Differences In Morphine Requirements Research Articles

Comparison between Ultrasound-Guided Pericapsular Nerve Group Block and Local Infiltration Analgesia for Postoperative Analgesia after Total Hip Arthroplasty: A Prospective Randomized Controlled Trial.

Pericapsular nerve group (PENG) blocking is a novel nerve block modality for analgesia after total hip arthroplasty (THA); however, its analgesic efficacy is unclear. We aimed to compare the analgesic effect of ultrasound-guided PENG blocking and periarticular local infiltration analgesia after THA. This study involved patients undergoing unilateral primary THA at our institution between October 2022 and December 2022. Based on a prospective double-blind, randomized approach, patients were randomly divided into two groups: the PENG and infiltration groups. The former received ultrasound-guided pericapsular nerve block before surgery while the latter received local anesthesia and local infiltration analgesia during surgery. The primary outcome was the amount of morphine used for rescue analgesia within 48 h after surgery and the visual analog scale (VAS) pain score at 3, 6, 12, 24, and 48 h after surgery. Secondary outcomes consisted of postoperative hip function on the first and second postoperative days, including hip extension angle and flexion, as well as distance traveled by the patient. Tertiary outcomes included length of hospital stay and postoperative adverse reactions. The data were analyzed using SPSS 26.0. Using the appropriate statistical methodology, continuous and categorical data were analyzed, and p < 0.05 was considered statistically significant. There was no clear difference in morphine requirements during the first 24 hours postoperatively (5.8 ± 5.9 vs. 6.0 ± 6.3, p = 0.910), in the total postoperative morphine consumption (7.5 ± 6.3 vs. 7.8 ± 6.6, p = 0.889), and in the postoperative resting VAS pain scores (p > 0.05). However, the exercise VAS score in the PENG group was significantly higher than that in the infiltration group within 12 hours after surgery (6.1 + 1.2 vs. 5.4 + 1.0, p = 0.008). There was no significant difference in hip function, length of hospital stay, or incidence of complications between the two groups. The analgesic effect and functional recovery of ultrasound-guided pericapsular nerve block for THA was not superior to that of periarticular local infiltration analgesia.

Genetic Profile and Cancer-Related Pain: A Tale from Two Outlier Cases with Bone Metastatic Disease

Dear Editor, Morphine is the mainstay of pharmacological treatment for moderate-to-severe cancer-related pain. However, different analgesic response is an important problem in palliative care [1]. Genetic variations seems to represent an important cause of this interindividual variability in polymorphisms of opioid receptors, transporters, and metabolizing enzymes, as well as in modulators/suppressors involved in perception and processing of pain information [1]. Therefore, genetic study of outlier cases might be an excellent opportunity to analyze the influence of some single-nucleotide polymorphisms (SNP) in nociception and morphine requirements. Here, we present the study of a genetic profile of two cases: one patient considered a low responder (Patient 1) and one considered sensitive to morphine (Patient 2), requiring about 40-fold less morphine. The difference in morphine requirements prompted us to study SNP that include different phases of analgesic response: μ-opioid receptor (OPRM1; rs1799971), catechol-O-methyltransferase (COMT; rs4680), multidrug resistance protein 1 (ABCB1; rs1128503, rs1045642), organic anion-transporting polypeptides 1A2 (OATP1A2; rs11568563), and UDP-glucuronosyltransferase-2B7 (UGT2B7; hCV32449742: rs7439366, rs7438284). Plasma concentrations of morphine and major metabolites (morphine-3-glucuronide (M3G) and morphine-6-glucuronide [M6G]) were also determined [2] and metabolic ratios were calculated. The first patient, a 23-year-old female presenting an osteosarcoma, bone metastasis, and complains of mixed pain (nociceptive and neuropathic pain), was receiving 800 mg/day of morphine. Coadministered drugs were gabapentin (1700 mg/day) and prednisolone (20 mg/day). Despite medication, the pain relief was not adequate, …

