Weeding Out the Problem: The Impact of Preoperative Cannabinoid Use on Pain in the Perioperative Period

The Association Between Preoperative Cannabis Use and Anxiety, Pain Scores and Opioid Consumption in Patients Undergoing Spinal Fusion: A Retrospective Cohort Study

Study DesignRetrospective cohort study.ObjectiveDespite increasing cannabis use, its prevalence in specific surgical groups is unclear, and its impact on perioperative care and outcomes is understudied. This study estimates cannabis use incidence in patients undergoing lumbar spine surgery and explores associations between preoperative use and anxiety, pain scores, and postoperative opioid consumption. We hypothesized a correlation between cannabis use and decreased reliance on opioids for postoperative pain relief.MethodsThis single-center retrospective cohort study included 204 patients undergoing single or multilevel spinal fusion surgery between July 2022 and August 2023. Self-reported cannabis use, demographics, surgical characteristics, numeric rating scale (NRS) pain scores, anxiety, inpatient opioid consumption, and discharge prescribing (total morphine equivalent dose) were extracted from electronic medical records (EMR). Patients were categorized into cannabis users or non-cannabis users, and group differences were analyzed using bivariable and multivariable regression.ResultsOf 204 patients, 27 (13.2%) were cannabis users and 177 (86.8%) were non-users. Cannabis users were younger (P = 0.007), more likely male (P = 0.028), and Caucasian (P = 0.032) than non-users. Preoperative cannabis use correlated significantly with anxiety disorder (P = 0.023) and higher preoperative (P = 0.016) and postoperative (P = 0.002) NRS pain scores. Multivariable analysis showed cannabis use associated with higher preoperative (P = 0.015) but not postoperative (P = 0.073) pain scores. No significant differences were found in preoperative, discharge opioid prescribing or postoperative opioid consumption.ConclusionThe incidence of cannabis use was low, but positively associated with anxiety and higher preoperative NRS pain scores. Large, well-powered trials are needed to understand cannabis's impact on spine surgery outcomes.

Bidirectional relationships between pain and patterns of cannabis and tobacco use in a US nationally representative sample

ABSTRACT

One-fifth of US adults experience chronic pain, which is associated with increased tobacco and cannabis use. Although bidirectional relationships between tobacco and pain have been demonstrated, pathways between pain, cannabis use, and co-use of cannabis and tobacco are understudied. We aimed to estimate the effects of (1) substance use (exclusive and co-use of cannabis and tobacco) on later pain intensity, and (2) pain intensity on later substance use. Data were from 31,983 adults in biennial surveys (2015-2021) of the US nationally representative longitudinal Population Assessment of Tobacco and Health Study (n = 71,055 pairs of consecutive surveys; T1 and T2). Past-week pain intensity was dichotomized (≤4/10 no/low pain; >4/10 moderate/severe pain). Mutually exclusive substance use categories (past 30 days) were no cannabis/tobacco use; exclusive cannabis/tobacco use; and co-use. Logistic regression assessed whether T1 substance use affected moderate/severe pain at T2. Multinomial models assessed whether pain status at T1 affected substance use at T2. Compared with no cannabis/tobacco use at T1, co-use (OR: 2.29 [95% CI: 2.09-2.51]), exclusive tobacco use (2.00 [1.86-2.14]), and exclusive cannabis use (1.35 [1.13-1.61]) were all associated with moderate/severe pain at T2. Moderate/severe pain at T1 increased odds of co-use (2.43 [2.22-2.66]), exclusive tobacco (2.12 [1.98-2.28]), and exclusive cannabis use (1.46 [1.29-1.65]) compared with no cannabis/tobacco use at T2, and increased odds of co-use at T2 compared with exclusive cannabis/tobacco use. Findings demonstrated bidirectional relationships between pain and the exclusive use and co-use of cannabis and tobacco and indicate potential synergy in the co-use of cannabis and tobacco with respect to pain.

Perioperative management of the patient on cannabis and cannabinoids: A review

BACKGROUND

The rise in global cannabis use has led anaesthetists to encounter an increasing number of patients on cannabis and cannabinoids. With cannabis influencing the perioperative period, anaesthetists will face associated challenges managing these patients.

OBJECTIVE

This review aims to summarise this literature on perioperative care for patients with long-term cannabis consumption or cannabis use disorder.

