Intravenous Morphine Research Articles

Serratus intercostal interfascial plane block in supraumbilical surgery: a prospective randomized comparison.

Upper abdominal wall surgical incisions may lead to a severe postoperative pain. Therefore, adequate analgesia is important. Here we investigate whether the low serratus-intercostal interfascial plane block (SIPB) achieves an effective analgesia, considering opioids consumption, pain control and recovery quality in upper abdominal surgeries. This blinded, randomized controlled study was conducted on 102 patients undergoing open upper abdominal wall surgery under general anesthesia. All patients who received serratus-intercostal plane block at the eighth rib as analgesic technique were included in SIPB group and in control group those who received continuous intravenous morphine analgesia. Pain scores in numeric verbal scale (NVS) and opioids consumption at 0, 6, 12, 24 and 48 hours postoperatively were assessed. The quality of the postoperative recovery was evaluated using the QoR-15 questionnaire at 24 hours. This study showed lower postoperative opioid consumption at 24 hours (P<0.0001; 4.17 mg vs. 41.52 mg of morphine) and better pain control (P<0.005) with mean pain scores (NVS 1.8±1.5 vs. 4.8±1.6) in group 0 (SIPB). The global QoR-15 scores 24 hours postoperatively were higher (better quality) in the SIPB group (122 vs. 100). The low serratus-intercostal interfascial plane block (SIPB) provides efficient analgesia leading to a saving of opioids and improvement of the recovery quality in patients undergoing upper abdominal wall surgeries.

Anesthetic management in laparoscopic living donor hepatectomy, the first case-series in Thailand

Background: Laparoscopic living donor hepatectomy began early in 2020 at our institution. This surgery was the first case and a new experience in Thailand. Perioperative and anesthetic management should not only concern anesthetic and surgical com plications but also graft function, including ischemic time. In this paper, we review anesthetic considerations and perioperative management in laparoscopic living donor hepatectomy as a new experience in Thailand. Methods: All four living donors were selected and underwent elective laparoscopic living donor hepatectomy at the university hospital. Results: Differences in anesthetic considerations between laparoscopic liver resection in pathologic livers versus donor liver graft typically include heparin administration, intravenous indocyanine green, and prolong ischemic time after major vessels clamping. During the operation, only one case had subcutaneous emphysema and one other case had oliguria. There were no in traoperative hypothermia in all cases. All the patients were able to be extubated at the end of surgery inside the operation room. For postoperative pain control, two cases were given intravenous morphine patient-controlled analgesia, while the others were given continuous intravenous morphine infusion. However, emergent explore laparotomy was performed in one case to stop postoperative bleeding from the surgical site. Conclusions: The advantages of minimal invasive technique include a potential reduction in blood loss and transfusion require ment, lower incidence of intraoperative hypothermia, as well as decreased postoperative pain and opioid consumption. However, complications that must be taken into account include the effect of pneumoperitoneum, patient’s positioning, and emergent conversion to open surgery. As this surgery is largely dependent on the surgeon’s experience, operation time may be extended in some cases. As an anesthesiologist, practical and effective anesthetic management is essential to improve patient outcomes.

Evaluation of topical morphine for treatment of oral mucositis in cancer patients.

Oral mucositis is a painful side effect to chemotherapy. Orally applied opioids may offer analgesia with fewer side effects than systemic opioids. A randomized trial comparing the analgesic effect of a morphine oromucosal solution (OM) to placebo and a positive control group receiving intravenous (IV) morphine as an add-on treatment to morphine patient-controlled analgesia (PCA) in a mixed population of paediatric and adult haematology patients. All patients in the study were equipped with a morphine PCA pump and the participating patients were instructed to use this pump as an escape. Primary outcome was morphine consumption (mg/kg/hour) on the PCA pump. Secondary outcomes included pain intensity difference at rest and when performing oral hygiene, time to first PCA bolus, nutrition intake and adverse events. A total of 60 patients (38 children <18 years) were randomized. Thirty patients were allocated to morphine OM/placebo IV (group MO), 15 patients to placebo OM/morphine IV (group MI) and 15 patients to placebo OM/placebo IV (group P). The median morphine consumption in the MO group (22.7 mcg/kg/hour 95% confidence interval (CI) 19.4-29.4 mcg/kg/hour, p = 0.38) was not significantly different from the placebo group (24.6 mcg/kg/hour 95% CI 16.8-34.4 mcg/kg/hour, p = 0.44) or the MI group (13.7 mcg/kg/hour 95% CI 9.7-37.8 mcg/kg/hour). For the secondary outcomes, the analysis of summed pain intensity difference after the first, third and fourth administrations of study medication indicated a reduction in pain for the MI group compared to the P and MO groups. No serious adverse events were reported. The findings indicate that the analgesic effect of peripherally applied morphine is not significantly different from placebo, and parenteral opioids should continue to be the standard of care.

