Efficacy and safety of patient-controlled opioid analgesia for acute postoperative pain. A quantitative systematic review

Relationship between intraoperative requirement for anesthetics and postoperative analgesic consumption in laparoscopic colectomy: a randomized controlled double-blinded study

BACKGROUND

This study investigated the relationship between intraoperative requirement for an inhalational anesthetic (sevoflurane) or an opioid (remifentanil) and postoperative analgesic consumption.

METHODS

The study included 200 adult patients undergoing elective laparoscopic colectomy. In the sevoflurane group, the effect-site concentration of remifentanil was fixed at 1.0 ng/ml, while the inspiratory sevoflurane concentration was adjusted to maintain an appropriate anesthetic depth. In the remifentanil group, the end-expiratory sevoflurane concentration was fixed at 1.0 vol.%, and the remifentanil concentration was adjusted. Pain scores and cumulative postoperative analgesic consumptions were evaluated at 2, 6, 24, and 48 h after surgery.

RESULTS

Average end-tidal concentration of sevoflurane and effect-site concentration of remifentanil were 2.0 ± 0.4 vol.% and 3.9 ± 1.4 ng/ml in the sevoflurane and remifentanil groups, respectively. Cumulative postoperative analgesic consumption at 48 h postoperatively was 55 ± 26 ml in the sevoflurane group and 57 ± 33 ml in the remifentanil group. In the remifentanil group, the postoperative cumulative analgesic consumptions at 2 and 6 h were positively correlated with intraoperative remifentanil requirements (2 h: r = 0.36, P < 0.001; 6 h: r = 0.38, P < 0.001). However, there was no significant correlation in the sevoflurane group (r = 0.04, P = 0.691).

CONCLUSIONS

The amount of intraoperative requirement of short acting opioid, remifentanil, is correlated with postoperative analgesic consumption within postoperative 6 h. It may be contributed by the development of acute opioid tolerance. However, intraoperative sevoflurane requirement had no effect on postoperative analgesic consumption.

Enhanced Recovery After Surgery Protocols and Spinal Deformity

The authors outline a review of preoperative, intraoperative, and postoperative considerations surrounding adult spinal deformity. Preoperative management topics include imaging, hemoglobin A1c levels before spine surgery, osteoporotic management, and prehabilitation. Topics surrounding intraoperative management include the use of antibiotics, liposomal bupivacaine, and Foley catheters. The authors also discuss postoperative questions surrounding analgesia, nausea and vomiting, thromboembolic prophylaxis, and early mobilization. Throughout their discussion, the authors incorporate enhanced recovery after surgery protocols to hopefully lead to future discussions regarding optimizing complex spinal patients.

Impact of Genetic Variants on Postoperative Pain and Fentanyl Dose Requirement in Patients Undergoing Major Breast Surgery: A Candidate Gene Association Study

BACKGROUND

Postoperative analgesia is crucial for the early and effective recovery of patients undergoing surgery. Although postoperative multimodal analgesia is widely practiced, opioids such as fentanyl are still one of the best analgesics. The analgesic response of fentanyl varies widely among individuals, probably due to genetic and nongenetic factors. Among genetic factors, single nucleotide polymorphisms (SNPs) may influence its analgesic response by altering the structure or function of genes involved in nociceptive, fentanyl pharmacodynamic, and pharmacokinetic pathways. Thus, it is necessary to comprehensively ascertain if the SNPs present in the aforementioned pathways are associated with interindividual differences in fentanyl requirement. In this study, we evaluated the association between 10 candidate SNPs in 9 genes and 24-hour postoperative fentanyl dose (primary outcome) and also with postoperative pain scores and time for first analgesia (secondary outcomes).

METHODS

A total of 257 South Indian women, aged 18-70 years, with American Society of Anesthesiologists (ASA) physical status I-III, undergoing major breast surgery under general anesthesia, were included in the study. Patients were genotyped for candidate SNPs using real-time polymerase chain reaction. All patients received a standardized intravenous fentanyl infusion through a patient-controlled analgesic (PCA) pump, and the 24-hour postoperative fentanyl dose requirement was measured using PCA.

RESULTS

The median 24-hour postoperative fentanyl requirement was higher in rs1799971 carriers (G/G versus A/A + A/G-620 μg [500-700] vs 460 μg [400-580]) with a geometric mean (GM) ratio of 1.91 (95% confidence interval [CI], 1.071-1.327). The median 24-hour pain scores were higher in rs4680 carriers (A/G + A/A versus G/G-34 [30-38] vs 31 [30-38]) with a GM ratio of 1.059 (95% CI, 1.018-1.101) and were lower in rs1045642 carriers (A/A + A/G versus G/G-34 [30-38] vs 30 [30-34]) with a GM ratio of 0.936 (95% CI, 0.889-0.987). The median time for first analgesic was lower in rs734784 carriers [C/C versus T/T + C/T-240 minutes (180-270) vs 240 minutes (210-270)] with a GM ratio of 0.902 (95% CI, 0.837-0.972). Five of 9 clinical factors, namely, history of diabetes, hypertension, hypothyroidism, anesthesia duration, and intraoperative fentanyl requirement were associated with different outcomes individually ( P < .05) and were used to adjust the respective associations.

CONCLUSIONS

The SNP opioid receptor mu-1 ( OPRM1 ) (rs1799971) was associated with higher postoperative fentanyl requirement in South Indian patients undergoing major breast surgery. Twenty-four hour postoperative pain scores were higher in catechol-O-methyl transferase ( COMT ) (rs4680) carriers and lower in ATP binding cassette subfamily B member 1 ( ABCB1 ) (rs1045642) carriers, whereas time for first analgesic was lower in potassium channel subunit 1 ( KCNS1 ) (rs734784) carriers. However, these exploratory findings must be confirmed in a larger study.

Neonatal outcomes when intravenous esketamine is added to the parturients transferred from labor analgesia to emergency cesarean section: a retrospective analysis report

OBJECTIVES

The use of intravenous analgesics during emergency cesarean section may lead to adverse neonatal outcomes. In our study, we investigated whether a single intravenous (i.v.) dose of 25 mg esketamine administered to parturients with inadequate analgesia during epidural anesthesia for cesarean section would affect the neonate.

DESIGN

We reviewed the records of parturients who were transferred from labor analgesia to epidural anesthesia for emergency cesarean section from January 2021 to April 2022. Parturients were grouped by whether they received esketamine infusions during the incision-delivery interval. Neonatal outcomes, including umbilical arterial-blood gas analysis (UABGA), Apgar score, and total days spent by the neonate in the hospital, were compared between the two groups. The secondary outcomes of this study included BP, heart rate (HR), SPO₂ and the incidence of adverse effects in parturients during operation.

SETTING

China.

RESULTS

After propensity score matching, 31 patients remained in each of the non-esketamine and esketamine groups. There were no significant differences in neonatal outcomes, including UABGA, Apgar score, and total days in the hospital, between the two groups. Additionally, our study showed a similar hemodynamic performance in parturients between the two groups during operation.

CONCLUSIONS

Intravenous esketamine (25 mg) is safe for neonates when it is given to parturients transferred from labor analgesia to emergency cesarean section.

Comparison between ketorolac- and fentanyl-based patient-controlled analgesia for acute kidney injury after robot-assisted radical prostatectomy: a retrospective propensity score-matched analysis

PURPOSE

It is unclear whether ketorolac-based patient-controlled analgesia (PCA) leads to acute kidney injury (AKI) after robot-assisted radical prostatectomy (RARP) in patients susceptible to AKI. We compared the postoperative AKI incidence with ketorolac- and fentanyl-based PCA after RARP.

METHODS

After medical record review, eligible patients were divided in ketorolac and fentanyl groups. We conducted propensity score matching of 3239 patients and assigned 641 matched patients to each group, and compared the AKI incidence. We investigated potential risk factors for postoperative AKI, defined according to the Kidney Disease Improving Global Outcomes criteria. We collected preoperative data (age, height, weight, body mass index, American Society of Anesthesiologists physical status, medical history, creatinine level, estimated glomerular filtration rate, and hemoglobin level) and intraoperative data (maintenance anesthetics, surgery duration, anesthesia duration, crystalloid amount, colloid use, total amount of fluid administered, estimated blood loss, norepinephrine use, phenylephrine use, and PCA type).

RESULTS

The postoperative AKI incidence was significantly higher in the ketorolac than in the fentanyl group, both before (31.1% vs. 20.4%; p < 0.001) and after (31.5% vs. 22.6%; p < 0.001) matching. In the univariate analysis, ketorolac was significantly associated with postoperative AKI, both before (odds ratio [OR], 1.762; 95% confidence interval [CI], 1.475-2.105; p < 0.001) and after (OR, 1.574; 95% CI, 1.227-2.019; p < 0.001) matching. In the multivariate analysis, ketorolac-based PCA was independently associated with development of postoperative AKI in the matched groups (OR, 1.659; 95% CI, 1.283-2.147; p < 0.001).

CONCLUSION

Ketorolac-based PCA may increase postoperative AKI incidence after RARP; thus, renal function should be monitored in these patients.

Effects of single-injection intercostal nerve block as a component of multimodal analgesia for pediatrics undergoing autologous auricular reconstruction: A double-blinded, prospective, and randomized study

Background

ː Pain management is essential in postoperative settings, especially with pediatric patients. Donor site pain after rib cartilage harvest is severe, particularly during the early postoperative period. This study aimed to explore the effectiveness of ultrasound guided single-injection intercostal nerve block (ICNB) as a component of multimodal analgesia for pediatrics undergoing autologous auricular reconstruction.

Methods

ː Fifty pediatric patients aged 6-16 years and scheduled for 2 rib cartilages harvest surgery were enrolled in this double-blind, prospective and randomized study. Pediatrics were randomly assigned into two groups: the intercostal nerve block group (group B) and the control group (group C). The nerve block was performed with 2 ml 0.25% ropivacaine each intercostal nerve in group B. Patients from group C received Tramadol 2 mg/kg by the end of the surgery as control. Tramadol-based patient-controlled intravenous analgesia and rescue analgesia were given in both groups. The primary outcome was pain scores at early postoperative period (VAS and FLACC scale, 4 h, and 8 h). The secondary outcome was the postoperative Tramadol consumption and time point of first rescue analgesic demand.

