Intravenous morphine titration

OBJECTIVES: To describe principles of intravenous (i.v.) morphine titration. To analyse current knowledge based on the experimental and clinical studies. To describe clinical implications in the operating room, postanaesthesia care unit (PACU), prehospital care, emergency and intensive care units (ICU), and cancerology. To provide recommendations for clinical practice. DATA SOURCES: Search in the Medline database without limitation, using the following keywords: morphine titration. STUDY SELECTION: All types of articles were selected including prospective randomised (or not randomised) studies in adults and children, practice guidelines, reviews, editorials and case reports. DATA SYNTHESIS: Intravenous (i.v.) morphine titration is a pharmacological method which involves morphine boluses administration until pain relief, allowing a limitation in morphine side effects which are mainly dose dependent. I.v. morphine titration is widely used in prehospital care, emergency unit, PACU, ICU, and cancerology, in young and elderly patients. In the PACU, when the VAS (visual analogue scale) increases to more than 30 mm, i.v. morphine titration every five minutes with an unlimited number of 2 or 3 mg boluses provides an efficient analgesic regimen in adults. Titration is performed until pain relief (VAS < or =30), sedation that is the most frequent side effect during i.v. morphine titration (Ramsay score >1), severe side effects (like respiratory depression). CONCLUSION: Because of important pharmacological variability in morphine need, iv morphine titration is a simple method which allows a rapid and efficient pain relief notably in the postoperative care.     

Pain relief after arthroscopic knee surgery--intraarticular sufentanil vs morphine

BACKGROUND: Prevention of postoperative pain by injecting opioid into the knee joint is believed to support the hypothesis of peripheral opioid receptor activation in inflammation. Main outcomes were reduction of pain intensity and need for supplementary analgesics. The aim of the present study was to evaluate the analgesic effects of intraarticular sufentanil in comparison with morphine, following arthroscopic procedures of knee joint. METHODS: In this prospective, double-blind study, 45 patients were randomized in three equal number groups to receive either sufentanil 5 ug (group S), morphine 3 mg (group M) or normal saline 20 cc as placebo, (group P) intra-articularly at the end of arthroscopic knee surgery, under general anesthesia. Pain levels at rest and at intervals of 1,2,4,8,12,14 hours and during movement of knee at discharge time, were measured by a Visual Analog Scale (VAS) and Numeric Rating Scale (NRS) postoperatively and the day after surgery. RESULTS: Significant difference between the groups (p < 0.001) were found. Pain scores were statistically lower in the sufentanil (S) and morphine (M) groups in comparison with the normal saline placebo (P) group. Inta-articular sufentanil was however more effective than morphine. CONCLUSION: The Intra-articular injection of morphine and sufentanil, reduce both the post arthroscopic knee procedures pain, and the need for supplementary analgesics. However, sufentanil, 5 microg is more effective than morphine.     

Forty-eight hours of postoperative pain relief after total hip arthroplasty with a novel, extended-release epidural morphine formulation

BACKGROUND: Epidural morphine has proven analgesic efficacy in the postoperative period and is widely used. This study evaluated the efficacy of extended-release epidural morphine (EREM; DepoDur; Endo Pharmaceuticals Inc., Chadds Ford, PA; SkyePharma, Inc., San Diego, CA) in providing pain relief for 48 h after surgery. METHODS: Patients (n = 200) scheduled to undergo total hip arthroplasty were randomized to receive a single dose of 15, 20, or 25 mg EREM or placebo. After surgery and after asking for pain medication, patients had access to intravenous patient-controlled analgesia fentanyl for breakthrough pain as needed. Postoperative intravenous patient-controlled analgesia fentanyl use, time to first postoperative fentanyl use, pain intensity at rest and with activity, patient and surgeon ratings of pain control, and adverse events were recorded. RESULTS: All EREM dosages reduced the mean (+/- SD) fentanyl use versus placebo (510 +/- 708 vs. 2,091 +/- 1,803 microg; P < 0.0001) and delayed the median time to first dose of fentanyl (21.3 vs. 3.6 h; P < 0.0001). All EREM groups had significantly improved pain control at rest through 48 h postdose (area under the curve [0-48 h]) compared with placebo (P < 0.0005). More EREM-treated patients rated their pain control as good or very good compared with placebo (at 24 h: 90 vs. 65%, P < 0.0001; at 48 h: 83 vs. 67%, P < 0.05). No supplemental analgesia was needed in 25% of EREM-treated patients and 2% of placebo-treated patients at 48 h (P < 0.05). The safety profile of EREM was consistent with that of other epidurally administered opioid analgesics. CONCLUSIONS: EREM provided significant postoperative pain relief over a 48-h period after hip surgery, without the need for indwelling epidural catheters.     

