Opioids in renal failure and dialysis patients

Intraoperative Methadone Use Is Associated With Reduced Postoperative Pain and More Rapid Opioid Weaning After Coronary Artery Bypass Grafting

OBJECTIVE

To explore the association between intraoperative methadone use, postoperative pain, and opioid consumption after coronary artery bypass grafting (CABG) surgery.

DESIGN

Retrospective cohort study.

SETTING

Single academic medical center.

PARTICIPANTS

Patients undergoing isolated CABG over a 5-year period.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Demographic data, comorbidities, and intraoperative anesthetic medications were recorded. Primary study outcomes were average and maximum pain scores and morphine milligram equivalent consumption on the first 2 postoperative days (PODs). Linear mixed-effects regression models were used to examine the effect of intraoperative methadone use on study outcomes. Among 1,338 patients, 78.6% received intraoperative methadone (0.2 mg/kg). Patients who did not receive methadone had higher average (estimated [Est], 0.48; 95% confidence interval [CI], 0.22-0.73; p < 0.001) and maximum postoperative (Est, 0.49; 95% CI, 0.23-0.75; p < 0.001) pain scores over PODs 0 to 2. For postoperative opioid consumption, there was a significant intraoperative methadone use-time interaction effect on postoperative opioid use (odds ratio [OR], 2.21; 95% CI, 1.74-2.80; p < 0.001). Across PODs 0 to 2, patients who received intraoperative methadone had a faster decline in postoperative opioid use than those who did not receive intraoperative methadone. Patients who did not receive intraoperative methadone were extubated slightly faster (OR, 0.82; 95% CI, 0.72-0.93; p < 0.01).

CONCLUSIONS

Our data suggest that the use of intraoperative methadone is safe, reduces postoperative pain, and expedites weaning from postoperative opioids after CABG surgery.

Late pregnancy in women with renal transplants: A multidisciplinary guide

Kidney transplant recipients are at risk of complications in late pregnancy, with increased rates of pre-eclampsia, intrauterine growth restriction and preterm birth. It is recommended that these women receive more intensive monitoring after 20 weeks' gestation, ideally provided by a multidisciplinary team in a tertiary centre. This review focuses on the management of late pregnancy in kidney transplant recipients, from the perspective of different members of the multidisciplinary team. This includes evidence and guidance to inform the nephrologist, obstetrician, obstetric anaesthetist, transplant surgeon, midwife, and a summary of the woman's perspective. The review outlines a late pregnancy and early postnatal care pathway as a common algorithm to be used by the whole multidisciplinary team.

Postoperative pain management after abdominal transplantations

PURPOSE OF REVIEW

The aim of this review article is to present current recommendations as well as knowledge gaps and controversies pertaining to commonly utilized postoperative pain management after solid organ transplantation in the abdominal cavity.

RECENT FINDINGS

Postsurgical pain has been identified as one of the major challenges in recovery and treatment after solid organ transplants. Many perioperative interventions and management strategies are available for reducing and managing postoperative pain. Management should be tailored to the individual needs, taking an interdisciplinary and holistic approach and following enhanced recovery after surgery guidelines. Many centers currently utilize peripheral and neuraxial blocks during transplantation surgery, but these techniques are far from standardized practices. The utilization of these procedures is often dependent on transplantation centers' historical methods and perioperative cultures.

SUMMARY

The optimal pain management regimen has not yet been definitively established, and current scientific evidence does not yet support the endorsement of a certain analgesic approach. This objective necessitates the need for high-quality randomized controlled trials.

A LC-MS/MS method for the simultaneous quantification of 17 opioids in biosolids

The solid product of wastewater treatment plants is commonly used as a fertiliser to increase sustainability and waste reuse. It has undergone extensive treatment to remove high nutrient loads, pathogens and heavy metals but the extensive matrix of household chemicals, pesticides and pharmaceuticals remains, untargeted by most treatment technologies. These compounds, particularly pharmaceuticals, have been detected in biosolids with there being evidence of uptake by plants. With the current opioid pandemic in North America and overprescription, a simple method is required for the extraction of opioids from a solid medium as to ascertain the concentrations the environment is exposed to. A sonication-liquid-liquid extracted method was developed where biosolids were suspended in water and extracted using ethyl acetate before analysis on LC MS/MS. Sodium and potassium chloride were compared along with acidic and alkaline conditions. The optimised method utilised NaCl at a pH of 12 and was validated for 17 opioids, achieving linearity >0.987, 86-113% matrix effect and 0.1-10 μg/kg limits of detection. Upon analysis of biosolids destined for agriculture, 14 opioids were detected across all samples in a concentration range of 1-289 μg/kg.

Continuous Erector Spinae Plane Block for Pain Management in a Pediatric Kidney Transplant Recipient: A Case Report and Review of the Current Literature

Pain management in patients undergoing kidney transplantation requires careful consideration due to their altered physiology, and potential risks associated with certain analgesic options. In recent years, personalized and multimodal approaches have proven to be pivotal in perioperative pain management, as well as in children. Implementing regional analgesia methods offers a valuable solution in many pediatric surgical settings and the erector spinae plane block (ESPB) could represent a possible analgesic strategy in pediatric patients undergoing renal transplantation. Here, we report the case of a 13-year-old child who underwent living-donor kidney transplantation (LDKx) and received continuous erector spinae plane block (ESPB) for perioperative pain management. This multimodal approach with continuous ESPB resulted in optimal pain control without the need for opioids, allowing for early mobilization and for an optimal postoperative course.

COVID-19 and End of Life in a Quaternary Australian Hospital: Referral for Palliative Care Consultation

Background

The coronavirus disease 2019 (COVID-19) pandemic resulted in complex physical and psychosocial symptom burden at end of life. The benefit of specialist palliative care input in other disease states has been established, however, there is little evidence on referral patterns to these services in patients dying from COVID-19.

Objectives

This retrospective audit investigated the referral patterns for patients who died from COVID-19 at a quaternary hospital in South Australia (the Royal Adelaide Hospital) over a six-month period in 2022, and whether demographic features or COVID-19 specific factors had an impact on whether these patients received specialist palliative care services (PCS). The second aim was to identify prescription patterns for patients in the last 24 hours of life, and whether this was impacted by referral.

Method

Data were obtained from electronic medical records and analyzed using binary logistic regressions for referral to PCS versus no referral based on various predictors.

Results

There was no significant difference comparing patient demographics or COVID-19 specific factors with referral to PCS. There was statistical significance between patients who received referral to PCS and those who had a higher oral morphine equivalent daily dose (OMEDD) in the 24 hours before death, as well as the presence of a continuous subcutaneous infusion. Although the cause of this relationship is undetermined, it may represent the prescription patterns of the palliative care physicians during consultation or potentially higher symptom burden prompting referral. There was also a higher proportion of patients who received hydromorphone compared with other opioids, though the OMEDD was consistent with other published literature.

Challenges in management of refractory pain and sedation in infants

The survival of preterm infants continues to improve, along with an increased in neonatal intensive care unit (NICU) management of chronic infants who are medically complex infants who have prolonged hospital stays, sometimes up until 2 years of age. Despite advances in neonatal and infant care, the management of pain and sedation in chronic NICU patients continues to be a challenge. Challenges such as development of appropriate pain, sedation, and withdrawal scales along with unfamiliarity of the NICU care team with pediatric disease states and pharmacotherapy complicate management of these patients. Opioid induced hyperalgesia (OIH) and delirium may play a large role in these refractory cases, yet are often not considered in the NICU population. Drug therapy interventions such as gabapentin, ketamine, risperidone, and others have limited data for safety and efficacy in this population. This article summarizes the available literature regarding the evidence for diagnosis and management of infants with refractory pain and sedation along with the challenges that clinicians face when managing these patients.

Development of prescribing indicators related to opioid-related harm in patients with chronic pain in primary care-a modified e-Delphi study

BACKGROUND

Long-term opioid use is associated with dependency, addiction, and serious adverse events. Although a framework to reduce inappropriate opioid prescribing exists, there is no consensus on prescribing indicators for preventable opioid-related problems in patients with chronic pain in primary care in the UK. This study aimed to identify opioid prescription scenarios for developing indicators for prescribing opioids to patients with chronic pain in primary care.