Results

ː VAS score was significantly lower in group B than group C at 4 h and 8 h postoperatively [2.5(2-5) vs. 4(2.5-5.5), p = 0.041 at 4 h; 3(2.5-4.5) vs. 4(3-5), p = 0.047 at 8 h]. Total Tramadol consumption in group B decreased significantly in contrast with group C at 8 h (p < 0.01), 12 h, 24 h and 48 h (p < 0.05, respectively). The first rescue analgesia demand and number of rescue Tramadol in block group was considerably delayed or reduced than control group (p < 0.01, p < 0.05, respectively).

Conclusions

ː Our findings indicated that ultrasound guided ICNB slightly but significantly reduced pain scores, and Tramadol consumption in pediatric patients after rib cartilage harvest as compared to who didn't receive nerve block at 4 h and 8 h postoperatively. Unified ICNB ropivacaine dosage might detrimental to providing superior analgesia.

Effects of hydromorphone-based intravenous patient-controlled analgesia with and without a low basal infusion on postoperative hypoxaemia: study protocol for a randomised controlled clinical trial

INTRODUCTION

When patients receive patient-controlled intravenous analgesia (PCIA), no basal infusion is always recommended, as the addition of a basal infusion increases the occurrence of postoperative opioid-induced respiratory depression. However, few studies have investigated whether low basal infusions increase the incidence of postoperative hypoxaemia relative to no basal infusion. We intend to conduct a clinical trial to test the hypothesis that PCIA with a low basal infusion does not increase the occurrence of postoperative hypoxaemia relative to PCIA with no basal infusion.

METHODS AND ANALYSIS

This single-centre parallel randomised controlled clinical trial will be conducted with 160 patients undergoing gastrointestinal tumour surgery. The assigned nurse will set analgesic pumps (low or no basal infusion PCIA) according to block-based randomisation sequence. Other investigators and all participants will be blinded to intervention allocation. All patients will be monitored continuously with the ep pod, a wireless wearable device, recording of oxygen saturation (SpO₂) and daily ambulation duration for 48 hours postoperatively. Three follow-up evaluations will be conducted to assess the analgesic effect (Numeric Rating Scale (NRS) pain score) and opioid-related side effects (Overall Benefit of Analgesic Score (OBAS)). The primary outcome will be the area under the curve for hypoxaemia (defined as SpO₂<95%) per hour. The secondary outcomes will be the areas under the curve for hypoxaemia defined as SpO₂<90% and <85% per hour, hydromorphone consumption, OBASs at 24 and 48 hours postoperatively, NRS scores at 4, 24 and 48 hours postoperatively, and the ambulation time per hour over 48 hours.

ETHICS AND DISSEMINATION

The study has been approved by the Xijing Hospital Ethics Committee (KY20212163-F-1). Written informed consent will be obtained from all patients or their authorised surrogates. All data will be managed with confidentiality. Findings will be disseminated at international conferences and in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ChiCTR2100054317.

The effect of newly designed dual-channel elastomeric pump for intravenous patient-controlled analgesia after total laparoscopic hysterectomy: a randomized, double-blind, prospective study

BACKGROUND

A newly designed intravenous patient-controlled analgesia (PCA) device with a dual-channel elastomeric infusion pump has been recently introduced. One channel is a continuous line with a constant flow rate basal infusion, while the other channel has an adjustable flow rate and bolus function and is labeled as a selector-bolus channel. This study compared dual and single-channel intravenous PCA in terms of clinical effect and quality of recovery.

METHODS

Eighty-four patients undergoing total laparoscopic hysterectomy were randomly allocated to a 1-channel group (n = 41) or a 2-channel group (n = 43). Only the selector-bolus channel was utilized, but the continuous channel was not utilized in the 1-channel group, but both channels were utilized in the 2-channel group. In the 1-channel group, 16 μg/kg of fentanyl, 2 mg/kg of ketorolac, and 12 mg of ondansetron with normal saline were administered to the selector-bolus channel and normal saline only in the continuous channel for blinding. In the 2-channel group, 16 μg/kg of fentanyl was administered to the selector-bolus channel, and ketorolac (2 mg/kg) and ondansetron (12 mg) were administered via the continuous channel. The quality of recovery was evaluated preoperatively and 24 h postoperatively using the Quality of Recovery-40 (QoR-40). Cumulative PCA consumption, postoperative pain rated using the numeric rating scale (NRS; during rest/cough), and postoperative nausea were evaluated 6, 12, 24, 36, and 48 h after surgery. Incidence of vomiting and use of antiemetics and rescue analgesics was measured.

RESULTS

The 24-h postoperative QoR-40 score was higher in the 2-channel group than in the 1-channel group (P=0.031). The incidence of nausea at 12 h and 36 h was significantly higher in the 1-channel group (P=0.043 and 0.040, respectively), and antiemetic use was more frequent in the 1-channel group (P=0.049). Patient satisfaction was higher in the 2-channel group (P=0.036). No significant differences were observed in pain scores during resting/cough or cumulative PCA consumption.

CONCLUSIONS

The 2-channel PCA showed better patient satisfaction with higher QoR-40 during the recovery compared with the 1-channel PCA. Better satisfaction was associated with lower nausea and reduced rescue antiemetics by maintaining the infusion of adjuvant analgesic agents and antiemetic agents constantly by utilizing dual channels.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov , NCT04082039 on 9 September 2019.

Influence of genetic variants on remifentanil sensitivity in Chinese women

WHAT IS KNOWN AND OBJECTIVE

Significant individual differences have been observed in pain sensitivity and analgesic effect of opioids. Previous studies have shown that genetic factors contributed to analgesics requirement obviously. Therefore, we investigated the role of genetic polymorphisms in the sensitivity to the analgesic effect of remifentanil in this study.

METHODS

One hundred thirty-seven patients undergoing gynaecological surgery were observed. Before procedures, we measured the basal pain threshold of each patient, including the pressure pain threshold and pressure pain tolerance threshold. Subsequently, patients received a continuous remifentanil infusion for 15 min at a constant rate of 0.2 μg/(kg min). The pain thresholds were measured again after the remifentanil infusion. Moreover, respiratory depression was estimated using oxygen saturation during infusion. DNA was extracted from peripheral venous blood and genotyped using SNaPshot technology.

RESULTS AND DISCUSSION

Polymorphisms were found in genes associated with the individual variation in analgesia. Participants carrying OPRM1 rs9397685 AA, ADRB1 rs1801253 CC, and GCH1 rs8007267 CC polymorphisms showed higher sensitivity to analgesic effect induced by remifentanil, and the participants carrying the OPRD1 rs2234918 TT showed lower sensitivity to remifentanil-related respiratory depression. Moreover, individual susceptibility to remifentanil increases with age.

WHAT IS NEW AND CONCLUSION

Gene variation in OPRM1 rs9397685 AA, ADRB1 rs1801253 CC, GCH1 rs8007267 CC, and OPRD1 rs2234918 TT were related to the conspicuous interindividual differences in the analgesia and respiratory depression of remifentanil, mainly by affecting the target protein receptors and relative metabolic enzymes.

Postoperative Pain, Analgesic Choices, and Ileus: A Snapshot from a Teaching Hospital in a Developing Country

Background  Pain relief can be achieved by diversity of methods with analgesics being the basic form of treatment. Analgesic safety and clinical effectiveness are the core factors in determining the analgesic of choice. One adverse effect of concern with opioids is the postoperative ileus (POI).

Objective  In this study, we looked at the severity of postoperative pain, the type of analgesics used to control the pain, and the incidence of POI at Baghdad Teaching Hospital. We hypothesized that we would find an association between the type of analgesia used and POI.

Methods  This observational study was conducted among 100 patients who were residents at the general surgery wards of Baghdad Teaching Hospital. A structured questionnaire was employed focusing on types of analgesics, degree of pain control, and the presence of ileus.

Results  Sixty-nine percent of patients received a combination of opioids and nonopioids. Moderate-to-severe pain was the most commonly reported category on pain scales. More than half of the patients (57%) were found to have POI during their hospital stay and there was a statistically significant association between the type of analgesia and POI development ( p =0.001).

Conclusions  A mix of analgesics (opioids and nonopioids) was the most common regimen at our center. The majority of the surgical inpatients reported having moderate-to-severe pain on both pain scales used in this study. Ileus incidence following abdominal surgeries (61%) was significantly higher than the reported incidence worldwide (10–30%). Postoperative ileus has multifactorial causes, one of which is the use of opioids for pain control. Considering the high incidence of ileus in our center and the association we found between the use of opioids and ileus, further studies should look at the doses of opioids used and whether alternative analgesic methods might result in less ileus.

Intravenous versus Epidural Routes of Patient-Controlled Analgesia in Abdominal Surgery: Systematic Review with Meta-Analysis

OBJECTIVE

To compare the intravenous and epidural routes of patient-controlled anesthesia in abdominal surgery.

METHODS

We searched for randomized clinical trials that compared the intravenous and epidural modes of patient-controlled anesthesia in intra-abdominal surgery in adults. Data analysis was performed in RevMan 5.4. Heterogeneity was measured using I2 statistic. Risk of bias was assessed using the Jadad/Oxford quality scoring system.

RESULTS

Seven studies reporting 529 patients were included into the meta-analysis. For pain at rest, the mean difference with 95% confidence interval (CI) was -0.00 [-0.79, 0.78], p-value 0.99, while for pain on coughing, it was 0.43 [-0.02, 0.88], p-value 0.06, indicating that patient-controlled epidural analgesia (PCEA) was superior. For the sedation score, the mean difference with 95% CI was 0.26 [-0.37, 0.89], p-value 0.42, slightly favoring PCEA. For the length of hospital stay, the mean difference with 95% CI was 1.13 [0.29, 1.98], p-value 0.009, favoring PCEA. For postoperative complications, the risk ratio with 95% CI was 0.8 [0.62, 1.03], p-value 0.08, slightly favoring patient-controlled intravenous analgesia (PCIVA). A significant effect was observed for hypotension, favoring PCIVA.

