Epidural Normal Saline Research Articles

Comparison of Two Different Volumes of Epidural Normal Saline for Enhancing the Effects of Spinal Anesthesia in Adult Patients Undergoing Elective Lower Limb Surgeries: A Prospective Randomized Study

Background: The combined spinal-epidural (CSE) anesthesia technique gives a reliable subarachnoid block as well as the flexible epidural block. One of the modified technique of CSE is epidural volume expansion (EVE) in which normal saline or local anesthetic (LA) is instilled though epidural catheter leading to increase in level of sensory blockade. Aim of the study was to compare two different volumes of normal saline for enhancing the effects of spinal anaesthesia in adult patients undergoing elective lower limb surgeries.
 Methods: 90 patients were randomly divided into two group. Group A - 45 patients who were received intrathecal 2.0ml of 0.5% hyperbaric bupivacaine and epidural 10ml of 0.9% normal saline for EVE using CSE technique. Group B - 45 patients who were received intrathecal 2.0ml of 0.5% hyperbaric bupivacaine and epidural 15ml of 0.9% normal saline for EVE using CSE technique.
 Results: The demographic data were comparable in both groups. Significant difference was seen in total duration of sensory blockade between group A (192.11±9.80) and group B (Mean ± SD 215.33±17.57minutes) (p<0.0001). Total duration of motor blockade was longer in group B (Mean± SD: 181.91± 16.42) as compared to group A (Mean ± SD: 162.48 ± 9.35 minutes) (p<0.0001).
 Conclusion: We conclude that epidural volume expansion (EVE) with 15 ml epidural normal saline was associated with faster onset, higher level and early achieve maximum level of sensory blockade, longer two segment regression time, early onset and longer duration of motor blockade as compared to EVE with 10 ml epidural normal saline.

Reversal of Bupivacaine 0.5% Epidural Anesthesia Using Epidural Saline Washout

Background: Prolonged motor and sensory block following epidural anesthesia has been associated with patient dissatisfaction. Administration of epidural crystalloids in patient who had received bupivacaine 0.75% and lidocaine 2% epidural anesthesia. However, bupivacaine 0.5% is commonly used in our institutional and the effectiveness of bolus of NS in non-obstetrical patients undergoing 0.5% bupivacaine epidural anesthesia has not been investigated. The objective of this study was to determine the relationship of normal saline (NS) epidural flush volume to the recovery of motor and sensory block and its hemodynamic stability (blood pressure and heart rate) in non-obstetrical patients undergoing epidural anesthesia using 0.5% bupivacaine. Methods: Following surgery, subjects with T6 dermatome level of sensory, were randomized to 2 treatment groups. Group 1 (control, n = 11) received 1-mL epidural normal saline (NS). Group 2 (experimental, n = 11) received an epidural bolus of 30-mL NS. Assesment of motor and sensory block was performed at 15-minute intervals until complete motor and sensory recovery. Hemodynamic stability (blood pressure and heart rate) between two groups were also monitor every 15-minutes and determined. Results: Times to full motor recovery were significantly faster in the epidural bolus of 30-mL groups than in the control group (69 ± 19.66 vs 95 ± 11.83; p = 0.0017).). Conclusions: A more rapid recovery of motor block in patients undergoing 0.5% bupivacaine epidural anesthesia can be achieved with the use of 30-mL NS epidural washout, with hemodynamic stability.

