Dermatomal Level Research Articles

Pharmacokinetics and efficacy of ropivacaine for continuous epidural infusion in neonates and infants

The primary objective of this noncomparative study was to evaluate the pharmacokinetics of ropivacaine during a 48-72-h continuous epidural infusion of ropivacaine in children under 1 year. The secondary objectives were to assess efficacy and safety. Neonates and infants (ASA I-III, gestational age > or =37 weeks, > or =2.5 kg, scheduled for major abdominal or thoracic surgery) were included and separated into age groups: 0-30 (neonate), 31-90, 91-180, and 181-365 days. Ethics committee approval and informed parental consent were obtained before inclusion. An epidural catheter was introduced under general anesthesia at the appropriate dermatomal level. An initial bolus dose (0.9-2.0 mg.kg(-1) of ropivacaine 0.2%) was followed by an epidural infusion (0.2 mg.kg(-1).h(-1) for infants <180 days or 0.4 mg.kg(-1).h(-1) for infants >180 days). Plasma samples were collected every 12 h from 24 h, and on termination of the epidural infusion. Postoperative pain was evaluated using both the Objective Pain Scale and a four-graded descriptive scale. Forty-five infants, median age 116 (0-362) days, were included. Forty-three and 19 patients received an infusion for at least 48 and 72 h, respectively. Satisfactory analgesia was provided in the majority, only 20 patients were given supplementary medication during the infusion. In all age groups, plasma concentrations of unbound ropivacaine leveled at 24 h, without any further increase at 48 and 72 h. Because of lower clearance of unbound ropivacaine in neonates (mean 33 ml.min(-1).kg(-1)) than in infants above the age of 30 days (80, 124, and 163 ml.min(-1).kg(-1), respectively, in the age groups 31-90, 91-180, and 180-365 days), unbound ropivacaine concentrations at the end of infusion were higher in neonates [median 0.10 mg.l(-1) (0.04-0.21 mg.l(-1))] than in infants >30 days [median 0.03 mg.l(-1) (0.003-0.10 mg.l(-1))]. Epidural infusions (0.2-0.4 mg.kg(-1).h(-1) ropivacaine) provided satisfactory pain relief in neonates and infants under 1 year. As plasma concentrations of unbound ropivacaine were not influenced by the duration of the infusion, ropivacaine can be safely used for postoperative epidural infusion for 48-72 h. Levels of unbound ropivacaine were higher in the neonates than in the infants, but were below threshold concentrations for CNS toxicity in adults (> or =0.35 mg.l(-1)). This should not preclude the use of ropivacaine infusions in neonates but suggests a need for caution during the first weeks of life.

A comparison of the lateral, Oxford and sitting positions for performing combined spinal‐epidural anaesthesia for elective Caesarean section*

One hundred women were randomly allocated to the left lateral, Oxford or sitting position for induction of combined spinal-epidural anaesthesia for Caesarean section using 2.5 ml hyperbaric bupivacaine 0.5% and 10 mug fentanyl. Women in the left lateral were then turned to the right lateral position; women in the Oxford position were turned to the same position on their opposite side; and women in the sitting group were turned to the supine left tilt position. Women remained in these positions until ready for surgery, which was conducted in the supine position with a wedge placed under the right hip. Ephedrine requirements before re-positioning for surgery were less in the sitting position than in the other two positions: median (IQR [range]) doses for the lateral, Oxford and sitting groups were 21 (12-30 [6-48]), 18 (7.5-24 [6-48]) and 12 (6-21 [6-42]) mg, respectively; p = 0.04. Sensory block to touch sensation at the T5 dermatomal level was most quickly achieved in the lateral position with median (IQR [range]) block onset times for the lateral, Oxford and sitting groups of 9 (6-13 [4-30]), 15.5 (9-22 [4-34]) and 14 (9-18[6-36]) min, respectively; p = 0.004. In the Oxford position, more epidural catheters required dosing to achieve a sensory block of T5 before surgery: the number of patients (proportion) bolused in the lateral, Oxford and sitting groups was 1 (3%), 7 (22%) and 1 (3%), respectively; p = 0.01. We did not demonstrate any advantage in using the Oxford position for combined spinal-epidural anaesthesia for elective Caesarean section.

Is Transcutaneous Electrical Stimulation a Realistic Surrogate for Genuine Surgical Stimulation During Spinal Anesthesia for Cesarean Delivery?