CONCLUSIONS

Patient-controlled intravenous analgesia compared with patient-controlled epidural analgesia was associated with fewer episodes of hypotension. PCEA, on other hand, was associated with a shorter length of hospital stay. Pain control and other side effects did not differ significantly. Only three studies out of seven had an acceptable methodological quality. Thus, these conclusions should be taken with caution.

Comparison of Fentanyl plus different doses of dexamethasone with Fentanyl alone on postoperative pain, nausea, and vomiting after lower extremity orthopedic surgery

Intravenous patient controlled analgesia (PCA) with opioids to provide perioperative analgesia is commonly used after orthopedic surgery, but have side-effects. Addition of adjutant drugs results in reducing the side-effects and the dosage of opioids. The aim of current study was to evaluation the analgesic efficacy of combination of fentanyl and dexamethasone (8 and 16 mg) in compared with fentanyl alone in patients undergoing orthopedic surgery of the lower extremity. In a double-blind clinical trial, 102 patients were randomly allocated to receive PCA, which included: F+S group (fentanyl 1 mcg/ml + isotonic saline), F+8mD group (fentanyl 1 mcg/ml + dexamethasone 8 mg/ml), and F+16mD group (fentanyl 1 mcg/ml + dexamethasone 16 mg/ml). Anesthesia technique and rescue analgesia regimen were standardized. Postoperatively, pain was assessed based on visual analog scale (VAS). In addition, we evaluated the postoperative nausea and vomiting (POVN) in different groups. In over the post-operative period, the mean VAS-score was significantly lower in the F+16mD group than the F+S and the F+8mD groups (p<0.001 and p<0.01, respectively). In addition, the incidence of PONV significantly was lower in the F+18mD group than the F+S group (p<0.05). We conclude that the addition of preoperative intravenous high dose of dexamethasone (16 mg) to fentanyl was effective in reducing postoperative pain and PONV after orthopedic surgery of the lower extremity.

Comparison of Patient-Controlled Analgesia With Tramadol or Morphine After Video-Assisted Thoracoscopic Surgery in Geriatric Patients

Background

Although video-assisted thoracoscopic surgery (VATS) is a less invasive technique compared to thoracotomy, patients often experience postoperative pain. Hence, intravenous patient-controlled analgesia (PCA) is frequently used. The geriatric age group constitutes a significant portion of patients undergoing thoracic surgery. However, pain management can often be difficult in elderly patients. In this study, we aimed to examine the pain management techniques applied in geriatric patients who underwent VATS and to compare the efficacy and side effects of PCA with morphine and tramadol.

Methodology

The following patients were included in this study: aged 65 years and older, those who underwent elective VATS under general anesthesia, and those who underwent thoracic paravertebral block in the operating room for postoperative pain. We recorded diagnoses, demographic data, American Society of Anesthesiologists status, complications developed during the intraoperative or postoperative 24 hours, postoperative rest and cough Visual Analog Scale (VAS), and need for additional analgesics. The patients were divided into the following two groups: those treated with tramadol PCA (tramadol group) and those treated with morphine PCA (morphine group).

Results

A total of 65 patients were included in this study. Overall, 22 patients were administered tramadol PCA while 43 were administered morphine PCA. There was no statistically significant difference between the groups concerning complications. The 24-hour VAS resting score was statistically significantly lower in patients administered morphine than those administered tramadol (p < 0.05). There was no statistically significant difference between the groups concerning zero-minute, thirty-minute, one-hour, two-hour, six-hour, and twelve-hour VAS resting and cough scores at all times (p > 0.05).

Conclusions

There was no significant difference in the tramadol and morphine groups concerning analgesic efficacy, patient satisfaction, and side effects among geriatric patients who underwent VATS and were administered intravenous PCA. In our view, both tramadol and morphine can be used safely in geriatric patients requiring intravenous PCA. Moreover, because the 24-hour analgesic efficacy was observed to be better in the morphine group in our study, morphine can be preferred in geriatric patients.

Dexamethasone and postoperative analgesia in minimally invasive thoracic surgery: a retrospective cohort study

BACKGROUND

Dexamethasone is commonly used for the prevention of postoperative nausea and vomiting (PONV), and recent reviews suggest a role for dexamethasone in postoperative analgesia. The aim of this study is to evaluate the efficacy of dexamethasone as an analgesic adjuvant in minimally invasive thoracic surgery. Primary outcome was morphine consumption 24 h after surgery; secondary outcomes were pain control, measured as numeric rating scale (NRS), glycemic changes, PONV, and surgical wound infection.

RESULTS

We performed a retrospective cohort study considering 70 patients who underwent elective lobectomy, segmentectomy, or wedge resection surgery with a mini-thoracotomy approach or video-assisted thoracoscopic surgery (VATS). All patients received the same locoregional techniques and short-acting opioids during surgery; 46 patients received dexamethasone at induction. There were no significant differences in morphine consumption at 24 h (p = 0.09) and in postoperative pain scores. Nevertheless, a higher frequency of rescue therapy (p = 0.01) and a tendency for a higher attempted-PCA pushes count were observed in patients who did not receive dexamethasone. No cases of surgical wound infections were detected, and the incidence of PONV was similar in the two groups. Postoperative glycemia was transiently higher in the dexamethasone group (p = 0.004), but the need of hypoglycemic therapy was not significantly different.

CONCLUSIONS

Preoperative administration of dexamethasone did not cause a significant reduction in morphine consumption, but appears to be safe and plays a role in a multimodal anesthesia approach for patients undergoing elective minimally invasive thoracic surgery.

Effectiveness of Sublingual Buprenorphine and Fentanyl Pump in Controlling Pain After Open Cholecystectomy

Background

The proper management of postoperative pain improves patients’ quality of life, accelerates early postoperative recovery, shortens hospitalization period, and reduces medical costs. This study aimed to compare the effectiveness of intravenous fentanyl pump and sublingual buprenorphine tablet in controlling pain after open cholecystectomy.

Objectives

Evaluating the effectiveness of sublingual buprenorphine in reducing postoperative pain and complications after open cholecystectomy.

Methods

This study was a double-blind, randomized clinical trial. The study population encompassed those candidates undergoing open cholecystectomy, patients with ASA class I and II, individuals undergoing no other concomitant surgery, and patients in the age range of 20 - 50 years. The first group received sublingual buprenorphine 6, 12, and 18 hours after the first administration. The second group received fentanyl as patient-controlled analgesia (PCA) for 24 hours. Then nausea, vomiting, sedation, and Visual Analog Scale (VAS) scores were evaluated at the beginning, 2, 6, 12, 18, and 24 hours after surgery. The collected data were analyzed using SPSS software version 20.

Results

The mean age of the patients in the buprenorphine and fentanyl groups were 44.8 ± 5.5 and 42.8 ± 7.1 years, respectively. In this study, 22.5% of the patients in the buprenorphine group and 35.5% of the patients in the fentanyl group were male. During 6 and 24 hours after surgery, the pain level regarding the VAS scores was significantly lower in the buprenorphine group than in the fentanyl group; however, analgesic consumption was higher in the fentanyl group. In the early hours after surgery (2 and 6 hours), nausea and vomiting were lower in the buprenorphine group than in the fentanyl group even though the difference was not significant.

Conclusions

This study suggests buprenorphine as an effective drug for patients to reduce postoperative pain because of its limited complications, inexpensiveness, and more convenient administration method.

"The use of bilateral continuous erector spinae plane blocks for postoperative analgesia after right-sided living donor hepatectomy: A feasibility study"

BACKGROUND

Postoperative pain after living donor hepatectomy is significant. Postoperative coagulopathy may limit the use of epidural analgesia, the gold standard for pain control in abdominal surgery. The erector spinae plane block (ESPB) is a novel regional anesthesia technique that has been shown to provide effective analgesia in abdominal surgery. In this study, we examined the effect of continuous ESPB, administered via catheters, on perioperative opioid requirements after right living donor hepatectomies for liver transplantation.

METHODS

We performed a retrospective cohort study in patients undergoing right living donor hepatectomy. Twenty-four patients who received preoperative ESPB were compared to 51 historical controls who did not receive regional anesthesia. The primary endpoint was the total amount of oral morphine equivalents (OMEs) required on the day of surgery and postoperative day (POD) 1.

RESULTS

Patients in the ESPB group required a lower total amount of OMEs on the day of surgery and POD 1 [141 (107-188) mg] compared the control group [293 (220-380) mg; P < .001].

CONCLUSIONS

The use of continuous ESPB significantly reduced opioid consumption following right living donor hepatectomy.

An Innovative Pain Control Method Using Peripheral Nerve Block and Patient-Controlled Analgesia With Ketorolac After Bone Surgery in the Ankle Area: A Prospective Study

Although postoperative pain is inevitable after bone surgery, there is no general consensus regarding its ideal management. We hypothesized that the combination of ultrasound-guided peripheral nerve block (PNB) and patient-controlled analgesia (PCA) with ketorolac would be useful for pain control and reducing opioid usage. This prospective study aimed to evaluate the effectiveness of this method. This study included 95 patients aged >18 years who underwent bone surgery in the ankle area from June to December 2018. All operations were performed under anesthetic PNB, and additional PNB was given for pain control ∼11 hours after preoperative PNB. An additional PCA with ketorolac, started before rebound pain was experienced, was used for pain control in group A (49 patients) but not group B (46 patients). We used intramuscular injection with pethidine or ketorolac as rescue analgesics if pain persisted. A visual analogue scale (VAS) for pain was used to quantify pain at 6, 12, 18, 24, 36, 48, and 72 hours postoperatively. Patient satisfaction was assessed, along with side effects in both groups. VAS pain scores differed significantly between the groups at 24 hours after the operation (p = .013). All patients in group A were satisfied with the pain control method; however, 5 patients in group B were dissatisfied (p = .001), 3 owing to severe postoperative pain and 2 owing to postoperative nausea and vomiting. An average of 0.75 and 11.40 mg pethidine per patient was used in groups A and B, respectively, for 3 days. We concluded that the combined use of ultrasound-guided PNB and PCA with ketorolac can be an effective postoperative method of pain control that can reduce opioid usage.

