Clinical effects of epidural block during labour. A prospective study

The aim of this study was to evaluate the clinical effects of epidural block for pain relief during labour in an obstetric unit which manages mainly high-risk pregnancies. In the majority of the 62 patients studied only 5 ml of a 0,5% solution of bupivacaine was sufficient for effective pain relief. In 75% of patients total pain relief was obtained. Complications of the procedure were hypotension in 32% of patients and bladder atony needing catheterization in 19%. The mean fall in blood pressure was greater in patients with pre-existing hypertension. The incidence of instrumental delivery was 40%, inadequate bearing-down effort being the indication in 54% of these cases. An abnormal fetal heart rate pattern on cardiotocography developed in 13 of 58 fetuses who were monitored internally, while in 3 cases an abnormal pattern because even more abnormal (in one-third of these cases this followed hypotension in the mother). The only statistically significant change in fetal heart rate patterns on cardiotocography was a decrease in the beat-to-beat variability. Epidural block is a very effective form of pain relief during labour but has potentially serious effects, especially in high-risk pregnancies. Precautions to minimize the risk of complications include the administration of intravenous fluid before the procedure and careful monitoring of the patient and her unborn baby. A cardiotocographic monitor is essential for the latter purpose.     

The effect of rotation of an epidural needle

A study using postmortem dura mater demonstrated that rotation of the epidural needle significantly decreases the force required to puncture the dura. It is recommended that epidural needles should not be rotated after insertion of the tip into the epidural space.     

The effects of spread of block and adrenaline on cardiac output after epidural anesthesia in young children: a randomized, double-blind, prospective study

Epidural anesthesia is considered to be without significant hemodynamic consequence in young children. However, conversely to adults, few studies have investigated cardiac output. Using transesophageal Doppler monitoring of cardiac output, we prospectively investigated hemodynamic alterations in 48 children (median age, 22.5 mo) receiving sevoflurane general anesthesia combined with caudal or thoracolumbar epidural anesthesia. They were randomly assigned to receive 0.8 mL/kg of plain local anesthetic mixture (lidocaine 1% + bupivacaine 0.25% (50/50) + 1 microg/mL of fentanyl) or 1 mL/kg of the same mixture with 5 microg/mL of adrenaline. No significant hemodynamic alteration was elicited in caudal and thoracolumbar groups receiving the plain mixture except a moderate decrease in heart rate. Conversely, a mixture with adrenaline added provoked a significant decrease in mean arterial blood pressure by 14% and 17%, in systemic vascular resistance by 24% and 40%, and an increase in cardiac output by 20% and 34% in caudal and thoracolumbar groups, respectively. The adrenaline effect was greater by the thoracolumbar than the caudal approach. In young children, epidural anesthesia induces an increase in cardiac output only when adrenaline is added to local anesthetics, probably through its systemic absorption from the epidural space. IMPLICATIONS: Epidural anesthesia may induce significant hemodynamic changes, well documented in adults. Using noninvasive hemodynamic monitoring in children, we reported an increase in cardiac output and a decrease in arterial blood pressure only when epinephrine was added to epidurally-injected local anesthetics.     

Morphine and hydromorphone epidural analgesia. A prospective, randomized comparison.

Because evidence from uncontrolled, unblinded studies suggested fewer side effects from epidural hydromorphone than from epidural morphine, we employed a randomized, blinded study design to compare the side effects of lumbar epidural morphine and hydromorphone in 55 adult, non-obstetric patients undergoing major surgical procedures. A bolus dose of epidural study drug was given at least 1 h prior to the conclusion of surgery, followed by a continuous infusion of the same drug for two postoperative days. Infusions were titrated to patient comfort. Visual analog scale (VAS) pain scores, VAS sedation scores, and subjective ratings of nausea and pruritus were assessed twice daily. The two treatments provided equivalent analgesia. Sedation scores and prevalence of nausea did not differ significantly between groups. Prevalence of pruritus, however, differed significantly on postoperative day 1, with moderate to severe pruritus reported by 44.4% of patients in the morphine group versus 11.5% in the hydromorphone group (P < .01). On post-operative day 2, reports of pruritus by patients receiving morphine remained higher than those among the hydromorphone-treated subjects, although this difference was no longer statistically significant (32% vs. 16.7%, P = .18). We conclude that lumbar epidural morphine and hydromorphone afford comparable analgesia, but the occurrence of moderate to severe pruritus on the first postoperative day is reduced by the use of hydromorphone.     