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.     

Wirksamkeit von periartikulär appliziertem Morphin nach Schulterarthroskopien

Peripheral opioid receptors have been found in inflamed synovia and the analgesic effect of intra-articularly administered morphine after arthroscopic knee surgery has been proven. There is controversy about efficacy of intraarticular morphine after shoulder arthroscopy. Thirty-two patients with impingement syndrome underwent subacromial decompression in the course of arthroscopic shoulder surgery. At the end of the operation morphine (5 mg) or saline was injected periarticularly. Pain intensity (rest and passive mobilisation) was recorded after recovery and after 1,2,4, and 24 hours (Numeric Rating Scale); the use of rescue medication (piritramide by patient controlled analgesia) was noted. No relevant pain reduction was apparent in the morphine group. Piritramide consumption was identical in both groups (19.7 +/- 16 mg vs. 19.8 +/- 19 mg). We conclude that periarticularly administered morphine in arthroscopic subacromial decompression in the dosage applied in this study does exert no relevant analgesic effect. This is possibly due to the fact that either subacromial tissue, despite of chronic inflammation, does not show the same reagibility as synovia or it is a problem of the nearly complete resection of the subacromial bursa.     

Caudal morphine for pain relief following anal surgery.

A prospective randomised trial was conducted to evaluate caudal morphine for pain relief following anal surgery. Thirty-three male patients were divided into two groups. Group I (17 patients) were given morphine 10 mg in saline 25 ml injected into the caudal epidural space at the end of surgery. Group II (16 patients) were given intramuscular morphine 10 mg on request in the postoperative period. Pain was assessed at 2, 6, 12 and 24 hours after surgery using the linear analogue of pain score. There was significant pain relief in Group I compared with Group II. There was no instance of respiratory depression in patients of either group. In Group I, five patients suffered urinary retention and three patients transient pruritus.     

Intrathecal + PCA morphine improves analgesia during the first 24 hr after major abdominal surgery compared to PCA alone

PURPOSE: To compare, over a 48-hr follow-up period, the analgesia and side-effects of patient controlled iv analgesia (PCA) with morphine alone vs combined intrathecal and PCA morphine (IT+PCA) in patients undergoing major abdominal surgery. METHODS: Sixty adult patients undergoing abdominal surgery for cancer were randomly allocated to receive preoperative IT (0.3 or 0.4 mg) plus postoperative PCA morphine or postoperative PCA morphine alone. Postoperative analgesia was tested at rest and while coughing on a visual analogue pain scale and morphine consumption was recorded. Patients' satisfaction, arterial oxygen saturation, respiratory rate, episodes of nausea, vomiting and pruritus were also noted. RESULTS: Analgesia at rest and while coughing was significantly better in the IT+PCA morphine group (rest: P = 0.01; coughing: P = 0.005) on the first postoperative day only. IT+PCA morphine constantly provided adequate analgesia during this period. Morphine consumption was lower in the IT+PCA morphine group during this period also (IT+PCA: 9 (17) vs PCA: 40 (26); mg of morphine, mean (SD), P = 0.0001). No difference was found in pain relief and morphine consumption between the groups on the second postoperative day. Nausea and vomiting were more frequent with IT+PCA morphine on the first postoperative day. No respiratory depression occurred in either group. Satisfaction was high in both groups. CONCLUSIONS: IT+PCA morphine improves patient comfort constantly during the first postoperative day after major abdominal surgery. However, after the first postoperative day, IT+PCA morphine provides no additional benefit.     