METHODS

Scenarios of opioid prescribing indicators were identified from a literature review, guidelines, and government reports. Twenty-one indicators were identified and presented in various opioid scenarios concerning opioid-related harm and adverse effects, drug-drug interactions, and drug-disease interactions in certain disease conditions. After receiving ethics approval, two rounds of electronic Delphi panel technique surveys were conducted with 24 expert panellists from the UK (clinicians, pharmacists, and independent prescribers) from August 2020 to February 2021. Each indicator was rated on a 1-9 scale from inappropriate to appropriate. The score's median, 30th and 70th percentiles, and disagreement index were calculated.

RESULTS

The panel unanimously agreed that 15 out of the 21 opioid prescribing scenarios were inappropriate, primarily due to their potential for causing harm to patients. This consensus was reflected in the low appropriateness scores (median ranging from 1 to 3). There were no scenarios with a high consensus that prescribing was appropriate. The indicators were considered inappropriate due to drug-disease interactions (n = 8), drug-drug interactions (n = 2), adverse effects (n = 3), and prescribed dose and duration (n = 2). Examples included prescribing opioids during pregnancy, concurrently with benzodiazepines, long-term without a laxative prescription and prescribing > 120-mg morphine milligram equivalent per day or long-term duration over 3 months after surgery.

CONCLUSIONS

The high agreement on opioid prescribing indicators indicates that these potentially hazardous consequences are relevant and concerning to healthcare practitioners. Future research is needed to evaluate the feasibility and implementation of these indicators within primary care settings. This research will provide valuable insights and evidence to support opioid prescribing and deprescribing strategies. Moreover, the findings will be crucial in informing primary care practitioners and shaping quality outcome frameworks and other initiatives to enhance the safety and quality of care in primary care settings.

Assessment of drug utilization and potentially inappropriate medications in hemodialysis patients with end-stage renal dysfunction: A study in a tertiary care hospital in Bahrain

BACKGROUND

Patients undergoing dialysis pose therapeutic challenges in terms of polypharmacy, administration of potentially inappropriate drugs, and drugs with the potential risk of toxicity.

OBJECTIVE

This study evaluated the use of drugs, potentially inappropriate medicines (PIM), drugs with risk of Torsades de Pointes (TdP), and the complexity of the prescribed regimen using the medication regimen complexity index scale in patients undergoing hemodialysis.

METHODS

A retrospective cohort study was carried out amongst patients receiving hemodialysis. Drugs were classified into one of four classes: (i) drugs used in managing renal complications, (ii) cardiovascular drugs, (iii) anti-diabetic drugs, (iv) drugs for symptomatic management, and (v) others. Drugs were considered as PIM according to the Can-SOLVE CKD working group from a network of Canadian nephrology health professionals. The study adhered to the CredibleMeds classification of drugs with known, possible, and conditional risk of TdP and the complexity of prescribed medicines was evaluated based on the pre-validated medication regimen complexity index scale based on form/route, frequency of dosing, and requirement of special instructions.

RESULTS

Sixty-three participants were included in the study (49 males and 14 females) with the median (range) age of 45 (21-66) years. Cardiovascular drugs followed by drugs used for managing renal complications were the most common classes administered. Notably, 12 (19.1%) patients received one of the non-steroidal anti-inflammatory drugs, 21 (33.3%) received a proton pump inhibitor, three (4.8%) received pregabalin, two (3.2%) received opioid drugs, and one (1.6%) was administered celecoxib. Atorvastatin, furosemide, omeprazole, and allopurinol were the most common PIM drugs administered to the study participants followed by others. Drugs used for symptomatic management had significantly more PIM compared to other classes (p < 0.0001). Six (9.5%) patients received drugs with known TdP risk, one with possible TdP risk, and 61 with conditional risk. Median (range) medical regimen complexity index score was 26.5 (2-62.5).

CONCLUSION

A huge burden of drug therapy was observed in the hemodialysis patients in terms of higher proportions of PIM, complex medical regimen, and prescription of drugs with risk of TdP. Implementation of clinical decision support tools enhancing rational prescription and identification of drugs with TdP risk, introducing antimicrobial stewardship, and stepwise deprescription of the drugs with the least benefit-risk ratio are warranted.

Evaluation and Treatment of Acute Trauma Pain in Older Adults

In the context of an ageing population, the demographic sands of trauma are shifting. Increasingly, trauma units are serving older adults who have sustained injuries in low-energy falls from a standing height. Older age is commonly associated with changes in physiology, as well as an increased prevalence of frailty and multimorbidity, including cardiac, renal and liver disease. These factors can complicate the safe and effective administration of analgesia in the older trauma patient. Trauma services therefore need to adapt to meet this demographic shift and ensure that trauma clinicians are sufficiently skilled in treating pain in complex older people. This article is dedicated to the management of acute trauma pain in older adults. It aims to highlight the notable clinical challenges of managing older trauma patients compared with their younger counterparts. It offers an overview of the evidence and practical opinion on the merits and drawbacks of commonly used analgesics, as well as more novel and emerging analgesic adjuncts. A search of Medline (Ovid, from inception to 7 November 2022) was conducted by a medical librarian to identify relevant articles using keyword and subject heading terms for trauma, pain, older adults and analgesics. Results were limited to articles published in the last 10 years and English language. Relevant articles' references were hand-screened to identify other relevant articles. There is paucity of dedicated high-quality evidence to guide management of trauma-related pain in older adults. Ageing-related changes in physiology, the accumulation of multimorbidity, frailty and the risk of inducing delirium secondary to analgesic medication present a suite of challenges in the older trauma patient. An important nuance of treating pain in older trauma patients is the challenge of balancing iatrogenic adverse effects of analgesia against the harms of undertreated pain, the complications and consequences of which include immobility, pneumonia, sarcopenia, pressure ulcers, long-term functional decline, increased long-term care needs and mortality. In this article, the role of non-opioid agents including short-course non-steroidal anti-inflammatory drugs (NSAIDs) is discussed. Opioid selection and dosing are reviewed for older adults suffering from acute trauma pain in the context of kidney and liver disease. The evidence base and limitations of other adjuncts such as topical and intravenous lidocaine, ketamine and regional anaesthesia in acute geriatric trauma are discussed.

Opioid Prescription in Patients With Chronic Kidney Disease: A Systematic Review of Comparing Safety and Efficacy of Opioid Use in Chronic Kidney Disease Patients

Patients with diminished renal function necessitate special care. In patients with chronic kidney disease (CKD), opioid analgesics should be prescribed based on the severity of renal insufficiency; this will determine treatment options at the beginning and throughout the management of pain in CKD patients. The dosage of hydrophilic drugs and drugs with active metabolites should be adjusted according to the severity of CKD, and the process of treatment should be monitored by modifying drug dosages as necessary for background and breakthrough pain. Patients with CKD may benefit from opioid analgesics that are lipophilic, such as methadone, fentanyl, and buprenorphine, as the first line; however, fentanyl is inappropriate for patients undergoing hemodialysis. Opioid prescription in CKD patients is the subject of this systematic review, which aims to compare their safety and efficacy. This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 recommendations. Using three databases (PubMed, ScienceDirect, and Google Scholar), we collected and reviewed articles, including literature reviews, randomized control trials (RCTs), and systematic reviews published between 1980 and 2022, to enable us to gather enough valuable data on this rare topic. After applying appropriate filters, a total of 109 results were obtained. They were further screened and subjected to quality assessment tools, which finally yielded 11 studies included in this systematic review. This consisted of two RCTs, two systematic reviews, and seven narrative reviews. This review focused on the safety and appropriate use of opioids in patients with CKD. The accumulation of morphine and codeine metabolites may result in neurotoxic side effects. Hydromorphone and oxycodone are considered safe to administer but require careful adjustments in dosage. Common comorbidities among patients with CKD may amplify opioid-related adverse effects.