Clinical Outcome of a Randomized Controlled Blinded Trial of Open Versus Laparoscopic Nissen Fundoplication in Infants and Children

To compare the clinical outcome and endocrine response in children who were randomized to open or laparoscopic Nissen fundoplication using minimization. It is assumed that laparoscopic surgery is associated with less pain, quicker recovery and dampened endocrine response. Few randomized studies have been performed in children. Parents gave informed consent, and this study was approved and registered (ClinicalTrials.gov Identifier: NCT00231543). Anesthesia, postoperative analgesia and feeding were standardized. Parents and staff were blinded to allocation. Blood was taken for markers of endocrine response. Twenty open and 19 laparoscopic patients were comparable with respect to age, weight, neurological status, and presence of congenital anomalies. Median time to full feeds was 2 days in both groups (P = 0.85); hospital stay was 4.5 days in the open group versus 5.0 days in the laparoscopic group (P = 0.57). Pain was adequately managed in both groups and there was no difference in morphine requirements. Median follow-up was 22 (range 12-34) months. Dysphagia, recurrence and need for redo fundoplication were not different between groups; retching was higher after open surgery (56% vs. 6%; P = 0.003). Insulin levels decreased at 24 hours, and was 54% lower (P = 0.02) after laparoscopy. Cortisol was elevated immediately postoperative, but was 42% lower (P = 0.02) after laparoscopy. There was no difference in the postoperative analgesia requirements and recovery. Laparoscopy decreased insulin levels to a greater extent, but caused less of a response in cortisol. Early postoperative outcome confirmed equal efficacy, but fewer children with retching after laparoscopy.

Morphine Metabolism After Major Liver Surgery

Impaired metabolism of morphine may lead to an increase in sedation and respiratory depression. In the present study we investigated morphine pharmacokinetics in patients who had undergone liver resection (n = 15) compared to a control group undergoing colon resection (n = 15). Morphine was administered IV by patient-controlled analgesia. Plasma concentrations of morphine, morphine-6-glucuronide, and morphine-3-glucuronide were measured 2-3 times daily for the first two postoperative days. Pain intensity scores were assessed three times daily and respiratory rate and sedation scores every third hour. There were no differences in morphine requirements 1.1 (0.8-2.5 [median, interquartile range]) mg/h (liver resection) and 1.5 (1.1-1.7) mg/h (colon resection) [P = 0.84]) or in pain intensity scores (P > 0.3) between the groups. Plasma morphine concentrations were higher in patients undergoing liver resection than in the control group (P < 0.01) reflecting a lower rate of morphine metabolism. Plasma morphine concentrations were correlated with the volume of liver resection (P < 0.02). However, plasma concentrations of morphine-6-glucuronide and morphine-3-glucuronide did not differ between the groups (P = 0.62 and P = 0.48, respectively). There was a higher incidence of sedation (P = 0.02), but not respiratory depression (P = 0.48), after liver resection. The study demonstrates that plasma concentrations of morphine are higher in patients undergoing liver resection compared with patients undergoing colon resection. Sedation scores were higher in patients undergoing liver resection. Caution is therefore recommended when administering morphine to this patient group.

Sex- and Age-Related Differences in Morphine Requirements for Postoperative Pain Relief

Survey of Anesthesiology: August 2006 - Volume 50 - Issue 4 - p 205 doi: 10.1097/01.sa.0000234705.14990.18

Sex- and Age-related Differences in Morphine Requirements for Postoperative Pain Relief