Analgesic efficacy of inhaled morphine in patients after bunionectomy surgery

BACKGROUND: The AERx Pain Management System (Aradigm Corporation, Hayward, CA) is a novel pulmonary delivery system for the systemic administration of morphine. The authors compared the relative analgesic efficacy and safety of the AERx Pain Management System with those of placebo and intravenous morphine in an orthopedic postsurgical pain model. METHODS: Eighty-nine male and female PS-1 to PS-3 patients underwent standardized bunionectomy surgery and received multiple doses of inhaled or intravenous placebo, inhaled morphine (one inhalation [2.2 mg] or three inhalations [6.6 mg]), or intravenous morphine (4 mg) in a blinded fashion. Open-label rescue morphine (2 mg) was also available as needed. Pain intensity, pain relief, and time to pain relief were measured after the first dose. Global evaluation, morphine consumption, vital signs, and adverse events were monitored for 8 h after treatment. Blinded study personnel performed all treatment administrations and pain assessments. RESULTS: Three inhalations of morphine and 4 mg intravenous morphine provided comparable single- and multiple-dose analgesia. One inhalation of morphine was statistically indistinguishable from placebo. Three inhalations of morphine and 4 mg intravenous morphine both consistently demonstrated significantly greater analgesic efficacy than did placebo and one inhalation of morphine. CONCLUSIONS: Comparable analgesic efficacy was demonstrated between a carefully matched dose of inhaled and intravenous morphine in a postsurgical pain model.     

Low-dose sufentanil dœs not potentiate intra-thecal morphine for perioperative analgesia after major colorectal surgery

PURPOSE: Both intrathecal sufentanil (ITS) and intrathecal morphine (ITM) improve analgesia in obstetrical or cardiac procedures. From a pharmacokinetic standpoint, combining these two opioids may improve perioperative analgesia. We performed a prospective randomized double-blind study to compare the analgesic efficacy of ITM alone vs a mixture of a low dose of ITS plus ITM for perioperative pain relief in colorectal surgery. METHODS: Eighty adult patients undergoing colorectal surgery were randomly allocated to receive either 0.4 mg ITM alone or 10 microg ITS plus 0.4 mg ITM before general anesthesia. Intraoperative intravenous sufentanil consumption, postoperative morphine consumption delivered with a patient controlled analgesia device, pain scores, patient satisfaction and adverse effects were recorded for the first 48 hr postoperatively. RESULTS: No differences were observed between groups with respect to intraoperative sufentanil consumption (39 +/- 23 microg in group ITM and 40 +/- 25 microg in group ITS plus ITM, P = 0.85) and in postoperative morphine consumption in postanesthesia care unit (6 +/- 5 mg vs 6 +/- 5 mg, P = 0.59), at 24 hr (26 +/- 17 vs 24 +/- 15 mg, P = 0.59) and at 48 hr (47 +/- 31 vs 44 +/- 22 mg, P = 0.58). Similarly, no differences were observed in regards to pain relief, patient satisfaction and incidence of adverse effects. CONCLUSIONS: These results do not support the addition of 10 microg ITS to 0.4 mg ITM for colorectal surgery, as low dose sufentanil does not improve intraoperative and postoperative analgesia in this setting.     

Does morphine premedication influence the pain and consumption of postoperative analgesics after total knee arthroplasty?