Topical Capsaicin for Treating Cannabinoid Hyperemesis Syndrome

Introduction Cannabinoid hyperemesis syndrome (CHS), associated with chronic cannabis use, presents with cyclic abdominal pain, nausea, and vomiting. With increasing use of marijuana, the incidence of CHS is expected to increase. Most patients with CHS make frequent visits to the emergency room and are usually refractory to conventional treatment. We, therefore, present a case of CHS successfully treated with topical capsaicin application. Case Presentation. A 41-year-old female with a recent excess use of cannabis presented to the emergency department for evaluation of recurrent excruciating epigastric pain accompanied by severe nausea and vomiting. She had similar, milder symptoms a year ago and underwent endoscopic evaluation which was negative except for mild reflux esophagitis for which she was started on a proton pump inhibitor. On this presentation, basic laboratory workup, EKG, and CT scan of abdomen and pelvis were unremarkable. A detailed abdominal exam was only positive for mild epigastric tenderness. She was instructed to continue pantoprazole and pain medication and outpatient repeat esophagogastroduodenoscopy. The patient returned the next day with extreme retching, nausea, and vomiting and was admitted for further evaluation. Intravenous fluids, antiemetics, and morphine were started for pain control with no symptomatic improvement. A diagnosis of cannabis hyperemesis syndrome was made based on history of chronic marijuana use and otherwise negative workup. A trial of topical capsaicin, over the epigastric region, was tried that provided dramatic relief within 24 hours. Repeat endoscopic evaluation had no evidence of ulcers, celiac disease, or esophagitis. She was discharged on topical capsaicin and counselled on marijuana abstinence, with no return of symptoms. Conclusion Based on the dramatic resolution of symptoms with topical capsaicin, our case supports this promising intervention and provides an alternate approach to antiemetics and narcotics routinely used in patients with cannabis hyperemesis syndrome.

Effect of perioperative intravenous lidocaine for patients undergoing spine surgery

Background:Perioperative intravenous lidocaine has been reported to have analgesic and opioid-sparing effects in many kinds of surgery. Several studies have evaluated its use in the settings of spine surgery. The aim of the study is to examine the effect of intravenous lidocaine in patients undergoing spine surgery.Methods:We performed a quantitative systematic review. Databases of PubMed, Medline, Embase database and Cochrane library were investigated for eligible literatures from their establishments to June, 2019. Articles of randomized controlled trials that compared intravenous lidocaine to a control group in patients undergoing spine surgery were included. The primary outcome was postoperative pain intensity. Secondary outcomes included postoperative opioid consumption and the length of hospital stay.Result:Four randomized controlled trials with 275 patients were included in the study. postoperative pain compared with control was reduced at 6 hours after surgery (WMD −0.50, 95%CI, −0.76 to −0.25, P < .001), at 24 hours after surgery (WMD −0.50, 95%CI, −0.70 to −0.29, P < .001) and at 48 hours after surgery (WMD −0.57, 95%CI, −0.96 to −0.17, P = .005). The effect of intravenous lidocaine on postoperative opioid consumption compared with control revealed a significant effect (WMD −15.36, 95%CI, −21.40 to −9.33 mg intravenous morphine equivalents, P < .001).Conclusion:This quantitative analysis of randomized controlled trials demonstrated that the perioperative intravenous lidocaine was effective for reducing postoperative opioid consumption and pain in patients undergoing spine surgery. The intravenous lidocaine should be considered as an effective adjunct to improve analgesic outcomes in patients undergoing spine surgery. However, the quantity of the studies was very low, more research is needed.