Palliative Care in Kidney and Liver Diseases

The role of palliative care is to recognize patients with advanced illnesses who are at risk for poor outcomes and to alleviate their pain and suffering. Patients with both kidney and liver disease are a very vulnerable population due to the unique pathophysiologic relationship these two organs share, which often leads to an abbreviated life expectancy and a significant symptom burden. These patients face many challenges in their care. This article discusses the importance of prognostication for early palliative care referrals as well as the management of the two most common complaints patients with kidney and liver disease face: pain and ascites.

The Pharmacological Treatment of Chronic Pain: From Guidelines to Daily Clinical Practice

In agreement with the International Association for the Study of Pain, chronic pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage. To date, there are several types of pain: nociceptive, neuropathic, and nociplastic. In the present narrative review, we evaluated the characteristics of the drugs used for each type of pain, according to guidelines, and their effects in people with comorbidity to reduce the development of severe adverse events.

Morphine Versus Oxycodone for Cancer Pain Using a Catechol-O-methyltransferase Genotype Biomarker: A Multicenter, Randomized, Open-Label, Phase III Clinical Trial (RELIEF Study)

BACKGROUND

We hypothesized that the high-dose opioid requirement in patients carrying the rs4680-GG variant in the COMT gene encoding catechol-O-methyltransferase would be greater for patients taking morphine than for those taking oxycodone, thus providing a much-needed biomarker to inform opioid selection for cancer pain.

METHODS

A randomized, multicenter, open-label trial was conducted at a Japanese hospital's palliative care service. Patients with cancer pain treated with regular doses of nonsteroidal anti-inflammatory drugs or acetaminophen were enrolled and randomized (1:1) into morphine (group M) and oxycodone (group O) groups. The minimum standard dose of immediate-release (IR) oral opioids was repeatedly administered by palliative care physicians to achieve pain-reduction goals (Pain reduction ≥ 33% from baseline and up to ≤ 3 on a numerical rating scale). The primary endpoint was the proportion of subjects requiring high-dose opioids on day 0 with the GG genotype.

RESULTS

Of 140 participants who developed cancer-related pain among 378 subjects registered and pre-screened for the genotype, 139 were evaluated in the current study. Among patients carrying a COMT rs4680-GG genotype, 48.3% required high-dose opioids in group M, compared with the 20.0% in group O (95% CI, 3.7%-50.8%; P = .029). Of those with the non-GG genotype, 41.5% treated with morphine and 23.1% with oxycodone required high-dose opioids (95% CI, 3.3%-38.3%; P = 0.098).

CONCLUSION

Using the COMT rs4680 genotype alone is not recommended for selecting between morphine and oxycodone for pain relief.

A Single-Center Retrospective Comparison of Opioid Based and Multimodal Analgesic Regimens in Adult Cardiac Surgery

OBJECTIVES

To compare the outcomes of 2 multimodal analgesic regimens with an opioid-based one.

DESIGN

A 2-stage, retrospective study.

SETTING

A large tertiary-care facility.

PARTICIPANTS

Adult cardiac surgical patients.

INTERVENTIONS

Patients received one of three regimens: opioid-only or 2 multimodal regimens. The opioid regimen included intraoperative fentanyl and patient-controlled analgesia pumps. Multimodal regimen 1 included preoperative extended-release oxycodone, intraoperative ketamine infusion, and postoperative morphine suppository. Multimodal regimen 2 included intraoperative methadone and dexmedetomidine infusion.

MEASUREMENTS AND MAIN RESULTS

Outcomes measured included opioid use, pain scores, time to tracheal extubation, postoperative antiemetic use as a surrogate marker for postoperative nausea and vomiting (PONV), age, sex, surgical procedure(s), body mass index, time to first bowel movement, intensive care unit length of stay (LOS), and hospital LOS. Intraoperative median oral morphine equivalents (OMEs) declined from 425 mg (314, 518) to 150 mg (75, 150) and 230 mg (160, 240), p < 0.001, in multimodal regimens 1 and 2, respectively, compared with the opioid-only regimen. Predischarge opioid use was reduced from a median OME of 7.5 mg (0, 22.5) to 5 mg (0, 22.5) and 0 mg (0, 15.0), p < 0.001, in multimodal regimens 1 and 2, respectively. Pain scores were reduced in the multimodal regimen 2 for hours 0 to 6 (estimated difference = -1.5, 95% CI -1.8 to -1.2, p < 0.001) compared with the opioid-only regimen. The PONV treatment was reduced in multimodal regimen 1 versus the opioid-based or multimodal regimen 2 (53% v 64% and 62%), and time to tracheal extubation was clinically equivalent across all regimens: 4.2 (2.8, 6.0), 3.6 (2.3, 5.7), and (3.0, 6.2) hours for the opioid and multimodal regimens 1 and 2, respectively.

CONCLUSIONS

Multimodal analgesic regimens, particularly when incorporating methadone and dexmedetomidine, significantly reduced total and predischarge opioid use in cardiac surgical patients.

Choosing the right chronic medication for hemodialysis patients. A short ABC for the dialysis nephrologist

BACKGROUND

Adapting drug treatments for patients on hemodialysis with multiple chronic pathologies is a complex affair. When prescribing a medication, the risk-benefit analysis usually focuses primarily on the indication of the drug class prescribed. However, the pharmacokinetics of the chosen drug should also be taken into account. The purpose of our review was to identify the drugs to be favored in each therapeutic class, according to their safety and pharmacokinetic profiles, for the most common chronic diseases in patients on chronic hemodialysis.

METHODS

We conducted a narrative review of the literature using Medline and Web of Science databases, targeting studies on the most commonly-prescribed drugs for non-communicable diseases in patients on chronic hemodialysis.

RESULTS

The search identified 1224 articles, 95 of which were further analyzed. The main classes of drugs included concern the cardiovascular system (anti-hypertensives, anti-arrhythmics, anti-thrombotics, hypocholesterolemics), the endocrine and metabolic pathways (anti-diabetics, gastric anti-secretory, anticoagulant, thyroid hormones, anti-gout) and psychiatric and neurological disorders (antidepressants, anxiolytics, antipsychotics and anti-epileptics).

CONCLUSION

We report on the most often prescribed drugs for chronic pathologies in patients on chronic hemodialysis. Most of them require adaptation, and in some cases one better alternative stands out among the drug class. More pharmacokinetic data are needed to define the pharmacokinetics in the various dialysis techniques.

Medication Management in the Critically Ill Patient with Acute Kidney Injury

ABSTRACT

AKI occurs frequently in critically ill patients. Patients with AKI, including those who require KRT, experience multiple pharmacokinetic and pharmacodynamic perturbations that dynamically influence medication effectiveness and safety. Patients with AKI may experience both subtherapeutic drug concentrations, which lead to ineffective therapy, and supratherapeutic drug concentrations, which increase the risk for toxicity. In critically ill patients with AKI not requiring KRT, conventional GFR estimation equations, especially those based on serum creatinine, have several limitations that can limit the accuracy when used for medication dosing. Alternative methods to estimate kidney function may be informative, including use of measured urinary creatinine clearance, kinetic eGFR, and equations that integrate novel kidney biomarkers. For critically ill patients with AKI requiring KRT, physicochemical properties of the drug, the KRT prescription and circuit configuration, and patient-specific factors each contribute to medication clearance. Evidence-based guidance for medication dosing during AKI requiring KRT is often limited. A working knowledge of the basic tenets of drug elimination during KRT can provide a framework for how to approach decision making when the literature is lacking. Iterative re-evaluation of a patient's progress toward therapeutic goals with a medication must occur over the arc of critical illness, including and especially in the setting of dynamic kidney function.

Risk factors of perioperative acute kidney injury in elderly patients: a single-center retrospective study

PURPOSE

The elderly are vulnerable to perioperative acute kidney injury. The aim of this study was to determine the risk factors that associated with acute kidney injury among elderly patients.

