A pilot study of the rectus sheath block for pain control after umbilical hernia repair

BACKGROUND: Umbilical hernia repair, a common day surgery procedure in children, is associated with significant postoperative discomfort. The rectus sheath block may offer improved pain management following umbilical hernia repair. In this pilot study, we compared the efficacy of the rectus sheath block with that of our current standard practice--local anesthetic infiltration into the surgical wound--for pain control after umbilical hernia repair in children. METHODS: Fourteen children, aged 1-8 years, undergoing umbilical hernia repair were randomly assigned to receive either a rectus sheath block or local anesthetic infiltration into the surgical wound at completion of surgery. Anesthetic management was standardized. Each analgesic technique was performed using 0.8 ml x kg(-1) of 0.25% bupivacaine with epinephrine 1:200,000. Postoperatively, an investigator who was blinded to the analgesic technique recorded the Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) scores and sedation scores every 10 min, and administered intravenous morphine 50 microg x kg(-1) for cases with CHEOPS scores > or = 8. Total morphine dose was recorded. Parents were telephoned the day after surgery to determine the overall satisfaction with pain control. RESULTS: Total postoperative morphine consumption did not differ significantly between groups, averaging 0.10 +/- 0.09 and 0.10 +/- 0.07 mg x kg(-1) for the local infiltration and rectus sheath groups, respectively. There were no significant differences in pain or sedation scores, and no complications related to either analgesic technique. DISCUSSION: Our results suggest that the rectus sheath block has no advantage over infiltration of local anesthetic into the surgical wound for postoperative pain management in children undergoing umbilical hernia repair.     

New insights in postoperative pain therapy

In this review, novel clinical studies on postoperative pain therapy are summarized. Based on these studies, several conclusions can be drawn: i) following tonsillectomy, postoperative therapy with NSAIDs leads to a significant increase in the number of reoperations; thus NSAIDs should be used with caution; ii) COX-2 inhibitors in combination with intravenous opioids improve recovery and functional outcome after knee replacement surgery; iii) the combination therapy of different non-opioid analgesics has no proven clinical efficacy and should not be used routinely; iv) patients' age is not a determinant in postoperative opioid titration after surgery; in contrast, it does predict opioid consumption during the first postoperative day; v) morphine and piritramide have identical analgesic efficacy and induce nausea and vomiting with the incidence; opioid selection can, thus, be based on economic considerations and vi) if tramadol is ineffective in postoperative pain therapy, this might be caused by an allelic variant of one of the cytochrome P450 enzymes (CYP2D6); these patients should be treated with a different opioid.     

Control of postoperative pain in heart surgery. Comparison of analgesics

BACKGROUND: Evaluation of the efficacy of three analgesic drugs (tramadol, ketorolac, and morphine) for the control of postoperative pain in cardiac surgery. METHODS: Design: prospective randomized study. Setting: University Hospital, Postoperative intensive care unit. Participants and intervention: sixty patients, who underwent cardiac surgery, were studied. They were randomly allocated in four groups, treated with a different postoperative analgesic therapy: A) tramadol in continuous infusion; B) ketorolac in continuous infusion; C) tramadol, in repeated boluses; D) morphine, in repeated boluses. Measurements: the analgesic efficacy of each drug and administration protocol was evaluated by hemodynamic stability, arterial blood gases analysis, Visual Analogue Scale (VAS), resting and after cough, the VAS derivatives PID and SPID, the concentration of plasma epinephrine and norepinephrine, at eight postoperative times. Adverse effects were also registered. RESULTS: Only tramadol, in continuous i.v. infusion, achieves the required analgesic effect, significantly decreasing both VAS scores, at the end of the administration of the drug. This treatment reduced epinephrine plasma levels in the first postoperative day, when the residual analgesic effect of surgical anesthesia can be considered disappeared. CONCLUSIONS: Tramadol in continuous infusion (dose 12 mg/h) proved to be effective for the control of postoperative pain after cardiac surgery. The proposed dose represents a good compromise between analgesic efficacy and interference with the vital functions of operated patients.     