Thoracic Paravertebral Block Achieves Better Pain Control Than Erector Spinae Plane Block and Intercostal Nerve Block in Thoracoscopic Surgery: A Randomized Study

The objective of this study was to compare analgesic efficacy of erector spinae plane block (ESPB), thoracic paravertebral block (TPVB), and intercostal nerve block (ICNB) after video-assisted thoracoscopic surgery (VATS). Prospective, randomized, single-blind study. University hospital, single institution. Adult patients undergoing VATS. Ultrasonography-guided ESPB, ultrasonography-guided TPVB, or ICNB. Patients were enrolled into the following three groups according to analgesia technique as ESPB, TPVB, or ICNB, respectively, group erector spinae plane block (GESP) (n = 35), group thoracic paravertebral block (GTPV) (n = 35), and group intercostal nerve block (GICN) (n = 36). Multimodal analgesia was achieved with paracetamol, tenoxicam, and intravenous morphine (via patient-controlled analgesia) for all study groups. Pain scores were assessed by visual analog scale, and morphine consumption, rescue analgesic requirement, and side effects were recorded postoperatively. Dynamic visual analog scale at the first hour as primary outcome was determined five (two-seven), four (one-six) and (two-six) in GESP, GTPV, and GICN, respectively. Dynamic pain scores were significantly lower in GTPV compared with GESP and GICN at 24 hours (p < 0.017). Dynamic pain scores in GICN were significantly lower at 12 hours compared with GESP (p < 0.017). Morphine consumption for the first 24 hours was similar in GICN and GTPV, and it was significantly lower in GICN and GTPV in comparison to GESP (p < 0.017). Rescue analgesic requirement and side effects were similar among groups. All three blocks can obtain sufficient analgesia after VATS; however, TPVB appeared to be the preferable method compared with ESPB and ICNB, with a more successful analgesia and less morphine consumption.

Comparative study between continuous adductor canal block and intravenous morphine for postoperative analgesia in total knee arthroplasty

BackgroundPostoperative pain after total knee arthroplasty (TKA) is known to range from moderate (30% of patients) to severe (60% of patients). Inadequate management for postoperative pain may induce various immobility-related complications, muscle weakness, and chronic pain. Therefore, post-TKA analgesia is crucial, not only for patients’ satisfaction, but for improving surgical outcomes and reducing complications. The present study aims to compare the effect of ultrasound-guided adductor canal block ACB (saphenous nerve block) versus incremental dose of intravenous morphine after total knee arthroplasty surgery.ResultsThe results of this study revealed no difference between group A and group B as regards postoperative quadriceps muscle strength; maximal knee flexion, total distance ambulated, and postoperative vital data (heart rate per minute and respiratory rate per minute). However, group A showed better postoperative pain control, lower doses of intravenous morphine consumption and lower incidence of nausea and vomiting.ConclusionContinuous adductor canal block (saphenous nerve block) is superior to intravenous morphine in decreasing postoperative pain and decreasing total morphine consumption and adverse effects as nausea and vomiting, but both are equivalent in preserving quadriceps muscle power.

The analgesic effectiveness of ilioinguinal-iliohypogastric block for caesarean delivery: A meta-analysis and trial sequential analysis.