A prospective, randomized study of computer-assisted and conventional total knee arthroplasty. Three-dimensional evaluation of implant alignment and rotation

BACKGROUND: Despite the use of modern instruments in total knee arthroplasty, component malalignment remains a problem. Whether a computer-assisted implantation technique can improve the accuracy of the spatial positioning of an implant is a matter of debate. The objective of this study was to determine whether computer-assisted total knee arthroplasty is superior to the conventional surgical method with regard to the precision of implant positioning. METHODS: The spatial positioning of the implant in sixty total knee arthroplasties (thirty-two imageless computer-assisted and twenty-eight conventional implantations) was determined three-dimensionally with use of computed tomographic measurement, which allowed derotation and full extension of the knee in order to avoid projection-related imaging errors. RESULTS: The overall mechanical axis showed a range of between 4.8 degrees of valgus and 6.6 degrees of varus alignment in the frontal plane for conventionally implanted arthroplasty components compared with a significantly smaller range of between 2.9 degrees of valgus and 3.1 degrees of varus alignment for computer-assisted implantations (p = 0.004). In relation to the tibial implant, the mean deviation (and standard deviation) from the mechanical axis was 2.0 degrees +/- 1.7 degrees for the conventional surgical method and 1.4 degrees +/- 0.9 degrees for the navigated implantation. The rotational deviation from the referenced axis of the femoral component was between 3.3 degrees of internal rotation and 5.0 degrees of external rotation for the conventional implantation method, with a mean deviation of 0.1 degrees +/- 2.2 degrees. Femoral components implanted with computer assistance showed a deviation of between 4.7 degrees of internal rotation and 2.2 degrees of external rotation, with a mean deviation of 0.3 degrees +/- 1.4 degrees. CONCLUSIONS: In this study, with our technique of filtering out projection-related imaging errors, computer-assisted implantation of total knee replacements improved the frontal and sagittal alignment of the femoral component but not of the tibial component. We found that the rotational alignment of the component was not improved through navigation by solely referencing to the epicondylar axis for the femur and the tuberosity for the tibia.     

The differential flow of epidural local anaesthetic via needle or catheter: a prospective randomized double-blind study

The extent of epidural anaesthesia and pattern of spread of contrast medium, using different injection techniques, has not been well documented. Therefore, in this prospective, randomized double-blind study, the extent of anaesthesia and pattern of spread of contrast medium following an epidural bolus injection, via either a Tuohy needle or an epidural catheter, were compared. The study had two parts. In the first, 59 of 79 patients scheduled for a lower extremity operation under epidural anaesthesia were randomly allocated to one of the two groups. Anaesthesia was achieved with an epidural injection of 10 to 15 ml (including a 3 ml test dose) of 0.75% ropivacaine and fentanyl 25 microg via either a Tuohy needle (Group N, n=31) or a catheter (Group C, n=28). The level of sensory anaesthesia was recorded. In the second part, the remaining 20 patients were randomized to initially receive 5 ml of contrast medium via either a Tuohy needle (Group NE, n= 10) or a catheter (Group CE, n = 10). The extent of spread was recorded radiologically. Unilateral or missed blocks and additional dose requirement were absent in Groups N and C. No differences were found in the extent of sensory anaesthesia or the spread of contrast medium. Twenty per cent of catheter tips lay outside the lateral margins of the vertebral bodies. We found that an epidural bolus injection, via either a Tuohy needle or a catheter, made no difference in regard to spread of local anaesthetic or contrast medium in the epidural space.     

