Patient-controlled Analgesia Demand Research Articles

The Efficacy of Submucosal Tramadol in the Postoperative Treatment of Pain Following Septoplasty Operations

Tramadol is a centrally acting opioid which is effective for moderate-severe pain and is being used for various acute and chronic pain scenarios. The primary endpoint of this controlled, randomized double blind study was to evaluate the effect of submucosal tramadol on VAS scores after septoplasty operations and secondary endpoint was to investigate the effects on total opioid and additional analgesic consumption and patient satisfaction. 60 patients scheduled for septoplasty under general anaesthesia were enrolled. In Group T, at the end of surgery following hemostasis, 2mg/kg tramadol was applied as submucosal infiltration to both surgical sites, 2ml (total 4ml), by the surgeon. In Group P, at the end of surgery following hemostasis, 2ml isotonic solution (total 4ml) was applied as submucosal infiltration to both surgical sites by the surgeon. Total opioid consumption, VAS scores, patient satisfaction was evaluated at the end of 24h VAS values were higher in Group P on the first and second postoperative hours. Patient controlled analgesia demand and delivery values were higher in Group P on the postoperative 1, 2, 4, 6, 12 and 24th hours. Patient satisfaction was higher and opioid consumption was lower in Group T compared to Group P. There was no difference in additional analgesic consumption between two groups. The results show that patients receiving tramadol had lower VAS scores compared with the placebo groups postoperatively.

Pattern discovery from patient controlled analgesia demand behavior

Unlike previous research on patient controlled analgesia, this study explores patient demand behavior over time. We apply clustering methods to disclose demand patterns among patients over the first 24h of analgesic medication after surgery. We consider demographic, biomedical, and surgery-related data in statistical analyses to determine predictors for patient demand behavior, and use stepwise regression and Bayes risk analysis to evaluate the influence of demand pattern on analgesic requirements. We identify three demand patterns from 1655 patient controlled analgesia request log files. Statistical tests show correlations of gender (p=.0022), diastolic blood pressure (p=.025), surgery type (p=.0028), and surgical duration (p<.0095) with demand patterns. Stepwise regression and Bayes risk analysis show demand pattern plays the most important role in analgesic consumption prediction (p=0.E+0). This study suggests analgesia request patterns over time exist among patients, and clustering can disclose demand behavioral patterns.

Caregivers Helping in Relieving Pain – C.H.I.R.P. Project

Children who undergo hematopoietic stem cell transplant experience significant pain and discomfort related to the side effects of treatment. Standard methods of analgesia delivery, specifically patient controlled analgesia (PCA), are not appropriate for young children as they do not have the cognitive ability to connect their pain to alleviation with operating a PCA demand button. Currently, Duke University Hospital policy does not allow caregivers to push the button due to concerns for patient safety.

Needle‐Free Electroacupuncture for Postoperative Pain Management

This study examined the effects of needle-free electroacupuncture, at ST36 on postoperative pain following hysterectomy. Based on a double-blind, sham and different intervention controlled clinical experimental design, 47 women were randomly allocated to four different groups. Except for those in the control group (Group 1, n = 13), a course of treatment was given of either sham (Group 2, n = 12), high-frequency stimulation (Group 3, n = 12), or low-frequency stimulation (Group 4, n = 10). All groups were assessed during the postoperative period for 24 hours. The Visual Analogue Scale was used to determine the amount of perceived pain felt by each subject. Differences were found between the means postoperatively at three, four, eight, 16 and 24 hours. Post hoc comparison tests indicated that Group 4 was significantly different from Groups 1, 2, and 3 at 24 hours. A one-way ANOVA analysis for total patient-controlled analgesia demand and doses indicated significant differences between the groups F(3, 42) = 3.59, P < .05. Post hoc analysis confirmed the differences between Groups 1 (M = 84.54) and 4 (M = 41.60). Treatment outcomes of this therapy showed a positive effect for the management of postoperative pain.