Effects of diclofenac and intra-articular morphine/bupivacaine on postarthroscopic pain control

BACKGROUND: This study was undertaken to compare analgesic effects and requirements for supplemental analgesic therapy after knee arthroscopy in patients given intraarticular morphine/bupivacaine, diclofenac i.m., or both compared with placebo. METHOD: In a randomised, double-blind controlled trial 40 patients were divided into four groups. Patients received 25 ml of 0.25% bupivacaine and 2 mg of morphine intraarticularly in group I, 75 mg of diclofenac i.m. in group III, the combination of 75 mg of diclofenac i.m. and 25 ml of 0.25% bupivacaine and 2 mg of morphine intraarticularly in group II, and placebo in group IV. Postoperative analgesia was provided with fentanyl in the recovery room and acetaminophen was given for subsequent pain relief. RESULTS: In the postoperative period, VAS scores for pain were highest in the placebo group, whereas they were lowest in the combination group. VAS scores were significantly lower in group I and II than group IV at the postoperative 2nd hour (p < 0.05). VAS score was significantly lower in group II than groups III and IV at the postoperative 3rd hour (p < 0.01). VAS scores were significantly lower in group I, II and III than group IV at the postoperative 6th hour (p < 0.05). Fentanyl consumption was significantly lower in group II than group IV (p < 0.05). Acetaminophen consumption in groups II and III were significantly lower than group IV (p < 0.05). CONCLUSION: The combination of diclofenac i.m. and intraarticular morphine/bupivacaine appears to be the most beneficial analgesic combination due to its lower VAS scores and supplemental analgesic requirements in the postoperative period.     

Postthoracotomy pain and pulmonary function following epidural and systemic morphine

Thirty patients undergoing thoracotomy for lung resection were entered in a randomized, double-blind trial comparing the effects of epidural (E) versus intravenous (iv) morphine on postoperative pain and pulmonary function. Postoperatively the patients were given repeated doses of either 5.0 mg of morphine epidurally or 0.05-0.07 mg/kg morphine intravenously until there were no further spontaneous complaints of pain. Two, 8, and 24 h postoperatively, the following indices were measured: linear analogue pain score, somnolence score, vital signs, arterial PaO2, PaCO2, and pH, forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and peak expiratory flow rate (PEFR). Patients receiving epidural morphine had significantly less pain at 2 h (P less than 0.01) and 8 h (P less than 0.004) postoperatively. There was no difference in vital signs except for significantly slower respiratory rates at 2 h (P less than 0.04), 8 h (P less than 0.02) and 24 h (P less than 0.01) in the epidural group. No significant differences occurred in the somnolence scores or blood-gas measurements, which were within normal limits.(ABSTRACT TRUNCATED AT 250 WORDS)     

Differential analgesic effects of low-dose epidural morphine and morphine-bupivacaine at rest and during mobilization after major abdominal surgery.

In a double-blind, randomized study, epidural infusions of low-dose morphine (0.2 mg/h) combined with low-dose bupivacaine (10 mg/h) were compared with epidural infusions of low-dose morphine (0.2 mg/h) alone for postoperative analgesia at rest and during mobilization and cough in 24 patients after elective major abdominal surgery. All patients in addition received systemic piroxicam (20 mg daily). No significant differences were observed between the groups at any assessment of pain at rest (P greater than 0.05), whereas pain in the morphine/bupivacaine group was significantly reduced during mobilization from the supine into the sitting position 12 and 30 h after surgical incision and during cough 8, 12, and 30 h after surgical incision (P less than 0.05). We conclude, that low-dose epidural bupivacaine potentiates postoperative low-dose epidural morphine analgesia during mobilization and cough. Evaluation of postoperative analgesic regimens should include assessment of pain during various activities as different analgesics may have differential effects on pain at rest and during mobilization.     

