A Review of Adjunctive CNS Medications Used for the Treatment of Post-Surgical Pain

Impact of a Transitional Pain Service on postoperative opioid trajectories: a retrospective cohort study

INTRODUCTION

It has been well described that a small but significant proportion of patients continue to use opioids months after surgical discharge. We sought to evaluate postdischarge opioid use of patients who were seen by a Transitional Pain Service compared with controls.

METHODS

We conducted a retrospective cohort study using administrative data of individuals who underwent surgery in Ontario, Canada from 2014 to 2018. Matched cohort pairs were created by matching Transitional Pain Service patients to patients of other academic hospitals in Ontario who were not enrolled in a Transitional Pain Service. Segmented regression was performed to assess changes in monthly mean daily opioid dosage.

RESULTS

A total of 209 Transitional Pain Service patients were matched to 209 patients who underwent surgery at other academic centers. Over the 12 months after surgery, the mean daily dose decreased by an estimated 3.53 morphine milligram equivalents (95% CI 2.67 to 4.39, p<0.001) per month for the Transitional Pain Service group, compared with a decline of only 1.05 morphine milligram equivalents (95% CI 0.43 to 1.66, p<0.001) for the controls. The difference-in-difference change in opioid use for the Transitional Pain Service group versus the control group was -2.48 morphine milligram equivalents per month (95% CI -3.54 to -1.43, p=0.003).

DISCUSSION

Patients enrolled in the Transitional Pain Service were able to achieve opioid dose reduction faster than in the control cohorts. The difficulty in finding an appropriate control group for this retrospective study highlights the need for future randomized controlled trials to determine efficacy.

Evaluation of Oral Pregabalin as a Preemptive Adjuvant for Postoperative Pain in Patients Undergoing Coronary Artery Bypass Grafting With General Anesthesia and High Thoracic Epidural: A Randomized Controlled Study

Aim This study aimed to evaluate the effectiveness of oral pregabalin as a preventive supplement in managing postoperative pain in patients undergoing coronary artery bypass grafting (CABG) with a combination of general anesthesia and high thoracic epidural anesthesia. Material and methods This 18-month randomized controlled study at a tertiary hospital's anesthesiology department included 62 American Society of Anesthesiologists (ASA) II or III patients aged 35-75 with left ventricular ejection fraction >35%. Placebo (Group B, n = 31) or pregabalin (Group A, n = 31) was randomly allocated. Group A got 150 mg of pregabalin the night before surgery and 75 mg on postoperative days 0 and 1, whereas Group B received a placebo. Postoperative pain was evaluated using the Verbal Numerical Scale and Visual Analogue Scale, while sedation was assessed with the Ramsay Sedation Scale. Statistical analysis was performed using SPSS for Windows, Version 16.0 (Released 2007; SPSS Inc., Chicago). Results In this study, pregabalin significantly reduced postoperative pain on Day 0 and Day 1 (p < 0.001) compared to the placebo. The pregabalin group exhibited higher sedation scores on Day 0 (p < 0.001), but there were no significant differences on Day 1. Inotrope requirements were similar between both groups. Conclusions CABG patients' postoperative pain was greatly reduced by pregabalin without impacting sedation or inotrope needs. These data imply that pregabalin was a useful supplementary analgesic for CABG patients' multimodal pain treatment.

Opioid free analgesia after return home in ambulatory colonic surgery patients: a single-center observational study

BACKGROUND

Because of the adverse effects of morphine and its derivatives, non-opioid analgesia procedures are proposed after outpatient surgery. Without opioids, the ability to provide quality analgesia after the patient returns home may be questioned. We examined whether an opioid-free strategy could ensure satisfactory analgesia after ambulatory laparoscopic colectomy.

METHODS

We performed a retrospective observational single-center study (of prospective collected database) including all patients eligible for scheduled outpatient colectomy. Postoperative analgesia was provided by paracetamol and nefopam. Postoperative follow-up included pain at mobilization (assessed by a numerical rating scale, NRS), hemodynamic variables, temperature, resumption of transit and biological markers of postoperative inflammation. The primary outcome was the proportion of patients with moderate to severe pain (NRS > 4) the day after surgery.

