A new therapeutic option for postoperative pain management with oxycodone HCI injection

Future liver remnant volume is associated with postoperative fentanyl consumption following open donor hepatectomy: a retrospective multivariate analysis

PURPOSE

Liver resection has a risk of postoperative hepatic dysfunction, including drug metabolism. Since fentanyl is primarily metabolized in the liver, liver resection requires exercising caution against fentanyl overdose in postoperative analgesia. The rationale for dose adjustment of fentanyl in the preoperative prescription for patients undergoing liver resection remains unclear. We examined whether postoperative fentanyl consumption is associated with the future liver remnant after liver resection and investigated factors influencing fentanyl consumption.

METHODS

In this retrospective study, 89 living liver donors undergoing open liver resection received intravenous patient-controlled analgesia with fentanyl 2 mg with thoracic epidural analgesia. The primary outcome was postoperative hourly consumption of intravenous patient-controlled analgesia with fentanyl. Future liver remnant volume (ml) and the ratio of future liver remnant volume to whole liver volume (%) were estimated by computed tomography volumetry and compared to determine which correlated more strongly with fentanyl hourly consumption. Multivariable analysis identified independent factors affecting fentanyl consumption, with adjustments for patient characteristics and intravenous patient-controlled analgesia setting.

RESULTS

Future liver remnant volume (ml) was significantly correlated more strongly than the ratio of future liver remnant (%) with postoperative fentanyl consumption (r = 0.53 vs. 0.36, p < 0.001). Larger future liver remnant volume (β = 0.25, p = 0.006) and age < 45 years (β = 0.24, p = 0.009) were independently associated with higher fentanyl consumption, while sex and weight were not.

CONCLUSIONS

Future liver remnant volume was significantly associated with postoperative fentanyl consumption. Smaller remnant liver volume and older age (≥ 45 years) were independent factors reducing postoperative fentanyl consumption in patients undergoing open donor hepatectomy.

Analgesic effects of ultrasound-guided four-quadrant transabdominal plane block in patients with cytoreductive surgery with hyperthermic intraperitoneal chemotherapy: a prospective, randomized, controlled study

Background

Postoperative pain occurring after cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is difficult to control because of extensive surgical injuries and long incisions. We assessed whether the addition of a four-quadrant transabdominal plane (4Q-TAP) block could help in analgesic control.

Methods

Seventy-two patients scheduled to undergo elective CRS with HIPEC and intravenous patient-controlled analgesia (IV PCA) were enrolled. The patients received 4Q-TAP blocks in a 10 ml mixture of 2% lidocaine and 0.75% ropivacaine per site (4Q-TAP group, n = 36) or normal saline (control group, n = 33). Oxycodone in the post-anesthesia care unit (PACU) and pethidine or tramadol in the ward were used as rescue analgesics. The primary outcome was less than 3 times of rescue analgesic administration (%) in the ward for 5 postoperative days. Secondary endpoints included oxycodone requirement in PACU, fentanyl doses of IV PCA, morphine milligram equivalent (MME) of total opioid use, hospital stay, and postoperative complications.

Results

During 5 postoperative days, there was no difference in pain scores and total rescue analgesic administration between two groups. However, the use of oxycodone in PACU (P = 0.011), fentanyl requirement in IV PCA (P = 0.029), and MME/kg of total opioid use (median, 2.35 vs. 3.21 mg/kg, P = 0.009) were significantly smaller in the 4Q-TAP group. Hospital stay and incidence of postoperative morbidity were similar in both groups.

Conclusions

The 4Q-TAP block enhanced multimodal analgesia and decreased opioid requirements in patients with CRS with HIPEC, but did not change postoperative recovery outcomes.

Oxycodone target concentration dosing for acute pain in children

BACKGROUND

Oxycodone pharmacokinetics have been described in premature neonates through to obese adults. Covariate influences have been accounted for using allometry (size) and maturation of oxycodone clearance with age. The target concentration is dependent on pain intensity that may differ over pain duration or between individuals.

METHODS

We assumed a target concentration of 35 mcg.L^-1 (acceptable range ±20%) to be associated with adequate analgesia without increased risk of adverse effects from respiratory depression. Pharmacokinetic simulation was used to estimate dose in neonates through to obese adults given intravenous or parenteral oxycodone.

RESULTS

There were 84% of simulated oxycodone concentrations within the acceptable range during maintenance dosing. Variability around the simulated target concentration decreased with age. The maturation of oxycodone clearance is reflected in changes to context-sensitive halftime where clearance is immature in neonates compared with older children and adults. The intravenous loading and maintenance doses for a typical 5-year-old child are 100 mcg.kg^-1 and 33 mcg.kg^-1 .h^-1 . In a typical adult, the loading dose is 100 mcg.kg^-1 and maintenance dose 23 mcg.kg^-1 .h^-1 .

CONCLUSION

Simulation was used to suggest loading and maintenance doses to attain an oxycodone concentration of 35 mcg.L^-1 predicted in adults. Although the covariates age and weight contribute 92% variability for clearance, there remains variability accounting for 16% of concentrations outside the target range. Duration of analgesic effect after ceasing infusion is anticipated to be longer in neonates where context-sensitive halftime is greater than older children and adults.