Several studies have investigated differential block during spinal anesthesia using transcutaneous electrical stimulation (TES) applied to patient's skin. These TES stimuli are claimed to be a surrogate for surgical stimulation, but TES has never been shown to be a realistic surrogate for a surgical stimulus during regional anesthesia. We investigated whether patients could appreciate nonpainful TES at the same time as they were undergoing painless cesarean delivery surgery. We applied a nonpainful TES (10 mA, 50 Hz, 1-s duration) to the skin, at 5 different dermatomal levels, in 20 women undergoing elective cesarean delivery during spinal anesthesia. During surgery, all the women were totally pain free but we noted that the level of block to TES was variable: in 30% of women, TES could be felt at the T10 dermatome or more caudally. The first appreciation of touch was consistently at T6 or above. The fact that a nonpainful TES stimulus could be appreciated within the dermatomes directly involved in transmitting surgical stimuli, at a time when the patients were totally pain free, suggests that TES at the tested levels is of little value as a surrogate surgical stimulus.

A case of normal ropivacaine concentration causing grand mal seizure after epidural injection

A case of normal ropivacaine concentration causing grand mal seizure after epidural injection

Comparison of plain and hyperbaric solutions of ropivacaine for spinal anaesthesia

Preliminary work has shown that ropivacaine provides spinal anaesthesia of shorter duration than bupivacaine, and may be of particular use in the day-case setting. However, there are few data comparing the actions of plain and hyperbaric solutions of this drug. Forty ASA grade I-II patients undergoing elective perineal surgery under spinal anaesthesia were randomized to receive 3 ml ropivacaine 5 mg ml(-1), either in plain solution or with glucose 50 mg ml(-1). The extent and duration of sensory and motor block, pulse rate, blood pressure, and time to mobilization were recorded. Two patients (one per group) were withdrawn because of total block failure. There were significant differences in median time to onset of sensory block at T10 (plain 10 min; hyperbaric 5 min; P<0.01), median maximum extent (plain T8; hyperbaric T4; P<0.05), and median duration of sensory block at T10 (plain 25 min; hyperbaric 115 min; P<0.001). However, median times to complete regression of both sensory (270 vs 240 min; P<0.05) and motor (180 vs 120 min; P<0.001) block were longer in the plain group. Patients therefore mobilized sooner in the hyperbaric group (218 [n=16] vs 286 min [n=17]; P<0.01). All the hyperbaric blocks were adequate for surgery, but three patients receiving plain ropivacaine required general anaesthesia. Addition of glucose 50 mg ml(-1) to ropivacaine 5 mg ml(-1) increases the speed of onset, block reliability, duration of useful block for perineal surgery, and speed of recovery. Plain solutions are less reliable for surgery above a dermatomal level of L1.

Cervical epidural analgesia via a thoracic approach using nerve stimulation guidance in an adult patient undergoing elbow surgery

Objective This case report describes the placement of a cervical epidural catheter via the thoracic approach, using nerve stimulation, in a patient undergoing elbow surgery. Case report An epidural catheter was easily advanced to the C5 dermatome level from the T4–5 interspace, using nerve stimulation guidance. Successful perioperative analgesia was accomplished using an infusion of ropivacaine 0.2% with 0.05 mg/mL morphine at 4 mL/h. Conclusions This case report suggests that electrical stimulation may allow one to accurately position epidural catheters in the central neuraxial space to provide reliable, effective analgesia of the upper extremity. This approach might be an alternative way to deliver cervical epidural analgesia for patients undergoing upper extremity surgery.

The Effects of a Tourniquet on Serum Catecholamine Levels for General and Spinal Anesthesia in Total Knee Replacement