Evidence of pre-emptive analgetic effect of opioid would offer great potential benefit to patients with postoperative pain, a better pain relief with less opioid. The aim of this double blind randomised trial was to study the effect of intramuscular morphine premedication on postoperative pain.
Forty-one patients undergoing total knee arthroplasty were randomly allocated to four groups. Two groups received epidural morphine, 4 mg immediately after operation and 3 mg ten hours later, and two groups the same volume of saline. All patients had access to intravenous PCA-fentanyl. One epidural morphine and one epidural saline group (PreEpiMo and PreMo, respectively) received morphine, 0.14 mg/kg i.m. as premedication. Pain was measured with a visual analogue scale (VAS). Respiration was monitored by means of pulseoximetry, arterial blood gas analysis and rate of breathing.
Morphine premedication reduced postoperative pain in the immediate postoperative period in patients with epidural placebo (PreMo), hut the effect was absent in patients with PreEpiMo. Epidural morphine (EpiMo) provided stable analgesia with reduced need of PCA-fentanyl. Two patients (10%) (one in EpiMo and one in PreEpiMo) developed respiratory depression requiring naloxone treatment. The dosage of epidural morphine used in this study was a likely explanation of this depression. Nausea, vomiting, itching and urinary retention were the most frequent side effects without significant differences between the groups. In conclusion, morphine premedication had a temporary rest effect on the postoperative pain. Epidural morphine provides a better analgesia than intravenous PCA-fentanyl.     

Rectally administered diclofenac (Voltaren) reduces vomiting compared with opioid (morphine) after strabismus surgery in children

BACKGROUND: Nausea, vomiting and pain are common complications after strabismus surgery in children. Diclofenac, a non-steroid anti-inflammatory drug, is widely used to treat acute and chronic pain but there are few reports of its use given rectally in children undergoing strabismus surgery. This open randomised study was designed to investigate the analgesic and anti-emetic properties of rectally administered diclofenac compared with opioid (morphine) given i.v. in connection with strabismus surgery in children. METHODS: After obtaining approval from the local ethics committee and written informed consent from the parents, 50 ASA class I-II children, 4-16 years of age, were randomised to receive either rectally administered diclofenac (Voltaren) 1 mg/kg or i.v. opioid (morphine) 0.05 mg/kg perioperatively. The children were consecutively operated upon from May 1999 to January 2001. Anaesthesia was induced with fentanyl and propofol and maintained with propofol. Nitrous oxide was omitted. The postoperative pain was assessed after arrival at the post anaesthesia care unit (PACU) by using the validated Wong and Baker scale (FACES) Pain Rating Scale. Postoperative nausea and vomiting (PONV) was assessed by measuring the frequency of vomiting and the degree of nausea. RESULTS: In the diclofenac group the incidence of PONV during the first 24 h was 12% (of which one child had severe vomiting). The incidence of PONV was much higher, 72% (P = 0.0000), in the morphine group, where 56% of the children also had severe vomiting. There were no difference in pain score between the two groups. Recovery time at the PACU was longer (P < 0.002) and the postoperative analgesic requirement higher in the morphine group (10 vs. 5 children). No children needed overnight admission to the hospital. CONCLUSION: Diclofenac given rectally is an effective analgesic for this kind of surgery and gives less postoperative nausea than i.v. morphine. No serious adverse events were observed.     

Postoperative titration of intravenous morphine in the elderly patient.

BACKGROUND: Intravenous morphine titration is used to obtain rapid and complete postoperative pain relief. Whether this titration can be safely administered in the elderly patients remains a matter for debate. METHODS: Intravenous morphine titration was administered as a bolus of 2 (body weight < or = 60 kg) or 3 (body weight > 60 kg) mg. The interval between each bolus was 5 min. There was no limitation in the number of boluses given until pain relief or severe adverse effect occurred. The visual analog scale threshold required to administer morphine was 30 mm, and pain relief was defined as a visual analog scale score of 30 mm or less. Patients were divided into two groups: young and elderly (age > or = 70 yr) patients. Data were expressed as mean +/- SD. RESULTS: Eight hundred seventy-five patients (83%) were young and 175 patients (17%) were elderly. At the end of morphine titration, the visual analog scale score and the number of patients with pain relief were not significantly different between groups. The total dose of morphine per kilograms of body weight administered was not significantly different between groups (0.15 +/- 0.10 vs. 0.14 +/- 0.09 mg/kg, not significant). No significant differences were observed in the incidence of morphine-related adverse effects (13 vs. 14%, not significant), the number of sedated patients (60 vs. 60%, not significant), and the number of patients whose titration had to be stopped (2 vs. 2%, not significant). CONCLUSION: Intravenous morphine titration can be safely administered to elderly patients. Because titration is adapted to individual pain, the same protocol can be applied to young and elderly patients.     