An effective analgesia strategy following caesarean delivery should be designed to improve fetomaternal outcomes. Much recent research has focused on the efficacy of ilioinguinal-iliohypogastric (II-IH) block for providing such analgesia. A systematic review and meta-analysis of randomised controlled trials. To investigate the effectiveness of II-IH block in patients undergoing caesarean delivery. The primary outcome was the cumulative parenteral morphine equivalents at 24 h. Pain scores at 4 to 6 and 24 h postsurgery, time to first rescue analgesia and adverse effects were the secondary outcomes analysed. Two reviewers searched independently PubMed, Embase, Google Scholar and the Cochrane central registers of a controlled trial from their inception until June 2020. Prospective randomised control trials comparing II-IH block with either systemic analgesia alone or a placebo block (non-active controls) were eligible for inclusion. Only trials that reported their methods comprehensibly and transparently were included. Cochrane methodology was used to assess the risk of bias. Data are presented as mean difference with 95% confidence interval (CI). Thirteen trials comprising a total of 858 patients were included. Opioid (intravenous morphine equivalents) consumption was reduced by 15.57 mg (95% CI -19.87 to -11.28; P < 0.00001; I2 = 95%) during the first 24 h in patients receiving II-IH block when compared with placebo or no block. Patients receiving general anaesthesia showed a greater reduction in morphine requirement at 24 h than those receiving neuraxial anaesthesia. Adequate 'information size' for the above outcome was confirmed with trial sequential analysis to rule out the possibility of a false-positive result. II-IH also significantly reduced pain scores at rest more so at 4 to 6 h than at 24 h. Our study suggests that the use of II-IH blocks is associated with a lower 24 h requirement for intravenous morphine equivalents in patients undergoing caesarean delivery. However, given the methodological limitations, data should be interpreted with caution until more studies are available.

Hydromorphone versus morphine: a historical cohort study to evaluate the quality of postoperative analgesia.

Opioids are the most widely used therapy for pain during the postoperative period. It has been suggested by some that hydromorphone is clinically superior. Our primary objective was to determine if there is a difference in postoperative pain score ratings between adult patients receiving intravenous hydromorphone vs intravenous morphine on discharge from the post-anesthesia care unit (PACU). For this historical cohort study, convenience sampling was used to identify the first 605 patients ≥ 18 yr undergoing elective, non-cardiac surgery. Patients were categorized based on treatment in the PACU with hydromorphone (n = 326) or morphine (n = 279). Pain scores (scale of 0-10), nausea/vomiting (scale of 0-3), pruritis (scale of 0-3), and sedation (scale of 0-4), as well as total opioid dose administered from arrival in the PACU until readiness to discharge were evaluated. For the primary outcome of pain reported at discharge from the PACU, there was no significant difference between the mean (standard deviation) hydromorphone numeric rating scale (NRS) [2.8 (1.6)] and the morphine NRS [2.5 (1.5)] after adjusting for potential confounders (adjusted mean difference, 0.10; 95% confidence interval, -0.21 to 0.42; P = 0.53). Similarly, there were no significant between-group differences in length of stay in the PACU, satisfactory analgesia, nausea/vomiting, and sedation. This study serves to help guide the decision-making process for selecting either morphine or hydromorphone for acute postoperative analgesia. Overall, we found no significant difference for analgesia or for common opioid-related adverse effects between these two opioids in the postoperative period at the time of discharge from the PACU. Furthermore, according to this data, the equipotency ratio of hydromorphone to morphine is closer to 1:6.5 rather than the commonly employed 1:5 ratio.

Physiologically-Based Pharmacokinetic Model of Morphine and Morphine-3-Glucuronide in Nonalcoholic Steatohepatitis.

Nonalcoholic steatohepatitis (NASH), the progressive form of nonalcoholic fatty liver disease, is increasing in prevalence. NASH-related alterations in hepatic protein expression (e.g., transporters) and in overall physiology may affect drug exposure by altering drug disposition and elimination. The aim of this study was to build a physiologically-based pharmacokinetic (PBPK) model to predict drug exposure in NASH by incorporating NASH-related changes in hepatic transporters. Morphine and morphine-3-glucuronide (M3G) were used as model compounds. A PBPK model of morphine with permeability-limited hepatic disposition was extended to include M3G disposition and enterohepatic recycling (EHR). The model captured the area under the plasma concentration-time curve (AUC) of morphine and M3G after intravenous morphine administration within 0.82-fold and 1.94-fold of observed values from 3 independent clinical studies for healthy adult subjects (6, 10, and 14 individuals). When NASH-related changes in multidrug resistance-associated protein 2 (MRP2) and MRP3 were incorporated into the model, the predicted M3G mean AUC in NASH was 1.34-fold higher compared to healthy subjects, which is slightly lower than the observed value (1.63-fold). Exploratory simulations on other physiological changes occurring in NASH (e.g., moderate decreases in glomerular filtration rate and portal vein blood flow) revealed that the effect of transporter changes was most prominent. Additionally, NASH-related transporter changes resulted in decreased morphine EHR, which could be important for drugs with extensive EHR. This study is an important first step to predict drug disposition in complex diseases such as NASH using PBPK modeling.