1570 THE EFFECT OF DIFFERENT DELIVERY RATE ON SHOCKWAVE LITHOTRIPSY TREATMENT OUTCOME, RENAL INJURY AND PAIN TOLERANCE

You have accessJournal of UrologyStone Disease: SWL, Ureteroscopic or Percutaneous Stone Removal II1 Apr 20101570 THE EFFECT OF DIFFERENT DELIVERY RATE ON SHOCKWAVE LITHOTRIPSY TREATMENT OUTCOME, RENAL INJURY AND PAIN TOLERANCE Anthony Lo, Mayur Gohel, Ngn-yee Lee, and Chi-fai Ng Anthony LoAnthony Lo More articles by this author , Mayur GohelMayur Gohel More articles by this author , Ngn-yee LeeNgn-yee Lee More articles by this author , and Chi-fai NgChi-fai Ng More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.1336AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Shockwave delivery rate has been stated to improve stone clearance, protect against induced renal injury and enhance pain tolerance but there is no comprehensive assessment on these three aspects in a single centre.Therefore, we would like to compare the effect of slow and fast shockwave delivery rates on three aspects mentioned above. METHODS Patients with radio-opaque renal stone sized from 5 mm to 20 mm were randomized to receive either 60 SWs/min or 120 SWs/min using a Sonolith Vision lithotripter (Technomed, France). Successful outcome was defined as either stone free or fragments < 4 mm at 12 weeks after SWL. Renal injury was assessed by measuring Interleukin-18 (IL-18), neutrophil gelatinase-associated lipocalin (NGAL) and N-acetyl-£]-D-glucosaminidase (NAG) in spot urine collected at a day before SWL (baseline), immediately (post-treatment), 2 days, 7 days and 4 weeks after SWL. Pain tolerance was quantified by the usage of alfentanil patient-controlled analgesia (PCA). Pain was assessed using numeric rating scale (NRS) scores (0-10). PCA demand and PCA administrated were recorded at every 250J until the end of treatment at 1000J or complete fragmentation. RESULTS 103 patients were recruited and randomly assigned to either group. The patient characteristics of the two groups were comparable. Successful rates were 48.98% at 60 SWs/min and 44.90% at 120 SWs/min (p = 0.686). For stone sized < 10 mm, the successful rates were 48.57% and 61.29% in 60 SWs/min and 120 SWs/min respectively (p = 0.302). However, 50% verse 16.7% successful outcome were found respectively at 60 SWs/min and 120 SWs/min for stone sized ≥ 10mm (p =0.052). There were higher IL-18 level at immediate after SWL in 60 SWs/min (p< 0.01), when compared to 120 SWs/min. The mean levels of NGAL and NAG at immediate after SWL did not reach the significant level. All the markers were back to pretreatment level at 4 weeks after treatment. Total PCA demand (12.1 ¡Ó 19.6 at 60 SWs/min verse 10.0 ¡Ó 27.9 at 120SWs/min), administrated (142.4 ¡Ó 171.6 & micro; g at 60 SWs/min verse 121.1 ¡Ó 131.6 &micro; g at 120SWs/min) and overall pain score medians (4 at 60 SWs/min verse 4.25 at 120 SWs/min) were not statistically different in both groups. CONCLUSIONS Better stone clearance is achieved in larger renal stone only. 60 SWs/min delivery rate may induce more renal damage than that caused by 120 SWs/min. Patients¡¦ pain tolerance in terms of pain perception and PCA usage is about the same. The future use of slower delivery rate may be reassessed. Hong Kong, Hong Kong© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e607 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Anthony Lo More articles by this author Mayur Gohel More articles by this author Ngn-yee Lee More articles by this author Chi-fai Ng More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Compartment Syndrome and Patient-Controlled Analgesia in Children – Analgesic Complication or Early Warning System?

We present two cases of children who developed compartment syndrome after upper limb fractures. Morphine patient-controlled analgesia was used in a bolus-only mode for analgesia (bolus 20 microg/kg, five minute lockout and hourly limit of 150 microg/kg). An increase in patient-controlled analgesia use was observed up to 12 hours before the decision was made to proceed to fasciotomy but neither child exceeded the hourly limit or had an excessive increase in pain scores. Clinical risk factors for compartment syndrome should be identified and appropriate monitoring instituted. A subtle increase in patient-controlled analgesia use may be an early indicator of impending compartment syndrome before classical signs such as reporting of pain, pallor paraesthesiae, paralysis and pulselessness develop. These cases and review of the literature suggest techniques which may assist earlier diagnosis of compartment syndrome include setting a more conservative hourly limit of morphine patient-controlled analgesia such as 80 to 100 microg/kg/hour and graphing of patient-controlled analgesia demands and boluses, pain scores at rest and pain scores with passive flexion and extension of digits. These practices could identify trends that pain or analgesia requirement is increasing leading to earlier diagnosis of compartment syndrome.