Analgesic efficacy of postoperative bilateral, ultrasound-guided, posterior transversus abdominis plane block for laparoscopic colorectal cancer surgery: a randomized, prospective, controlled study

Background

We assessed whether a postoperative bilateral, ultrasound-guided, posterior transversus abdominis plane (TAP) block could reduce 24 h rescue tramadol requirement compared with placebo in patients undergoing elective laparoscopic colorectal cancer surgery.

Methods

Patients scheduled to undergo elective laparoscopic surgery following the diagnosis of colorectal cancer were included in this study and randomized into Group and Group Control. The patients received a postoperative bilateral, ultrasound-guided, posterior TAP block in either 20 mL of 0.5% ropivacaine (Group TAP) per side or an equivalent volume of normal saline (Group Control). The primary outcome was the cumulative consumption of rescue tramadol within 24 h after the surgery. Secondary endpoints included (1) resting and movement numerical rating scale (NRS) pain scores at 2, 4, 6, 12, 24, 48, and 72 h; (2) incidences of related side effects; (3) time to the first request for rescue tramadol; (4) patient satisfaction regarding postoperative analgesia; (5) time to restoration of intestinal function; (6) time to mobilization; and (7) the length of hospital stay.

Results

In total, 92 patients were randomized, and 82 patients completed the analysis. The total rescue tramadol requirement (median [interquartile range]) within the first 24 h was lower in Group TAP (0 [0, 87.5] mg) than in Group Control (100 [100, 200] mg), P < 0.001. The posterior TAP block reduced resting and movement NRS pain scores at 2, 4, 6, 12, and 24 h after surgery (all P < 0.001) but showed similar scores at 48 h or 72 h. A higher level of satisfaction with postoperative analgesia was observed in Group TAP on day 1 (P = 0.002), which was similar on days 2 (P = 0.702) and 3 (P = 0.551), compared with the Group Control. A few incidences of opioid-related side effects (P < 0.001) and a lower percentage of patients requiring rescue tramadol analgesia within 24 h (P < 0.001) were observed in Group TAP. The time to the first request for rescue analgesia was prolonged, and the time to mobilization and flatus was reduced with a shorter hospital stay in Group TAP as compared with Group Control.

Conclusions

A postoperative bilateral, ultrasound-guided, posterior TAP block resulted in better pain management and a faster recovery in patients undergoing laparoscopic colorectal cancer surgery, without adverse effects.

Trial registration

The study was registered at http://www.chictr.org.cn (ChiCTR-IPR-17012650; Sep 12, 2017).

Cannabis sativa: Interdisciplinary Strategies and Avenues for Medical and Commercial Progression Outside of CBD and THC

Cannabis sativa (Cannabis) is one of the world’s most well-known, yet maligned plant species. However, significant recent research is starting to unveil the potential of Cannabis to produce secondary compounds that may offer a suite of medical benefits, elevating this unique plant species from its illicit narcotic status into a genuine biopharmaceutical. This review summarises the lengthy history of Cannabis and details the molecular pathways that underpin the production of key secondary metabolites that may confer medical efficacy. We also provide an up-to-date summary of the molecular targets and potential of the relatively unknown minor compounds offered by the Cannabis plant. Furthermore, we detail the recent advances in plant science, as well as synthetic biology, and the pharmacology surrounding Cannabis. Given the relative infancy of Cannabis research, we go on to highlight the parallels to previous research conducted in another medically relevant and versatile plant, Papaver somniferum (opium poppy), as an indicator of the possible future direction of Cannabis plant biology. Overall, this review highlights the future directions of cannabis research outside of the medical biology aspects of its well-characterised constituents and explores additional avenues for the potential improvement of the medical potential of the Cannabis plant.

Comparison of Postoperative Renal Function between Non-Steroidal Anti-Inflammatory Drug and Opioids for Patient-Controlled Analgesia after Laparoscopic Nephrectomy: A Retrospective Cohort Study

Non-steroidal anti-inflammatory drugs (NSAIDs) can be used as opioid alternatives for patient-controlled analgesia (PCA). However, their use after nephrectomy has raised concerns regarding possible nephrotoxicity. This study compared postoperative renal function and postoperative outcomes between patients using NSAID and patients using opioids for PCA in nephrectomy. In this retrospective observational study, records were reviewed for 913 patients who underwent laparoscopic or robot-assisted laparoscopic nephrectomy from 2015 to 2017. After propensity score matching, 247 patients per group were analyzed. Glomerular filtration rate (GFR) percentages (postoperative value divided by preoperative value), blood urea nitrogen (BUN)/creatinine ratios, and serum creatinine percentages were compared at 2 weeks, 6 months, and 1 year after surgery between users of NSAID and users of opioids for PCA. Additionally, postoperative complication rates, postoperative acute kidney injury (AKI) incidences, postoperative pain scores, and lengths of hospital stay were compared between groups. Postoperative GFR percentages, BUN/creatinine ratios, and serum creatinine percentages were similar between the two groups. There were no significant differences in the rates of postoperative complications, incidences of AKI, and pain scores at 30 min, 6 h, 48 h, or 7 days postoperatively. The length of hospital stay was significantly shorter in the NSAID group than in the opioid group. This study showed no association between the use of NSAID for PCA after laparoscopic nephrectomy and the incidence of postoperative renal dysfunction.

Postoperative Pain Management in Total Knee Arthroplasty

Total knee arthroplasty (TKA) is one of the most common surgeries performed to relieve joint pain in patients with end‐stage osteoarthritis or rheumatic arthritis of the knee. However, TKA is followed by moderate to severe postoperative pain that affects postoperative rehabilitation, patient satisfaction, and overall outcomes. Historically, opioids have been widely used for perioperative pain management of TKA. However, opioids are associated with undesirable adverse effects, such as nausea, respiratory depression, and retention of urine, which limit their application in daily clinical practice. The aim of this review was to discuss the current postoperative pain management regimens for TKA. Our review of the literature demonstrated that multimodal analgesia is considered the optimal regimen for perioperative pain management of TKA and improves clinical outcomes and patient satisfaction, through a combination of several types of medications and delivery routes, including preemptive analgesia, neuraxial anesthesia, peripheral nerve blockade, patient‐controlled analgesia and local infiltration analgesia, and oral opioid/nonopioid medications. Multimodal analgesia provides superior pain relief, promotes recovery of the knee, and reduces opioid consumption and related adverse effects in patients undergoing TKA.

Morphine Dose Optimization in Critically Ill Pediatric Patients With Acute Respiratory Failure: A Population Pharmacokinetic-Pharmacogenomic Study

OBJECTIVE

To develop a pharmacokinetic-pharmacogenomic population model of morphine in critically ill children with acute respiratory failure.

DESIGN

Prospective pharmacokinetic-pharmacogenomic observational study.

SETTING

Thirteen PICUs across the United States.

PATIENTS

Pediatric subjects (n = 66) mechanically ventilated for acute respiratory failure, weight greater than or equal to 7 kg, receiving morphine and/or midazolam continuous infusions.

INTERVENTIONS

Serial blood sampling for drug quantification and a single blood collection for genomic evaluation.

MEASUREMENTS AND MAIN RESULTS

Concentrations of morphine, the two main metabolites, morphine-3-glucuronide and morphine-6-glucuronide, were quantified by high-performance liquid chromatography tandem mass spectrometry/mass spectroscopy. Subjects were genotyped using the Illumina HumanOmniExpress genome-wide single nucleotide polymorphism chip. Nonlinear mixed-effects modeling was performed to develop the pharmacokinetic-pharmacogenomic model. A two-compartment model with linear elimination and two individual compartments for metabolites best describe morphine disposition in this population. Our analysis demonstrates that body weight and postmenstrual age are relevant predictors of pharmacokinetic parameters of morphine and its metabolites. Furthermore, our research shows that a duration of mechanical ventilation greater than or equal to 10 days reduces metabolite formation and elimination upwards of 30%. However, due to the small sample size and relative heterogeneity of the population, no heritable factors associated with uridine diphosphate glucuronyl transferase 2B7 metabolism of morphine were identified.

CONCLUSIONS

The results provide a better understanding of the disposition of morphine and its metabolites in critically ill children with acute respiratory failure requiring mechanical ventilation due to nonheritable factors. It also provides the groundwork for developing additional studies to investigate the role of heritable factors.

Midazolam Dose Optimization in Critically Ill Pediatric Patients With Acute Respiratory Failure: A Population Pharmacokinetic-Pharmacogenomic Study

OBJECTIVES

To develop a pharmacokinetic-pharmacogenomic population model of midazolam in critically ill children with primary respiratory failure.

DESIGN

Prospective pharmacokinetic-pharmacogenomic observational study.

SETTING

Thirteen PICUs across the United States.

PATIENTS

Pediatric subjects mechanically ventilated for acute respiratory failure, weight greater than or equal to 7 kg, receiving morphine and/or midazolam continuous infusions.

INTERVENTIONS

Serial blood sampling for drug quantification and a single blood collection for genomic evaluation.

MEASUREMENTS AND MAIN RESULTS

Concentrations of midazolam, the 1' (1`-hydroxymidazolam metabolite) and 4' (4`-hydroxymidazolam metabolite) hydroxyl, and the 1' and 4' glucuronide metabolites were measured. Subjects were genotyped using the Illumina HumanOmniExpress genome-wide single nucleotide polymorphism chip. Nonlinear mixed effects modeling was performed to develop the pharmacokinetic-pharmacogenomic model. Body weight, age, hepatic and renal functions, and the UGT2B7 rs62298861 polymorphism are relevant predictors of midazolam pharmacokinetic variables. The estimated midazolam clearance was 0.61 L/min/70kg. Time to reach 50% complete mature midazolam and 1`-hydroxymidazolam metabolite/4`-hydroxymidazolam metabolite clearances was 1.0 and 0.97 years postmenstrual age. The final model suggested a decrease in midazolam clearance with increase in alanine transaminase and a lower clearance of the glucuronide metabolites with a renal dysfunction. In the pharmacogenomic analysis, rs62298861 and rs28365062 in the UGT2B7 gene were in high linkage disequilibrium. Minor alleles were associated with a higher 1`-hydroxymidazolam metabolite clearance in Caucasians. In the pharmacokinetic-pharmacogenomic model, clearance was expected to increase by 10% in heterozygous and 20% in homozygous for the minor allele with respect to homozygous for the major allele.