METHODS

Clinical data of elderly patients (> 65 years) who underwent noncardiac, nonrenal surgery between Dec 1 2009 and July 1 2016 were collected for this single-centered historical cohort study. Univariate and multivariate analyses were conducted to explore the risk factors that contribute to acute kidney injury, which was defined as a serum creatinine increase >0.3 mg/dL within 48 h or 1.5 times increase in serum creatinine within 7 days after surgery.

RESULTS

7775 patients were eligible for the final analysis, among which 511 (6.57%) patients developed acute kidney injury. We observed 21 risk factors being associated with perioperative acute kidney injury, with the most important disposing factors being history of kidney disease (adjusted OR = 2.94, 95% CI 2.25-3.84), operation time > 180 min (aOR = 2.93, 95% CI 2.04-4.24), preoperative eGFR [15, 30) (aOR = 2.43, 95% CI 1.29-4.45), and protective factor being intraoperative use of sufentanil (aOR = 0.35, 95% CI 0.23-0.54).

CONCLUSION

This study determined risk factors for perioperative acute kidney injury among the elderly in the Second Xiangya Hospital and visualized the risk factors using nomogram and Excel calculator, which may provide some clues to further investigations. Overall, the prevalence of AKI among this large cohort is 6.57%.

CLINICAL TRIALS REGISTRATION

http://www.chictr.org.cn ; ChiCTR1900027007; October 28, 2019.

Subcostal transversus abdominis plane block for postoperative analgesia in liver transplant recipients: a before-and-after study

INTRODUCTION

Postoperative pain management after orthotopic liver transplantation is complex due to impaired liver function and frequent acute kidney dysfunction. Subcostal transversus abdominis plane (TAP) block may be of interest in this population. The aim of this study was to evaluate the impact of subcostal TAP block on opioid consumption after liver transplantation.

METHODS

We conducted a before-and-after single center study. During the first period, we included patients whom did not receive an analgesic TAP block. During the second period, we included those with bilateral ultrasound-guided subcostal TAP block (20 mL ropivacaïne 0.2% each side). Patients requiring sedation within 48 hours of surgery as well as patients with combined liver and kidney transplants or skin-only closures were excluded. The primary outcome was cumulative oral morphine consumption within 48 hours after surgery. Secondary outcomes included pain scores and TAP block-related complications.

RESULTS

A total of 132 patients were included in the non-TAP block group and 78 patients in the TAP block group. The median oral morphine equivalent consumption (IQR) within 48 hours following surgery was 74 mg (39; 112) for the non-TAP block group and 50 mg (20; 80) for the TAP block group (p<0.001). There was no difference in pain scores between the two groups. No complications related to the TAP block were reported.

CONCLUSION

Subcostal TAP block appears to have a small opioid reducing effect after orthotopic liver transplantation surgery.

Renal medicine in the intensive care unit: a narrative review

Kidney disease, both acute and chronic, is commonly encountered on the intensive care unit. Due to the role the kidneys play in whole body homeostasis, it follows that their dysfunction has wide-ranging implications and can affect prescribing and therapeutic management. This narrative review discusses the pathophysiology of acute kidney injury and chronic kidney disease, and how this relates to critically unwell patients. We cover several aspects of the management of renal dysfunction on the critical care unit, exploring some of the recurrent themes within the literature, including type and timing of kidney replacement therapy, management of acute kidney injury, as well as discussing how novel biomarkers for acute kidney injury may help to identify patients suffering from acute kidney injury as well as risk stratifying these patients. We discuss how early involvement of specialist nephrology services can improve outcomes in patients with kidney disease as well as offer valuable diagnostic and specialist management advice, particularly for patients with established end stage kidney disease and patients who are already known to nephrology services. We also explore some of the ongoing research questions that need to be answered within this arena.

Systemic Opioids for Dyspnea in Cancer Patients: A Real-world Observational Study

CONTEXT

Although Systemic opioids are recommended as a pharmacological treatment for cancer-related dyspnea, their effectiveness and safety needs to be investigated in a real-world context OBJECTIVES: To evaluate the effectiveness and safety of systemic regular opioids for dyspnea in cancer patients, in the real-world palliative care practice.

METHODS

This was a multicenter prospective observational study. We consecutively enrolled adult cancer patients starting regular opioids (morphine, oxycodone, hydromorphone, or fentanyl) for dyspnea from 12 palliative care services across Japan. We evaluated dyspnea intensity using the Numerical Rating Scale (NRS) and Integrated Palliative Outcome Scale (IPOS) every 24 hours until 72 hours after starting opioids (T1-T3). We also evaluated common opioid-related adverse events (AEs) and other severe AEs.

RESULTS

We enrolled 402 cancer patients. The proportion of responders was 68.8% (95%confidence intervals (CI): 0.63-0.74) at T1, 75.7% (95%CI: 0.70-0.81) at T2, and 82.1% (95%CI: 0.76-0.87) at T3. The mean differences in dyspnea NRS from baseline were 1.73 (95%CI: 1.46-1.99) at T1, 1.99 (95%CI: 1.71-2.28) at T2, and 2.47 (95%CI:2.13-2.82) at T3. The most common treatment-emergent AE was somnolence with an incidence of the severe form of approximately 10% throughout the study period. In the multivariate analysis, baseline dyspnea NRS ≥6 had a positive correlation with dyspnea relief by systemic regular opioids, while liver metastasis, clinician-predicted survival days, and opioid tolerance had a negative correlation.

CONCLUSION

Regular systemic opioids were effective for dyspnea in real-world cancer patients.

Steady-State Pharmacokinetics of Intravenous Hydromorphone in Japanese Patients with Renal Impairment and Cancer Pain

Background: The opioid analgesic hydromorphone has a low renal excretion ratio; however, exposure after oral administration is several times higher in those with moderate or severe renal impairment. Objectives: We evaluated the impact of renal impairment on the steady-state pharmacokinetics of intravenously administered hydromorphone in patients with cancer being treated for pain. Design: This was an open-label, prospective, parallel-comparison, interventional clinical pharmacology study. Setting/Subjects: This study was conducted at one hospital in Japan. Using creatinine clearance (CLcr) values, patients were grouped according to kidney function: CLcr ≥90 mL/min (normal), 60-<90 mL/min (mild impairment), 30-<60 mL/min (moderate impairment), or <30 mL/min (severe impairment). Measurements: Hydromorphone was administered by constant infusion to patients at the same constant dose rate as at the time of enrollment. Hydromorphone and its glucuronide metabolite concentrations in plasma and urine were measured by liquid chromatography-mass spectrometry. Pharmacokinetic parameters at steady state were assessed using noncompartmental analysis. Results: Thirty-two patients were enrolled (normal, n = 3; mild, n = 10; moderate, n = 15; and severe, n = 4). Adjusted geometric mean ratios for hydromorphone steady-state clearance (CLss) for patients with impaired versus normal renal function were 0.69 (90% confidence interval [CI], 0.41-1.14), 0.52 (90% CI, 0.31-0.84), and 0.55 (90% CI, 0.30-1.02) for mild, moderate, or severe impairment, respectively. Exposures to the metabolite hydromorphone-3-glucuronide generally increased with renal impairment. No adverse event was reported. Conclusion: Hydromorphone CLss in patients with impaired renal function (moderate and severe) was decreased ∼50% of that of normal renal function.