Different Doses of Oxycodone for Endoscopic Injection Sclerotherapy of Esophageal Varices

Background

The aim of the present study was to evaluate the effects of different doses of oxycodone during endoscopic injection sclerotherapy (EIS) for esophageal varices with painless sclerosing agents.

Material/Methods

A total of 119 patients were randomly divided into 3 groups: Group A, midazolam and 0.075 mg/kg oxycodone (n=40); Group B, midazolam and 0.1 mg/kg oxycodone (n=40); and Group C, midazolam and 0.125 mg/kg oxycodone (n=39). The main observation index was the incidence of body movement during the perioperative period. The secondary indices were additional propofol usage; postoperative analgesic usage; other adverse effects, such as hypoxia, myoclonus, and cough; and satisfaction scores for surgeons and patients.

Results

The incidence rates for body movement during the perioperative period in groups A, B, and C were 33%, 13%, and 0, respectively (P<0.001). The satisfaction scores for surgeons and patients were highest in Group C (0.125 mg/kg oxycodone). The incidence rates for hypoxia before EIS were 15%, 8%, and 33% (P=0.026) and during EIS were 23%, 3%, and 0% (P<0.001), respectively. There were no significant between-group differences with respect to other adverse effects.

Conclusions

The ideal dose of oxycodone for perioperative analgesia during EIS for esophageal varices is 0.125 mg/kg.

A Scoping Review of Intravenous Opioid Pain Protocols and Their Dose-Time Intervals in the Management of Acute Postoperative Pain in the Postanesthesia Care Unit

PURPOSE

This review aims to explore intravenous opioid pain protocols and their dose-time intervals in managing acute postoperative pain in adults in the postanesthesia care unit (PACU).

DESIGN

A scoping review using a systematic search strategy.

METHODS

Sixteen articles were identified from MEDLINE, CINAHL, PubMed, Embase, and Cochrane specific to the aims.

FINDINGS

The literature demonstrated several variations on dose-time intervals used for opioid pain protocol administration globally. Furthermore, opioid analgesic pain protocols in the PACU appear to be effective in postoperative pain management. However, the literature did not identify optimal time intervals related to dose administration within these protocols.

CONCLUSIONS

Literature gaps were identified regarding the significance of dose-time intervals when using opioid analgesic pain protocols in the PACU.

Pain Management by Nurses in Level 2 and Level 3 Hospitals in China

BACKGROUND

Pain management practice differs among hospitals in China; however, no studies have examined the association between hospital level and nursing practice of pain management.

AIMS

To evaluate the nursing practice of pain management in orthopedics wards of level 3 and 2 hospitals and compare the differences in pain management regulations, policies, and perceived barriers.

DESIGN

This was a cross-sectional descriptive study.

SETTING

This study was conducted during the 10th International Congress of the Chinese Orthopedic Association, November 19-22, 2015.

PARTICIPANTS

Subjects: The sample included 121 nurses from China.

METHODS

Quantitative research methods were used to assess pain management practice by 121 Chinese nurses as well as barriers to nursing practice.

RESULTS

Nurses in level 3 hospitals were more likely to evaluate patients' pain intensity (85.23% vs. 65.38%, p < .05) and quality (77.27% vs. 53.85%, p < .05) than those in level 2 hospitals. Compared with level 2 hospitals, level 3 hospitals were more likely to participate in the Painless Orthopedics Ward program (53.41% vs. 23.08%, p < .01), conduct pain management knowledge training (88.64% vs. 69.23%, p < .05), and establish pain management regulations (68.18% vs. 34.62%, p < .01). Level 2 hospital nurses reported a higher score for barriers than level 3 hospital nurses (3.27 vs. 2.45, p < .05).

CONCLUSIONS

Nurses from level 2 hospitals received less education on pain management and also paid less attention to and faced more restrictions for pain management than nurses from level 3 hospitals.

Pretreatment with Oxycodone Simultaneously Reduces Etomidate-Induced Myoclonus and Rocuronium-Induced Withdrawal Movements During Rapid-Sequence Induction

Background

Etomidate and rocuronium are often paired in rapid-sequence anesthesia induction. However, the effect of pretreatment with oxycodone on myoclonic and withdrawal movements has not been previously investigated.

The aim of this study was to evaluate the effects of oxycodone on the incidence and severity of etomidate-induced myoclonus and rocuronium-induced nociceptive withdrawal movements during rapidsequence anesthesia induction.

Material/Methods

We randomly divided 120 patients into the saline group (group S) and the oxycodone group (group O) (n=60 in each group). Patients received 0.05 mg/kg oxycodone or saline intravenously 2 min before administration of 0.3 mg/kg etomidate. The occurrence and severity of myoclonus were assessed after administration of etomidate, then rocuronium was injected, followed by evaluation of withdrawal movements.