CONCLUSIONS

This work leveraged available knowledge on nonheritable and heritable factors affecting midazolam pharmacokinetic in pediatric subjects with primary respiratory failure requiring mechanical ventilation, providing the basis for a future implementation of an individual-based approach to sedation.

Comparison of tramadol versus tramadol with paracetamol for efficacy of postoperative pain management in lumbar discectomy: A randomised controlled study

PURPOSE

Despite developments in the treatment of pain, the availability of new drugs or increased knowledge of pain management, postoperative pain control after different surgeries remains inadequate. We aimed to compare the postoperative analgesic efficacy of tramadol versus tramadol with paracetamol after lumbar discectomy.

DESIGN, SETTING, PARTICIPANTS

Sixty patients undergoing lumbar discectomy were randomly assigned into two groups.

METHODS

Patients in Group T (n = 30) received tramadol (1 mg/kg), and patients in Group TP (n = 30) received tramadol (1 mg/kg) with paracetamol (1 g) 30 minutes before the end of surgery and paracetamol was continued during the postoperative period at 6 hours intervals for the first 24 hours. Patient-controlled analgesia with tramadol was used during the postoperative period.

MAIN OUTCOME MEASURES

Duration, postoperative pain scores, Ramsay sedation scores, analgesic consumption, and side effects were recorded in all patients during the postoperative period. Continuous random variables were tested for normal distribution using the Kolmogorov-Smirnov test, than Student's t-test was used for means comparisons between groups. For discrete random variables chi-square tests and McNemar test was used.

RESULTS

Demographic data, mean duration of anaesthesia and surgery were similar in both groups. Postoperative pain scores were significantly higher in Group T than Group TP at 5; 15; 20; and 30 minutes (P = .021, P = .004, P = .002, P = .018). Late postoperative pain scores were similar. Total tramadol consumption in Group T (106.12 ± 4.84 mg) was higher than Group TP (81.20 ± 2.53) during the 24 hours postoperative period. However, continuing the paracetamol at 6 hours interval did not change late postoperative pain scores.

CONCLUSION

The administration of tramadol with paracetamol was more effective than tramadol alone for early acute postoperative pain therapy following lumbar discectomy. Therefore, while adding paracetamol in early pain management is recommended, continuing paracetamol for the late postoperative period is not advised.

Dose-Ranging Study of Ramosetron for the Prevention of Nausea and Vomiting after Laparoscopic Gynecological Surgery: A Prospective Randomized Study

Patients undergoing laparoscopic gynecologic surgery and receiving postoperative analgesia with opioids have a high risk of postoperative nausea and vomiting (PONV). We compared the antiemetic efficacy of three doses of ramosetron in this high-risk population. In this prospective, double-blind trial, 174 patients randomly received ramosetron 0.3 mg (R0.3 group; n = 58), 0.45 mg (R0.45 group; n = 58), or 0.6 mg (R0.6 group; n = 58) at the end of surgery. The primary outcome was the incidence of PONV during the first postoperative 48 h. Nausea severity, pain scores, adverse events, and patient satisfaction (1-4; 4, excellent) were assessed. The incidence of PONV was not different between groups (35%, 38%, and 35% in R0.3, R0.45, and R0.6 groups; p = 0.905). Nausea severity, pain scores, and incidence of adverse events (dizziness, headache, or sedation) were similar between groups. Compared to the R0.3 group, the R0.45 and R0.6 groups had lower incidence of premature discontinuation of fentanyl-based patient-controlled analgesia primarily because of intractable PONV (9% and 5% vs. 24%; p = 0.038), and higher satisfaction scores (3.4 ± 0.8 and 3.3 ± 0.7 vs. 2.4 ± 0.9; p = 0.005). Compared to ramosetron 0.3 mg, ramosetron 0.45 and 0.6 mg did not reduce PONV, but reduced premature discontinuation of patient-controlled analgesia and increased patient satisfaction, without increasing adverse events.

Stratified pain management counseling and implementation improving patient satisfaction: a prospective, pilot study

BACKGROUND

Post-operative pain is unpleasant for patients and may worsen surgical recovery. Peri-operative multimodal analgesia has been used for many years; however, its efficacy still needs improvement. In the present study, a thorough peri-operative pain counseling and stratified management program based on risk assessment was implemented, with the goal of improving post-operative analgesia and patient satisfaction.

METHODS

This prospective, controlled, pilot study included 361 patients who underwent elective surgery. Of these 361 patients, 187 received peri-operative pain risk assessment and stratified analgesia and counseling (stratified analgesia group), while 174 received conventional multimodal analgesia (conventional group). The two groups were compared regarding the post-operative pain intensity, rescue analgesia administration, post-operative quality of recovery as assessed via the quality of recovery 40 questionnaire, total dosage of peri-operative opioids, analgesic satisfaction, and analgesic costs.

RESULTS

Compared with the conventional group, the stratified analgesia group reported decreased pain intensity during motion at 24 h post-operatively and required lower dosages of rescue analgesia (P = 0.03). The total quality of recovery 40 questionnaire score and the scores for physical wellbeing and pain were significantly better in the stratified analgesia group than the conventional group (P = 0.04); the stratified analgesia group also reported better scores for analgesic satisfaction (P = 0.03) and received lower dosages of opioids (P = 0.03). Analgesic costs were lower in the stratified analgesia group than the conventional group; the cost-effective ratio was 109 in the conventional group and 62 in the stratified analgesia group.

CONCLUSIONS

The analgesic efficacy was improved by the implementation of stratified analgesia based on surgical pain risk assessment and counseling. This stratified analgesia protocol increased the patients' analgesic satisfaction and improved the quality of recovery without increasing healthcare costs. The present findings may help improve the efficacy of peri-operative multimodal analgesia in clinical practice.

CLINICAL TRIAL REGISTRY

NCT02728973; https://clinicaltrials.gov/ct2/show/NCT02728973?term=NCT02728973&draw=2&rank=1.

Patient-Controlled Versus Clinician-Controlled Sedation With Propofol: Systematic Review and Meta-analysis With Trial Sequential Analyses

BACKGROUND

Sedation with propofol is frequently used to facilitate diagnostic and therapeutic procedures. Propofol can be administrated by the patient (patient-controlled sedation [PCS]) or by a clinician (clinician-controlled sedation [CCS]). We aimed to compare these 2 techniques.

METHODS

PubMed, Embase, CENTRAL, and trial registries were searched up to October 2017 for randomized controlled trials comparing PCS with CCS with propofol. The primary end points were the risks of presenting at least 1 episode of oxygen desaturation, arterial hypotension, and bradycardia, and the risk of requiring a rescue intervention (pharmacologic therapies or physical maneuvers) for sedation-related adverse events. Secondary end points were the dose of propofol administrated, operator and patient satisfaction, and the risk of oversedation. A random-effects model and an α level of .02 to adjust for multiple analyses were used throughout. Trial sequential analyses were performed for primary outcomes. Quality of evidence was assessed according to the Grades of Recommendation, Assessment, Development, and Evaluation system.

RESULTS

Thirteen trials (1103 patients; median age, 47 years; American Society of Anesthesiologists physical status I-III) describing various diagnostic and therapeutic procedures with propofol sedation were included. PCS had no impact on the risk of oxygen desaturation (11 trials, 31/448 patients [6.9%] with PCS versus 46/481 [9.6%] with CCS; risk ratio, 0.74 [98% confidence interval, 0.35-1.56]) but decreased the risk of requiring a rescue intervention for adverse events (11 trials, 29/449 patients [6.5%] with PCS versus 74/482 [15.4%] with CCS; risk ratio, 0.45 [98% confidence interval, 0.25-0.81]). For both outcomes, Trial sequential analyses suggested that further trials were unlikely to change the results, although the quality of evidence was graded very low for all primary outcomes. For the risk of arterial hypotension and bradycardia, the required sample size for a definitive conclusion had not been reached. Analysis of secondary outcomes suggested that PCS decreased the risk of oversedation and had no impact on propofol dose administrated, or on operator or patient satisfaction.

CONCLUSIONS

PCS with propofol, compared with CCS with propofol, had no impact on the risk of oxygen desaturation, but significantly decreased the risk of rescue interventions for sedation-related adverse events. Further high-quality trials are required to assess the risks and benefits of PCS.

Analgesia after major laparoscopic surgery in patients with chronic kidney disease: A retrospective cohort study

The amount of reduction in opioid doses and its effect on postoperative pain outcomes in chronic kidney disease (CKD) patients in the perioperative setting remains unclear. This study aimed to investigate differences in postoperative pain outcomes after major laparoscopic surgery between patients with CKD and those with normal preoperative kidney function. Medical records of patients who underwent laparoscopic major abdominal surgery from January 2010 to December 2016 were retrospectively reviewed, and 6,612 patients were finally included. During postoperative day (POD) 0–3, patients with an estimated glomerular filtration rate (eGFR) < 30 mL min⁻¹ 1.73 m⁻² had 3.5% lower morphine equivalent consumption than those with an eGFR ≥ 90 mL min⁻¹ 1.73 m⁻² (P = 0.023), whereas patients with preoperative eGFR between 60–90 mL min⁻¹ 1.73 m⁻² and 30–60 mL min⁻¹ 1.73 m⁻² showed no significant differences in morphine equivalent consumption. Additionally, pain scores at rest during POD 0–3 were not significantly associated with preoperative kidney function. In conclusion, our results suggest that patients with mild to moderate CKD (stage 2–3) did not require reduction of opioid analgesics during POD 0–3, compared to patients with normal preoperative kidney function. Only patients with severe CKD (stage ≥ 4) might require a slight reduction of opioid analgesics.

Effects on postoperative nausea and vomiting of nefopam versus fentanyl following bimaxillary orthognathic surgery: a prospective double-blind randomized controlled trial

Background

Postoperative nausea and vomiting (PONV) frequently occurs following bimaxillary orthognathic surgeries. Compared to opioids, Nefopam is associated with lower incidences of PONV, and does not induce gastrointestinal tract injury, coagulopathy, nephrotoxicity, or fracture healing dysfunction, which are common side effects of Nonsteroidal anti-inflammatory drugs. We compared nefopam- and fentanyl-induced incidence of PONV in patients with access to patient-controlled analgesia (PCA) following bimaxillary orthognathic surgeries.