A prospective, randomized, double-blind comparison of epidural levobupivacaine 0.5% with epidural ropivacaine 0.75% for lower limb procedures

BACKGROUND AND OBJECTIVE: This prospective, randomized, observer-blinded study compared onset time and duration of epidural anaesthesia produced by with levobupivacaine and ropivacaine for lower limb surgery. METHODS: ASA I-III adult patients undergoing elective lower limb procedures were randomized to receive epidural levobupivacaine 0.5% 15 mL (n = 30) or epidural ropivacaine 0.75% 15 mL (n = 35). A blinded observer evaluated onset time and regression of motor and sensory block, and intraoperative needs for fentanyl supplementation (0.1 mg intravenously). RESULTS: With levobupivacaine, onset time was 29 +/- 24 min, with ropivacaine it was 25 +/- 22 min (P = 0.41). Complete resolution of motor block required 105 +/- 63 min with levobupivacaine and 95 +/- 48 min with ropivacaine (P = 0.86). The time for regression of sensory block to T12 was 185 +/- 77 min with levobupivacaine and 201 +/- 75 min with ropivacaine (P = 0.46). Analgesic supplementation was required in one patient receiving levobupivacaine (3.5%) and in two patients receiving ropivacaine (5.7%) (P = 0.99). CONCLUSIONS: In adults undergoing lower limb surgery, levobupivacaine 0.5% 15 mL produces an epidural block with the same clinical profile as ropivacaine 0.75% 15 mL.     

Thermal effects of epidural anesthetic block]

In a sample of 20 healthy men (ASA I) we studied the thermal effects induced after epidural anesthetic blockade with bupivacaine (0.625%) and their relationship with the level of sensitive blockade to puncture or to cold. After 30 min of epidural injection of bupivacaine the level of cephalic analgesia was D IX (D IX +/- 2 segments) and that of cold discrimination D VII (D VII +/- 2 segments) being the thermo-algesic differential blockade of 2 to 3 segments. During epidural anesthesia there was a significant increase in foot skin temperature (4.1 +/- 1 centigrade degrees, p less than 0.001) without any appreciable skin temperature change at the thorax, abdomen, thigh, and calves. It is concluded that epidural anesthesia with bupivacaine (0.625%) at a sensitive analgesic level D IX produces significant increases in skin temperature only at the foot. This indicates that the extension level of sympathetic blockade is lower that of the analgesia.     

Continuous epidural block versus continuous popliteal nerve block for postoperative pain relief after major podiatric surgery in children: a prospective, comparative randomized study

Foot and ankle surgery in children is very painful postoperatively. Adverse effects from opioids and continuous epidural block (CEB) limit their use in children. Continuous popliteal nerve blocks (CPNB) have not been studied for this indication in children. In this prospective, randomized study we evaluated the effectiveness and adverse events of CPNB or CEB in children after podiatric surgery. Fifty-two children scheduled for foot surgery were separated into four groups by age and analgesia technique. After general anesthesia, 0.5 to 1 mL/kg of an equal-volume mixture of 0.25% bupivacaine and 1% lidocaine with 1:200000 epinephrine was injected via epidural or popliteal catheters. In the postoperative period, 0.1 mL x kg(-1) x h(-1) (group CPNB) or 0.2 mL x kg(-1) x h(-1) (group CEB) of 0.2% ropivacaine was administered for 48 h. Niflumic acid was routinely used. Adverse events were noted in each treatment group. Postoperative pain during motion was evaluated at 1, 6, 12, 18, 24, 36, and 48 h. Requirement for rescue analgesia (first-line propacetamol 30 mg/kg 4 times daily or second-line 0.2 mg/kg IV nalbuphine), and motor blockade were recorded. Parental satisfaction was noted at 48 h. Twenty-seven patients were included in the CEB groups and 25 in CPNB groups. There were 32 children 1 to 6 yr of age (CPNB = 15; CEB = 17) and 20 children 7 to 12 yr of age (CPNB = 10; CEB = 10). The demographic data were comparable among groups. Postoperative analgesia was excellent for the two continuous block techniques and in the two age groups. Motor block intensity was equal between techniques. Adverse events (postoperative nausea or vomiting, urinary retention, and premature discontinuation of local anesthetic infusion in the 1- to 6-yr-old group) were significantly more frequent in the CEB group (P < 0.05). Eighty-six percent of the parents in the CEB groups and 100% in the CPNB groups were satisfied. We conclude that although both CEB and CPNB resulted in excellent postoperative analgesia in this study, CPNB was associated with less urinary retention and nausea and vomiting. Therefore, we recommend CPNB as the ideal form of postoperative analgesia after major podiatric surgery in 1- to 12-yr-old children.     