Comparative evaluation of hematobiochemical effects of caudal epidural administration of detomidine, lidocaine, and lidocaine/detomidine in dromedary calf camels

The present study aims to comparatively evaluate the effects of caudal epidural detomidine, lidocaine, and lidocaine/detomidine on hematobiochemical parameters in dromedary calf camels. A total of ten male dromedary calf camels (Camelus dromedarius) with the age of 20 ± 2 weeks and weight of 85 ± 5.5 kg were used for the study. The animals were enrolled to five groups (4 experimental and 1 control group) in a randomized, crossover Latin square design, with a minimum washout period of 7 days between treatments. Calves in groups DL and DH received epidural low (25 μg kg−1) and high (50 μg kg−1) dose of detomidine, respectively. Groups L and L/D received epidural lidocaine (0.22 mg kg−1) and lidocaine/detomidine (0.22 mg kg−1/50 μg kg−1), respectively. Calves in the control group were assigned to receive epidural normal saline. Correct spinal needle (18-gauge, 3.7 cm) insertion in the epidural space was confirmed by hanging drop method and loss of resistance to the drug injection. Blood samples were collected at T0 (baseline), T2, and T24 hours and were divided into two parts: one for hematological evaluation and the other one for serological analyses. Sera were analyzed for sodium (Na+), potassium (K+), calcium (Ca2+), creatinine (Cr), blood urea nitrogen (BUN), glucose (Glu), alanine transaminase (ALT), and aspartate transaminase (AST). One-way ANOVA with Tukey’s post hoc tests was used to compare mean values of hematobiochemical indices at similar times among different groups of studies. Except for packed cell volume (PCV), all hematological parameters showed no statistically significant changes during our experiment. At T24, PCV value decreased significantly in DH and L/D groups, compared with DL, L, and control groups (p ≤ 0.001). Serum concentrations of biochemical variables including Na+, Ca2+, ALT, AST, Cr, and BUN were not significantly different among all groups during the experiment (p > 0.05). At T24 hours, serum concentrations of K+ and Glu showed a significant increase in DH and L/D groups, compared with other studies groups (p < 0.05). Therefore, epidural high dose detomidine in combination with lidocaine is not recommended for calf camels suffering from conditions including hematological, metabolic, acid-base, and electrolyte problems.

ED50 of intrathecal ropivacaine for cesarean delivery with and without epidural volume extension with normal saline: a randomized controlled study.

BackgroundIt was reported that epidural volume extension could decrease the ED50 of intrathecal plain bupivacaine. In this study, we investigated the ED50 of intrathecal hyperbaric ropivacaine followed by epidural normal saline bolus for cesarean section.MethodsSixty parturients were allocated into two groups in this prospective study. About 10 mL of epidural normal saline was given after the intrathecal dose of hyperbaric ropivacaine in the Group S (normal saline group), and no epidural injection of normal saline was given after the intrathecal ropivacainve injection in the Group C (control group). The dose of intrathecal ropivacaine for each parturient was decided by up-down allocation method. The initial dose was set as 10 mg. Effective anesthesia was defined as the level of T6 or above achieved within 10 minutes after intrathecal injection and no additional epidural drug to complete operation. The Massey formula was applied to calculate the ED50 of intrathecal ropivacaine.ResultsThe ED50 of intrathecal ropivacaine for cesarean section determined by up-and-down method was 7.51 mg (95% CI, 7.09–7.93 mg) in the Group S and 8.29 mg (95% CI, 7.73–8.85 mg) in the Group C, and there was a significant difference in ED50 of ropivacaine between the two groups (P<0.05). Compared with the Group C, the ED50 of intrathecal ropivacaine decreased when followed by epidural normal saline bolus.ConclusionThe ED50 of intrathecal hyperbaric ropivacaine for cesarean section is 8.29 mg, and it is reduced when followed by epidural normal saline bolus (www.chictr.org.cn, registration number: ChiCTR-ROC-17013382).

Anesthetic approach to postdural puncture headache in the peripartum period: An Israeli national survey.