A combination of gabapentin and local anaesthetics attenuates acute and late pain after abdominal hysterectomy

BACKGROUND AND OBJECTIVE: Gabapentin and local anaesthetics may decrease postoperative pain and analgesic needs. The aim of the study was to investigate the effect of the combination of these drugs on the analgesic needs as well as on acute and late pain after abdominal hysterectomy. METHODS: Sixty patients undergoing abdominal hysterectomy were randomly assigned to receive postoperatively oral gabapentin 400 mg 6 hourly for 7 days plus continuous wound infusion of ropivacaine 0.75% for 30 h or placebo capsules identical to those of gabapentin for 7 days and continuous wound infusion of normal saline for 30 h. Morphine consumption (PCA) for 48 h, paracetamol 500 mg plus codeine 30 mg (Lonalgal tablets) intake on days 3-7, visual analogue pain scores at rest and after cough during the first 7 postoperative days, the need for analgesics at home and the presence and incidence of pain after 1 month were recorded. RESULTS: The treatment group consumed less cumulative morphine over the first 48 h (31 +/- 13.2 mg vs. 50 +/- 20.5 mg in controls, P < 0.001) and less Lonalgal tablets on days 3-7 (z = 2.54, P = 0.011). The visual analogue score values at rest and after cough did not differ between the groups during the first 7 postoperative days. One month postoperatively, fewer patients in the treatment group experienced pain due to surgery than in the control group (17/27 vs. 21/24, P = 0.045). CONCLUSION: Gabapentin and continuous wound infusion with ropivacaine 0.75% decreased analgesic needs and late pain in patients undergoing abdominal hysterectomy.     

Preoperative infiltration of the surgical area enhances postoperative analgesia of a combined low–dose epidural bupivacaine and morphine regimen after upper abdominal surgery

In a randomized, blinded trial we assessed the value of adding preoperative infiltration of the surgical area with bupivacaine to a low dose epidural regimen for postoperative pain treatment. Forty–nine patients scheduled for major upper abdominal surgery during combined thoracic epidural (bupivacaine + morphine) and general anaesthesia were studied. Postoperative analgesia was epidural bupivacaine 10 mg hr^-1 + morphine 0.2 mg hr^-1 for 72 h. The patients randomly received preoperative infiltration of the surgical area with bupivacaine 0.25%, 40 ml (group I); or no infiltration (group II). Pain was evaluated at rest, during cough and during mobilization six and eight h after start of surgery, and at 8 a.m. and 4 p.m. on the following days until 72 h after start of surgery. The sensory level of analgesia was evaluated by pin prick. We found no difference between the two groups during rest and cough. However, during mobilization group I had lower pain scores compared to group II ( P < 0.05). There was a significant reduction in the need for supplemental intramuscular morphine in the treatment group compared to the control group ( P <0.05). Thus an enhanced analgesic effect was demonstrated by adding preoperative infiltration of the surgical area with local anaesthetic to a low dose epidural bupivacaine/morphine regimen after upper abdominal surgery.     

七氟烷、地氟烷或丙泊酚麻醉术后疼痛和镇痛药需求量的比较

背景全身麻醉药可产生伤害反应从而影响手术后疼痛,在一些手术后疼痛的研究中,均没有考虑全麻药对镇痛药需要量的影响,仅有最近一项研究显示丙泊酚麻醉的手术后镇痛效果比异氟烷麻醉好。方法前瞻性、随机、双盲研究,记录在七氰烷、地氟烷或丙泊酚麻醉下行腹式子宫切除术或子宫肌瘤切除手术患者手术后2、4、8、和24小时吗啡的需要量和疼痛评分（疼痛视觉模拟评分,VAS）,手术中维持BIS35～45。同时记录患者送至麻醉监护室时的疼痛评分。结果3组患者手术后2、4、8或24小时,吗啡累积消耗量无差异（P=0．50）。手术后24小时内吗啡消耗量：七氟烷组28±13．8mg;地氟垸组25±11.7mg;丙泊酚组27±16．1mg。疼痛评分在患者转运至麻醉监护室即刻、手术后2、4、8和24小时,分别在静息及咳嗽状态下评估,显示3组间无差异（静息时P=0．40、0．39、0．50、0．47、0．06;咳嗽后P=0．67、0．45、0,22、0．26、0．29）．结论手术后24小时吗啡消耗量和手术后疼痛情况在七氟烷、地氟烷或丙泊酚3组间差异无显著性。     