Background: Pneumatic tourniquets are most frequently used during operations on the lower extremities, especially during knee operations, and provide a bloodless surgical field and prevent excessive blood loss. But tourniquets increase blood pressure, though the cause has not been identified. We thought that plasma catecholamine is increased by pneumatic tourniquet inflation. Troponin I is specific cardiac marker in myocardiac injury. So we measured plasma catecholamine and Troponin I under general and spinal anesthesia in patients undergoing total knee replacement. Methods: We divided the patients into two groups, the first group (Group I, n = 25) was the general anesthesia group and second group (Group II, n = 26) the spinal anesthesia group. All patients underwent an operation for total knee replacement. Serum enzyme levels are instable so we tried to keep changes at a minimal level. Thus all operations were carried out by the same group of surgeons, in the same operating room, at the same time (AM 8：00 start operation). The same tourniquet was applied for all subjects (tourniquet pressure 350 mmHg, 9 cm width). Group I patients had general anesthesia with - - Enflurane. Group II patients had spinal anesthesia with 0.5% tetracaine: the dermatomal level of sensory blockade to pin-prick was T6 - T4. We measured blood pressure, heart rate, Sp, ECG, serum catecolamine and trophonine I. Blood sampling were performed preoperation, 50 minutes after tourniquet application, and 30 minutes after operation to obtained serum catecholamine and trophonine I levesl. Result: Mean arterial pressure increased in group I during tourniquet inflation. The serum catecholamine level was higher in group I than in group II. The serum troponin I level was statistically significance in the general anesthesia groups (Group I). Conclusions: It might be suggested that an increased level of serum catecholamine causes tourniquet induced hypertension. Myocardial injury due to tourniquet induced hypertension was not affected by anesthesia type (general anesthesia or spinal anesthesia).

Continuous Thoracic Paravertebral Block for Pain Management Following Thoracotomy

Background: Continuous thoracic paravertebral block (C-TPVB) produces multidermatomal, ipsilateral, somatic and sympathetic nerve blockade, and is one of the options for pain management following thoracotomy. Herein, our experience of a continuous paravertebral infusion of ropivacaine for pain management following a thoracotomy is reported. Methods: Thirty two patients who underwent a thoracotomy were investigated. TPVB was performed using the Eason and Wyatt's technique at the T3-4 or T4-5 intervertebral space with an 18 G, 8 cm Tuohy needle. An epidural catheter was placed into the TPVS through the 18 G Tuohy needle, and advanced 4 - 5 cm into the TPVS. Eight ml of 1 % mepivacaine was injected into the thoracic paravertebral space (TPVS) and the dermatomal level checked by cold sensation. After the TPVB, general anesthesia was performed. When the visceral pleural had been closed, 8 ml of 0.3% ropivacaine was injected through the catheter, and 4 ml/h of 0.3% ropivacaine 0.3% continuous infused. The postoperative pain visual analog scale (VAS) was checked 2, 8, 24 and 48 hours after the operation in the resting and coughing states. Also, the requirements of the total dose of analgesic drug were recorded. The range of ann motion at the thoracotomy site, the side effects and patients' satisfaction were checked. Results: The mean VAS scores were 3.0 1.1 and 3.2 1.0 in the resting and coughing states, respectively, but there was no significant difference between the two states. The mean degree of ann motion was 1.47 0.5 and the patient satisfaction was good. Conclusions: Our results suggest that continuous thoracic paravertebral block with ropivacaine is an effective method for providing continuous pain relief in patients undergoing a unilateral thoracotomy.

Comparison of Bupivacaine and Normal Saline for Epidural Top-up on Sensory Blockade Level during Combined Spinal Epidural Anesthesia

Background: An increase in the maximum level of sensory blockade by epidural 'top-up' in combined spinal epidural anesthesia may be explained by two mechanisms; a volume effect, compressing the dural sac, and a local anesthetic effect. This study was undertaken to investigate the relative importance of these factors. Methods: Eighty patients about to undergo lower limb surgery under combined spinal epidural anesthesia were randomly assigned to four groups. Using the needle-through-needle technique, all patients received a subarachnoid injection of 8 mg of heavy bupivacaine through an epidural catheter. At 30 minutes after subarachnoid injection, an epidural top-up was given according to a randomization code. Experimental groups received 10 ml of saline, 10 ml of bupivacaine 0.25%, or 10 ml of bupivacaine 0.5%. The control group received no epidural top-up. The level of sensory blockade was checked by using the pinprick test at 5, 10, 15, 20, 25 and 30 minutes after subarachnoid injection, and at 5, 10, 15, 20, 25 and 30 minutes after epidural top-up. Blood pressure, heart rate and the incidence of side effects soh as hypotension, bradycardia, nausea, and high block were analyzed. Results: There was no significant difference in maximum level of sensory block among the 10 ml saline, 10 ml bupivacaine 0.25% or 10 ml bupivacaine 0.5% treated groups during epidural phase. Although blood pressure and heart rate were decreased, there were no differences among experimental groups during epidural phase. The most common side effect during combined spinal epidural anesthesia was hypotension. The incidence of bradycardia and high sensory block (above T4 dermatome level) was similar among the groups. Conclusions: After the maximum level of sensory blockade due to subarachnoid injection has been established, an epidural top-up with 10 ml of saline or 10 ml of either 0.25% or 0.5% bupivacaine did not significantly increase the level of subarachnoid block in patients with lower extremity surgery. The author concludes the there were no differences among groups with regard to the volume effect and local anesthetic effect in terms of the sensory blockade level during the epidural phase. However, mod pressure and heart rate in the epidural top-up groups reduced with operation time.