RESULTS

Data from 144 patients were analyzed. The majority were men aged 59 ± 12 years with a mean BMI of 27 [25-30] kg/m2. ASA scores were 1 for 14%, 2 for 59% and 3 for 27% of patients. Forty-seven patients (33%) underwent surgery for cancer, 94 for sigmoiditis (65%) and 3 (2%) for another colonic pathology. Postoperative pain was affected by time since surgery (Q3 = 52.4,p < 0.001) and decreased significantly from day to day. The incidence of moderate to severe pain at mobilization (NRS > 4) on the first day after surgery was (0.19; 95% CI, 0.13-0.27).

CONCLUSION

Non-opioid analgesia after ambulatory laparoscopic colectomy seems efficient to ensure adequate analgesia. This therapeutic strategy makes it possible to avoid the adverse effects of opioids.

TRIAL REGISTRATION

The study was retrospectively registered and approved by the relevant institutional review board (CERAR) reference IRB 00010254-2018 - 188). All patients gave written informed consent for analysis of their data. The anonymous database was declared to the French Data Protection Authority (CNIL) (reference 221 2976 v0 of April 12, 2019).

New Serotonin-Norepinephrine Reuptake Inhibitors and Their Anesthetic and Analgesic Considerations

Serotonin-norepinephrine reuptake inhibitors (SNRIs) inhibit the presynaptic neuronal uptake of serotonin and norepinephrine and prolong the effects of the monoamines in the synaptic cleft within the central nervous system, leading to increased postsynaptic receptor activation and neuronal activities. Serotonin-norepinephrine reuptake inhibitors can have multiple clinical indications, including as the first-line agents for the management of depression and anxiety, and as analgesics in the treatment of chronic pain. The effects of reuptake inhibition of norepinephrine and serotonin are often dose-dependent and agent-dependent. There are five FDA-approved serotonin-norepinephrine reuptake inhibitors (desvenlafaxine, duloxetine, levomilnacipran, milnacipran and sibutramine) currently being marketed in the United States. As the COVID-19 pandemic significantly increased the incidence and prevalence of anxiety and depression across the country, there are significantly increased prescriptions of these medications perioperatively. Thus, anesthesiologists are more likely than ever to have patients administered with these agents and scheduled for elective or emergency surgical procedures. A thorough understanding of these commonly prescribed serotonin-norepinephrine reuptake inhibitors and their interactions with commonly utilized anesthetic agents is paramount. There are two potentially increased risks related to the continuation of SNRIs through the perioperative period: intraoperative bleeding and serotonin syndrome. SNRIs have some off-label uses, more new indications, and ever-increasing new applications in perioperative practice. This article aims to review the commonly prescribed serotonin-norepinephrine reuptake inhibitors and the current clinical evidence regarding their considerations in perioperative anesthesia and analgesia.

Chronic Post-Surgical Pain in the Frail Older Adult

Older adults are the fastest growing segment of the population and surgical procedures in this group increase each year. Chronic post-surgical pain is an important consideration in the older adult as it affects recovery, physical functioning, and overall quality of life. It is increasingly recognized as a public health issue but there is a need to improve our understanding of the disease process as well as the appropriate treatment and prevention. Frailty, delirium, and cognition influence post-operative outcomes in older adults and have been implicated in the development of chronic post-surgical pain. Further research must be conducted to fully understand the role they play in the occurrence of chronic post-surgical pain in the older adult. Additionally, careful attention must be given to the physiologic, cognitive, and comorbidity differences between the older adult and the general population. This is critical for elucidating the proper chronic post-surgical pain treatment and prevention strategies to ensure that the older adult undergoing surgical intervention will have an appropriate and desirable post-operative outcome.

Outpatient Pharmacy Prescriptions During the First Year Following Serious Combat Injury: A Retrospective Analysis

INTRODUCTION

Limited research has analyzed the full range of outpatient medication prescription activity following serious combat injury. The objectives of this study were to describe (1) outpatient medication prescriptions and refills during the first 12 months after serious combat injury, (2) longitudinal changes in medication prescriptions during the first-year postinjury, and (3) patient characteristics associated with outpatient prescriptions.