The effects of tramadol and morphine on immune responses and pain after surgery in cancer patients

There has been growing interest in determining the possible immune consequences of opioid administration for the management of postoperative pain. We studied the effects of morphine and tramadol on pain and immune function during the postoperative period in 30 patients undergoing abdominal surgery for uterine carcinoma. Phytohemoagglutinin-induced T lymphocyte proliferation and natural killer cell activity were evaluated immediately before and after surgery, and 2 h after the acute administration of either 10 mg of morphine IM or 100 mg tramadol IM for pain. In all patients, phytohemagglutinin-induced lymphoproliferation was significantly depressed by surgical stress. However, in the morphine-treated group, proliferative values remained lower than basal levels for 2 h after treatment, whereas in tramadol-administered patients proliferative values returned to basal levels. Natural killer cell activity was not significantly affected by surgery nor by morphine administration, whereas tramadol significantly enhanced the activity of natural killer cells. Both drugs produced a comparable reduction in postoperative pain. We conclude that, as previously observed in the experimental animal, tramadol and morphine, when administered in analgesic doses, induce different immune effects. Implications: Recent studies suggest that opioids can have an adverse impact on the immune system. Because surgical stress also induces immune dysfunction, the search for analgesic drugs devoid of immunosuppressive effects is of import. This study compared the effects on immune responses of morphine and of the atypical opioid analgesic, tramadol, given for postoperative pain to gynecological cancer patients. Tramadol and morphine showed comparable analgesic activity; however, tramadol, in contrast to morphine, induced an improvement of postoperative immunosuppression and, therefore, may be preferred to morphine for the treatment of postoperative pain.     

A qualitative systematic review of morphine treatment in children with postoperative pain

BACKGROUND: Postoperative pain management in children is often empirical rather than evidence based. Morphine is the pharmacological treatment most widely used and although considered safe for children, adequate scientific data on morphine's pharmacokinetics, efficacy and safety are lacking. This systematic review aimed to evaluate the available literature examining different pediatric morphine regimens with respect to dosage, analgesic efficacy and incidence of side effects. METHODS: Thirty-six randomized, double-blind controlled clinical trials with 49 comparisons, including multiple dosage regimens and routes of administration were included. The primary outcome measures for analgesic efficacy (pain intensity, time to first analgesic request and need for rescue analgesics) together with the incidence of morphine-related side effects were evaluated qualitatively by significant difference (P < 0.05) as reported in the original investigations. RESULTS: Overall, significant improvements in the defined outcome measures on analgesic efficacy were only observed when morphine was compared with inactive control interventions. No relation between morphine dosage and analgesic efficacy was detected. The most common morphine-related side effects were vomiting and sedation, with significantly higher incidences observed after morphine administration in half of all comparisons. CONCLUSIONS: Although several factors may justify its use as first line therapy in many parts of the world, morphine alone is not the most suitable analgesic for postoperative pain in pediatric patients, as it does not have superior analgesic effect and a higher incidence of side effects compared with active control interventions. More standardized clinical trials with multimodal regimens as well as guidelines for evaluating pediatric medicines are desirable in the future.     