Postoperative morphine consumption in the elderly patient

BACKGROUND: It has been suggested that the dose of intravenous morphine used during postoperative titration is not modified by aging. The authors therefore studied morphine requirements in patients undergoing total hip replacement. METHODS: Intravenous morphine titration was administered as boluses, then subcutaneous morphine was administered every 4 h over 24 h. Pain was assessed by use of the visual analog scale (0 to 100), and the threshold required to administer morphine was 30. Young and elderly (> or =70 yr old) patients were compared. Data are mean +/- SD or odds ratio (OR) [95% CI]. RESULTS: Two hundred twenty-four patients (68%) were young and 105 (32%) were elderly. The initial visual analog scale was not significantly different between groups. The dose of intravenous morphine in the postanesthesia care unit was not significantly different between young and elderly patients (0.15 +/- 0.11 vs. 0.14 +/- 0.10 mg/kg, P = NS), in contrast to the dose of subcutaneous morphine (0.18 +/- 0.18 vs. 0.11 +/- 0.11 mg/kg, P < 0.001) in the ward. Only severe pain (visual analog scale of 70 or greater; OR, 10.5 [4.5-24.8]) was significantly associated with a high dose (greater than 0.15 mg/kg) of intravenous morphine, whereas severe pain (OR, 2.5 [1.6-4.0]), age less than 60 yr (OR, 2.3 [1.4-3.8]), and absence of a nonsteroidal antiinflammatory drug (OR, 1.9 [1.2-3.1]) were significantly associated with a high dose (greater than 0.12 mg/kg) of subcutaneous morphine. CONCLUSIONS: The dose of intravenous morphine during titration is not modified in elderly patients, in contrast to the dose administered subcutaneously over a prolonged period.     

Continuous epidural infusion of morphine for treatment of pain after thoracic surgery: a new technique

We evaluated postoperative pain relief and the incidence of side effects of three methods of thoracic epidural analgesia. Ninety patients, divided into three equal groups, received postoperative analgesia after thoracic surgery either as intermittent epidural injections of bupivacaine (25 mg/5 ml, 0.5% solution) as needed, or, intermittent epidural injections of morphine (5 mg/5 ml of normal saline, 0.1% solution) as needed, or continuous epidural infusion of morphine (0.1 mg, in 1 ml of normal saline) per hour supplemented with intravenous morphine (2 mg) upon request. Pain relief was evaluated by each patient on a pain scale visual analogue and by pain relief questionnaire for a period of 72 hr. Postoperative pain relief was achieved equally with these three methods of epidural analgesia in all patients with no significant difference between groups. Intermittent epidural injection of bupivacaine relieved pain for 4.9 +/- 1.9 (SD) hr/injection and was associated with urinary retention in all patients, with numbness and weakness of the hands in 12 patients, and with severe hypotension in 7 patients. Intermittent epidural injection of morphine relieved pain for 5.8 +/- 2.3 hr/injection and was associated with urinary retention in all patients, with pruritus in 12 patients, and with central narcosis and respiratory depression in 8 patients. Continuous epidural infusion of morphine with occasional intravenous morphine (2 mg) supplementation also effectively relieved postoperative pain and was associated with minimal systemic side effects. One patient complained of pruritus, and two patients developed urinary retention.(ABSTRACT TRUNCATED AT 250 WORDS)     

Continuous epidural infusion of morphine for pain relief after cardiac operations