Acute Kidney Injury Predictors and Outcomes after Cardiac Surgery in Children with Congenital Heart Disease: An Observational Cohort Study

Acute Kidney Injury (AKI) commonly complicates cardiac surgery in children with congenital heart disease (CHD). In this study we assessed incidence, risk factors, and outcomes of postoperative AKI, while testing the hypothesis that, depending on the underlying diagnosis, there would be significant differences in AKI incidence among different diagnostic groups. We conducted an observational cohort study of children with CHD undergoing cardiac surgery in a single tertiary center between January 2019 and August 2021 (n = 362). Kidney Disease Improving Global Outcome (KDIGO) criteria were used to determine the incidence of postoperative AKI. Diagnosis was incorporated into multivariate models using an anatomic-based CHD classification system. Overall survival was estimated using Kaplan−Meier curves. Log-rank test and adjusted Cox proportional hazard modelling were used to test for differences in survival distributions and determine AKI effect on survival function, respectively. AKI occurred in 70 (19.3%), with 21.4% in-hospital mortality for AKI group. Younger age, lower weight, longer cardiopulmonary bypass time, preoperative mechanical ventilation and diagnostic category were associated with postoperative AKI. Resolution rate was 92.7% prior to hospital discharge for survivors. AKI was associated with longer duration of mechanical ventilation, ICU and hospital length of stay. AKI patients had significantly higher probability of all-cause mortality postoperatively when compared to the non-AKI group (log-rank test, p < 0.001). Adjusted hazard ratio for AKI versus non-AKI group was 11.08 (95% CI 2.45−50.01; p = 0.002). Diagnostic category was associated with cardiac surgery-related AKI in children with CHD, a finding supporting the development of lesion specific models for risk stratification. Postoperative AKI had detrimental impact on clinical outcomes and was associated with decreased survival to hospital discharge.

Application of Propofol Target-Controlled Infusion for Optimized Hemodynamic Status in ESRD Patients Receiving Arteriovenous Access Surgery: A Randomized Controlled Trial

Background and Objectives: End-stage renal disease (ESRD) is associated with increased anesthetic risks such as cardiovascular events resulting in higher perioperative mortality rates. This study investigated the perioperative and postoperative outcomes in ESRD patients receiving propofol target-controlled infusion with brachial plexus block during arteriovenous (AV) access surgery. Materials and Methods: We recruited fifty consecutive patients scheduled to receive AV access surgery. While all patients received general anesthesia combined with ultrasound-guided brachial plexus block, the patients were randomly assigned to one of two general anesthesia maintenance groups, with 23 receiving propofol target-controlled infusion (TCI) and 24 receiving sevoflurane inhalation. We measured perioperative mean arterial pressure (MAP), heart rate, and cardiac output and recorded postoperative pain status and adverse events in both groups. Results: ESRD patients receiving propofol TCI had significantly less reduction in blood pressure than those receiving sevoflurane inhalation (p < 0.05) during AV access surgery. Perioperative cardiac output and heart rate were similar in both groups. Both groups reported relatively low postoperative pain score and a low incidence of adverse events. Conclusions: Propofol TCI with brachial plexus block can be used as an effective anesthesia regimen for ESRD patients receiving AV access surgery. It can be used with less blood pressure fluctuation than inhalational anesthesia.

Acute kidney injury-associated delirium: a review of clinical and pathophysiological mechanisms

Acute kidney injury is a known clinical risk factor for delirium, an acute cognitive dysfunction that is commonly encountered in the critically ill population. In this comprehensive review of clinical and basic research studies, we detail the epidemiology, clinical implications, pathogenesis, and management strategies of patients with acute kidney injury-associated delirium. Specifically addressed are the pathological roles of endogenous toxin or drug accumulation, acute kidney injury-mediated neuroinflammation, and acute kidney injury-associated volume overload as discrete potential biological mechanisms of the condition. The optimization of clinical contributors and normalization of renal function are reviewed as pragmatic management strategies in addition to potential and emerging therapeutic approaches.

Perioperative Management of Calciphylaxis: Literature Review and Treatment Recommendations

Calciphylaxis is a serious and rare medical condition that leads to substantial clinical manifestations including pain, creating perioperative and treatment challenges. No standard treatment protocol exists nor are comprehensive guidelines available for perioperative management of patients with calciphylaxis. In this review, we evaluate existing literature (January 2000 to May 2021) with the aim to offer guidance for treating patients with this challenging disease through the perioperative period. Although no therapies are currently considered standard for treating calciphylaxis, multiple interventions are available for improving symptoms. Preoperative and intraoperative management involves monitoring and optimizing patient comorbid conditions and any possible electrolyte imbalances. Postoperative management can be challenging when potential calciphylaxis triggers are indicated, such as warfarin and corticosteroids. In addition, poor wound healing and difficult pain control are common. Therefore, a multifactorial approach to controlling postoperative pain is recommended that includes the use of nerve blocks, renal-sparing opioids, benzodiazepines, and/or ketamine. We present preoperative, intraoperative, and postoperative recommendations for treating calciphylaxis with levels of evidence when appropriate.

New Insight Concerning Therapeutic Drug Monitoring-The Importance of the Concept of Psychonephrology

Recently, the concept of psychonephrology was developed and has been recognized as a field of study that focuses on nephrology and mental health fields, such as psychiatry and psychosomatic medicine. Indeed, patients with chronic kidney disease frequently suffer from mental problems as the disease stage progresses. Most psychotropic drugs are hepatically metabolized, but some are unmetabolized and eliminated renally. However, renal disease may affect the pharmacokinetics of many psychotropic drugs, as the decreased renal function not only delays the urinary excretion of the drug and its metabolites but also alters various pharmacokinetic factors, such as protein-binding, enterohepatic circulation, and activity of drug-metabolizing enzymes. Therefore, when prescribing drug therapy for patients with both renal disease and mental issues, we should consider reducing the dosage of psychotropic drugs that are eliminated mainly via the kidney and also carefully monitor the blood drug concentrations of other drugs with a high extrarenal clearance, such as those that are largely metabolized in the liver. Furthermore, we should carefully consider the dialyzability of each psychotropic drug, as the dialyzability impacts the drug clearance in patients with end-stage renal failure undergoing dialysis. Therapeutic drug monitoring (TDM) may be a useful tool for adjusting the dosage of psychotropic drugs appropriately in patients with renal disease. We herein review the pharmacokinetic considerations for psychotropic drugs in patients with renal disease as well as those undergoing dialysis and offer new insight concerning TDM in the field of psychonephrology.

Opioids for chronic pain management in patients with dialysis-dependent kidney failure

Chronic pain is highly prevalent among adults treated with maintenance haemodialysis (HD) and has profound negative effects. Over four decades, research has demonstrated that 50-80% of adult patients treated with HD report having pain. Half of patients with HD-dependent kidney failure (HDKF) have chronic moderate-to-severe pain, which is similar to the burden of pain in patients with cancer. However, pain management in patients with HDKF is often ineffective as most patients report that their pain is inadequately treated. Opioid analgesics are prescribed more frequently for patients receiving HD than for individuals in the general population with chronic pain, and are associated with increased morbidity, mortality and health-care resource use. Furthermore, current opioid prescribing patterns are frequently inconsistent with guideline-recommended care. Evidence for the effectiveness of opioids in pain management in general, and in patients with HDKF specifically, is lacking. Nonetheless, long-term opioid therapy has a role in the treatment of some patients when used selectively, carefully and combined with an ongoing assessment of risks and benefits. Here, we provide a comprehensive overview of the use of opioid therapy in patients with HDKF and chronic pain, including a discussion of buprenorphine, which has potential as an analgesic option for patients receiving HD owing to its unique pharmacological properties.

Palliative care for children and young people with stage 5 chronic kidney disease

Death from stage 5 chronic kidney disease (CKD 5) in childhood or adolescence is rare, but something that all paediatric renal physicians and most paediatricians will encounter. In this paper, we present the literature on three key areas of palliative care practice essential to good clinical management: shared decision-making, advance care planning, and symptom management, with particular reference to CKD 5 where kidney transplant is not an option and where a decision has been made to withdraw or withhold dialysis. Some areas of care, particularly with regard to symptom management, have not been well-studied in children and young people (CYP) with CKD 5 and recommendations with regard to drug choice and dose modification are based on adult literature, known pharmacokinetics, and clinical experience.

Development and Validation of Pediatric Opioid Analgesia Self-Instruction System (PedOASIS): An Opioid Knowledge Tool for Pediatric Clinicians

BACKGROUND

Acute pain is common in children and young adults with cancer and sickle cell disease. Current training curricula fail to adequately impart skills for pain management. We sought to develop and validate an education and assessment tool to address the safe effective use of opioids for pain management by pediatrics trainees.

