivacaine and sufentanil. We sought to determine whether the addition of spinal neostigmine to these drugs would further enhance labor analgesia. By use of a combined spinal/epidural technique, 36 patients were randomized to receive a hyperbaric spinal injection of bupivacaine 2.5 mg plus clonidine 50 microg and sufentanil 10 microg with or without neostigmine 10 microg. Pain, maternal hemodynamics, fetal heart rate, nausea, pruritus, sedation, motor block, sensory levels to pinprick, and maternal oxygen saturation were assessed at regularly specified intervals after spinal injection until additional analgesia was requested. The duration of spinal analgesia was similar between groups (215 +/- 60 min in the Control group versus 205 +/- 62 min in the Neostigmine group). Likewise, pain scores, the duration of labor, Apgar scores, and side effects were similar between groups except that patients administered neostigmine experienced significantly more nausea and vomiting (53% vs 7%, P = 0.01). We conclude that spinal neostigmine 10 microg produces severe nausea and does not potentiate the duration of spinal analgesia in laboring women from spinal bupivacaine, clonidine, and sufentanil. IMPLICATIONS: Spinal neostigmine 10 microg as an adjunct to spinal bupivacaine, clonidine, and sufentanil produces severe nausea and fails to potentiate analgesia in laboring women.     

Ambulatory surgery patients may be discharged before voiding after short-acting spinal and epidural anesthesia

BACKGROUND: Voiding before discharge is usually required after outpatient epidural or spinal anesthesia because of concern about bladder overdistention and dysfunction. Shorter duration spinal and epidural anesthesia may allow return of bladder function before overdistention occurs in low-risk patients (those younger than age 70, not having hernia, rectal, or urologic surgery, and without a history of voiding difficulty), and predischarge voiding may not be necessary. METHODS: After institutional review board approval and informed consent, 201 low-risk ambulatory patients were prospectively studied in either a standard or accelerated pathway after undergoing spinal or epidural anesthesia with procaine, lidocaine, 2-chloroprocaine, or less than 7 mg bupivacaine; epinephrine was not used in any anesthetic. Standard pathway patients (n = 70) were required to void before discharge. Accelerated pathway (n = 131) patients were not required to void. (After randomization of an initial 163 patients to one of the two tracks, 38 additional patients were assigned to the accelerated pathway.) If accelerated pathway patients voided, they were discharged when all other discharge criteria were met. If they did not spontaneously void after block resolution, a bladder ultrasound (BUS) was performed. If the BUS indicated a urine volume of less than 400 ml, the patients were discharged and instructed to return to the emergency department if they were unable to void within 8 h of discharge. If the BUS indicated a urine volume of greater than 400 ml, the patients were reassessed in 1 h and were discharged if they could void spontaneously. If they could not void spontaneously, they were catheterized to facilitate discharge. All patients were contacted the next day to assess the return of normal bladder function. RESULTS: All standard pathway patients voided without difficulty, and were discharged in 153 +/- 49 (SD) min. 62 patients in the accelerated pathway voided spontaneously after resolution of their block and were discharged in 127 +/- 41 min. 46 patients were discharged with a BUS less than 400 ml in 120 +/- 42 min. 23 patients had a BUS greater than 400 ml: of these, 20 patients voided within an hour and were discharged in 162 +/- 45 min. Three were catheterized after 1 h, and were discharged in 186 +/- 61 min. Mean discharge time for all patients in the accelerated pathway was 22 min shorter than the standard pathway (P = 0.002). No patients had difficulty voiding or returned to the hospital for urinary problems. None reported new urologic symptoms. CONCLUSIONS: Delay of discharge after outpatient spinal or epidural anesthesia with short-duration drugs for low-risk procedures is not necessary, and may result in prolonged discharge times.