Results

The total frequency of involuntary movements following sequential administration of etomidate and rocuronium was significantly lower in Group O than in Group S (28.3% vs. 90%, p<0.001). The total frequency and grade 3 severity of myoclonus following etomidate injection in Group O was significantly lower than in Group S (25.0% vs. 63.3% for total frequency; 0 vs. 10 for grade 3 severity, P<0.001). The total frequency and grade 3 intensity of withdrawal movements were significantly less in Group O than in Group S (6.7% vs. 73.3% for total frequency; 0 vs. 11 for grade 3 intensity, P<0.001).

Conclusions

Oxycodone is effective for simultaneously preventing etomidate-induced myoclonus and rocuronium-induced withdrawal movements during general anesthesia induction.

The Effectiveness of Intravenous Oxycodone in the Treatment of Acute Postoperative Pain: A Systematic Review

PURPOSE

Intravenous (IV) opioids are administered for management of acute postoperative pain in the postanesthesia care unit. The benefits of parenteral oxycodone for acute pain management are understudied. The purpose of this review was to evaluate the effectiveness of IV oxycodone for acute postoperative pain.

DESIGN

A systematic review of quantitative studies using the Joanna Briggs Institute approach.

METHODS

A search for randomized controlled trials was conducted, revealing 314 potentially relevant studies. These were compared with the inclusion criteria. Those that met these criteria were critically appraised.

FINDINGS

Participants (N = 506) in eight trials were included in this review. Four studies supported the use of IV oxycodone as patient-controlled analgesia and IV bolus. The remaining studies showed equipotent effects between oxycodone and control. Higher incidences of adverse effects were associated with IV oxycodone.

CONCLUSIONS

IV oxycodone can be considered as effective analgesia for acute postoperative pain with careful regards to its adverse effects.

Oxycodone versus fentanyl for intravenous patient-controlled analgesia after laparoscopic supracervical hysterectomy: A prospective, randomized, double-blind study

BACKGROUND

Oxycodone, a semisynthetic thebaine derivative opioid, is widely used for the relief of moderate to severe pain. The aim of this study was to compare the efficacy and side effects of oxycodone and fentanyl in the management of postoperative pain by intravenous patient-controlled analgesia (IV-PCA) in patients who underwent laparoscopic supracervical hysterectomy (LSH).

METHODS

The 127 patients were randomized to postoperative pain treatment with either oxycodone (n = 64, group O) or fentanyl group (n = 63, group F). Patients received 7.5 mg oxycodone or 100 μg fentanyl with 30-mg ketorolac at the end of anesthesia followed by IV-PCA (potency ratio 75:1) for 48 hours postoperatively. A blinded observer assessed postoperative pain based on the numerical rating scale (NRS), infused PCA dose, patient satisfaction, sedation level, and side effects.

RESULTS

Accumulated IV-PCA consumption in group O was less (63.5 ± 23.9 mL) than in group F (85.3 ± 2.41 mL) during the first 48 hours postoperatively (P = 0.012). The NRS score of group O was significantly lower than that of group F at 4 and 8 hours postoperatively (P < .001); however, the incidence of postoperative nausea and vomiting (PONV), dizziness, and drowsiness was significantly higher in group O than in group F. Patient satisfaction was lower in group O than in group F during the 48 hours after surgery (P < 0.001).

CONCLUSIONS

Oxycodone IV-PCA (potency ratio 1:75) provided superior analgesia to fentanyl IV-PCA after LSH; however, the higher incidence of side effects, including PONV, dizziness, and drowsiness, suggests that the doses used in this study were not equipotent.

Population pharmacokinetics and analgesic potency of oxycodone

AIMS

This prospective study aimed to characterize the population pharmacokinetics of intravenous oxycodone and to determine the minimum effective concentration (MEC) and minimum effective analgesic concentration (MEAC) of oxycodone for major open intra-abdominal surgery.

METHODS

In the pharmacokinetic study, patients were administered intravenous oxycodone (0.1 mg kg^-1 ), and arterial blood was sampled at pre-set intervals. In the analgesic-potency study, patients were administered intravenous oxycodone (0.1 mg kg^-1 ) 30 min before the end of the surgery, were placed in the postoperative anaesthesia care unit (PACU), and were asked to rate their pain every 10 min using a visual analogue scale (0 = no pain, 10 = most severe pain). On the first occasion that wound pain at rest and during compression was rated as ≥3 or ≥5, respectively, the first blood sample was obtained to determine the MEC. A second blood sample was obtained after titration with 2 mg of oxycodone to yield wound pain <3 at rest and <5 during wound compression, and MEAC was determined. MEC and MEAC were determined again in each patient.

RESULTS

In the population pharmacokinetic study (n = 54), oxycodone plasma concentration over time was well described by a three-compartment mammillary model. Lean body mass and age were significant covariates for the volume of distribution and metabolic clearance of the pharmacokinetic model of oxycodone, respectively. The analgesic-potency study (n = 50) showed that the median (95% CI) MEC and MEAC were 31.5 (19.2-42.8) and 74.1 (29.2-128.3) ng ml^-1 (first measurements) and 63.4 (15.6-120.1) and 76.1 (32.9-132.7) ng ml^-1 (second measurements), respectively.

CONCLUSIONS

In major intra-abdominal open surgery, the MEAC and analgesic potency of oxycodone were 75 ng ml^-1 and 60 ng ml^-1 , respectively.