Combination of infarctions in the posterior inferior cerebellar artery and anterior spinal artery territories

After an episode of vasodilator-induced systemic hypotension, a 75-year-old man developed ocular lateropulsion to the right, left-side-dominant quadriparesis, loss of superficial sensation below C4 dermatome level, and anuresis. Magnetic resonance imaging (MRI) showed infarcts in the right cerebellar hemisphere (posterior inferior cerebellar artery territory) and the upper cervical cord (anterior spinal artery territory); the combination of posterior inferior cerebellar artery (PICA) and anterior spinal artery (ASA) infarcts has not been reported previously. Angiography revealed severe stenosis in the bilateral vertebral arteries. Hemodynamic hypoperfusion of the stenotic vertebral arteries may cause this unusual combination.

Spinal anaesthesia: comparison of plain ropivacaine 5 mg ml-1 with bupivacaine 5 mg ml-1 for major orthopaedic surgery

Ropivacaine provides effective spinal anaesthesia for total hip arthroplasty. This study was designed to compare the efficacy and safety of plain ropivacaine with plain bupivacaine for spinal anaesthesia in patients undergoing total hip arthroplasty. Sixty-six patients, ASA I or II, were randomized to receive an intrathecal injection of one of two local anaesthetic solutions. Group R (n=32) received 3.5 ml of ropivacaine 5 mg ml(-1) (17.5 mg). Group B (n=34) received 3.5 ml of bupivacaine 5 mg ml(-1) (17.5 mg). The onset and duration of sensory block at dermatome level T10, maximum upper and lower spread of sensory block and the onset, intensity and duration of motor block were recorded, as were safety data. Onset of motor and sensory block was rapid with no significant differences between the two groups. The median time of onset of sensory block at the T10 dermatome was 2 min (range 2-5 min) in Group R and 2 min in Group B (range 2-9 min). The median duration of sensory block at the T10 dermatome was 3.0 h (range 1.5-4.6 h) in Group R and 3.5 h (2.7-5.2 h) in Group B (P<0.0001). The median duration of complete motor block (modified Bromage Scale 3) was significantly shorter in the ropivacaine group compared with the bupivacaine group (2.1 vs 3.9 h, P<0.001). Intrathecal administration of either 17.5 mg plain ropivacaine or 17.5 mg plain bupivacaine was well tolerated and an adequate block for total hip arthroplasty was achieved in all patients. A more rapid postoperative recovery of sensory and motor function was seen in Group R compared with Group B.

The Breaking of an Intrathecally-Placed Epidural Catheter During Extraction

The Breaking of an Intrathecally-Placed Epidural Catheter During Extraction

Retrospective evaluation of continuous epidural infusion for postoperative pain in children.

The safety and efficacy of postoperative epidural analgesia (EDA) in children are not well documented in larger series of patients given routine postoperative care. The aims of this study were to evaluate the efficacy of pain relief, determine the incidence and type of complications during the entire period of epidural pain treatment in children, and assess the factors affecting efficacy Children treated postoperatively with an EDA infusion during the period 18 September 1994 to 1 January 1999 were studied. Data regarding the age, gender, efficacy of analgesia, duration of epidural infusion, types of side-effects and complications, reasons for discontinuation, and types and duration of surgery were collected daily by the Acute Pain Treatment Service. The sensory dermatomal level of the surgical incision site was included retrospectively. Five hundred and eighteen epidural infusions were given to 476 children. Pain relief was rated as 'good' at 76% of visits. There were no major complications or sequelae. Thirty-seven per cent of the epidural infusions were prematurely discontinued, and 21% were discontinued because of unsatisfactory analgesia. Factors related to a higher percentage of unsatisfactory function were surgical incision site located above the umbilicus, gastroenterologic surgery, protracted surgery and age. Age and duration of surgery were significantly related to unsatisfactory function. This study shows that continuous epidural infusion for postoperative pain was satisfactory in most cases, and that no major side-effects or complications occurred in children nursed on regular wards. The early recognition of unsatisfactory function of an EDA is important for a child's well being.