Methods

Patients undergoing bimaxillary orthognathic surgeries were randomly divided into nefopam and fentanyl groups. Nefopam 120 mg or fentanyl 700 µg was mixed with normal saline to a final volume of 120 mL. Patients were given access to nefopam or fentanyl via PCA. Postoperative pain intensity and PONV were measured at 30 minutes and 1 hour after surgery in the recovery room and at 8, 24, 48, and 72 hours after surgery in the ward. The frequency of bolus delivery was compared at each time point.

Results

Eighty-nine patients were enrolled in this study, with 48 in the nefopam (N) group and 41 in the fentanyl (F) group. PONV occurred in 13 patients (27.7%) in the N group and 7 patients (17.1%) in the F group at 8 hours post-surgery (P = 0.568), and there were no significant differences between the two groups at any of the time points. VAS scores were 4.4 ± 2.0 and 3.7 ± 1.9 in the N and F groups, respectively, at 8 hours after surgery (P = 0.122), and cumulative bolus delivery was 10.7 ± 13.7 and 8.6 ± 8.5, respectively (P = 0.408). There were no significant differences in pain or bolus delivery at any of the remaining time points.

Conclusion

Patients who underwent bimaxillary orthognathic surgery and were given nefopam via PCA did not experience a lower rate of PONV compared to those that received fentanyl via PCA. Furthermore, nefopam and fentanyl did not provide significantly different postoperative pain control.

Vital sign monitoring with continuous pulse oximetry and wireless clinical notification after surgery (the VIGILANCE pilot study)-a randomized controlled pilot trial

Background

Respiratory depression is a serious perioperative complication associated with morbidity and mortality. Recently, technology has become available to wirelessly monitor patients on regular surgical wards with continuous pulse oximetry and wireless clinician notification with alarms. When a patient’s SpO₂ falls below a set threshold, the clinician is notified via a pager and may intervene earlier to prevent further clinical deterioration. To date, the technology has not been evaluated with a randomized controlled trial (RCT).

Methods

We designed a parallel-group unblinded pilot RCT of a wireless monitoring system on two surgical wards in an academic teaching hospital. Postsurgical patients with an anticipated length of stay of at least 1 day were included and randomized to standard care or standard care plus wireless respiratory monitoring for up to a 72-h period. The primary outcomes were feasibility outcomes: average patients recruited per week and tolerability of the system by patients. Secondary outcomes included (1) respiratory events (naloxone administration for respiratory depression, ICU transfers, and cardiac arrest team activation) and (2) system alarm types and details. The analysis of the outcomes was based on descriptive statistics and estimates reported using point (95% confidence intervals). Criteria for success of feasibility were recruitment of an average of 15 patients/week and 90% of the patients tolerating the system.

Results

The pilot trial enrolled 250 of the 335 patients screened for eligibility, with 126 and 124 patients entering the standard monitoring and wireless groups, respectively. Baseline demographics were similar between groups, except for slightly more women in the wireless group. Average patient recruitment per week was 14 95% CI [12, 16] patients. The wireless monitoring was quite tolerable with 86.6% (95% CI 78.2–92.7%) of patients completing the full course, and there were no other adverse events directly attributable to the monitoring. With regard to secondary outcomes, the respiratory event rate was low with only 1 event in the wireless group and none in the control group. The average number of alarms per week was 4.0 (95% CI, 1.6–6.4).

Conclusions

This pilot study demonstrated adequate patient recruitment and high tolerability of the wireless monitoring system. A full RCT that is powered to detect patient important outcomes such as respiratory depression is now underway.

Trial registration

ClinicalTrials.gov, Registration number NCT02907255, registered 7 September 2016—retrospectively registered.

Changing Patterns in the Acute Pain Service: Epidural versus Patient-controlled Analgesia

This study involved an audit and a survey of the Acute Pain Service at Princess Alexandra Hospital. It was found in the audit that the relative choice of epidural analgesia had declined by 50% over the five-year time period of 1998–2003. The survey of consultants showed that 82% of them had changed their practice and that they were performing fewer epidural anaesthetics. Two of the most common reasons given for this change in practice related to fear of litigation (34%) and lack of evidence (21%). These results show that within this department approaches to postoperative pain control had changed and that this appears to have resulted from factors such as the medicolegal environment and the possible influence of evidence based medicine.

Effects of glial glutamate transporter activator in formalin-induced pain behaviour in mice

BACKGROUND

Nociceptive pain remains a prevalent clinical problem and often poorly responsive to the currently available analgesics. Previous studies have shown that astroglial glutamate transporter-1 (GLT-1) in the hippocampus and anterior cingulate cortex (ACC) is critically involved in pain processing and modulation. However, the role of astroglial GLT-1 in nociceptive pain involving the hippocampus and ACC remains unknown. We investigated the role of 3-[[(2-Methylphenyl) methyl]thio]-6-(2-pyridinyl)-pyridazine (LDN-212320), a GLT-1 activator, in nociceptive pain model and hippocampal-dependent behavioural tasks in mice.

METHODS

We evaluated the effects of LDN-212320 in formalin-induced nociceptive pain model. In addition, formalin-induced impaired hippocampal-dependent behaviours were measured using Y-maze and object recognition test. Furthermore, GLT-1 expression and extracellular signal-regulated kinase phosphorylation (pERK1/2) were measured in the hippocampus and ACC using Western blot analysis and immunohistochemistry.

RESULTS

The LDN-212320 (10 or 20 mg/kg, i.p) significantly attenuated formalin-evoked nociceptive behaviour. The antinociceptive effects of LDN-212320 were reversed by systemic administration of DHK (10 mg/kg, i.p), a GLT-1 antagonist. Moreover, LDN-212320 (10 or 20 mg/kg, i.p) significantly reversed formalin-induced impaired hippocampal-dependent behaviour. In addition, LDN-212320 (10 or 20 mg/kg, i.p) increased GLT-1 expressions in the hippocampus and ACC. On the other hand, LDN-212320 (20 mg/kg, i.p) significantly reduced formalin induced-ERK phosphorylation, a marker of nociception, in the hippocampus and ACC.

CONCLUSION

These results suggest that the GLT-1 activator LDN-212320 prevents nociceptive pain by upregulating astroglial GLT-1 expression in the hippocampus and ACC. Therefore, GLT-1 activator could be a novel drug candidate for nociceptive pain.

SIGNIFICANCE

The present study provides new insights and evaluates the role of GLT-1 activator in the modulation of nociceptive pain involving hippocampus and ACC. Here, we provide evidence that GLT-1 activator could be a potential therapeutic utility for the treatment of nociceptive pain.

Patient-controlled epidural analgesia versus conventional epidural analgesia after total hip replacement - a randomized trial

AIMS

Patient-controlled analgesia (PCA) is usually considered a better option for pain management compared to conventional analgesia. The beneficial effect of PCA has been assessed in a number of studies; however, the results are inconsistent. The goal of this study was to compare of patient-controlled epidural analgesia (PCEA) to conventional epidural analgesia after total hip replacement (THR).

METHODS

This prospective study was performed at the Department of Anesthesia and Intensive Care Medicine at a tertiary university hospital. After THR, patients were admitted to the intensive care unit (ICU) and randomized to one of two groups (PCEA and non-PCEA). Postoperative pain in the PCEA group was treated using a standardized protocol, while the analgesia in the non-PCEA group was based on physician prescription according to the patient's clinical condition. The total consumption of analgesics, patients' satisfaction, pain intensity, and analgesia-related complications were recorded for 24 h after surgery.

RESULTS

The final sample consisted of 111 patients (PCEA group, n=55 and non-PCEA group, n=56). The PCEA group had significantly lower total consumption of analgesic mixtures (0.9±0.3 and 1.3±0.4 mL/kg per day, P<0.001).There was greater patient satisfaction (P<0.001) in the PCEA group. The mean pain intensity over 24 hours postoperatively was similar for both groups (P=0.14). There was no significant difference in rate of analgesia-related complications between the groups (hypotension, P=0.14; bradypnea, P=0.11).

CONCLUSION

Compared to conventional epidural analgesia based on physician prescription, PCEA led to less total analgesic consumption and greater patient satisfaction after THR.

CYP3A4 gene polymorphism is correlated with individual consumption of sufentanil

BACKGROUND

Pain is one of the major adverse clinical outcomes of cesarean section (CS). In the past few years, researchers and physicians have been optimizing post-operative analgesic modalities, but the results are still undesirable for the parturient. The cytochrome P-450 3A4 (CYP3A4) gene has been reported to contribute significantly to human liver microsomal oxidation of sufentanil and alfentanil.

METHODS

We detected the frequency of CYP3A4 mutant allele, which is associated with the metabolism of diverse drugs, including opioids used for anesthesia. We then investigated the correlation between sufentanil (an opioid analgesic) consumption and CYP3A4 genetic polymorphism.

RESULTS

We found the frequency of the CYP3A4∗1G (the mutant form of CYP3A) variant allele to be 0.279 in 71 parturients undergoing cesarean section and 137 age-matched parturients with vaginal delivery. Interestingly, the parturients with homozygous CYP3A4∗1G showed less sufentanil consumption compared with those having the wild-type genotype.

CONCLUSION

In summary, we found a correlation between CYP3A4 genetic polymorphism and sufentanil consumption. This might be helpful for optimizing the anesthesia strategies and reducing their side effects.

Managing epidural catheters in critical care beds: An observation analysis in the Republic of Ireland

In certain hospitals, epidural analgesia is restricted to critical care beds. Due to critical care bed strain, it is likely that many patients are unable to avail of epidural analgesia. The aims of the study were to retrospectively review the number of patients admitted to critical care beds for epidural analgesia over a two-year period 2015–16, to determine the duration of epidural analgesia, to identify the average critical care bed occupancy during this period, to get updated information on the implementation of acute pain service in the Republic of Ireland and the availability of ward-based epidural analgesia. One hundred and sixty patients had a midline laparotomy, 40 of which had an epidural (25%). Forty-two patients were admitted to a critical care bed for epidural analgesia. Aside from epidural analgesia, 12% had other indications for ICU admission. Median duration epidural analgesia was 1.64 days (IQR 0.98–2.14 days). ICU bed occupancy rates were 88.7% in 2015 and 85.1% in 2016. Acute pain service and ward-based epidural analgesia were available in 46 and 42% of hospitals, respectively. Restricting epidural use to a critical care setting is likely to result in reduced access to epidural analgesia. The implementation of acute pain service and availability of ward-based epidural analgesia in the Republic of Ireland are suboptimal.