METHODS

This review was conducted based on the PRISMA 2020 statement. A literature search was performed using Medline and Cochrane library databases to identify relevant reports published from 2003 to 2023. This search yielded 209 records. After screening, 17 articles were included.

RESULTS

Preoperative screening of patients for chronic cannabis use or cannabis use disorder can be valuable, due to the increased risk of postoperative myocardial infarction, more postoperative pain and opioid use. Moreover, regarding respiratory management, anaesthetists should prepare to manage bronchospasm and consider adjustments in ventilation. During the perioperative period, attention should be paid to potential interactions between anticoagulant medications and cannabinoids.

Cannabis and liver transplant in the era of legalization: Effects of pretransplant cannabis use on postoperative opioid use and transplant outcomes

Cannabis use is increasing in the United States, including among candidates for liver transplants (LTs). Although the anesthesia literature suggests an association between cannabis use and increased postoperative pain, the impact of cannabis use on post-LT opioid use remains unknown. This study investigates changes in cannabis use at a transplant center over time, as well as the impact of cannabis use on post-LT opioid use, health care utilization, and mortality. We included 4236 patients evaluated for LT at our institution between January 2013 and July 2023. Our primary risk factor was cannabis use, defined as urine toxicology positive for cannabis within 90 days of LT evaluation. Our primary outcome was post-LT opioid use, including oral morphine equivalents received during the LT hospitalization and discharge opioid prescriptions. We used multivariable logistic and quantile regression to compare post-LT opioid use, health care utilization outcomes, and mortality between cannabis users and nonusers. Cannabis use was associated with higher oral morphine equivalent use in the 48 hours after LT ( p =0.04). There were no statistically significant differences between groups in 72-hour ( p =0.07) or 7-day cumulative oral morphine equivalent ( p =0.33), opioid prescriptions on discharge ( p =0.25), hospital length of stay ( p =0.69), intensive care unit length of stay ( p =0.94), 90-day readmission ( p =0.66), or 90-day mortality ( p =0.96). While cannabis use before LT was associated with significantly higher opioid use in the immediate postoperative period, this did not translate to differences in opioid use beyond 48 hours after LT, or short-term health care utilization or clinical outcomes. These findings should help set provider expectations for immediate post-LT pain control. Our findings support the growing body of literature that fails to identify an association between pre-LT cannabis use and post-LT outcomes.

Do Medical and Recreational Marijuana State Laws Impact Trends in Postoperative Opioid Prescriptions Among Patients Who Have Undergone TJA?

BACKGROUND

Total joint arthroplasty (TJA) is a painful procedure frequently managed with opioid medication, which puts patients at risk for chronic opioid use. Marijuana is a pain modifier and may be an effector of opioid-use reduction. Recently, many states have legalized the use of medical and recreational marijuana, and these legalization events have correlated with reductions in opioid prescriptions. This trend has not yet been demonstrated in the context of orthopaedic surgery, and there is limited evidence overall investigating the effect of marijuana on perioperative opioid use in TJA.

QUESTION/PURPOSES

(1) Is legalization of medical marijuana associated with changes in perioperative opioid use in patients who have undergone TJA? (2) Is legalization of recreational marijuana associated with changes in perioperative opioid use in patients who have undergone TJA? (3) Are these changes observed in any specific subpopulations of patients who have undergone TJA?

METHODS

The MarketScan Commercial and Medicare Supplemental Claims and Encounters Database was queried to assess the relative effect of marijuana legalization on perioperative opioid use in THA and TKA between May 1, 2017, and September 30, 2021, which was around and after the time that the opioid crisis was declared a public health emergency. We identified 129,132 inpatient TJA procedures (THA = 49,718, TKA = 79,414). The perioperative period was defined as 30 days before surgery and 90 days after surgery. We used the recreational and medical marijuana legalization effective dates in all 50 states and Washington, DC to conduct a difference-in-difference analysis to compare trends of outpatient opioid prescriptions among patients who underwent TJA in states with legalizations of medical or recreational marijuana with those among patients who underwent TJA in states without a change in marijuana legalization status.

RESULTS

We observed no impact of medical marijuana legalization on morphine milligram equivalent (MME)/day (difference-in-difference change 4.38 [95% confidence interval (CI) -4.49 to 13.22]). However, recreational marijuana legalization implementation was associated with an increase in MME/day (difference-in-difference change 8.83 [95% CI 0.22 to 17.43]). When we looked at specific patient groups, the implementations of medical and recreational marijuana laws were both associated with increases in perioperative opioid prescriptions in women, while recreational marijuana legalization was associated with increased opioid use in patients undergoing TKA and patients without prior use of opioids.