Continuous Intra-Articular Infusion of Bupivacaine for Postoperative Pain Following Total Knee Arthroplasty

This study assessed the efficacy of local, continuous infusion of bupivacaine for pain control following total knee arthroplasty. Eleven men and 19 women with an average age of 65 years (range: 43-83 years) randomly received either 0.25% bupivacaine or normal saline by local infusion pump. Standard wound drainage also was implemented. Pain was assessed with a visual analog scale along with patient-controlled analgesia demand, narcotic delivery, and nonsteroidal anti-inflammatory administration. Drug lost to drainage also was assessed. Mean preoperative visual analog scores were similar between the saline and bupivacaine groups (6.5 +/- 1.4 and 6.1 +/- 2.0, respectively; P = .535). By the end of the second postoperative day, scores decreased to 3.4 +/- 3.2 for the saline group and 2.5 +/- 1.6 for the bupivacaine group. Although postoperative reductions were statistically significant (P = .007), the main treatment effect was not (P = .404). Mean narcotic demand and usage were 87 +/- 114.1 requests with usage of 11.8 +/- 12.3 mg for the saline group and 96 +/- 104.8 requests with usage of 7.5 +/- 3.8 mg for the bupivacaine group (P = .505). Cumulative ketorolac administration was 47 +/- 52.2 mg for the saline group and 83.6 +/- 64.9 mg for the bupivacaine group (P=.100). Hydrocodone-acetaminophen usage also was similar between the saline and bupivacaine groups (88 +/- 43.9 mg and 64.6 +/- 35 mg, respectively) (P = .112). Drug lost to drainage was estimated to be 27%. These findings suggest continuous local analgesic infusion after total knee arthroplasty does not offer significant improvements in either pain relief or medication use. Drug loss from drainage may exceed 25% and may compromise analgesic effectiveness.

The Analgesic Effect of Preemptive Lumbar Paravertebral Block in Patients Undergoing Laminectomy

Administration of morphine with intravenous patient-controlled analgesia (PCA) is a routine technique in postoperative pain relief on laminectomy. In this study, we aimed to evaulate the effect of preemptive paravertebral somatic block with levobupivacaine on postoperative morphine consumption. After approval of the Medical Faculty Ethics Commitee and patient consent, aged 20-70 years, American Society of Anesthesiologist physical status I–II, 100 patients who were undergoing laminectomy, were included. Patients were randomly divided into 2 groups: 0.1 mg/kg intravenous boluse mophine was given to patients in the first group 20 minutes before the end of operation and intravenous PCA morphine (40 mg morphine in 100 mL isotonic saline, PCA demand dose 0.02 mg kg−1, 20 min lockout time) was given after the operation. The patients in the second group were placed prone position after intubation, bilateral paravertebral somatic block was performed with 5 mL levobupivacaine 0,5% for each nerve to upper dermatome of laminectomy level. Intravenous PCA morphine was started after the end of operation. All patients were recieved 8 mg ondansetron for antiemesis. Postoperative systolic and diastolic blood pressures, heart rate, peripheral oxygen saturation values, pain [Visual Analog Scale (VAS)] scores, total morphine consumption and side effects were recorded. Demographic data, operation times and hemodynamic parameters of groups were similar. VAS scores were higher in group 1 than group 2 on postoperative 4, 6, and 12 hours (P<0.05). Total morphine consumption was recorded as 29.46±9.34 mg in group 1 and 2 and 88±7.28 mg in group 2 for 24 hours. Total morphine consumption was significantly lower in group 2 than group 1 (P<0.05). We conclude that the application of preemptive lumbar paravertebral somatic block with levobupivacaine reduce morphine requirement, provides more efficient analgesia, without change in hemodynamic parameters or side effects.