METHODS

The first version of the tool contained 10 case-based, multiple-choice questions. It was pilot tested within a medium-sized pediatric residency program using preintervention and postintervention surveys to assess residents' knowledge and comfort related to prescribing opioids. Content validation was performed through an expert panel of physicians. Internal reliability was tested by administering the tool to learners and practitioners with varying levels of training.

RESULTS

Comfort with choosing and converting between opioids increased significantly in pilot testing (P=0.005). Mean objective knowledge scores increased from 51% to 85.9% (P<0.001). The revised tool showed internal reliability within each group (Cronbach alpha 0.71 to 0.78) and significant differences in mean scores between groups (F ratio=9.45, P=0.0002).

CONCLUSIONS

This tool demonstrates validity and internal reliability. Its use was associated with short-term educational gains and it garnered overall favorable feedback from users. Further testing is needed to assess the duration of these gains.

Postoperative Pain Management in Enhanced Recovery Pathways

Postoperative pain is a common but often inadequately treated condition. Enhanced recovery pathways (ERPs) are increasingly being utilized to standardize perioperative care and improve outcomes. ERPs employ multimodal postoperative pain management strategies that minimize opioid use and promote recovery. While traditional opioid medications continue to play an important role in the treatment of postoperative pain, ERPs also rely on a wide range of non-opioid pharmacologic therapies as well as regional anesthesia techniques to manage pain in the postoperative setting. The evidence for the use of these interventions continues to evolve rapidly given the increasing focus on enhanced postoperative recovery. This article reviews the current evidence and knowledge gaps pertaining to commonly utilized modalities for postoperative pain management in ERPs.

Predicting opioid-induced oversedation in hospitalised patients: a multicentre observational study

OBJECTIVES

Opioid-induced respiratory depression (OIRD) and oversedation are rare but potentially devastating adverse events in hospitalised patients. We investigated which features predict an individual patient's risk of OIRD or oversedation; and developed a risk stratification tool that can be used to aid point-of-care clinical decision-making.

DESIGN

Retrospective observational study.

SETTING

Twelve acute care hospitals in a large not-for-profit integrated delivery system.

PARTICIPANTS

All inpatients ≥18 years admitted between 1 July 2016 and 30 June 2018 who received an opioid during their stay (163 190 unique hospitalisations).

MAIN OUTCOME MEASURES

The primary outcome was occurrence of sedation or respiratory depression severe enough that emergent reversal with naloxone was required, as determined from medical record review; if naloxone reversal was unsuccessful or if there was no evidence of hypoxic encephalopathy or death due to oversedation, it was not considered an oversedation event.

RESULTS

Age, sex, body mass index, chronic obstructive pulmonary disease, concurrent sedating medication, renal insufficiency, liver insufficiency, opioid naïvety, sleep apnoea and surgery were significantly associated with risk of oversedation. The strongest predictor was concurrent administration of another sedating medication (adjusted HR, 95% CI=3.88, 2.48 to 6.06); the most common such medications were benzodiazepines (29%), antidepressants (22%) and gamma-aminobutyric acid analogue (14.7%). The c-statistic for the final model was 0.755. The 24-point Oversedation Risk Criteria (ORC) score developed from the model stratifies patients as high (>20%, ≥21 points), moderate (11%-20%, 10-20 points) and low risk (≤10%, <10 points).

CONCLUSIONS

The ORC risk score identifies patients at high risk for OIRD or oversedation from routinely collected data, enabling targeted monitoring for early detection and intervention. It can also be applied to preventive strategies-for example, clinical decision support offered when concurrent prescriptions for opioids and other sedating medications are entered that shows how the chosen combination impacts the patient's risk.

Pharmacokinetics of bempedoic acid in patients with renal impairment

Bempedoic acid is an ATP citrate lyase inhibitor approved for the treatment of hypercholesterolemia. The objective of this phase I study was to assess the pharmacokinetics (PKs) and safety of bempedoic acid in 24 subjects with normal renal function or mild, moderate, or severe renal impairment. All subjects received a single oral bempedoic acid 180‐mg dose and PK parameters were monitored for up to 23 days. Resulting estimates of area under the concentration‐time curve exposure following bempedoic acid treatment were 1.5‐fold, 2.2‐fold, and 2.2‐fold higher in subjects with mild, moderate, or severe renal impairment, respectively, compared with subjects with normal renal function. With decreases in renal function, plasma free fraction was increased up to 20.1%, whereas total and unbound clearances were decreased by 55.2% and 62.6%, respectively, in subjects with severe renal impairment relative to those with normal renal function. These observed decreases in total and unbound oral clearance in subjects with decreased renal function are not explained by the increases in free fraction and might therefore also be attributable to changes in bioavailability or intrinsic clearance. Bempedoic acid was generally well‐tolerated and the incidence and type of adverse events were not affected by the degree of renal impairment. In conclusion, bempedoic acid exposures in subjects with renal impairment were increased up to approximately two‐fold with no safety signals identified, consistent with findings in phase III patients with mild or moderate renal impairment. No dose adjustments are necessary for patients with mild or moderate renal impairment.

Influence of genetic variants of opioid-related genes on opioid-induced adverse effects in patients with lung cancer: A STROBE-compliant observational study

Despite the dramatic advancement of cancer chemotherapy and immunotherapy, the insufficient progress has been made in basic or translational research on personalization of opioid therapy. Predicting the effectiveness of opioid analgesic therapy and the risk of adverse effects prior to therapy are expected to enable safer and more appropriate opioid therapy for cancer patients. In this study, we compared the incidence of opioid-induced adverse effects between patients with different variants of the genes related to responsiveness to opioid analgesics.Participants were 88 patients with lung cancer who provided general consent for exome sequencing and were treated with morphine or oxycodone at Shizuoka Cancer Center Hospital between April 2014 and August 2018. Incidence rates for 6 adverse effects of opioid therapy (somnolence, nausea, constipation, delirium, urinary retention, and pruritus) were determined and the influence of single nucleotide polymorphisms in coding regions of the opioid μ receptor 1 (OPRM1) (rs1799971), opioid δ receptor 1 (rs2234918), opioid κ receptor 1 (rs1051660), catechol-O-methyltransferase (COMT) (rs4680), dopamine receptor D2 (rs6275), adenosine triphosphate binding cassette B1 (rs1045642), G-protein regulated inward rectifier potassium channel 2 (rs2070995), and fatty acid amide hydrolase (rs324420) genes on those adverse effects were analyzed.Analysis of OPRM1 gene variant status (Asn133Asp A > G) showed that G/G homozygotes were at significantly lower risk of somnolence compared with A allele carriers (0% vs 28.4%; Fisher exact test, P = .005; OR, 0; 95% CI, 0-0.6), and analysis of COMT gene variant status (Val158Met, G > A) showed that G/G homozygotes were at significantly higher risk of somnolence compared with A allele carriers (35.0% vs 10.4%; Fisher exact test, P = .008; OR, 4.5; 95% CI, 1.4-18.1). No relationship between variant status and adverse effects was found for the other genes.These findings demonstrate that OPRM1 and COMT gene variants influence the risk of somnolence as an adverse effect of opioid analgesic therapy.

Adverse Drug Reactions in Japanese Patients with End-Stage Heart Failure Receiving Continuous Morphine Infusion: A Single-Center Retrospective Cohort Study

BACKGROUND

Opioids have been reported to be effective for refractory dyspnea in patients with advanced heart failure (HF) in the palliative care setting.

OBJECTIVE

The aim of this study was to evaluate the incidence of adverse drug reactions (ADRs) and their relationship with morphine dose/duration or renal insufficiency in patients with end-stage HF receiving continuous morphine infusion.

METHODS

We retrospectively studied 38 patients with end-stage HF receiving continuous intravenous or subcutaneous morphine infusion for the relief of breathlessness between 2014 and 2019 (mean age 78 years). The endpoints were nausea/vomiting, respiratory depression, and drowsiness, which are common morphine-related ADRs.