Postoperative pain relief and stress hormones were examined during the use of continuous epidural infusion of morphine at a rate of 0.1 mg/hr in 30 patients (Group B) after coronary artery bypass grafting. This was compared to our routine method of postoperative analgesia of intravenous morphine 2 mg/2 hr and as needed in another 30 patients (Group A). Continuous epidural morphine infusion required occasional supplementation with intravenous morphine and achieved effective analgesia in 80% of the patients. Pain relief was adequate in 50% of the patients in Group A. The mean dose of morphine used in Group B during the first 3 postoperative days was 5 mg per patient per day and was significantly lower than that used in Group A (mean 18 mg per patient per day). Serum morphine was undetectable (below 2.5 ng/ml) in Group B and was significantly lower than that in Group A (17 ng/ml). Epidural analgesia was associated with adequate postoperative pulmonary and cardiovascular functions; nausea and vomiting occurred in two patients. Levels of postoperative stress, serum cortisol, and beta-endorphin were significantly lower in Group B than in Group A. This study shows that continuous epidural infusion of morphine at a rate of 0.1 mg/hr provides selective and effective pain relief and reduces postoperative stress after cardiac operations. This method of analgesia was also associated with minimal side effects and provides an alternate approach for treatment of pain after cardiac operations.     

The antiemetic effect of dexamethasone during continuous subcutaneous infusion of morphine for postoperative pain relief

BACKGROUND: Dexamethasone is known to reduce the incidence of postoperative nausea and vomiting, associated with perioperative intrathecal, epidural, or intravenous morphine. However, the effect of dexamethasone on subcutaneous morphine is unclear. Therefore, we evaluated the antiemetic effect of intravenous dexamethasone during continuous subcutaneous infusion of morphine for postoperative pain relief. METHODS: Twenty patients scheduled for spinal surgery under general anesthesia were enrolled in this randomized, double-blind, and placebo-controlled study. The dexamethasone group (n=10) received dexamethasone 8 mg and the saline group (n=10) received the same amount of saline before the induction of anesthesia. Anesthesia was maintained with propofol and fentanyl. Postoperative pain was treated with continuous subcutaneous morphine via a patient-controlled analgesia device. Postoperatively patients were assessed during 48 hours for nausea and vomiting. RESULTS: Nausea or vomiting ascribable to the subcutaneous morphine developed in 40% of the patients in each group (P:NS). CONCLUSIONS: Our results suggest that the single dose of dexamethasone (8 mg) does not reduce postoperative nausea and vomiting associated with continuous subcutaneous infusion of morphine after spinal surgery.     

Adding ketamine to morphine for patient-controlled analgesia after major abdominal surgery: a double-blinded, randomized controlled trial.

In this double-blinded, randomized controlled trial we tested if the addition of ketamine to morphine for patient-controlled analgesia (PCA) resulted in improved analgesic efficacy and lower pain scores compared with morphine PCA alone after major abdominal surgery. Seventy-one patients were randomly allocated to receive either morphine 1 mg/mL (Group M) or morphine 1 mg/mL plus ketamine 1 mg/mL (Group MK) delivered via PCA after surgery. No other analgesics or regional blocks were permitted during the 48-h study period. Postoperatively there were no differences between the groups for subjective assessment of analgesic efficacy, pain scores at rest, and on movement, opioid consumption, or adverse events. Group MK patients performed worse in cognitive testing (P = 0.037). There was an increased risk of vivid dreaming in patients who received ketamine (relative risk = 1.8, 95% confidence interval 0.78-4.3). We conclude that small-dose ketamine combined with PCA morphine provides no benefit to patients undergoing major abdominal surgery. Implications: We performed a randomized, controlled trial comparing the use of ketamine and morphine with morphine alone to relieve pain after major abdominal surgery.Ketamine did not improve pain relief and merely increased side effects.     