A randomized,prospective, double-blinded evaluation of selective bowel decontamination in liver transplantation

BACKGROUND: Bacterial infection is a frequent, morbid, and mortal complication of liver transplantation. Selective bowel decontamination (SBD) has been reported to reduce the rate of bacterial infection after liver transplantation in uncontrolled trials, but benefits of this intervention have been less clear in controlled studies. METHODS: Eighty candidates for liver transplantation were randomly assigned in a double-blinded fashion to an SBD regimen consisting of gentamicin 80 mg+polymyxin E 100 mg+nystatin 2 million units (37 patients) or to nystatin alone (43 patients). Both treatments were administered orally in 10 ml (increasing to 20 ml, according to predefined criteria), four times daily, through day 21 after transplantation. Anal fecal swab cultures were performed on days 0, 4, 7, and 21. Rates of infection, death, and charges for medical care were assessed from day 0 through day 60. RESULTS: More than 85% of patients in both treatment groups began study treatment more than 3 days before transplantation. Rates of infection (32.4 vs. 27.9%), death (5.4 vs. 4.7%), or charges for medical care (median $194,000 vs. $163,000) were not reduced in patients assigned to SBD. On days 0, 4, 7, and 21, growth of aerobic gram-negative flora in fecal cultures of patients assigned to SBD was significantly less than that of patients taking nystatin alone; growth of aerobic gram-positive flora, anaerobes, and yeast was not significantly different. CONCLUSION: Routine use of SBD in patients undergoing liver transplantation is not associated with significant benefit.     

A prospective, randomized, double-blind evaluation of trigger-point injection therapy for low-back pain

The efficacy of trigger-point injection therapy in treatment of low-back strain was evaluated in a prospective, randomized, double-blind study. The patient population consisted of 63 individuals with low-back strain. Patients with this diagnosis had nonradiating low-back pain, normal neurologic examination, absence of tension signs, and lumbosacral roentgenograms interpreted as being within normal limits. They were treated conservatively for 4 weeks before entering the study. Injection therapy was of four different types: lidocaine, lidocaine combined with a steroid, acupuncture, and vapocoolant spray with acupressure. Results indicated that therapy without injected medication (63% improvement rate) was at least as effective as therapy with drug injection (42% improvement rate), at a P value of 0.09. Trigger-point therapy seems to be a useful adjunct in treatment of low-back strain. The injected substance apparently is not the critical factor, since direct mechanical stimulus to the trigger-point seems to give symptomatic relief equal to that of treatment with various types of injected medication.     

The use of epidural steroids in the treatment of lumbar radicular pain. A prospective, randomized, double-blind study

Seventy-three patients with lumbar radicular pain syndromes were treated in a prospective, randomized, double-blind fashion with either seven milliliters of methylprednisolone acetate and procaine or seven milliliters of physiological saline solution and procaine. All patients had radiographic confirmation of lumbar nerve-root compression, consistent with the clinical diagnosis of either an acute herniated nucleus pulposus or spinal stenosis. No statistically significant difference was observed between the control and experimental patients with either acute disc herniation or spinal stenosis. Long-term follow-up, averaging twenty months, failed to demonstrate the efficacy of a second injection of epidural steroids administered to the patients whose pain did not respond within twenty-four hours to an injection of either eighty milligrams of methylprednisolone acetate combined with five milliliters of 1 per cent procaine or two milliliters of sterile saline combined with five milliliters of 1 per cent procaine. Therefore, a decision to use epidural steroids must be made with the realization that we failed to demonstrate its clinical efficacy in this study and that reports of serious complications of this procedure have been published.     

Penile block for pain relief after circumcision in children. A randomized, prospective trial

The value of adjunctive penile block for analgesia, after circumcision in children using 0.5 percent bupivacaine has been evaluated in this randomized, prospective trial. Significantly more children without nerve block were found to require analgesics, administered by injection orally, in the first 12 hour period when compared with children given the nerve block. Penile block is a procedure that is safe, simple to achieve, free from complications, and covers the postoperative period when analgesia is much needed.