Low-Dose Ketamine Is a Viable Option for Control of Acute Pain in the ED

To compare the analgesic efficacy of intravenous low-dose ketamine and morphine, researchers performed a systematic review and meta-analysis of

Intravenous patient-controlled analgesia vs nurse administered oral oxycodone after total knee arthroplasty: a retrospective cohort study.

Severe post-operative pain is common after total knee arthroplasty. Patient-controlled analgesia is an alternative method of pain management, whereby a patient administers his or her own pain medication. Patients seem to prefer this method over nurse-administered analgesia. However, it remains unclear whether patients using patient-controlled analgesia devices use higher or lower doses of opioids compared to patients treated with oral opioids. This retrospective study examined 164 patients undergoing total knee arthroplasty. Post-operatively, 82 patients received oxycodone via intravenous patient-controlled analgesia devices, while the pain medication for 82 patients in the control group was administered by nurses. The main outcome measure was the consumption of intravenous opioid equivalents within 24h after surgery. Secondary outcome measures were the use of anti-emetic drugs and the length of stay. Furthermore, we evaluated opioid-related adverse event reports. The consumption of opioids during the first 24h after surgery and the use of anti-emetic drugs were similar in both groups. The median opioid dose of intravenous morphine equivalents was 41.1mg (interquartile range (IQR): 29.5-69.1mg) in the patient-controlled analgesia group and 40.5mg (IQR: 32.4-48.6mg) in the control group, respectively. The median length of stay was 2days (IQR: 2-3days) in the patient-controlled analgesia group and 3days (IQR: 2-3days) in the control group (p=0.02). The use of anti-emetic drugs was similar in both groups. The administration of oxycodone via intravenous patient-controlled analgesia devices does not lead to increased opioid or anti-emetic consumptions compared to nurse-administered pain medication after total knee arthroplasty. Patient-controlled analgesia might lead to shortened length of stay.

Impact of morphine treatment with and without metoclopramide co-administration on myocardial and microvascular injury in acute myocardial infarction: insights from a randomized trial

Abstract Background Intravenous morphine administration in patients with acute myocardial infarction (AMI) can adversely affect platelet inhibition induced by P2Y12 receptor antagonists, potentially resulting in an increased risk of adverse clinical events. In contrast, some evidence suggests that opioid agonists may have cardioprotective effects on the myocardium. Currently available data in this regard are, however, sparse, inconsistent, and methodologically limited. Purpose The aim of this study was to investigate the impact of morphine with or without metoclopramide (MCP) co-administration on myocardial and microvascular injury after AMI assessed by cardiac magnetic resonance (CMR). Methods This prospective, randomized, single-center study assigned 138 patients with AMI in a 1:1:1 ratio to (a) ticagrelor 180 mg plus intravenous morphine 5 mg (morphine group); (b) ticagrelor 180 mg plus intravenous morphine 5 mg and MCP 10 mg (morphine + MCP group); or (c) ticagrelor 180 mg plus intravenous placebo (control group). Study drugs were administered before primary percutaneous coronary intervention. CMR was performed in 101 patients on day 1–4 after the index event to assess infarct size, microvascular obstruction, and left ventricular ejection fraction. Results Infarct size was significantly smaller in the morphine only group as compared to controls (15.5%LV [IQR 5.0 to 21.4%LV] vs. 17.9%LV [IQR 12.3 to 32.9%LV]; p=0.047). Furthermore, the number of patients with microvascular obstruction was significantly lower after morphine administration (10/36 [28%] versus 21/39 [54%]; p=0.022) and the extent of microvascular obstruction was smaller (0%LV [0 to 1.40%LV] versus 0.74%LV [0 to 3.10%LV]; p=0.037). In multivariable regression analysis, morphine administration was independently associated with a reduced risk for the occurrence of microvascular obstruction (odds ratio 0.37; 95% confidence interval 0.14 to 0.93; p=0.035). Left ventricular ejection fraction did not differ significantly between the morphine and the control group (p=0.970) and there was no significant difference in left ventricular ejection fraction (p=0.790), infarct size (p=0.491), and extent (p=0.753) or presence (p=0.914) of microvascular obstruction when comparing the morphine + MCP group to the control group. Conclusions In this randomized study, intravenous administration of morphine prior to primary percutaneous coronary intervention resulted in a significant reduction of myocardial and microvascular damage following AMI. This potential cardioprotective effect of morphine requires further evaluation in well-designed future trials with clinical endpoints. Funding Acknowledgement Type of funding source: None