Accidental dural puncture frequency among pregnant women is about 1.5%, while approximately 60% of these women will suffer from post-dural puncture headache (PDPH) that may be debilitating. Following IRB approval, we conducted a national survey of the lead anesthesiologist in 23 labor and delivery rooms in Israel. Each survey inquired about medical center annual delivery volume, training program for residents, accidental dural puncture management, processing of information, and PDPH management strategies. Data were collected from all 23 surveyed hospitals. As for methods for PDPH prevention, in most hospitals (87%) a prophylactic epidural blood patch (EBP) is not considered. Injection of epidural normal saline after delivery as a preventive measure is never considered in most (78.3%) hospitals, while four (17.4%) hospitals reported of constitutive use of this technique and one hospital only occasionally. Duration of conservative treatment was 24-48hours in 95.7% of PDPH cases. In this survey, different aspects of treatment and PDPH management were examined. EBP is considered the gold standard in treating PDPH, although prophylactic blood patch is ineffective. We observed a tendency of very low performance of both prophylactic EBP and epidural normal saline administration after delivery in most centers. Most hospitals perform EBP after 24-48hours of conservative treatment, along with published recommendations that show increased EBP efficiency with this timeframe. In light of the survey information, we aim to reach a uniform literature-based management strategy across Israeli hospitals.

Comparative Study of Post Operative Analgesia with Epidural Clonidine and Epidural Normal Saline Using Combined Spinal Epidural Technique

Comparative Study of Post Operative Analgesia with Epidural Clonidine and Epidural Normal Saline Using Combined Spinal Epidural Technique

Effects of combined epidural analgesia with total intravenous anesthesia on risky patients underwent major abdominal surgery.

The aim of this study is to investigate the effects of combined epidural analgesia with total intravenous anaesthesia and only total intravenous anaesthesia on the different clinical parameters. Sixty high risk patients undergoing a major abdominal surgical procedure were included in this prospective, double blind, randomized study. Induction of anaesthesia was performed with IV remifentanil 0.5µg/kg and propofol titrated to achieve bispectral index score between 40 and 50. after intubation; in Group E, 0.1% bupivacaine and 2 µg/mL fentanyl were administered by an infusion rate at 0.15 ml/kg/h via the epidural catheter and Group C received epidural normal saline as same infusion rate. In group E, intraoperative MAP values were significantly lower than those in group C (p<0.05). Time of extubation, time of eye opening with audible warning and time of verbal response was significantly lower in group E than those in group C. Total anaesthetic drug consumption was significantly higher in group C than those in group E (p<0.05). Based on lower requirements for propofol and remifentanil as well as the favourable effects on clinical parameters; we conclude that bispectral index score guided combined epidural with total intravenous anaesthesia is superior to solely total intravenous anaesthesia in this type of surgery.

A randomized comparison of onset of anesthesia between spinal bupivacaine 5 mg with immediate epidural 2% lidocaine 5 mL and bupivacaine 10 mg for cesarean delivery

BackgroundPrevious studies using low-dose spinal anesthesia for cesarean delivery have focused on hypotension and efficacy. This study evaluated whether, using a combined spinal–epidural technique, there was a difference in onset of anesthesia for cesarean delivery between low-dose spinal with an immediate epidural local anesthetic bolus, and conventional-dose spinal anesthesia. MethodsForty healthy term nulliparous women undergoing elective cesarean delivery with a combined spinal–epidural technique were enrolled into this prospective, randomized, double-blind study. Patients were randomly allocated to the low-dose (Group L) or conventional-dose group (Group C). Patients in Group L received intrathecal isobaric bupivacaine 5mg with sufentanil 2.5μg followed by epidural 2% lidocaine 5mL; patients in Group C received intrathecal isobaric bupivacaine 10mg with sufentanil 2.5μg followed by epidural saline 5mL. The onset of anesthesia (defined as the time from spinal injection to a block to T6), incidence of hypotension, maximal sensory block, epidural supplementation and side effects were recorded. ResultsAll blocks reached T6 within 11min except for one patient in Group L. There were no differences in onset of anesthesia (9.9±3.2min in Group L vs. 8.5±1.2min in Group C, P=0.08), maximal block level and the number of patients who required epidural supplementation in both groups. Hypotension occurred in 8 patients (40%) in Group L and 15 patients (75%) in Group C (P=0.02). ConclusionsIntrathecal bupivacaine 5mg with immediate 2% epidural lidocaine 5mL provided comparable onset and efficacy of anesthesia as bupivacaine 10mg with immediate epidural normal saline 5mL for cesarean delivery.