CONCLUSION

We did not identify differences with respect to medical marijuana legalization implementation. However, we found that recreational marijuana legalization was associated with an increase in perioperative MME/day for TJA. This is important because surgeons in states with the implementation of recreational marijuana law should be aware of the potential for increased marijuana availability for their patients and how this may impact their postoperative course, particularly with respect to pain and opioid utilization.

LEVEL OF EVIDENCE

Level III, therapeutic study.

The role of cannabis on total hip and knee surgeries outcomes: a systematic review and meta-analysis

PURPOSE

Cannabis refers to medications derived from the Cannabis plant. Cannabis has long been used to treat a wide range of conditions. The widespread legalization of cannabis has increased its use. This meta-analysis evaluates the effects of preoperative cannabis usage on TKA and THA outcomes and complications.

METHODS

This review follows CRD Guidance for Undertaking Reviews in Healthcare and PRISMA 2020 guidelines. On October 12, 2023, we extensively searched MEDLINE (PubMed), Scopus, Cochrane Central Register of Controlled Trials, and Web of Science. There were no time, place, or language restrictions. We also examined the references and citations in the included publications to find relevant research.

RESULTS

We found 208 references in PubMed/Medline, Scopus, Web of Science, and other databases. After reviewing all publications, we identified 18 references that match the requirements for further assessment. The odds ratios (ORs) for reoperation and readmission are 1.35 (95% CI: 0.69, 2.66, and p-value = 0.38), and 0.89 (95% CI: 0.41, 1.92, and p-value = 0.76). Inpatient morphine milligram equivalent (MME) and length of stay (LOS) have a mean difference (MD) of -1.71 (95% CI: -13.46, 10.05, and p-value = 0.78), and - 0.13 (95% CI: -0.33, 0.08, and p-value = 0.23). The MD of the VAS pain score 24-72 h after surgery is 0.40 (95% CI: -0.07, 0.87, and p-value = 0.10). The odds ratio for PTE and DVT is 1.54 (95% CI: 0.1, 23.24, and p-value = 0.75), and 1.38 (95% CI: 1.08, 1.77, and p-value = 0.01), respectively.

CONCLUSION

Cannabis users experienced significantly higher rates of DVT following THA and TKA. Our subgroup analysis found that cannabis users who underwent TKA had considerably higher rates of reoperation (p-value = 0.10) and readmission (p-value ≤ 0.01), while those who underwent THA had significantly lower rates of PTE. These findings highlight the need to include cannabis use as a risk factor in surgical planning and patient care protocols, and further studies are warranted.

PROSPERO REGISTRATION

This study design and protocol were performed in accordance with the PRISMA Statement. The protocol was registered previously on PROSPERO CRD42024551078.

Cannabis Use and Anesthesia

Consistent evidence supporting the use of cannabinoids for management of acute pain is lacking. A small number of observational studies suggest cannabinoid use is associated with reduced opioid use but pain scores remain unchanged. The majority of randomized trials involving a variety of cannabinoid compounds have shown no benefit for acute pain. Chronic cannabis users may be at increased risk of experiencing elevated levels of acute pain and these individuals may require greater quantities of opioids compared to non-cannabis users. There is also evidence suggesting that chronic, high-dose cannabis users may be at increased risk of perioperative cardiovascular complications.

Utilizing Local Anesthesia Only for Penile and Scrotal Urologic Surgery: A Prospective Study on Patient Tolerability and Surgical Outcomes for a Sedation-free Option

OBJECTIVE

To prospectively assess surgical outcomes, complications, and patient-reported tolerability of invasive scrotal surgeries under local anesthesia (LA) alone, without sedation, compared to tolerability of penile procedures commonly performed in this manner.

METHODS

Adult patients undergoing penile and scrotal surgeries under LA only were enrolled from August 2022 to June 2023 (NCT05617261). Demographics, surgeon-perceived and patient-reported pain, and surgical variables were collected. Tolerability to the procedures and future anesthetic choice for a repeat procedure was assessed on follow-up. Complication data were collected, including recurrence, infection, excessive pain, and emergency room and family physician visits.