Hypnosis Versus Placebo During AtrialFlutter Ablation: The PAINLESS Study: ARandomizedControlled Trial.

The aim of this study was to assess the superiority of hypnosis versus placebo on pain perception and morphine consumption during typical atrial flutter (AFL) ablation. AFL ablation commonly requires intravenous opioid for analgesia, which can be associated with adverse outcomes. Hypnosis is an alternative technique with rising interest, but robust data in electrophysiological procedures are lacking. This single center, randomized controlled trial compared hypnosis and placebo during AFl ablation. Inaddition to the randomized intervention, all patients were treated according to the institution's standard of care analgesia protocol (administration of 1mg of intravenous morphine in case of self-reported pain≥5 on an 11-point numericrating scale or on demand). The primary endpoint was perceived pain quantified by patients using a visual analog scale. Between October 2017 and September 2019, 113 patients (mean age 70 ± 12 years, 21% women) were randomized to hypnosis (n=56) or placebo (n=57). Mean pain score was 4.0 ± 2.2 in the hypnosis group versus 5.5 ± 1.8 in the placebo group (p<0.001). Pain perception, assessed every 5min during the whole procedure, was consistently lower in the hypnosis group. Patients' sedation scores were also better in the hypnosis group than in the placebo group(8.3 ± 2.2 vs. 5.4 ± 2.5; p<0.001). Finally, morphine requirements were significantly lower in the hypnosis group (1.3 ± 1.3mg) compared with the placebo group (3.6 ± 1.8mg; p<0.001). In this first randomized trial, hypnosis during AFL ablation was superior to placebo for alleviating painand reducing morphine consumption.

Perioperative Analgesic Modalities for Breast Cancer Surgeries: A Prospective Randomized Controlled Trial.

PurposeVarious analgesic modalities are adopted for perioperative analgesia in breast cancer surgeries. This study aimed to compare the efficacy of intravenous morphine versus serratus anterior plane block (SAPB) and erector spinae plane block (ESPB) in breast cancer surgeries.Patients and MethodsSeventy-five breast cancer patients undergoing modified radical mastectomy from January 2020 to June 2020 were randomly allocated into 3 groups; the morphine group received morphine 0.1 mg/kg, the SAPB group received ultrasound-guided SAPB with 25 mL bupivacaine 0.25% and the ESPB group received ultrasound-guided ESPB with 25 mL bupivacaine 0.25%. A visual analogue scale (VAS) 0–10 was used to evaluate pain postoperatively, where 0 denotes no pain and 10 worst pain. If any patient in the 3 studied groups reported breakthrough pain with VAS ≥ 4 then a bolus of 3 mg morphine was given.ResultsThere was no difference in VAS scores between the 3 groups postoperatively. Morphine consumption was higher in the morphine group (9.19 ± 2.32 mg) than the SAPB group (4.00 ± 1.55 mg) and the ESPB group (4.20 ± 1.64 mg), respectively. First time to receive postoperative morphine was significantly longer for the ESPB and SAPB groups than the morphine group (20.40 ± 4.98 hours), (19.00 ± 5.9 hours), (5.00 ± 4.62 hours), respectively. Intraoperative hemodynamics and fentanyl consumption showed no difference between groups, whereas postoperative mean arterial blood pressure values at 2 and 4 hours were higher in the morphine group. Ramsay sedation score and postoperative nausea and vomiting values in the post anesthesia care unit were higher for the morphine group compared to the SAPB and ESPB groups. No complications related to the blocks were reported.ConclusionSAPB and ESPB can be used as an effective and safe alternative to opioids with fewer side effects in breast cancer patients undergoing modified radical mastectomy.Trial RegistrationThis trial was prospectively registered at Clinical Trials.gov on 22 January 2020 with registration number NCT04248608 (https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S0009JS5&selectaction=Edit&uid=U0004LIG&ts=7&cx=−81xkwa).