Patient-Controlled Analgesia and Length of Hospital Stay in Orthognathic Surgery: A Randomized Controlled Trial

PURPOSE

The objective of this prospective, randomized controlled pilot study of patients undergoing orthognathic surgery was to compare the hospital length of stay (LOS) in patients using intravenous patient-controlled analgesia (PCA) versus patients receiving scheduled and as-needed oral analgesia.

PATIENTS AND METHODS

A total of 40 patients (19 male and 21 female patients) aged 16 to 56 years (mean, 20.73 years; standard deviation, 6.87 years) were recruited prospectively and randomized to PCA and non-PCA groups of equal size. Recording of the patient-reported pain score using a visual analog scale was commenced at 8:00 am on day 1 after surgery until discharge. The pain score from routine nursing observations during the postoperative period was recorded until the patient was discharged from the hospital.

RESULTS

Randomization resulted in approximately equal proportions of male patients (45% vs 50%) and median ages (18.5 years vs 20 years) for the PCA group versus the non-PCA group; however, the PCA group was noted to have a higher proportion of double-jaw surgery (65% vs 40%). The median LOS was 2 days for both the PCA and non-PCA groups (P = .06). No statistically significant difference in pain scores was found between the 2 groups either at rest (P = .27) or on movement (P = .13).

CONCLUSIONS

No evidence was found to indicate the superiority of either the PCA or non-PCA regimen with respect to LOS and pain scores; however, this is not evidence of equivalence of the 2 pain management approaches.

Comparison of palonosetron and dexamethasone with ondansetron and dexamethasone for postoperative nausea and vomiting in postchemotherapy ovarian cancer surgeries requiring opioid-based patient-controlled analgesia: A randomised, double-blind, active controlled study

BACKGROUND AND AIMS

Patients undergoing ovarian cancer surgery after chemotherapy and requiring opioid-based patient-controlled analgesia (PCA) are at high-risk of postoperative nausea and vomiting (PONV). We aimed to assess the effect of palonosetron and dexamethasone combination for these patients for prevention of PONV.

METHODS

This study included 2 groups and 150 patients. At the time of wound closure, patients in group A received ondansetron 8 mg intravenous (IV) + dexamethasone 4 mg IV and group B received palonosetron 0.075 mg IV + dexamethasone 4 mg IV. Postoperatively for 48 hours, group A patients received ondansetron 4 mg 8 hourly IV, group B patients received normal saline 8 hourly IV in 2 cc syringe. The primary objective was the overall incidence of PONV. Independent t-test, Chi-square test, and Fisher's exact test were used and multivariate regression analysis was done.

RESULTS

Vomiting was significantly higher in group A (37.3%) as compared with group B (21.3%) at 0-48 hours (P = 0.031). Significantly more patients in Group A had nausea as compared with group B at 90-120 minutes (30.66% vs 18.66%, P = 0.043) and 6-24 hours (32.0% vs 22.66%, P = 0.029). PCA opioid usage in microgram was significantly higher in group A at 0-24 hours (690.53 ± 332.57 vs 576.85 ± 250.79, P = 0.024) and 0-48 hours (1126.10 ± 512.18 vs 952.13 ± 353.85, P = 0.030).

CONCLUSION

Palonosetron with dexamethasone is more effective than ondasetron with dexamethasone for prevention of PONV in post-chemotherapy ovarian cancer surgeries receiving opioid-based patient controlled analgesia.

Intraoperative and postoperative infusion of dexmedetomidine combined with intravenous butorphanol patient-controlled analgesia following total hysterectomy under laparoscopy

The present prospective, randomized, double-blinded, controlled study aimed to investigate the efficacy and safety of dexmedetomidine (DEX) combined with butorphanol for patient-controlled intravenous analgesia (PCIA) following total laparoscopic hysterectomy. A total of 88 patients undergoing total laparoscopic hysterectomy and receiving postoperative PCIA were divided into two groups following surgery. Patients received DEX 0.5 µg/kg intravenously in the DEX group or 0.9% normal saline in the control (CON) group following anesthesia induction. Postoperatively, the PCIA (10 mg butorphanol with 300 µg dexmedetomidine in the DEX group or without DEX in the CON group) was delivered as a 0.5 ml bolus (lockout interval of 15 min) with a continuous background infusion of 2 ml/h. Cardiovascular and respiratory variables, cumulative butorphanol consumption, pain scores, level of sedation, concerning adverse events and the degree of patient satisfaction were recorded for 24 h post-surgery. A total of 81 patients completed the study. Blood pressure and heart rate exhibited no significant difference between the two groups during surgery and for 24 h post-surgery. Compared with the CON group, patients in the DEX group required ~19% less butorphanol (P<0.05). During the first 24 h post-surgery, patients from the DEX group had a significantly lower visual analogue scale score at rest and movement states compared with the CON group (P<0.05). There was no significant difference in sedation score between the groups. The satisfaction scores were significantly higher in the DEX group compared with those in the CON group (P<0.05). Compared with the CON group, the DEX group exhibited a lower rate of postoperative nausea and vomiting (P<0.05). There was no occurrence of serious adverse events, including respiratory depression, hypotension, bradycardia and somnolence. In conclusion, following total laparoscopic hysterectomy, the loading dose of DEX (0.5 µg/kg) followed by a continuous infusion as an adjunct to butorphanol PCIA resulted in effective analgesia, significant butorphanol sparing and less butorphanol-induced nausea and vomiting without excessive sedation or adverse effects. The trial registration number was ChiCTR1800015675 at the Chinese Clinical Trial Registry (chictr.org.cn) and the date of registration was 4th April 2018.

Use of Intravenous Acetaminophen in Children for Analgesia After Spinal Fusion Surgery: A Randomized Clinical Trial

OBJECTIVES

Opioid pharmacotherapy is the cornerstone of postoperative analgesia. Despite its effectiveness, it has a variety of potential adverse effects. Therefore, a multimodal approach with non-opioid analgesics would be optimal. The aim of this study was to determine if intravenous (IV) acetaminophen would reduce opioid requirements and improve clinical outcomes in children after surgery.

METHODS

A single-center, randomized, double-blind study was conducted in 57 children (10-18 years old) undergoing posterior spine fusion surgery between July 2011 to May 2014. All subjects received either acetaminophen or placebo at the end of surgery, followed by repeated doses every 6 hours for a total of 8 doses.

RESULTS

In the first 24 postoperative hours, the average opioid consumption was lower for the active group compared with the placebo group (p = 0.02). The total unadjusted time to patient controlled analgesia (PCA) discontinuation was also longer in the placebo group than the active group (90 hours vs. 73 hours, p = 0.02); however, this was not statistically significant after normalizing for body weight. Additionally, time to first solid intake was longer without the use of acetaminophen (69 hours vs. 49 hours, p = 0.01).

CONCLUSIONS

Postoperative use of IV acetaminophen was associated with earlier time to diet advancement and discontinuation of IV analgesics and may result in lower opioid consumption.

Epidural analgesia versus patient-controlled intravenous analgesia for pain following intra-abdominal surgery in adults

BACKGROUND

Intravenous patient-controlled analgesia (IVPCA) with opioids and epidural analgesia (EA) using either continuous epidural administration (CEA) or patient-controlled (PCEA) techniques are popular approaches for analgesia following intra-abdominal surgery. Despite several attempts to compare the risks and benefits, the optimal form of analgesia for these procedures remains the subject of debate.

OBJECTIVES

The objective of this review was to update and expand a previously published Cochrane Review on IVPCA versus CEA for pain after intra-abdominal surgery with the addition of the comparator PCEA. We have compared both forms of EA to IVPCA. Where appropriate we have performed subgroup analysis for CEA versus PCEA.

SEARCH METHODS

We searched the following electronic databases for relevant studies: Cochrane Central Register of Controlled Trials (CENTRAL) (2017; Issue 8), MEDLINE (OvidSP) (1966 to September 2017), and Embase (OvidSP) (1988 to September 2017) using a combination of MeSH and text words. We searched the following trial registries: Australian New Zealand Clinical Trials Registry, ClinicalTrials.gov, and the EU Clinical Trials Register in September 2017, together with reference checking and citation searching to identify additional studies.We included only randomized controlled trials and used no language restrictions.

SELECTION CRITERIA

We included all parallel and cross-over randomized controlled trials (RCTs) comparing CEA or PCEA (or both) with IVPCA for postoperative pain relief in adults following intra-abdominal surgery.

DATA COLLECTION AND ANALYSIS

Two review authors (JS and EY) independently identified studies for eligibility and performed data extraction using a data extraction form. In cases of disagreement (three occasions) a third review author (MB) was consulted. We appraised each included study to assess the risk of bias as outlined in Section 8.5 of the Cochrane Handbook for Systematic Reviews of Interventions. We used GRADE to assess the quality of the evidence.