Spinal Anesthesia 0.75% Isobaric Ropivacaine with Fentanyl for a Lower Extremity Operation

Background: Opioids and local anesthetics administered together intrathecally have a potent synergistic analgesic effect and less hypotention using a minidose of local anesthetic. This study was designed to investigate the safety and efficacy of two doses of intrathecal isobaric ropivacaine/fentanyl in patients undergoing an operation of the lower extremities. Methods: Thirty patients undergoing an elective orthopedic surgical operation of the lower extremities were randomly assigned to two groups for spinal anesthesia. Patients in group I (n = 15) received 0.75% ropivacaine 14 mg/fentanyl 20, and patients in group II (n = 15) received 0.75% ropivacaine 16 mg/fentanyl 20. After spinal anesthesia, we measured the time to T10, peak dermatomal level, time to peak sensory level, time to maximum motor blockade, duration of complete motor block and duration of complete sensory block using the pin prick test and Bromage motor scale. Also circulatory variables were monitored every 5 min and side effects were measured for 3 days after spinal anesthesia. Results: There were no significant differences between the groups in time to T10, peak dermatomal level, time to peak sensory level, time to maximum motor blockade and duration of complete motor block, but duration of complete sensory block was significantly longer in the 0.75% ropivacaine 16 mg/fentanyl 20 group than the 0.75% ropivacaine 14 mg/fentanyl 20 group. Conclusions: Intrathecal 0.75% ropivacaine 14 mg/fentanyl and 0.75% ropivacaine 16 mg/fentanyl were equally suitable for a lower extremity operation.

Intrathecal ropivacaine for total hip arthroplasty: double-blind comparative study with isobaric 7.5 mg ml−1 and 10 mg ml−1 solutions

This study was designed to evaluate the efficacy and safety of two concentrations of intrathecal ropivacaine, 7.5 and 10 mg ml(-1), in patients undergoing total hip arthroplasty. One hundred and four patients, ASA I-III, were randomized to receive an intrathecal injection of one of two concentrations of isobaric ropivacaine. Group 1 (n=51) received 2.5 ml of 7.5 mg ml(-1) ropivacaine (18.75 mg). Group 2 (n=53) received 2.5 ml of 10 mg ml(-1) ropivacaine (25 mg). The onset and offset of sensory block at dermatome level T10, maximum upper and lower spread of sensory block and the onset, intensity and duration of motor block were recorded, as were safety data. Onset of motor and sensory block was rapid with no significant differences between the two groups. The median time of onset of sensory block at the T10 dermatome was 2 min (range 1-25 min) in Group 1 and 2 min (range 1-21 min) in Group 2. The median duration of sensory block at the T10 dermatome was 3.0 h (range 0.5-4.2 h) in Group 1 and 3.4 h (1.1-5.9 h) in Group 2 (P=0.002). The median duration of complete motor block was significantly prolonged (P<0.05) in Group 2 compared with Group 1 (1.9 vs 1.2 h, respectively). Anaesthetic conditions were excellent in all but one patient. Intrathecal ropivacaine, in doses of 18.75 and 25 mg, was well tolerated and provided effective anaesthesia for total hip arthroplasty.

Reversal of lidocaine with epinephrine epidural anesthesia using epidural saline washout