Sparing Effects of Sevoflurane Requirement during Combined Epidural-General Anesthesia Comparing to General Anesthesia for Laparoscopic Distal Gastrectomy

Background: Combined thoracic epidural-general anesthesia have many advantages, which are including early recovery, postoperative analgesia and less requirement of inhalation anesthetic. The aim of this study was to compare the requirements of sevoflurane during combined epidural-general anesthesia with those during only general anesthesia for laparoscopic distal gastrectomy. Methods: Forty patients undergoing laparoscopic distal gastectomy under general anesthesia were allocated randomly to two groups receiving infusion of epidural 0.375% ropivacaine mixed with 2g/ml sufentanil at 5 ml/hr following 8 ml bolus (group R), or epidural normal saline (group C) as the same method. All the patients were permitted to be infused to epidural 0.2% ropivacaine mixed with 1g/ml sufentanil at 5 ml/hr 30 minutes before end of surgery for postoperative analgesia. Anesthetic depth was maintained within 15% mean arterial blood pressure (MAP) of basal values. We recorded the end-tidal sevoflurane concentration (ETsev), mean arterial pressure (MAP) and heart rate (HR) at the critical time during the surgery (intubation, 3 minuets after intubation, skin incision, pneumoperitoneum, 3 minuets after pneumoperitoneum, end point of pneumoperitoneum, abdominal wall suture, extubation) and hourly consumptional volume of sevoflurane. Results: Both groups were similar in demographic data, surgery anesthetic time and postoperative pain score. But the stay time in post anesthetic care unit was significantly shorter in R group. ETsev were lower in group R than in group C during the study period. Actually approximately half volume of sevoflurane was consumed in group R comparing to group C. Conclusions: For laparoscopic distal gastrectomy, smaller amount of sevoflurane was used during combined thoracic epidural-general anesthesia than during general anesthesia.

Does Epidural Clonidine Decrease the Sevoflurane Concentration for Maintaining the BIS 50?

Background: The aim of this study was to investigate the influence of epidural clonidine on the BIS, and its potential dose-sparing effect on the sevoflurane requirement for maintaining the BIS 50. Methods: Forty ASA I or II patients aged 20 to 65, undergoing lower abdominal, gynecologic surgery under general anesthesia, were randomly allocated to either a 10 ml epidural normal saline injection group (n = 20) or a 10 ml epidural clonidine 3g/kg mixed with normal saline injection group (n = 20). They received 5 mg/kg thiopental sodium and 0.1mg/kg vecuronium bromide for induction, with no premedication. After surgical incision, the sevoflurane concentration was controlled to maintain the BIS 50. Epidural saline or clonidine was then injected and end-tidal sevoflurane concentration to maintain the BIS 50, the heart rate (HR) and mean arterial pressure (MBP) were measured every 5 min over a 20 minute period. Results: The end-tidal sevoflurane concentration in the clonidine group decreased by 27.5% after the epidural clonidine injection (1.49 0.23 vol% vs. 1.080.27 vol%; P 0.18 vol% vs. 1.330.21 vol%; P > 0.05). There were no changes in the heart rate and mean blood pressure in either group. Conclusions: Epidural clonidine causes a significant decrease in the BIS, and lowers the end-tidal sevoflurane concentration required for maintaining the BIS 50.