RESULTS

Of 38 patients with end-stage HF receiving continuous intravenous/subcutaneous morphine infusion, 14 (37%) experienced ADRs. The median estimated glomerular filtration rate (eGFR) was lower in patients with than in those without ADRs (16 [range 9-48] vs. 41 [range 8-133], respectively; p = 0.011). The ADRs with the highest incidence were drowsiness (n = 13), nausea/vomiting (n =5), and respiratory depression (n =3). There were no differences in the maintenance dose or duration of morphine administration between patients with and without ADRs. A baseline eGFR of 32 mL/min/1.73 m² was a good cutoff value for ADR prediction (sensitivity 86%, specificity 96%). A baseline eGFR < 32 mL/min/1.73 m² was significantly associated with the occurrence of morphine-related ADRs (odds ratio 6.63, 95% confidence interval 1.19-37.01).

CONCLUSIONS

Our results showed that 37% of patients with end-stage HF receiving continuous intravenous/subcutaneous morphine infusion experienced ADRs, especially drowsiness. Patients with eGFR < 32 mL/min/1.73 m² were likely to experience morphine-related ADRs.

Cancer Pain Syndromes

Pain from cancer can present in a multitude of ways. In this chapter, we will identify the types of cancer pain and their etiologies. Following this, we will explore how cancer pain can present as somatic pain, visceral pain, and neuropathic pain. We will explore the aspects of the history and physical examination that point to specific diagnoses of pain and how to appropriately treat each diagnosis appropriately. Finally, we will touch upon a phenomenon known as opioid neurotoxicity.

Problematic Opioid Use Among Older Adults: Epidemiology, Adverse Outcomes and Treatment Considerations

With the aging population, an increasing number of older adults (> 65 years) will be affected by problematic opioid use and opioid use disorder (OUD), with both illicit and prescription opioids. Problematic opioid use is defined as the use of opioids resulting in social, medical or psychological consequences, whereas OUD is a form of problematic use that meets diagnostic criteria as defined by the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition. Problematic use of opioids by older adults is associated with a number of pertinent adverse effects, including sedation, cognitive impairment, falls, fractures and constipation. Risk factors for problematic opioid use in this population include pain, comorbid medical illnesses, concurrent alcohol use disorder and depression. Treatment of OUD consists of acute detoxification and maintenance therapy. At this time, there have been no randomized controlled trials examining the effectiveness of pharmacological interventions for OUD in this population, with recommendations based on data from younger adults. Despite this, opioid agonist therapy (OAT) is recommended for both stages of treatment in older adults with OUD. Buprenorphine is recommended as a first line agent over methadone in the older adult population, due to a more favourable safety profile and relative accessibility. Use of methadone in this population is complicated by risk of QT interval prolongation and respiratory depression. Available observational data suggests that older adults respond well to OAT and age should not be a barrier to treatment. Further research is required to inform treatment decisions in this population.

Narcotic Use for Acute Postoperative Pain Management in Mohs Micrographic Surgery Patients With End Stage Renal Disease: A Review of the Literature

BACKGROUND

Uncontrolled acute postoperative pain presents a significant management challenge when opioids are used in patients with end-stage renal disease (ESRD). Currently, there is a lack of quality pharmacokinetic and pharmacodynamic data regarding opioid medication use in ESRD patients to optimize safe and effective management.

OBJECTIVE

To review the published literature on pharmacologic evidence for and against the use of opioid medications for acute postoperative pain following Mohs micrographic surgery in ESRD patients.

METHODS

A search of PubMed was conducted to identify articles on the pharmacokinetic and pharmacodynamic properties of opioid pain medications in ESRD patients through March 1, 2020.

RESULTS

Seventy-five articles were reviewed. Limited data exist on opioids safe for use in ESRD and are mostly confined to small case series. Studies suggest tramadol and hydromorphone could be considered when indicated. Methadone may be a safe option, but should be reserved for treatment coordinated by a trained pain subspecialist.

CONCLUSION

Randomized clinical trials are lacking. Studies that are available are not sufficient to perform a quantitative methodologic approach. Evidence supports the judicious use of postoperative opioid medications in ESRD patients at the lowest possible dose to achieve clinically meaningful improvement in pain and function.

The American Society of Pain and Neuroscience (ASPN) Best Practices and Guidelines for the Interventional Management of Cancer-Associated Pain

Moderate to severe pain occurs in many cancer patients during their clinical course and may stem from the primary pathology, metastasis, or as treatment side effects. Uncontrolled pain using conservative medical therapy can often lead to patient distress, loss of productivity, shorter life expectancy, longer hospital stays, and increase in healthcare utilization. Various publications shed light on strategies for conservative medical management for cancer pain and a few international publications have reviewed limited interventional data. Our multi-institutional working group was assembled to review and highlight the body of evidence that exists for opioid utilization for cancer pain, adjunct medication such as ketamine and methadone and interventional therapies. We discuss neurolysis via injections, neuromodulation including targeted drug delivery and spinal cord stimulation, vertebral tumor ablation and augmentation, radiotherapy and surgical techniques. In the United States, there is a significant variance in the interventional treatment of cancer pain based on fellowship training. As a first of its kind, this best practices and interventional guideline will offer evidenced-based recommendations for reducing pain and suffering associated with malignancy.

Drug-related challenges following primary total hip and knee arthroplasty

We aimed to characterize the in-hospital analgesic use among total hip or knee arthroplasty (THA or TKA) patients, and to identify possible drug-related challenges. We identified 15 263 patients operated with a THA or TKA between 1 January 2012 and 30 April 2016. The prevalence of analgesic users and patients with potential clinically relevant drug-drug interactions (DDIs), along with the prevalence of readmission among patients with vs. without a DDI, were calculated. A DDI was defined as the combination of (A) a diuretic, an angiotensin-converting enzyme inhibitor or an angiotensin II receptor blocker, and an non-steroidal anti-inflammatory Drug (NSAID); (B) warfarin and an NSAID; and (C) a benzodiazepine or a benzodiazepine-related drug and an opioid. The prevalence of analgesics administered in THA and TKA patients was 99.3% and 99.1% for paracetamol and 93.8% and 98.8% for opioids, respectively. The prevalence of patients who received interaction A, B or C was 8.4%, 2.5% and 40.7%, respectively. Patients with vs. without a DDI had a higher prevalence of 30-day readmission. In conclusion, most THA and TKA patients were administered paracetamol or opioids. The prevalence of 30-day readmission was higher in patients with than in patients without a potential clinically relevant DDI.

Transversus abdominis plane block versus quadratus lumborum block type 2 for analgesia in renal transplantation: A randomised trial

BACKGROUND

Several studies have shown an analgesic efficacy of a transversus abdominis plane block (TAPB) in reducing opioid requirements during and after cadaveric renal transplantation surgery, but the effect of a quadratus lumborum block (QLB) in this type of surgery is unclear.

OBJECTIVES

The main objective of this prospective, randomised, double-centre clinical study was to compare the analgesic efficacy of a one-sided lateral approach TAPB with a unilateral QLB type 2 in cadaveric renal transplantation surgery.

DESIGN

Randomised, single-blinded trial.

SETTING

Two University-affiliated tertiary care hospitals between April 2016 and May 2017.

PATIENTS

A total of 101 patients aged more than 18 years, scheduled for cadaveric renal transplantation.

INTERVENTIONS

On receiving ethical board approval and individual informed consent, consecutive patients were allocated randomly to receive either an ultrasound-guided single-shot lateral TAPB or an ultrasound-guided single-shot QLB type 2 on the surgical side using 20 ml of bupivacaine 0.25% with adrenaline after a standardised induction of general anaesthesia. All patients on surgical completion and recovery from general anaesthesia were admitted to the postanaesthesia care unit for 24 h. They received standardised intravenous patient-controlled analgesia with fentanyl, and their pain scores were noted at regular intervals.

MAIN OUTCOME MEASURES

The primary endpoint was total cumulative fentanyl dose used per kg body mass in the first 24 h after surgery. Secondary outcomes were the need to start a continuous infusion of fentanyl in addition to patient-controlled analgesia boluses during the stay in post-anaesthesia care unit, postoperative pain severity measured using a numerical rating scale, patient satisfaction with analgesic treatment, evidence of postoperative nausea and vomiting, pruritus and sedation level.