Plasma histamine concentrations in horses administered sodium penicillin, guaifenesin–xylazine–ketamine and isoflurane with morphine or butorphanol

ObjectiveVarious drugs administered to horses undergoing surgical procedures can release histamine. Histamine concentrations were evaluated in horses prepared for surgery and administered butorphanol or morphine intraoperative infusions. Study designProspective studies with one randomized. AnimalsA total of 44 client-owned horses. MethodsIn one study, anesthesia was induced with xylazine followed by ketamine–diazepam. Anesthesia was maintained with guaifenesin–xylazine–ketamine (GXK) during surgical preparation. For surgery, isoflurane was administered with intravenous (IV) morphine (group M: 0.15 mg kg–1 and 0.1 mg kg–1 hour–1; 15 horses) or butorphanol (group B: 0.05 mg kg–1 and 0.01 mg kg–1 hour–1; 15 horses). Histamine and morphine concentrations were measured using enzyme-linked immunoassay before opioid injection (time 0), and after 1, 2, 5, 30, 60 and 90 minutes. In a subsequent study, plasma histamine concentrations were measured in 14 horses before drug administration (baseline), 15 minutes after IV sodium penicillin and 15 minutes after starting GXK IV infusion. Statistical comparison was performed using anova for repeated measures. Pearson correlation compared morphine and histamine concentrations. Data are presented as mean ± standard deviation. Significance was assumed when p ≤ 0.05. ResultsWith histamine, differences occurred between baseline (3.2 ± 2.4 ng mL–1) and GXK (5.2 ± 7.1 ng mL–1) and between baseline and time 0 in group B (11.9 ± 13.4 ng mL–1) and group M (11.1 ± 12.4 ng mL–1). No differences occurred between baseline and after penicillin or between groups M and B. Morphine concentrations were higher at 1 minute following injection (8.1 ± 5.1 ng mL–1) than at 30 minutes (4.9 ± 3.1 ng mL–1) and 60 minutes (4.0 ± 2.5 ng mL–1). Histamine correlated with morphine at 2, 30 and 60 minutes. Conclusions and clinical relevanceGXK increased histamine concentration, but concentrations were similar with morphine and butorphanol.

Analgesic efficacy of infiltration between the popliteal artery and capsule of the knee (iPACK) block added to local infiltration analgesia and continuous adductor canal block after total knee arthroplasty: a randomized clinical trial

BackgroundA combination of motor-sparing analgesia with local infiltration analgesia (LIA) and continuous adductor canal block (CACB) may improve postoperative pain and functional recovery for total knee arthroplasty (TKA). We hypothesized...

Greater Conditioned Pain Modulation Is Associated With Enhanced Morphine Analgesia in Healthy Individuals and Patients With Chronic Low Back Pain.