Locked out and still knocking: predictors of excessive demands for postoperative intravenous patient-controlled analgesia

Psychosocial factors governing the use of postoperative, intravenous patient-controlled analgesia (PCA) have received little attention in spite of the fact that PCA is the most common modality for managing pain after surgery. The motivation behind requests for analgesia during lockout periods is not known. Unrelieved pain and need for pain medication are obvious reasons but other factors may be involved. The aim of the present study was to predict PCA lockout interval demands based on preoperative psychosocial factors. Approximately one week before major abdominal gynecologic surgery, 117 women completed the impact of events scale (IES) measuring intrusive thoughts and avoidant behaviours. Pain was measured by visual analogue scale at three, six, 12, 24 and 48 hr after surgery. Measures of anxiety and negative affect were obtained 24 and 48 hr after surgery. Cumulative morphine consumption and every PCA demand (drug delivered and not delivered) were downloaded from the PCA pump. Multiple regression analyses revealed that preoperative intrusive thoughts and avoidant behaviours about the upcoming surgery positively predicted PCA lockout interval demands after controlling for postoperative pain, morphine consumption, anxiety, and negative affect (R2 = 0.45; P < 0.0001). Path analysis showed a direct pathway from preoperative IES scores to lockout interval demands (beta = 0.23, P = 0.002) which was not associated with untreated pain, anxiety, or negative affect. Excessive demands for postoperative intravenous- PCA morphine during lockout intervals appear to reflect, in part, poor preoperative adaptation to surgery involving intrusive thoughts and avoidant behaviours about the upcoming surgery.

Preoperatıve Diclofenac Sodium and Tramadol for Pain Relief After Bimaxillary Osteotomy

The aim of this study was to compare the postoperative analgesic affects of preoperative use of a synthetic opioid tramadol and a nonsteroidal anti-inflammatory drug diclofenac sodium for postoperative pain, with placebo, in patients undergoing bimaxillary osteotomy. Thirty-six orthognathic surgery patients who underwent both Le Fort I osteotomy in the maxilla and bilateral sagittal split ramus osteotomy in the mandible as bimaxillary osteotomy were randomly allocated into 3 groups via sealed envelope technique. Group T (n = 12), group D (n = 12), and group P (n = 12) received preoperative 50 mg tramadol intramuscularly, 75 mg diclofenac sodium intramuscularly, and saline, respectively. Postoperative pain intensity (visual analog scale, verbal pain score), postoperative opioid consumption with intravenous patient-controlled analgesia, hemodynamic variables, and postoperative complications were compared among the 3 groups. The median number of patient-controlled analgesia demands (n) in group P (34, 28-39) was higher than other groups (group D 14, 11-13; group T 19, 12-25; P = .001). Total tramadol consumption was higher in group P (330 mg, 290-390) compared with group D (260 mg, 190-340; P = .046) and group T (270 mg, 200-330; P = .034). The 3 groups were comparable for the area under the hemodynamic variables time curves. The area under the visual analog scale and verbal pain score curves were lower in group D and group T compared with group P, however, there was no significant difference between group T and group D. Preoperative diclofenac or tramadol, compared with placebo, effectively decreases postoperative opioid consumption via intravenous patient-controlled analgesia.

Periprostatic Nerve Blockage Reduces Postoperative Analgesic Consumption and Pain Scores of Patients Undergoing Transurethral Prostate Resection