RESULTS

The 49 patients allocated to the QLB type 2 group used significantly less fentanyl per kg in the first 24 h after surgery than the 52 patients who received a TAPB (median [IQR] 4.2 [2.3 to 8.0] μg kg versus 6.7 [3.5 to 10.7] μg kg, P = 0.042). No statistically significant differences were noted in the secondary endpoints within the study, including the frequency of adverse effects of opioids.

CONCLUSION

The reduction of fentanyl consumption in the first 24 h after renal transplantation with no difference in pain intensity and patient satisfaction shows a beneficial effect of one-sided QLB type 2 over a one-sided TAPB in regards to postoperative analgesia. However, the reduction in opioid consumption did not affect the frequency of opioid-related adverse effects.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT02783586.

Working towards an ERAS Protocol for Pancreatic Transplantation: A Narrative Review

Enhanced recovery after surgery (ERAS) initially started in the early 2000s as a series of protocols to improve the perioperative care of surgical patients. They aimed to increase patient satisfaction while reducing postoperative complications and postoperative length of stay. Despite these protocols being widely adopted in many fields of surgery, they are yet to be adopted in pancreatic transplantation: a high-risk surgery with often prolonged length of postoperative stay and high rate of complications. We have analysed the literature in pancreatic and transplantation surgery to identify the necessary preoperative, intra-operative and postoperative components of an ERAS pathway in pancreas transplantation.

Pharmacogenomics of oxycodone: a narrative literature review

Oxycodone is a semisynthetic μ- and κ-opioid receptor with agonist with a broad scope of use including postoperative analgesia as well as control of neuropathic and cancer pain. Advantages over other opioids include prolonged duration of action, greater potency than morphine and lack of histamine release or ceiling effect. Individual responses to oxycodone can vary due to genetic differences. This review article aims to summarize the oxycodone literature and provide context on its pharmacogenomics and pharmacokinetics. The evidence for clinical effect of genetic polymorphisms on oxycodone is conflicting. There is stronger evidence linking polymorphic genetic enzymes CYP2D6 and CYP3A with therapeutic outcomes. Further, research is needed to discern all of oxycodone's metabolites and their contribution to the overall analgesic effect.

High-dose opioid utilization and mortality among individuals initiating hemodialysis

BACKGROUND

Individuals undergoing hemodialysis in the United States frequently report pain and receive three-fold more opioid prescriptions than the general population. While opioid use is appropriate for select patients, high-dose utilization may contribute to an increased risk of death due to possible accumulation of opioid metabolites.

METHODS

We studied high-dose opioid utilization (≥120 morphine milligram equivalents [MME] per day) among adults initiating hemodialysis in the United States between 2007 and 2014 using national registry data. We calculated the cumulative incidence (%) of high-dose utilization and depicted trends in the average percentage of days individuals were exposed to opioids. We used adjusted Cox proportional hazards models to identify which opioid doses were associated with mortality.

RESULTS

Among 327,344 adults undergoing hemodialysis, the cumulative incidence of high-dose utilization was 14.9% at 2 years after initiating hemodialysis. Among patients with ≥1 opioid prescription during follow-up, the average percentage of days exposed to high-dose utilization increased from 13.9% in 2007 to 26.1% in 2014. Compared to 0MME per day, doses < 60MME were not associated with an increased risk of mortality, but high-dose utilization was associated with a 1.63-fold (95% CI, 1.57, 1.69) increased risk of mortality. The risk of mortality associated with opioid dose was highest in the first year after hemodialysis initiation.

CONCLUSIONS

The risk of mortality associated with opioid utilization among individuals on hemodialysis increases as doses exceed 60MME per day and is greatest during periods of high-dose utilization. Patients and clinicians should carefully weigh the risks and benefits of opioid doses exceeding 60MME per day.

Utilizing multimodal analgesia to evaluate postoperative analgesic requirements in kidney transplant recipients

The use of non-opioid analgesics following surgery has proven beneficial in managing pain and decreasing adverse outcomes following surgery. Data assessing outcomes related to opioid use is limited in kidney transplant recipients (KTRs). We evaluated the effectiveness of implementing a reduced to no opioid use protocol in KTRs. This retrospective cohort study included adult KTRs between January 2017 and July 2019 with a multimodal analgesic protocol (MAP), focused on limiting opioids, implemented in August 2018. We compared analgesic requirements in morphine milligram equivalents (MME) during transplant admissions between the MAP cohort and traditional cohort. There were 217 KTRs who met the criteria. Inpatient opioid use was significantly reduced in the MAP cohort (16.5 ± 19.2 MME/day vs 24.7 ± 19.7 MME/day; P <.05) with no significant difference in pain scores. No use of opioids within six months of discharge was significantly increased in the MAP cohort (50% vs 7%; P <.001), and there were no reported deaths at six months in either cohort. The use of multimodal analgesia is beneficial in KTRs to provide adequate pain control with limited to no exposure of opioids during admission or at discharge.

Quantification of methadone and its metabolites: EDDP and EMDP determined in autopsy cases using LC-MS/MS

The paper presents a method for the determination of methadone, EDDP, and EMDP in postmortem biological materials using liquid-liquid extraction with ethyl acetate (pH9) and UHPLC-MS/MS technique. Methadone-d₉ and EDDP-d₃ were used as the internal standards. The method validation results for blood and urine were as follows: linearity: 0.5-1000 ng/ml; R²  > 0.9993 for methadone, EDDP and R²  > 0.9944 for EMDP. Intra- and inter-day precision: 0.1%-7.5% and 0.3%-8.6%, respectively; intra- and inter-day accuracy: -11.8% to 13.9% and -9.3 to 14.8%, respectively; recovery: 91.5%-123.0%; matrix effect: 83.5%-123.9%. This study also describes 18 postmortem cases, where methadone concentrations ranged 2.3-1180 ng/ml in blood (n = 17), from 11.0 to >10,000 ng/ml in urine (n = 13) and 135.2-409.0 in vitreous humor (VH, n = 3). EDDP concentrations ranged from not detectable to 180 ng/mL in blood, from 42.4 to >10,000 ng/ml in urine and 18.3-36.5 in VH. EMDP concentrations were found in four cases in blood from below LLOQ to 1.8 ng/ml and in seven cases in urine, ranged 2.1-243.0 ng/ml. EMDP was not detected in VH samples. The EDDP/methadone ratios and blood/urine ratios for methadone and EDDP in EMDP-positive and negative cases were performed. The paper presents mass spectra of other methadone metabolites, than EDDP and EMDP (ring hydroxylated methadone, ring hydroxylated EDDP, ring hydroxylated EMDP, methadol, and DDP). Simultaneous determination of methadone and its metabolites in order to unequivocally interpret the results of toxicological tests seems to be useful in cases related to prescription/illicit use of methadone.

Opioid Management in CKD

Patients with chronic kidney disease (CKD) experience a high pain and symptom burden. Concurrently, opioid prescription and use in patients with CKD continues to increase, leading to concern for opioid-related risks. Nephrologists increasingly face challenging clinical situations requiring further evaluation and treatment of pain, for which opioid use may be indicated. However, nephrologists are not commonly trained in pain management and may find it difficult to compile the necessary information and tools to effectively assess and treat potentially multidimensional pain. In these situations, they may benefit from using an evidence-based stepwise approach proposed in this article. We address current approaches to opioid use for pain management in CKD and offer a stepwise approach to individualized opioid assessment, focusing on kidney-specific concerns. This includes thorough evaluation of the pain experience, opioid use history, and treatment goals. We subsequently discuss considerations when initiating opioid therapy, strategies to reduce opioid-related risks, and recommended best practices for opioid stewardship in CKD. Using this sequential approach to opioid management, nephrologists can thereby gain a broad overview of key patient considerations, the foundation for understanding implications of opioid use, and a patient-tailored plan for opioid therapy.