RESULTS

Hundred and seven patients were enrolled with a mean age ± SD of 42.2 ± 16.4 years. There was a 100% procedural success rate and no cases of perioperative complications or escalation of anesthetic. Around 92.4% (n = 97) of patients indicated they would opt for LA only for a hypothetical repeat procedure. Of the minority opting for general anesthetic, most indicated discomfort or preferring an element of amnesia. No differences between intraoperative pain or tolerability scores of invasive scrotal procedures compared to penile procedures were observed. On univariate analysis, longer procedure duration (P = .003), cannabis use (P = .01), and higher intra-operative pain (P = .005) was associated with lower tolerability.

CONCLUSION

LA alone in an office-based setting is promising for scrotal surgeries. It offers similarly high patient tolerability compared to procedures that are routinely performed under LA, with the preservation of outcomes. Adopting this method has the potential for substantial cost savings, reduced wait times, enhanced accessibility, and improved surgical efficiency.

Considerations for Anesthesia in Older Adults with Cannabis Use

Over the past decade, legislative changes occurred in the USA and the western world that were followed by a substantial increase in reported use of cannabis among the general population. Among patients undergoing anesthesia for surgery or interventional procedures, older patients-often defined as adults over 65 years-are one of the fastest-growing populations. Within this group, the prevalence of cannabis use almost tripled over the past decade. In addition to habitual cannabis use, recommendations for treatment of chronic pain with cannabinoids have become increasingly more common. The clinical relevance of cannabis use in older adults is supported by recent studies linking it to increased anesthetic requirements as well as respiratory, cardiovascular, and psychiatric complications following surgery. Still, evidence remains equivocal, as these associations may largely depend on the type, frequency, and route of cannabis administration, and current research is mostly limited to retrospective cohort studies. Multisystemic effects of cannabis can become especially relevant in patients of advanced age undergoing anesthesia, characterized by physiological and pharmacodynamic alterations as well as a higher risks of drug-to-drug interactions. Best-practice guidelines emphasize the need for detailed, systematic preoperative screening for habits of cannabis use, including the history, type, and frequency, to guide perioperative management in these patients. This review discusses considerations for anesthesia in older patients with habitual cannabis use while highlighting strategies and recommendations to ensure safe and effective anesthesia care.

Cannabinoids and General Anesthetics: Revisiting Molecular Mechanisms of Their Pharmacological Interactions

Cannabis has been used for recreation and medical purposes for more than a millennium across the world; however, its use's consequences remain poorly understood. Although a growing number of surgical patients are regular cannabis consumers, little is known regarding the pharmacological interactions between cannabis and general anesthetics; consequently, there is not a solid consensus among anesthesiologists on the perioperative management of these patients. The existing evidence about the molecular mechanisms underlying pharmacological interactions between cannabinoids and anesthetic agents, both in animal models and in humans, shows divergent results. While some animal studies have demonstrated that phytocannabinoids (tetrahydrocannabinol [THC], cannabidiol [CBD], and cannabinol [CBN]) potentiate the anesthetic effects of inhalation and intravenous anesthetics, while others have found effects comparable with what has been described in humans so far. Clinical studies and case reports have consistently shown increased requirements of GABAergic anesthetic drugs (isoflurane, sevoflurane, propofol, midazolam) to achieve adequate levels of clinical anesthesia. Several potential molecular mechanisms have been proposed to explain the effects of these interactions. However, it is interesting to mention that in humans, it has been observed that the ingestion of THC enhances the hypnotic effect of ketamine. Animal studies have reported that cannabinoids enhance the analgesic effect of opioids due to a synergistic interaction of the endogenous cannabinoid system (ECS) with the endogenous opioid system (EOS) at the spinal cord level and in the central nervous system. However, human data reveals that cannabis users show higher scores of postoperative pain intensity as well as increased requirements of opioid medication for analgesia. This review aims to improve understanding of the molecular mechanisms and pharmacological interactions between cannabis and anesthetic drugs and the clinical outcomes that occur when these substances are used together.

Marijuana and Its Implications in Breast Reduction Surgery Outcomes and Quality of Life: A Matched Analysis

Background

With marijuana use on the rise, its influence on surgical outcomes, particularly for breast reduction, warrants investigation. This study aims to clarify marijuana's effects on breast reduction surgery outcomes, given its limited research focus despite potential perioperative implications.