Conditioned pain modulation (CPM) protocols index magnitude of descending pain inhibition. This study evaluated whether the degree of CPM, controlling for CPM expectancy confounds, was associated with analgesic and subjective responses to morphine and whether chronic pain status or sex moderated these effects. Participants included 92 individuals with chronic low back pain and 99 healthy controls, none using daily opioid analgesics. In a cross-over design, participants attended 2 identical laboratory sessions during which they received either intravenous morphine (0.08 mg/kg) or saline placebo before undergoing evoked pain assessment. In each session, participants engaged in ischemic forearm and heat pain tasks, and a CPM protocol combining ischemic pain (conditioning stimulus) and heat pain (test stimulus). Placebo-controlled morphine outcomes were derived as differences in pain and subjective effects across drug conditions. In hierarchical regressions controlling for CPM expectancies, greater placebo-condition CPM was associated with less subjective morphine unpleasantness (P=0.001) and greater morphine analgesia (P's<0.05) on both the ischemic pain task (Visual Analog Scale Pain Intensity and Unpleasantness) and heat pain task (Visual Analog Scale Pain Intensity, McGill Pain Questionnaire-Sensory, and Present Pain Intensity subscales). There was no moderation by sex or chronic low back pain status, except for the ischemic Present Pain Intensity outcome for which a significant 2-way interaction (P<0.05) was noted, with men showing a stronger positive relationship between CPM and morphine analgesia than women. Results suggest that CPM might predict analgesic and subjective responses to opioid administration. Further evaluation of CPM as an element of precision pain medicine algorithms may be warranted.

Effect of Intravenous Morphine Injection on Neurological Examination of Dogs With Thoracolumbar Intervertebral Disk Extrusion.

Objectives: We aimed to determine the effect of intravenous morphine injection on the modified Frankel scores of dogs with thoracolumbar intervertebral disk extrusion (IVDE).Methods: This was a prospective, blinded, randomized, and placebo-controlled study. We included dogs with a presumptive diagnosis of thoracolumbar IVDE that did not undergo analgesic, anti-inflammatory, or sedative treatment within the last 12 h. A neurological examination was performed and the deficits were graded using the modified Frankel score (MFS). Subsequently, each dog was randomly allocated to receive an intravenous injection of either morphine or placebo. After 30 min, the dogs were re-evaluated by the same veterinary officer who was blinded to the contents of the injections. Dogs were included in the study if IVDE was ultimately confirmed by surgery within one week of initial presentation.Results: Among the 79 dogs initially enrolled, 62 dogs met the inclusion criteria. Among them, thirty-two dogs received intravenous morphine injections and there was no difference between the pre- and post-injection modified Frankel scores. Thirty dogs received an intravenous placebo injection. One dog had a worsening of the MFS by one grade in the post-injection examination.Clinical Significance: In dogs with thoracolumbar intervertebral disk extrusion, an intravenous injection of morphine does not affect the modified Frankel score after 30 min compared with the pre-injection value. These findings support the use of an analgesic morphine dose if the neurological examination can be performed 30 min or later after the injection.

Single dose of intraoperative intravenous morphine for analgesia in children undergoing tonsillectomy: Randomized, double-blind clinical trial

IntroductionChildren undergoing tonsillectomy have severe pain in the postoperative period. One of the pharmacological options for analgesia is opioids, such as morphine. However, the risks of adverse effects, such as increased recovery time from anesthesia and respiratory depression, can limit its use. ObjectivesTo evaluate the use of intraoperative intravenous morphine to reduce immediate postoperative pain in children undergoing tonsillectomy. MethodsIn this double-blind randomized study, children aged 3–10 years were submitted to tonsillectomy, with or without adenoidectomy, and divided into two groups. Children in group M received 0.1 mg/kg of intravenous morphine during anesthetic induction, while those in the control group received conventional anesthesia without morphine. Postoperative pain perceptions were assessed at 30, 60, 120, 180 and 240 min after recovery from anesthesia, by the children themselves and also by their parents or guardians, using a facial pain scale. ResultsA total of 57 children were included, 30 in the group with morphine and 27 in the group without morphine. According to the children themselves, the postoperative pain was less at the evaluations performed at 30 min after awakening from anesthesia (p = 0.023), while according to their parents/guardians, the pain was less intense in the evaluations performed at 30 (p = 0.002), 60 (p = 0.006) and 180 min (p = 0.007) after awakening. Moreover, postoperative analgesics were less requested by children in the morphine group. No observed side effects were associated with the use of morphine. ConclusionA single dose of intravenous morphine during anesthetic induction reduced the intensity of immediate postoperative pain in children undergoing tonsillectomy, without increasing the time of awakening from anesthesia and with lower consumption of rescue analgesics.