Introduction: To evaluate the effects of periprostatic bupivacaine administration on pain control and analgesic consumption after transurethral prostate resection (TURP). Materials and Methods: The study included 40 male patients with benign prostatic hyperplasia who underwent TURP, and they were divided randomly into two groups. All patients were operated under general anesthesia. The study group patients (n = 20) received periprostatic bupivacaine (0.5% 20 ml) injection (group I), and the control patients (n = 20) received only saline (NaCl 0.9% 20 ml) injection (group II). All injections were performed bilaterally into the periprostatic areas immediately after the TURP procedure via the transperineal route. In the postoperative period, all patients (groups I and II) received tramadol using a patient-controlled analgesia device. Postoperative pain was assessed and recorded using the visual analog scale (VAS) at postoperative hours 1, 2, 3, 4, 5, 6, 7, 8, 12, 16, 20, 24, and 48. Total tramadol consumptions and additional analgesic requirements were also recorded and compared between groups. Results: There was no difference in demographic data between the two groups (p > 0.05). VAS scores of the patients at hours 1, 3, 4, 5, 7, 8, and 12 were found to be significantly lower in group I than in group II (p < 0.05). Total tramadol consumption and patient-controlled analgesia demands of groups I and II were 153.5 ± 52.4 vs. 465.0 ± 55.1 mg and 17.1 ± 7.7 vs. 77.8 ± 7.5 mg, respectively (p < 0.001). No side effect was observed regarding bupivacaine injections. Conclusions: Periprostatic bupivacaine administration was a useful and safe method for postoperative pain control and reduced analgesic consumption in patients undergoing TURP.

The effects of single‐dose tramadol on post‐operative pain and morphine requirements after coronary artery bypass surgery

To investigate the effects of a single dose of tramadol administered prior to extubation on post-operative pain and morphine consumption after coronary artery bypass surgery. Patients were randomized post-operatively into two groups (group T, n= 30; group P, n= 30). The technique of anaesthesia was standardized for all patients. The patients in group T received intravenous tramadol, 1 mg/kg, and the patients in group P received 2 ml of saline 0.9%, both approximately 1 h before extubation. After extubation, all patients were allowed to use the morphine patient-controlled analgesia (PCA) device for 24 h post-operatively. Post-operative data were recorded in the cardiac intensive care unit at 30 min, 1 h, 2 h, 4 h, 12 h and 24 h after extubation by the same anaesthesiologist, who had no knowledge of the groups, and the side-effects were also evaluated. In group P, the visual analogue scale (VAS) scores were found to be higher 30 min (P < 0.01), 1 h (P < 0.01), 2 h (P < 0.01) and 4 h (P < 0.05) after extubation. The patient comfort scores were higher in group T 30 min (P < 0.01), 1 h (P < 0.05), 2 h (P < 0.01) and 4 h (P < 0.01) after extubation. The total morphine consumption was higher in group P at all evaluation times (P < 0.01), and the numbers of PCA demands and boluses were also higher in group P (P < 0.01). The study demonstrated that a single dose of tramadol administered prior to extubation following coronary artery bypass surgery is associated with a decrease of up to 25% in morphine consumption, a decrease in the VAS scores and an improvement in patient comfort within the first 4 h post-operatively.

Is Postoperative Pain a Self-Fulfilling Prophecy? Expectancy Effects on Postoperative Pain and Patient-Controlled Analgesia Use Among Adolescent Surgical Patients

To explore relationships among anxiety, anticipated pain, coping styles, postoperative pain, and patient-controlled analgesia (PCA) use among adolescent surgical patients and their parents. Sixty-five 12- to 18-year-old surgical patients undergoing surgery with postoperative PCA pain management were included. Before surgery, adolescents and parents reported anxiety and expected levels of postoperative pain. Pain catastrophizing and coping style were assessed within 48 hr after surgery, with pain scores and PCA use recorded through the end of the second postoperative day. Adolescents' preoperative psychological characteristics (anxiety and anticipated pain) predicted postoperative pain scores, number of PCA injections and demands, and the PCA injections:demands ratio, with reports of anticipated pain associating most closely with these postoperative pain outcomes. Parental anxiety and anticipated pain did not predict teens' postoperative pain. Coping style did not moderate the relationship between anticipated pain and pain outcomes. Findings are interpreted as suggesting a self-fulfilling prophecy in adolescents' postoperative pain experience wherein teens who expect to have high levels of postoperative pain ultimately report more pain and use more opioid PCA medication than those who report lower levels of pain.