Intra-articular morphine and/or bupivacaine in the management of pain after total knee arthroplasty

The purpose of this study was to determine if intra-articular injection of morphine or bupivacaine significantly decreased postoperative pain as well as the use of intravenous narcotics for pain relief in patients undergoing total knee arthroplasty (TKA). In a prospective, double-blind, randomized fashion, 105 patients undergoing TKA were divided into the following 4 groups defined by the intra-articular injection they received: group 1 (n = 27) received saline solution, group 2 (n = 26) received morphine sulfate (5 mg), group 3 (n = 24) received bupivacaine (50 mg), and group 4 (n = 28) received a combination of morphine sulfate and bupivacaine. The injections were administered immediately after wound closure by the Hemovac drainage tubing that remained clamped for 45 minutes after surgery to allow for absorption. Before surgery and at 2, 4, 6, 24, and 48 hours after surgery, pain intensity was recorded using a visual analog scale. Postoperative supplemental intravenous morphine and/or meperidine was administered via a patient-controlled analgesia device, and 24-hour drug usage was tabulated. Results were suggestive of a modest short-term reduction in pain scores in the morphine and bupivacaine treatment groups compared with placebo (saline); however, results were statistically significant only at 4 hours because of the great variability in the pain score data. The total amount of postoperative pain medication used in the first 24 hours after surgery was not statistically significant between the 4 treatment groups. Thus, the results put into question the benefit of postoperative intraarticular administration of morphine or bupivacaine in patients undergoing TKA.     

Evaluating the Effect of Intravenous Acetaminophen in Multimodal Analgesia After Total Hip Arthroplasty: A Randomized Controlled Trial

BackgroundPostoperative pain is a significant concern of patients before surgery. Multimodal pain management is an effective method of pain control after major orthopedic surgery. Acetaminophen is the most commonly used analgesic for the management of pain. It was hypothesized that 1000 mg of intravenous acetaminophen (IA) dosed every 6 hours would significantly reduce the postoperative pain score at rest and the opioid consumption volume in patients who would undergo total hip arthroplasty (THA) when compared to a control group.MethodsA single-center, prospective, open-label randomized control study was conducted. A total of 97 patients undergoing unilateral primary THA were divided into 2 groups: the study group (IA) (n = 45) and the control group (n = 52). The study group received administered IA after surgery, while the control group received only a standard pain control. Both groups received a preoperative femoral nerve block and postoperative intravenous fentanyl citrate. The primary outcome was the evaluation of the pain score at rest 24 hours after surgery. The pain score was measured using the Numerical Rating Scale. The primary outcome of this study was analyzed using generalized estimating equation.ResultsThe IA group had a significant improvement in Numerical Rating Scale score at rest 24 hours after THA compared to the control group (−0.91, 95% confidence interval −1.56 to −0.26, P = .006), suggesting a positive effect of IA usage for pain relief. The total fentanyl citrate consumption after surgery for 24 hours was significantly lower in the IA group than those of the control group (52.07 ± 7.64 vs 57.83 ± 12.44 mg, P < .001).ConclusionPostoperative administration of IA significantly reduced the postoperative pain score and opioid consumption volume after primary THA. IA was useful as one role of multimodal pain management after THA.Level of Evidence: Level 2.     

A background infusion of morphine enhances patient-controlled analgesia after cardiac surgery

PURPOSE: We compared the efficacy of patient-controlled analgesia (PCA), with or without a background infusion of morphine, on postoperative pain relief in patients extubated in the operating room after coronary artery bypass grafting (CABG) surgery. METHODS: With Faculty Ethics approval, 60 consenting adults undergoing elective coronary artery surgery were randomly assigned to receive either morphine PCA alone (group PCA-A, n = 30) or morphine PCA plus a background infusion (group PCA-B, n = 30) for 24 hr postoperatively. Pain scores with verbal rating scale (VRS; from 0 to 10) at rest, sedation scores, morphine consumption and delivery/demand ratios were assessed at zero, one, two, four, six, 12 and 24 hr after surgery. Hemodynamic variables and arterial blood gases were also recorded in the same periods. RESULTS: Sedation scores in the two groups were similar. At all study periods after the first postoperative hour, VRS remained below 5 in both groups. Pain scores were significantly lower in the background infusion group, which also had greater cumulative morphine consumption (61.7 +/- 10.9 mg vs 38.5 +/- 16.2 mg). There were no episodes of hypoxemia or hypertension. CONCLUSION: Morphine PCA effectively controlled postoperative pain after cardiac surgery. The addition of a background infusion of morphine enhanced analgesia and increased morphine consumption.