The Effect of Epidural Bupivacaine on Induction and Maintenance Doses of Propofol (Evaluated by Bispectral Index) and Maintenance Doses of Fentanyl and Vecuronium

The growing interest in combining local and general anesthesia has led to studies investigating possible interactions between general anesthesia and local anesthetics administered via spinal, epidural, IV, or IM routes. However, no study has evaluated the effect of local anesthetics on all three components of balanced anesthesia, i.e., hypnosis, analgesia, and muscle relaxation. In this prospective, randomized, double-blind study, we investigated the effect of epidural bupivacaine on the dose requirement of propofol (as evaluated by using the bispectral index [BIS]), fentanyl, and vecuronium for general anesthesia. This study consisted of 30 adults, ASA physical status I and II, undergoing Whipple's pancreaticoduodenectomy for periampullary carcinoma lasting >4 h. An epidural catheter was placed between T9-10. Depending on the group allocation, 10 mL of the study drug was administered as a bolus followed by an infusion at 6 mL/h via the epidural catheter. Patients were divided into 2 groups of 15 each. Patients in the control group received epidural normal saline whereas those in the bupivacaine group received epidural bupivacaine 0.1%. Induction of anesthesia was performed with IV fentanyl 2 mug/kg and propofol titrated to achieve BIS between 40-50. Endotracheal intubation was facilitated by the IV administration of vecuronium 0.1 mg/kg and patient's lungs were ventilated with 66% nitrous oxide in oxygen. After intubation, infusion of propofol 1% was titrated to maintain BIS between 40-50. Inadequate analgesia was defined as an increase in systolic blood pressure and/or heart rate by >20% of baseline values in response to surgical stimulus and was treated with bolus fentanyl 0.5 mug/kg. Neuromuscular monitoring was used to assess the need for additional doses of vecuronium. Data were analyzed by using the Student's t-test and P </= 0.05 was considered significant. The requirement of propofol for induction and maintenance of anesthesia in the bupivacaine group was 1.3 +/- 0.3 mg/kg and 2.4 +/- 0.9 mg . kg(-1) . h(-1), respectively, compared with 2.4 +/- 0.6 mg/kg and 4.4 +/- 1.6 mg . kg(-1) . h(-1) observed in the control group (P < 0.05). Significant reduction was also observed in the requirement of vecuronium and fentanyl during maintenance in the bupivacaine group (P < 0.05). We conclude that epidural bupivacaine given before induction of anesthesia reduces the requirement of propofol, fentanyl, and vecuronium during general anesthesia.

Effect of pre-emptive ketamine on sensory changes and postoperative pain after thoracotomy: comparison of epidural and intramuscular routes

In this study we have evaluated the efficacy of ketamine via i.m. and epidural routes for the control of post-thoracotomy pain. The study was randomized, double blinded and placebo controlled. With the approval of the Faculty Ethics Committee, 60 patients undergoing elective thoracotomy were randomized into three equal groups. Group IM had i.m. ketamine 1 mg kg(-1) in 2 ml plus epidural normal saline; Group EPI had epidural ketamine 1 mg kg(-1) in 10 ml plus i.m. normal saline; Group C had epidural normal saline 10 ml plus i.m. normal saline 10 ml. Anaesthesia was standardized. Postoperative analgesia was maintained with epidural patient-controlled analgesia using bupivacaine and morphine. Visual analogue scale values and analgesic consumption were evaluated at 2, 4, 6, 8, 10, 12, 24 and 48 h after surgery. The areas of allodynia, pin-prick hyperalgesia and pressure hyperalgesia were measured at 48 h, and days 15 and 30 in all groups. Intraoperative fentanyl requirement was significantly lower in Group EPI than Group C. The morphine and bupivacaine requirements were significantly lower in Group EPI than the other two groups in the postoperative period. There was reduced pin-prick hyperalgesia and touch allodynia in the EPI group. There were no side-effects attributable to ketamine. The results of the present study demonstrate that pre-emptive epidural ketamine is effective in reducing intra- and postoperative analgesic requirements, hyperalgesia and touch allodynia.

The effects of epidural morphine on cardiac and renal sympathetic nerve activity in alpha-chloralose-anesthetized cats.