Background and Objectives: Prolonged motor and sensory block following epidural anesthesia can be associated with extended postoperative care unit stays and patient dissatisfaction. Previous studies have demonstrated a more rapid motor recovery following the administration of epidural crystalloids in patients who had received plain bupivacaine and lidocaine epidural anesthesia. However, epinephrine is commonly added to local anesthetics to improve the quality and prolong the duration of the epidural block. The objective of this study was to determine the relationship of 0.9% NaCl epidural catheter flush volume (i.e., washout) to the recovery of motor and sensory block in patients undergoing 2% lidocaine with epinephrine epidural anesthesia. Methods: A prospective, randomized, double-blind study design was utilized. Thirty-three subjects scheduled for elective gynecologic or obstetrical surgical procedures underwent epidural anesthesia using 2% lidocaine with epinephrine (1:200,000). A T4 dermatome level of analgesia, determined by toothpick prick, was maintained intraoperatively. Following surgery, subjects were randomized to 1 of 3 treatment groups. Group 1 (control, n = 11) received no epidural 0.9% NaCl (normal saline [NS]) postoperatively. Group 2 (15 mL NS × 1, n = 10) received an epidural bolus of 15 mL NS. Group 3 (15 mL NS × 2, n = 12) received an epidural bolus of 15 mL NS postoperatively and a second 15-mL NS bolus 15 minutes later. Assessment of motor and sensory block was performed at 15-minute intervals until complete motor and sensory recovery. Results: Times to partial and full motor and sensory recovery were significantly faster in the epidural NS groups than in the control group. Full motor recovery was more rapid in subjects receiving two 15-mL NS epidural NS boluses (30 mL total) compared with those receiving a single 15-mL NS bolus (108 ± 9 min v 136 ± 13 min) and significantly faster than control group subjects (153 ± 14 min). Both NS × 1 and NS × 2 epidural bolus groups experienced significantly reduced times to complete sensory recovery when compared with the control group (NS × 1 = 154 ± 13 min, NS × 2 = 153 ± 9 min, control 195 ± 14 min). Conclusions: A more rapid recovery of motor and sensory block in patients undergoing 2% lidocaine with epinephrine epidural anesthesia can be achieved with the use of 30 mL NS epidural washout. Reg Anesth Pain Med 2001;26:246-251.

The Effect of Montage on the Analgesic Response to Percutaneous Neuromodulation Therapy

The analgesic response to percutaneous neuromodulation therapy (PNT) is influenced by the location, frequency, and duration of electrical stimulation. We evaluated the effect of different patterns of stimulation (montages) on the acute analgesic response to PNT when applied at the same dermatomal levels in 72 consenting patients with low back pain. All of the patients received a standardized montage (I) and three alternative montage (II–IV) patterns according to a randomized, single-blinded, crossover study design. All of the PNT treatments were administered at identical alternating stimulation frequencies of 15 and 30 Hz for a period of 30 min, three times per week for two consecutive weeks, with 1 wk “off” between each modality. Pretreatment assessments included the health status survey short form (SF-36) questionnaire, as well as visual analog scale scores for pain, physical activity, and quality of sleep (with 0 = the best to 10 = the worst). The pain visual analog scale was repeated 5–10 min after each treatment session. The daily oral analgesic usage was recorded in a patient diary. All four montages produced significant improvements in pain (42%–64%), physical activity (35%–51%), and quality of sleep (28%–46%), as well as 23% to 47% reductions in the daily oral analgesic usage. However, Montage II was significantly more effective than the standard (Montage I) and the other two montages studied. These data suggest that the pattern of stimulation (i.e., montage) can influence the acute analgesic response to PNT. Implications With electroanalgesic techniques such as percutaneous neuromodulation therapy, the pattern of the electrical stimulation can influence the acute analgesic response even when identical stimuli are administered at the same dermatomal levels.

Percutaneous neuromodulation therapy; does the location of electrical stimulation effect the acute analgesic response? (University of Texas Southwestern Medical Center at Dallas, Dallas, TX) Anesth Analg 2000;91:949–954.