MAIN RESULTS

We included 32 studies (1716 participants) in our review. There are 10 studies awaiting classification and one ongoing study. A total of 869 participants (51%) received EA and 847 (49%) received IVPCA. The EA trials included 16 trials with CEA (418 participants) and 16 trials with PCEA (451 participants). The studies included a broad range of surgical procedures (including hysterectomies, radical prostatectomies, Caesarean sections, colorectal and upper gastrointestinal procedures), a wide range of adult ages, and were performed in several different countries.Our pooled analyses suggested a benefit with regard to pain scores (using a visual analogue scale between 0 and 100) in favour of EA techniques at rest. The mean pain reduction at rest from waking to six hours after operation was 5.7 points (95% confidence interval (CI) 1.9 to 9.5; 7 trials, 384 participants; moderate-quality evidence). From seven to 24 hours, the mean pain reduction was 9.0 points (95% CI 4.6 to 13.4; 11 trials, 558 participants; moderate-quality evidence). From 24 hours the mean pain reduction was 5.1 points (95% CI 0.9 to 9.4; 7 trials, 393 participants; moderate-quality evidence). Due to high statistical heterogeneity, no pooled analysis was possible for the estimation of pain on movement at any time. Two single studies (one using CEA and one PCEA) reported lower pain scores with EA compared to IVPCA at 0 to 6 hours and 7 to 24 hours. At > 24 hours the results from 2 studies (both CEA) were conflicting.We found no difference in mortality between EA and IVPCA, although the only deaths reported were in the EA group (5/287, 1.7%). The risk ratio (RR) of death with EA compared to using IVPCA was 3.37 (95% CI 0.72 to 15.88; 9 trials, 560 participants; low-quality evidence).A single study suggested that the use of EA may result in fewer episodes of respiratory depression, with an RR of 0.47 (95% CI 0.04 to 5.69; 1 trial; low-quality evidence). The successful placement of an epidural catheter can be technically challenging. The improvements in pain scores above were accompanied by an increase in the risk of failure of the analgesic technique with EA (RR 2.48, 95% CI 1.13 to 5.45; 10 trials, 678 participants; moderate-quality evidence); the occurrence of pruritus (RR 2.36, 95% CI 1.67 to 3.35; 8 trials, 492 participants; moderate-quality evidence); and episodes of hypotension requiring intervention (RR 7.13, 95% CI 2.87 to 17.75; 6 trials, 479 participants; moderate-quality evidence). There was no clear evidence of an advantage of one technique over another for other adverse effects considered in this review (Venous thromboembolism with EA (RR 0.32, 95% CI 0.03 to 2.95; 2 trials, 101 participants; low-quality evidence); nausea and vomiting (RR 0.94, 95% CI 0.69 to 1.27; 10 trials, 645 participants; moderate-quality evidence); sedation requiring intervention (RR 0.87, 95% CI 0.40 to 1.87; 4 trials, 223 participants; moderate-quality evidence); or episodes of desaturation to less than 90% (RR 1.29, 95% CI 0.71 to 2.37; 5 trials, 328 participants; moderate-quality evidence)).

AUTHORS' CONCLUSIONS

The additional pain reduction at rest associated with the use of EA rather than IVPCA is modest and unlikely to be clinically important. Single-trial estimates provide low-quality evidence that there may be an additional reduction in pain on movement, which is clinically important. Any improvement needs to be interpreted with the understanding that the use of EA is also associated with an increased chance of failure to successfully institute analgesia, and an increased likelihood of episodes of hypotension requiring intervention and pruritus. We have rated the evidence as of moderate quality given study limitations in most of the contributing studies. Further large RCTs are required to determine the ideal analgesic technique. The 10 studies awaiting classification may alter the conclusions of the review once assessed.

Assessment and pathophysiology of pain in cardiac surgery

Analysis of the problem of surgical pain is important in view of the fact that the success of surgical treatment depends largely on proper pain management during the first few days after a cardiosurgical procedure. Postoperative pain is due to intraoperative damage to tissue. It is acute pain of high intensity proportional to the type of procedure. The pain is most intense during the first 24 hours following the surgery and decreases on subsequent days. Its intensity is higher in younger subjects than elderly and obese patients, and preoperative anxiety is also a factor that increases postoperative pain. Ineffective postoperative analgesic therapy may cause several complications that are dangerous to a patient. Inappropriate postoperative pain management may result in chronic pain, immunosuppression, infections, and less effective wound healing. Understanding and better knowledge of physiological disorders and adverse effects resulting from surgical trauma, anesthesia, and extracorporeal circulation, as well as the development of standards for intensive postoperative care units are critical to the improvement of early treatment outcomes and patient comfort.

Non-invasive patient-controlled analgesia in the management of acute postoperative pain in the hospital setting

OBJECTIVE

Acute postoperative pain is experienced by the majority of hospitalized patients undergoing surgical procedures, with many reporting inadequate pain relief and/or high levels of dissatisfaction with their pain management. Patient-controlled analgesia (PCA) ensures patient involvement in acute pain control, a key component for implementing a quality management system. This narrative article overviews the clinical evidence for conventional PCA and briefly discusses new, non-invasive PCA systems, namely the sufentanil sublingual tablet system (SSTS) and the fentanyl iontophoretic transdermal system (FITS).

METHODS

A Medline literature search ("patient-controlled analgesia" and "acute postoperative pain") was conducted to 1 April 2017; results from the main clinical trials are discussed. Additional literature was identified from the reference lists of cited publications.

RESULTS

Moderate to low quality evidence supports opioid-based intravenous PCA as an efficacious alternative to non-patient-controlled systemic analgesia for postoperative pain. However, despite the benefits of PCA, conventional intravenous PCA is limited by system-, drug- and human-related issues. The non-invasive SSTS and FITS have demonstrated good efficacy and safety in placebo- and intravenous morphine PCA-controlled trials, and are associated with high patient/healthcare practitioner satisfaction/ease of care ratings and offer early patient mobilization.

CONCLUSIONS

Evidence-based guidelines for acute postoperative pain management support the use of multimodal regimens in many situations. As effective and safe alternatives to conventional PCA, and with the added benefits of being non-invasive, easy to use and allowing early patient mobilization, the newer PCA systems may complement multimodal approaches, or potentially replace certain regimens, in hospitalized patients with acute postoperative pain.

Analysis of adverse outcomes in the post-anesthesia care unit based on anesthesia liability data

STUDY OBJECTIVE

The aim of this study is to provide a contemporary medicolegal analysis of claims brought against anesthesiologists in the United States for events occurring in the post-anesthesia care unit (PACU).

DESIGN

In this retrospective analysis, we analyzed closed claims data from the Controlled Risk Insurance Company (CRICO) Comparative Benchmarking System (CBS) database.

SETTING

Claims closed between January 1, 2010 and December 31, 2014 were included for analysis if the alleged damaging event occurred in a PACU and anesthesiology was named as the primary responsible service.

PATIENTS

Forty-three claims were included for analysis. Data regarding ASA physical status and comorbidities were obtained, whenever available. Ages ranged from 18 to 94. Patients underwent a variety of surgical procedures. Severity of adverse outcomes ranged from temporary minor impairment to death.

INTERVENTIONS

Patients receiving care in the PACU.

MEASUREMENTS

Information gathered for this study includes patient demographic data, alleged injury type and severity, operating surgical specialty, contributing factors to the alleged damaging event, and case outcome. Some of these data were drawn directly from coded variables in the CRICO CBS database, and some were gathered by the authors from narrative case summaries.

RESULTS

Settlement payments were made in 48.8% of claims. A greater proportion of claims involving death resulted in payment compared to cases involving other types of injury (69% vs 37%, p = 0.04). Respiratory injuries (32.6% of cases), nerve injuries (16.3%), and airway injuries (11.6%) were common. Missed or delayed diagnoses in the PACU were cited as contributing factors in 56.3% of cases resulting in the death of a patient. Of all claims in this series, 48.8% involved orthopedic surgery.

CONCLUSIONS

The immediate post-operative period entails significant risk for serious complications, particularly respiratory injury and complications of airway management. Appropriate monitoring of patients by responsible providers in the PACU is crucial to timely diagnosis of potentially severe complications, as missed and delayed diagnoses were a factor in a number of the cases reviewed.

Association of nefopam use with postoperative nausea and vomiting in gynecological patients receiving prophylactic ramosetron: A retrospective study

Background

Postoperative nausea and vomiting (PONV) is a common adverse effect of opioid-based intravenous patient-controlled analgesia (IV PCA). Nefopam has been considered as a good candidate for inclusion in multimodal analgesia because of its opioid sparing effect, but it can be emetic. This study aims to examine whether the use of nefopam combined with fentanyl in IV PCA was associated with the higher incidence of PONV in patients receiving prophylactic ramosetron after gynecological surgery.

Methods

Data from 296 patients who underwent gynecological surgery were retrospectively reviewed. The patients received IV PCA containing either fentanyl 1500 μg and ketorolac 90 mg (Group K) or fentanyl 1500 μg and nefopam 80 mg (Group N). All patients in both groups received 0.3 mg of ramosetron at the end of surgery. The primary outcome measure was the incidence of PONV during the 3-day postoperative period.

Results

No difference was observed in the incidence of PONV during the 3-day postoperative period between the two groups. However, the incidence of nausea on postoperative day 2 was significantly higher in Group N (10.3%) than in Group K (2.8%) (P = 0.016). Multivariable logistic regression analysis showed that the use of nefopam was not associated with a higher incidence of PONV (adjusted odds ratio, 1.616; 95% confidence interval, 0.952–2.743, P = 0.076). There were no differences in postoperative pain scores between the two groups.

Conclusion

The combined use of nefopam with fentanyl in IV PCA was not associated with the higher incidence of PONV compared with the use of ketorolac and fentanyl combination in patients who received ramosetron as PONV prophylactic agent. However, prospective trials are required for a confirmative conclusion.

Is preoperative hypocholesterolemia a risk factor for severe postoperative pain? Analysis of 1,944 patients after laparoscopic colorectal cancer surgery

Purpose

This study aimed to identify the effect of preoperative serum total cholesterol on postoperative pain outcome in patients who had undergone laparoscopic colorectal cancer surgery.

Methods

We retrospectively reviewed the medical records of patients diagnosed with colorectal cancer who had undergone laparoscopic colorectal surgery from January 1, 2011, to June 30, 2017, to identify the relationship of total cholesterol levels within a month prior to surgery with the numeric rating scale (NRS) scores and total opioid consumption on postoperative days (PODs) 0–2.

Results

We included 1,944 patients. No significant correlations were observed between total cholesterol and the NRS (POD 0), NRS (POD 1), and oral morphine equivalents (PODs 0–2) (P>0.05). There was no significant difference between the low (<160 mg/dL), medium (160–199 mg/dL), and high (≥200 mg/dL) groups in NRS scores on PODs 0, 1, or 2 (P>0.05). Furthermore, there was no significant association in multivariate linear regression analysis for postoperative opioid consumption according to preoperative serum total cholesterol level (coefficient 0.08, 95% CI −0.01 to 0.18, P=0.81).

Conclusion

This study showed that there was no meaningful association between preoperative total cholesterol level and postoperative pain outcome after laparoscopic colorectal cancer surgery.