Epidural morphine yields postoperative pain relief and hemodynamic stability. However, the effects of epidural morphine on sympathetic tone are unclear. This study was designed to elucidate the effects of epidural morphine on cardiac (CSNA) and renal (RSNA) sympathetic nerve activity by direct measurement in anesthetized cats. Thirty mongrel cats anesthetized with alpha-chloralose were randomly assigned to one of the following five groups: control (0.2 ml/kg thoracic epidural normal saline; n=5); thoracic epidural morphine (n=9); lumbar epidural morphine (n=6); vagotomized, sinoaortic denervated, thoracic epidural morphine (n=5); or intravenous morphine (n=5). Mean arterial pressure (MAP), heart rate (HR), CSNA, and RSNA were measured 0, 15, 30, 60, 90, and 120 min after saline or morphine (200 microg/kg) administration and 15 min after reversal with 200 microg naloxone given intravenously. In the control group, no changes in measured variables were found after either thoracic epidural saline or intravenous naloxone. Thoracic and lumbar epidural morphine both significantly reduced MAP, HR, CSNA, and RSNA 30 through 120 min after morphine administration (P < 0.05). These changes were reversed by intravenous naloxone. Changes after thoracic epidural morphine administration in vagotomized, baroreceptor-denervated cats were similar to those in intact cats. Intravenous morphine produced no significant changes except for a decrease in MAP, which was reversed by intravenous naloxone. In contrast to intravenous morphine, thoracic and lumbar epidural morphine both inhibited cardiac and renal sympathetic nerve activity and consequently reduced MAP and HR in alpha-chloralose anesthetized cats.

Epidural Verapamil Reduces Analgesic Consumption After Lower Abdominal Surgery

In this double-blind study, we administered lumbar epidural bupivacaine or bupivacaine plus verapamil to investigate the possible role of the calcium channel blocker, verapamil, in postoperative pain. One hundred patients (ASA physical class I or II) scheduled for lower abdominal surgery were randomly assigned to one of four groups. Group 1 received 10 mL of 0.5% epidural bupivacaine injected 15 min before incision, followed by 10 mL of epidural normal saline 30 min after incision. Group 2 received 10 mL of epidural normal saline injected before incision, followed by 10 mL of 0.5% epidural bupivacaine 30 min after incision. Group 3 received 10 mL of 0.5% epidural bupivacaine plus 5 mg of verapamil injected before incision, followed by 10 mL of epidural normal saline 30 min after incision. Group 4 received the same drugs as Group 3, in the reverse order. Pain and mood numeric rating scores, sedation scores, Prince Henry scores, patient-controlled cumulative postoperative analgesic consumption, and the incidence of side effects were assessed 2, 6, 12, 24, and 48 h after the operation in each group. Cumulative postoperative analgesic consumption in Groups 3 and 4 was significantly lower (P < 0.05) than that in Groups 1 and 2 24 and 48 h after surgery. There were no differences in the pain, mood, and sedation scores and the incidence of side effects among the four groups. We conclude that epidural verapamil decreases postoperative pain, possibly by interfering with normal sensory processing and by preventing the establishment of central sensitization. Implications: Calcium plays an important role in pain physiology at the spinal cord level. We examined the effect of bupivacaine plus verapamil (calcium channel blocker) and of bupivacaine alone. We demonstrated that the combination, administered epidurally, resulted in less postoperative analgesic consumption than bupivacaine alone. (Anesth Analg 1998;86:786-90)

Pre-emptive lumbar epidural anaesthesia reduces postoperative pain and patient-controlled morphine consumption after lower abdominal surgery