Sex-related differences in the perception of pain and susceptibility to opioids remain a matter of debate. Intravenous morphine titration used to obtain pain relief in the immediate postoperative period is a unique clinical model for assessing the effect of sex on reported pain. Because of the wide variation in dose requirements for pain management, the authors conducted a prospective study in a large population and also assessed the effect of aging. Intravenous morphine titration was administered as a bolus of 2 (body weight <or= 60 kg) or 3 mg (body weight > 60 kg) during the immediate postoperative period. The interval between each bolus was 5 min. The visual analog pain scale (VAS) threshold required to administer morphine was 30, and pain relief was defined as a VAS score of 30 or less. Data are expressed as mean +/- SD. Data from 4,317 patients were analyzed; 54% of the patients were male, and 46% were female. The mean morphine dose required to obtain pain relief was 11.9 +/- 6.8 mg or 0.173 +/- 0.103 mg/kg. Women had a higher initial VAS score (74 +/- 19 vs. 71 +/- 19; P < 0.001) and required a greater dose of morphine (0.183 +/- 0.111 vs. 0.165 +/- 0.095 mg/kg; P < 0.001). In contrast, no significant difference was noted in elderly (aged > 75 yr) patients (0.163 +/- 0.083 vs. 0.157 +/- 0.085 mg/kg). Women experienced more severe postoperative pain and required a greater dose (+11%) of morphine than men in the immediate postoperative period. This sex-related difference disappeared in elderly patients.

Opioid analgesia in the newborn

Pain in neonates is now well established. Studies of the developmental neurobiology of pain have revealed that pain processing in the immature is very different from that in the mature nervous system. Neonates undergo considerable maturation of peripheral, spinal and supraspinal afferent pain transmission over the early postnatal period but are able to respond to tissue injury with specific behaviour and with autonomic, hormonal and metabolic signs of stress and distress. Opioid analgesia is now widely used in neonates. There is evidence that morphine requirements may be low in the youngest patients. Sensory threshold testing in rat pups has shown that the analgesic potency of systemic morphine mechanical stimulation is significantly greater in the neonate and declines with postnatal age. The changing morphine sensitivity in the postnatal period may be part of a general reorganisation in the structure and function of primary afferent synapses, neurotransmitter/receptor expression and function and excitatory and inhibitory modulation from higher brain centres. Importantly opioid receptor expression undergoes significant developmental regulation – mu opioid receptors, observed to be exuberantly expressed in the neonatal rat, have been found to be functional. These findings have important implications for the human neonate as they provide a possible explanation for the differences in morphine requirements observed in the youngest patients. The study of the underlying mechanisms of pain and analgesia in development has enabled important changes in clinical practice. However, pain in the newborn remains poorly understood and continued research and intensive study in this area is essential for further effective analgesic intervention and the discovery of new targets for therapy.

The functional expression of mu opioid receptors on sensory neurons is developmentally regulated; morphine analgesia is less selective in the neonate

Opioid requirements in neonatal patients are reported to be lower than older infants and this may be a reflection of the developmental regulation of opioid receptors. In this study we have investigated the postnatal regulation of Mu opioid receptor (MOR) function in both rat lumbar dorsal root ganglion (DRG) cultures and behavioural mechanical and thermal reflex tests in rat pups. Immunostaining with MOR and selective neurofilament (NF200) antibodies was combined with calcium imaging of MOR function in cultured neonatal and adult rat dorsal root ganglion cells. Calcium imaging showed that a significantly greater number of neonatal DRG neurons expressed functional MOR compared to adult (56.5±3.4 versus 39.9±1.5%, n=8, mean±SEM, P<0.001). This expression is confined to the large, neurofilament positive sensory neurons, while expression in small, nociceptive, neurofilament negative neurons remains unchanged. Sensory threshold testing in rat pups showed that the analgesic potency of systemic morphine to mechanical stimulation is significantly greater in the neonate and declines with postnatal age. Morphine analgesic potency in thermal nociceptive tests did not change with postnatal age. These experiments show that the MOR expressed on large DRG neurons in neonates are functional and are subject to postnatal developmental regulation. This changing functional receptor profile is consistent with greater morphine potency in mechanical, but not thermal, sensory tests in young animals. These results have important clinical implications for the use of morphine in neonates and provide a possible explanation for the differences in morphine requirements observed in the youngest patients.

Intravenous Lidocaine

Intravenous Lidocaine