Effect of Intraoperative Continuous I.V. Fentanyl on Tourniquet Induced Cardiovascular Changes and Postoperative Preemptive Analgesia in Total Knee Replacements

Background: It is difficult to treat tourniquet-induced hypertension despite adequate anesthesia, and the mechanism of that is not known. And it may be possible that intraoperative continuous infusion of opioid induces preemptive analgesia postoperatively. We investigated the effect of intraoperative continuous i.v. fentanyl on tourniquet induced cardiovascular changes and postoperative preemptive analgesia in total knee replacements. Methods: Sixty patients were randomly assigned to two groups; In study group (1.5 loading and 0.5 continuous infusion of fentanyl before skin incision and tourniquet inflation) and control group (no treatment). Anesthesia was maintained with enflurane (1-2 MAC) and 50% nitrous oxide in oxygen. Arterial pressure and heart rate were compared between two groups. They received postoperative pain treatment with patient-controlled analgesia (PCA) with fentanyl during the postoperative 48 hours after total knee replacement. Visual analog scale (VAS) scores at either rest or movement were used to assess pain. Total fentanyl dose delivered, number of PCA requests, supplemental analgesics, overall satisfaction score and adverse events were evaluated. Results: There were no significant differences between the two groups on cardiovascular changes by tourniquet induced pain effect. VAS, PCA delivered dose and PCA demands at movement in the 24-48 hour decreased in study group compared with control group (P

Combination of low-dose (0.1 mg) intrathecal morphine and patient-controlled intravenous morphine in the management of postoperative pain following abdominal hysterectomy

The aim of this double-blind prospective randomized study was to investigate combination of low-dose (0.1 mg) intrathecal morphine and patient-controlled intravenous morphine in the management of postoperative pain following abdominal hysterectomy. Side-effects, satisfaction and sedation were also evaluated.Fifty patients (ASA I) between 30 and 65 years of age, scheduled for elective abdominal hysterectomy were randomized to receive intrathecal 0.1 mg of morphine sulfate (ITM) or placebo and intravenous morphine (IVM). Both groups received standard general anesthesia. In the ITM group, 0.1 mg morphine was administered intrathecally just before emergence from anesthesia while an equal volume of sterile saline was administered in the IVM group. Thereafter, all patients received IV morphine via a patient controlled analgesia (PCA) pump, set to deliver a bolus of 1 mg with a lock-out of 7 minutes and maximum dose of 20 mg per 4 hours. Hemodynamics, respiration, PCA demands, VAS, sedation scores, total morphine consumption, satisfaction and side effects were recorded for 24 hours after surgery.There were no significant differences between the groups with respect to satisfaction score. Total morphine consumption was lower in the ITM group; VAS scores at the first 8 hours were lower in the ITM group. Sedation scores at 4, 8, and 12th hours were higher in the ITM group. There was no significant difference in terms of adverse effects.In conclusion, intrathecal morphine (0.1 mg) combined with intravenous PCA is a safe and effective method of providing analgesia after hysterectomy as evidenced by lower pain scores and total morphine consumption and improved patient satisfaction.

Addition of meperidine to bupivacaine for spinal anaesthesia for Caesarean section†

In a prospective, randomized, double-blind, placebo-controlled trial, we investigated the effect of adding meperidine 10 mg to intrathecal bupivacaine on the duration of early postoperative analgesia in 40 patients having elective Caesarean section under spinal anaesthesia. Patients received intrathecal injection of 0.5% hyperbaric bupivacaine 2.0 ml plus either normal saline 0.2 ml (saline group) or 5% meperidine 0.2 ml (meperidine group). After operation, all patients were given i.v. patient-controlled analgesia using morphine. The duration of effective analgesia, defined as the time from intrathecal injection to first patient-controlled analgesia demand, was greater in the meperidine group (mean 234 min, 95% confidence interval 200-269 min) compared with the saline group (mean 125 min, 95% confidence interval 111-138 min; P<0.001). The 24 h morphine requirement was similar in the two groups. The meperidine group had a greater incidence of intraoperative nausea or vomiting compared with the saline group (11 vs 3; P=0.02). Addition of meperidine 10 mg to intrathecal bupivacaine for Caesarean section is associated with prolonged postoperative analgesia but with greater intraoperative nausea and vomiting.