The present study tested the hypothesis that patients receiving epidural bupivacaine before surgery would require less morphine postoperatively and/or report less intense pain than patients receiving epidural bupivacaine after incision but before the end of surgery. Forty-two patients (ASA class I-III) scheduled for lower abdominal surgery were randomly assigned to 1 of 2 groups of equal size and prospectively studied using a double-blind, placebo-controlled crossover design. Epidural catheters were placed in the T12-L1 or L1-L2 interspaces pre-operatively, the position of the catheter was confirmed with 3% chloroprocaine with epinephrine 1:200,000, and sensory testing was carried out until levels had receded to below T12. Group 1 received 15 ml of 0.5% epidural bupivacaine injected 35 min before incision followed by 15 ml of epidural normal saline 30 min after incision. Group 2 received 15 ml of epidural normal saline injected 37 min before incision followed by 15 ml of 0.5% epidural bupivacaine 30 min after incision. General anaesthesia was induced with thiopental (4–6 mg/kg) and maintained with N 2O/O 2 and isoflurane. Paralysis was achieved with pancuronium (0.1 mg/kg). Opioids were not used as pre-medication or during surgery. Postoperative analgesia consisted of patient-controlled (PCA) intravenous morphine. Visual analogue pain scores (VAS) (at rest and after standardized mobilization) did not differ significantly between the 2 groups but McGill Pain Questionnaire (MPQ) pain ratings were significantly lower in group 1 at the 24 and 72 h assessments. Group 1 used significantly less morphine than did group 2 between 12 and 24 h after surgery. Cumulative PCA morphine consumption in group 1 (55.2 ± 4.7 mg) was significantly lower than in group 2 (71.7 ± 6.1 mg) 24 h and 48 h (group 1: 86.8 ± 6.3 mg vs. group 2: 108.9 ± 9.8 mg) after surgery, but not at the 72 h assessment. Reduction in morphine dose at 24, 48 and 72 h amounted to 30%, 25% and 22%, respectively. The results suggest that single-shot pre-emptive epidural local anaesthesia is associated with a short-term morphine-sparing effect which is most pronounced between 12 and 24 h after surgery. Extending the pre-operative blockade into the postoperative period may prolong the initial advantage conferred by pre-emptive epidural local anaesthesia.

A comparison of lumbar epidural and intravenous fentanyl infusions for post-thoracotomy analgesia

This double-blind randomised study compared the analgesic efficacy, respiratory effects, side effects, and pharmacokinetic disposition of 24 hr lumbar epidural and intravenous infusions of the same dosage regimen of fentanyl (1.5 micrograms.kg-1 bolus then 1 microgram.kg-1.hr-1 infusion) in 50 patients after thoracotomy. Patients received either epidural fentanyl and intravenous normal saline, or epidural normal saline and intravenous fentanyl, for postoperative analgesia, after a standard low-dose alfentanil and isoflurane general anaesthetic. Visual analogue pain scores were lower in the epidural group (P < 0.05) only at two hours postoperatively, and there was no difference in the amount of supplementary morphine self-administered by patient-controlled analgesic pump. A mainly spinal analgesic effect probably occurred in the first few hours since fentanyl was not detectable in the plasma of patients in the epidural group until two hours after bolus injection; its concentration was less at that time than after intravenous injection (P < 0.05). Thereafter there was no difference in the plasma concentration profiles between the two groups. Seven patients in the epidural group and ten patients in the intravenous group received naloxone for PaCO2 > 50 mmHg, and one patient in the intravenous group had the infusions stopped because of PaCO2 elevation and somnolence. In patients who did not receive naloxone, the epidural route produced better analgesia throughout the study period (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

A Double-Blind Assessment of Segmental Sensory Changes with Epidural Fentanyl Versus Epidural Saline in Patients Undergoing Extracorporeal Shock-Wave Lithotripsy

Segmental changes to pin prick and cold stimuli were tested in a double-blind manner in pain-free patients scheduled for extracorporeal shockwave lithotripsy (ESWL). Fifty patients were randomly allocated to receive either epidural fentanyl (100 micrograms in 10 ml normal saline) or 10 ml epidural normal saline. In a further 25 patients an epidural catheter was inserted but no solution injected. In contrast to this latter group, epidural fentanyl and normal saline both produced segmental sensory changes. There were no significant differences between fentanyl and normal saline groups in the number of patients reporting sensory changes to pin prick, rate of onset of these changes, or segmental level. For cold stimuli, more patients in the fentanyl group than in the normal saline group reported a change (16 vs. 8; P = 0.02) but the segmental level was similar. The effect of normal saline as a diluent in epidurally administered opioids may be of clinical importance.