MATERIALS AND METHODS

This was a retrospective analysis of existing health and pharmacy data for a random sample of U.S. service members who sustained serious combat injuries in the Iraq and Afghanistan conflicts, 2010-2013 (n = 381). Serious injury was defined by an Injury Severity Score (ISS) of 9 or greater. These patients typically participate in military rehabilitation programs (eg, amputation care) where prescription medications are essential. Data sources were the Expeditionary Medical Encounter Database for injury-specific data, the Pharmacy Data Transaction Service for outpatient medication prescriptions and refills, and the Military Health System Data Repository for diagnostic codes of pain and psychological disorders. Military trauma nurses reviewed casualty records to identify types of injuries. Using the American Hospital Formulary Service Pharmacologic-Therapeutic Classification system, clinicians identified 13 categories of prescription medications (eg, opioid, psychotherapeutic, immunologic) for analysis. Multivariable negative binomial and logistic regression analyses evaluated significant associations between independent variables (eg, blast injury, traumatic brain injury [TBI], ISS, limb amputation, diagnoses of chronic pain, or psychological disorders) and prescription measures (ie, number or category of medication prescriptions). We also describe longitudinal changes in prescription activity postinjury across consecutive quarterly intervals (91 days) during the first-year postinjury.

RESULTS

During the first-year postinjury, patients averaged 61 outpatient prescriptions, including all initial prescriptions and refills. They averaged eight different categories of medications, primarily opioid, immunologic, gastrointestinal/genitourinary, central nervous system (CNS), nonopioid analgesic, and psychotherapeutic medications (representing 82% of prescriptions) during the first year. Prescription activity generally declined across quarters. There was still substantial prescription activity during the fourth quarter, as 79% of patients had at least one prescription. From 39 to 49% of patients had fourth-quarter prescriptions for opioid, CNS, or psychotherapeutic medications. Longitudinally, we found that 24-34% of patients had an opioid, CNS, or psychotherapeutic prescription during each of the final three quarters. In multivariable analysis, ISS, limb amputation (particularly bilateral amputation), and diagnoses of chronic pain and post-traumatic stress disorder (PTSD) were associated with significantly higher counts of individual and multiple medication prescriptions. TBI was associated with significantly lower numbers of prescriptions for certain medications.

CONCLUSIONS

This is one of the first studies to provide a systematic analysis of outpatient medication prescriptions following serious combat injury. The results indicate substantial prescription activity from multiple medication categories throughout the first-year postinjury. Diagnoses of chronic pain, PTSD, and limb amputation and ISS were associated with significantly higher counts of prescriptions overall and more prescription medication categories. This study provides initial evidence to better understand medication prescription activity following serious combat injury. The results inform future research on medication prescription practices and planning for rehabilitation.

Efeitos da abreviação do jejum pré-operatório com solução de carboidrato e proteína em sintomas pós-operatórios de cirurgias ginecológicas: ensaio clínico randomizado controlado duplo-cego

RESUMO Objetivo: investigar os efeitos da abreviação do jejum pré-operatório, uma recomendação do protocolo de “Aceleração da Recuperação Total Pós-operatória” (ACERTO), em sintomas pós-operatórios de pacientes submetidas à cirurgias ginecológicas. Métodos: estudo controlado, randomizado, duplo-cego, de 80 cirurgias ginecológicas realizadas no período de janeiro a junho de 2016. As pacientes foram aleatoriamente alocadas em dois grupos: Grupo Controle, com 42 pacientes, e Grupo Suco, com 38, e que receberam, respectivamente, 200ml de solução inerte ou 200ml de líquido enriquecido com carboidrato e proteína quatro horas antes da cirurgia. Os sintomas pós-operatórios estudados foram sede, fome, dor, agitação, satisfação e bem-estar, em ambos os grupos. Para medir a intensidade dos sintomas foi utilizada a Escala Visual Analógica (EVA), associada à Escala Facial (EF) para dor, aplicadas dez horas após a cirurgia. Resultados: as pacientes do Grupo Suco apresentaram menos dor (3,51x1,59), sede (3,63x0,85), fome (3,86x2,09) e agitação (2,54x0,82) em relação ao Grupo Controle (P<0,05). As variáveis satisfação (6,89x8,68) e bem-estar (5,51x7,12) foram maiores (P<0,05) quando houve a ingestão do líquido contendo carboidrato e proteína (Grupo Suco) em relação à solução inerte (Grupo Controle). Conclusão: a abreviação do jejum pré-operatório com líquido contendo carboidrato e proteína antes de cirurgias ginecológicas reduz sede, fome, dor, agitação e favorece maior satisfação e bem-estar do que a ingestão de solução inerte.