A comparison of bupivacaine-fentanyl-morphine with bupivacaine-fentanyl-diamorphine for caesarean section under spinal anaesthesia

In a randomised double-blind trial, postoperative analgesia and side effects of intrathecal morphine 0.1mg and intrathecal diamorphine 0.25mg were compared. Sixty women were randomised to receive intrathecal injection of 12.5mg hyperbaric bupivacaine and 12.5μg fentanyl with either morphine 0.1mg (group M), or diamorphine 0.25mg (group D). All women received 100mg diclofenac rectally at the end of surgery and were given intravenous morphine via a patient controlled analgesia (PCA) system. Pain, PCA morphine usage and side effects were assessed at 2, 4, 8 and 24h after spinal anaesthesia. The two groups were comparable for quality of intraoperative analgesia. There were no significant differences between the groups in time to first PCA demand, morphine consumption or oral analgesic use in each time period. Significantly more patients in group M were nauseated at 4h whilst at 24h nausea was significantly worse in group D. There was no significant difference between the groups in the number of women vomiting in the 24-h period. The two groups were comparable for pruritus and drowsiness. We conclude that 0.25mg subarachnoid diamorphine is a suitable alternative to 0.1mg morphine for post caesarean section analgesia.

Comparison of an Effective Dose of Intravenous Postoperative Patient-controlled Analgesia with Nalbuphine

Background: The management of postoperative pain with traditional narcotic analgesic regimen is associated with an unacceptably high failure rate and at best has represented a cautious compromise between adequate analgesia and the risk of complications, particularly that of respiratory depression. The purpose of this investigation was to compare the efficacy and safety of nalbuphine given by patient-controlled analgesia (PCA) with differential dosages after total knee replacement. Methods: A double-blind clinical trial of 75 patients who received intravenous nalbuphine with patientcontrolled analgesia during the postoperative first 48 hours after total knee replacement, was carried. Patients were assigned to three groups by the concentration of nalbuphine: Group 1 (n = 25), 2 mg/ml; Group 2, 4 mg/ml; Group 3, 6 mg/ml. The settings of PCA in three groups were same. Results: Visual analog scale (VAS) scores were used to assess pain. Group 2 and 3 patients reported significant lower VAS over the postoperatively 6 hours and 12 hours at either rest or movement compared to group 1. PCA demands, delivered doses and PCA nalbuphine dosage per hours except supplemental analgesic doses in the first 48 hours were lower in group 2 and 3 compared to group 1. There were significant differences among groups at postoperatively 6 and 12 hours in nausea, vomiting and sedation of the side effects. Conclusions: IV PCA with nalbuphine is thought to be potent and safe for postoperative pain relief without the major morbidity like respiratory depression, in addition, the careful observation and treatment on the side effect like nausea, vomiting and sedation, is surely needed. (Korean J Anesthesiol 2001; 40: 195∼200) ꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏ

The minimum effective concentration of opioids: A revisitation with patient controlled analgesia fentanyl

Background and Objectives: Whether patients titrate themselves to an individualized blood or plasma opioid concentration (the so-called minimum effective concentration or [MEC]) has been debated extensively. Nevertheless, there is consistent opinion that during patient controlled analgesia (PCA) patients balance acceptable pain relief against unacceptable side effects. This study sought to characterize fentanyl used by PCA with respect to MEC and factors influencing PCA use. Methods: An intensive study of 25 patients with observations over the first 24 hours after orthopedic surgery was planned on the premise that this approach would provide a measure of the fentanyl MEC. This necessitated repeated measurements of pain scores and plasma fentanyl concentrations before and 10 minutes after every PCA demand. In addition, a battery of psychological tests was given before and approximately 48 hours after surgery. Results: Logistic difficulties of maintaining a 24-hour study design resulted in its termination after 5 patients. The patients had convincingly distinct MECs (ranging from 0.23 to 0.99 ng/mL). The relationship between plasma fentanyl concentration and pain score was steep, such that small changes in concentration coincided with marked changes in pain relief. Despite preoperative expectations of achieving satisfaction in postoperative analgesia, not all patients titrated themselves to a pain-free state; all but one were satisfied with PCA. Surprisingly few side effects were reported. Unfortunately, the small sample size made systematic analysis of the psychological tests impossible. Conclusions: This study found evidence to support the concepts of an individual MEC and a therapeutic window of fentanyl used with PCA. Reg Anesth Pain Med 2000;25:259-267.

Benzocaine-Induced Methemoglobinemia

Benzocaine-Induced Methemoglobinemia