Postoperative pain and analgesic responses are similar in male and female Sprague-Dawley rats

PURPOSE: Controversy exists concerning the influence of gender on pain sensitivity and response to analgesics both in animal and human studies. The present study compares postoperative pain scores in male and female rats and how they respond to analgesic interventions. METHODS: Unilateral plantar foot incisions were made in Sprague-Dawley rats of both genders, producing mechanical allodynia in an established model of postoperative pain. Postoperative pain scores were monitored for four days following incision to identify intrinsic differences between the two groups. Animals were tested with analgesics (opioids, alpha(2)-adrenergic agonists, acetylcholine esterase inhibitors, gabapentin) both systemically and intrathecally on the day after incision to assess gender differences in the anti-allodynic effect of these drugs. RESULTS: In the plantar foot incision model of postoperative pain there was no gender difference in postoperative mechanical hypersensitivity (von Frey filaments) over four days. Morphine (3 mg x kg(-1)) and gabapentin (25 mg x kg(-1)) administered intraperitoneally decreased postoperative mechanical hypersensitivity, but with no gender difference. Intrathecal morphine (1-2 nmol), gabapentin (60-120 nmol), clonidine (45 nmol), and neostigmine (6.6 nmol) also showed no gender difference in analgesic effect. CONCLUSION: The results of this study demonstrate that in Sprague-Dawley rats there are no gender differences in postoperative pain perception or the response to analgesics, indicating that this strain of rats can be used without introducing gender bias in studies of postoperative pain.     

Management of acute and postoperative pain

The optimal management of postoperative pain is a prerequisite for early recovery and shorter hospital stays. The use of multimodal analgesia techniques involving the use of opioid and non-opioid (local anesthetics, ketamine, acetaminophen, and non-steroidal anti-inflammatory drugs) analgesic drugs can markedly enhance pain relief in the perioperative period.     

Posterior perineal block with ropivacaine 0.75% for pain control during and after hemorrhoidectomy

BACKGROUND AND OBJECTIVES: As perioperative pain management is a difficult challenge during hemorrhoidectomy, we tested the hypothesis that posterior perineal block (PPB) with local anesthetics alone is able to provide adequate pain control during and after surgery. METHODS: In a prospective, blinded, randomized study, we studied analgesic conditions and side effects of PPB in American Society of Anesthesiologists (ASA) I-II patients undergoing hemorrhoidectomy. Patients received general anesthesia (GA) either with PPB (0.75% ropivacaine, 40 mL (PPB group) or without PPB (control group). All patients received intravenous morphine patient-controlled analgesia (PCA) for postoperative pain control (morphine, 1.5 mg-boluses, 8-minute lockout interval). Intra- and postoperative opioids consumption was recorded, and pain assessments were performed at 1, 2, 4, 8, 12, and 24 hours using a visual analog scale (VAS). RESULTS: VAS scores were significantly lower during the first 8 postoperative hours in the PPB group as compared with the control group (P <.001). The PPB group required significantly less opioids during anesthesia (P <.001) and during the first postoperative day (P <.001) as compared with the control group. Time to first defecation and duration of hospitalization were identical in both groups. CONCLUSIONS: The present study shows that PPB with 40 mL 0.75% ropivacaine (300 mg) was a simple, effective, and safe method to provide better postoperative analgesia than PCA alone following surgical hemorrhoidectomy. In addition, PPB was shown to significantly reduce opioid consumption intraoperatively and during the first postoperative day.     

Rectal indomethacin reduces postoperative pain and morphine use after cardiac surgery

PURPOSE: To evaluate the combination of rectal indomethacin with patient controlled intravenous morphine analgesia (PCA) on postoperative pain relief and opioid use after cardiac surgery. METHODS: With institutional ethics approval, 57 consenting adults undergoing elective aortocoronary bypass surgery were randomly assigned preoperatively in a double-blind fashion to receive either placebo (n = 26) or indomethacin 100 mg suppositories (n = 31), 2-3 hr postoperatively, and 12 hr later. Both groups utilized PCA morphine. Pain scores in the two treatment groups were assessed on a 10-cm visual analogue scale (VAS) (at rest and with cough) at 4, 6, 12, 18 and 24 hr after initial dosing, and were analyzed through a 2 x 5 repeated measures of variance. The 24 hr analgesic consumption, 12 and 24 hr chest tube blood loss, and time to tracheal extubation were also recorded, and compared for the two treatment arms through Student's t test on independent samples. RESULTS: Postoperative morphine consumption in the first 24 hr was 38% less in the indomethacin group (22.40 +/- 12.55 mg) than the placebo group (35.99 +/- 25.84 mg), P = 0.019. Pain scores, measured with a VAS, were 26% to 66% lower in the indomethacin vs placebo group at rest (P = 0.006), but not with cough, for all times assessed. There was no difference in blood loss (at 12 hr) or time to tracheal extubation for both groups. CONCLUSION: The combination of indomethacin with morphine after cardiac surgery results in reduced postoperative pain scores and opioid use without an increase in side effects.     