This article studied the effect of the location of electrical stimulation on the acute analgesic response to percutaneous neuromodulation therapy in patients with nonradiating neck pain. Sixty‐eight patients received 3 different nonpharmacologic modalities, namely “needles only (neck), local (neck) dermatomal stimulation, and remote (lower back) dermatomal stimulation in a random sequence over the course of an 11‐week study period. All treatments were given for 30 min, 3 times per week for 3 weeks with 1 week “off” between each modality. The assessment tools included the health status survey short form (SF‐36) questionnaire as well as 10‐cm visual analog scales for assessing pain, physical activity, and quality of sleep. The pain visual analog scale was repeated 5‐10 min after each treatment session. The daily oral nonopioid analgesic requirements were recorded in the patient diary during the entire study period. At the end of each 3‐week treatment block, the SF‐36 questionnaire was repeated. Compared with needles only and remote dermatomal stimulation, local dermatomal stimulation produced a significantly greater decrease in pain, increase in physical activity, and improvement in the quality of sleep compared with baseline values (P &lt; 0.05). The posttreatment SF‐36 test results revealed that all 3 modalities produced improvements compared with the prestudy scores for both the physical component summary and mental component summary. However, the magnitude of the changes in the physical component summary and mental component summary with local dermatomal stimulation was significantly greater than needle only or remote dermatomal stimulation. No side effects were reported at the needle insertion sites. Conclude that electrical stimulation at the specific dermatomal levels corresponding to the local pathology produces greater short‐term improvements in pain control, physical activity, and quality of sleep in patients with chronic neck pain.Comment by Alan Kaye, M.D. Percutaneous neuromodulation is a therapy in which percutaneous electrical nerve stimulation is applied for short‐term relief of various pain syndromes. In this study involving 68 patients by White et al, the effects of neuromodulation therapy were studied with nonradiating neck pain. Local dermatomal stimulation consisted of placement of 10 32‐gauge stainless steel acupuncture needle probes to a depth of 2‐4 cm into the soft tissue and paraspinous muscles in the cervical region. For electrical therapy, 10 probes were connected to 5 bipolar leads from a low‐output electrical generator and stimulated for 30 min at 15 and 30 cycles/s. Finally, remote dermatomal electrical therapy consisted of placement of 10 32‐gauge stainless steel acupuncture‐like needle probes to a depth of 2‐4 cm into the soft tissue and/or paraspinous muscle in the lower back region. Each modality was administered to all patients 3 times per week for 3 consecutive weeks with 1 week off between each modality. Most parameters compared after demonstrated improvement locally and a reduction in daily usage of oral nonopioid analgesic medications. Future studies are warranted, in particular those in which long‐term benefits are assessed. The authors should be commended for studying this alternative treatment strategy and its role in mediating or modulating complex pain syndromes.

The Assessment of Dermatomal Level of Surgical Anesthesia After Spinal Tetracaine

Transcutaneous electrical stimulation (TES), a 60-mA, 50-Hz continuous square wave, has been considered equivalent to surgical incision. We examined whether TES at a smaller current (10 mA) can be used to predict surgical anesthesia and compare the results with sensory block to cold, pinprick, and touch after the administration of spinal tetracaine. Two groups of 40 consecutive patients, 17-69 yr old and 70 yr old or older received a subarachnoid injection of 0. 5% tetracaine in 10% glucose or saline according to the type of surgery. Patients undergoing abdominal surgery received glucose solution, and those scheduled for lower extremities surgery received saline solution, and thus, the resultant four groups of patients were studied. Neural block was assessed by the loss of sensation to cold, pinprick, touch, and TES at 10 mA (T10s), and tolerance (i.e., the loss of pain or discomfort) to TES at 10 (T10p) and 60 (T60) mA. Dermatomal levels of sensory block to cold, pinprick, and touch that were cephalad to T60 varied widely. In contrast, dermatomal levels of T10s and T10p cephalad to T60 were less variable, and the difference between T10s and T60 was the smallest among all the differences in any groups. Our results demonstrate that, regardless of patient age and baricity of a local anesthetic solution, T10s is a good predictor of T60 equivalent to the dermatomal level of surgical anesthesia. Our results show that the loss of sensation to transcutaneous electrical stimulation at 10 mA, but not cold, pinprick, or touch, is a good predictor of the dermatomal level of block to transcutaneous electrical stimulation at 60 mA, which is considered equivalent to the dermatomal level of surgical anesthesia after the administration of spinal anesthesia.

Epidural and caudal anesthesia performed under general anesthesia: The pediatric experience

The performance of regional anesthetic techniques on anesthetized children is an accepted standard of care in the international pediatric anesthesia community. Despite recent editorials condemning its practice in adults, these combined techniques continue to grow in pediatric anesthesia. Prospective and retrospective studies have been published establishing their safety and efficacy. Complications have been recognized in these studies and in case reports. These complications are related to inadvertent intravascular injection of local anesthetics, epidural identification by loss of resistance with air, inadequate knowledge of pediatric anatomy, and inappropriate equipment selection, not because the child was under general anesthesia. These complication rates compare favorably with similar techniques performed on conscious adults. Continuous epidural techniques are widely employed with significant effort directed at achieving the appropriate dermatomal level so local anesthetic-opioid infusions can be provided postoperatively. Performing these techniques in patients under general anesthesia facilitates the application of regional anesthesia in children. Copyright © 2000 by W.B. Saunders Company