A comparison of intra-operative or postoperative exposure to music--a controlled trial of the effects on postoperative pain

The effect of intra-operative compared to postoperative music on postoperative pain was evaluated in a controlled trial. In all, 151 patients undergoing day case surgery for inguinal hernia repair or varicose vein surgery under general anaesthesia were randomly allocated to three groups: group 1 listened to music intra-operatively, group 2 listened to music postoperatively and group 3, the control group, listened to 'white noise'. The anaesthetic and postoperative analgesic techniques were standardised. Pain was assessed using a numeric rating scale (0-10) and patients requirements for postoperative morphine, paracetamol and ibuprofen was recorded. The effect of music on nausea, fatigue and anxiety was also investigated. The results showed that patients exposed to music intra-operatively or postoperatively reported significantly lower pain intensity at 1 and 2 h postoperatively and patients in the postoperative music group required less morphine at 1 h compared to the control group. No differences were noted in the other variables. This study demonstrates that there is a short-term pain-reducing effect of music therapy however, the beneficial effects do not differ if the patient is exposed to music intra-operatively or postoperatively.     

Comparison of continuous epidural fentanyl and morphine for postoperative pain management after upper abdominal surgery]

Fentanyl and morphine were administered epidurally to the patients after upper abdominal surgery for postoperative pain management. One hundred and ninety patients were divided into 3 groups; F group: bolus and continuous administration of fentanyl, M group: bolus and continuous administration of morphine, FM group: bolus of fentanyl and morphine and continuous administration of morphine. Pain scores of 1, 2, 3, 4, 8, 12 hours after administration and of the next morning were examined and side effects were recorded. Pain scores at 1 and 2 hours in F and FM group were significantly lower than those in M group. There were no significant differences in the scores among 3 groups from 3 hours to the next morning. The incidence of itching in F group was significantly less than in other groups. Respiratory depression (less than respiratory rate 8.min-1) occurred in 2 cases in M and FM group, but no case in F group. FM group had no advantage compared with F group. We conclude that continuous epidural infusion of fentanyl is more useful than morphine for postoperative pain management after upper abdominal surgery.     

Inguinal tensile strength and pain level after Shouldice repair

Background: Tension of the abdominal wall in the inguinal region induced by Shouldice repair of an inguinal hernia is said to be responsible for elevated postoperative pain levels. Patients and methods: In 20 patients we recorded the inguinal tensile strength during closure of the hernial gap using a wound retractor equipped with strain gauges. Postoperative pain levels were scaled using a visual analogous score, and correlated with the tensile strength of the inguinal abdominal wall together with peak flow and forced expiratory volume in 1 s (FEV1) 8, 24, and 48 h after the time of operation. Results: Shouldice repair caused an average increase in inguinal tensile strength of 2.9±0.58 N (mean±SEM). The pain level expressed by active patients was twice the value obtained from resting patients (41.55±6.3% vs 20.81±7.1% 8 h after operation), but decreased slightly later on. Peak flow during forced expiration was depressed to about 80% of the control values, whereas the 1-s volume during forced expiration decreased only to 95% of the control value. We excluded any correlation between the recorded individual inguinal tensile strength or the changes in distance between the lateral edge of the rectus sheath and the base of the inguinal ligament and the postoperative pain level. Conclusion: We failed to see any evidence for the hypothesis that higher inguinal tensile strength induced by Shouldice repair leads to an elevated level of postoperative pain. If there is any effect, it may be masked by other factors with a stronger influence. Electronic Publication