Methods

A retrospective review was conducted from 2016 to 2022 of patients with/without marijuana use undergoing breast reduction. Propensity score-matching considered age, body mass index, ptosis, and breast tissue mass. Patient demographics, clinical attributes, and postoperative details were analyzed. Quality-of-life (QoL) changes were gauged using pre- and postoperative BREAST-Q.

Results

Of 415 patients who underwent breast reduction, 140 patients documented marijuana use. After propensity matching, a total of 108 patients (54 marijuana users versus 54 nonusers) were analyzed. The average age was 39 years ± 12 and body mass index 30.1 kg/m2 ± 5.3. There were no differences between the 2 groups in comorbidities, breast symmetry, excision patterns, pedicle use, or drain count (P > 0.05). Furthermore, surgical outcomes including surgical site occurrences, scarring, pain levels, hypersensitivity, or sensation loss were comparable between the groups (P > 0.05). There were also no differences in number of readmissions, reoperations, or emergency department visits (P > 0.05). Both groups showed enhanced postoperative QoL, regardless of marijuana usage.

Conclusions

This study indicates that marijuana use does not significantly impact breast reduction surgery outcomes. Comparable surgical results and postoperative QoL improvements were observed in both marijuana users and nonusers. This study provides surgeons with the knowledge to offer more informed patient counseling regarding the implications of marijuana use in relation to breast reduction procedures.

Association Between Cannabis Use and Opioid Consumption, Pain, and Respiratory Complications After Surgery: A Retrospective Cohort Analysis

BACKGROUND

Cannabis is a widely used illicit drug with effects on different pain pathways. However, interactions between cannabis and postoperative pain are unclear. Cannabis smoking also affects the lungs, but the impact of cannabis use on postoperative pulmonary complications is unknown. We hypothesized that preoperative cannabis use in adults having elective surgery is associated with higher postoperative opioid consumption. Secondarily, we tested the hypothesis that cannabis use is associated with higher pain scores, hypoxemia (oxygen saturation [Sp o2 ]/fraction of inspired oxygen [F io2 ] ratio), and higher postoperative pulmonary complications compared to nonuse of cannabis.

METHODS

In this retrospective study, we included adult patients who had elective surgeries at Cleveland Clinic Main Campus between January 2010 and December 2020. The exposure was use of cannabis within 30 days before surgery, and the control group never used cannabis. Patients who had regional anesthesia or chronic pain diagnosis were excluded. The primary outcome was postoperative opioid consumption; 3 secondary outcomes were time-weighted average (TWA) postoperative pain score, TWA Sp o2 /F io2 ratio, and composite of pulmonary complications after surgery. We assessed the association between cannabis use and opioid consumption during the first 24 postoperative hours using linear regression on log-transformed opioid consumption with a propensity score-based method (inverse probability of treatment weighting [IPTW]) adjusting for confounders. We further adjusted for imbalanced confounding variables after IPTW was applied.

RESULTS

In total, 1683 of 34,521 patients were identified as cannabis users. Cannabis use was associated with increased opioid consumption, with an adjusted ratio of geometric means (95% confidence interval [CI]) of 1.30 (1.22-1.38; P < .0001) for cannabis users versus nonusers. Secondarily, (1) cannabis use was associated with increased TWA pain score, with a difference in means of 0.57 (95% CI, 0.46-0.67; P < .0001); (2) cannabis use was not associated with TWA Sp o2 /F io2 , with an adjusted difference in means of 0.5 (95% CI, -3.1 to 4.2; P = .76); and (3) cannabis use was not associated with a collapsed composite of pulmonary complications, with estimated odds ratio of 0.90 (95% CI, 0.71-1.13; P = .34).

CONCLUSIONS

Adult cannabis users undergoing surgeries were found to have significantly higher postoperative opioid consumption and pain scores than nonusers. Cannabis use did not have a clinically meaningful association with hypoxia or composite pulmonary complications.

Opioid consumption before discharge predicts outpatient opioid use in adolescents undergoing surgery

BACKGROUND

The majority of adolescents undergoing surgery report unused prescription opioids after surgery, increasing the risk of diversion, misuse, and addiction. Adult studies have demonstrated that opioid use 24 hours before discharge corresponds with opioid use at home. We hypothesized that inpatient opioid consumption is associated with outpatient opioid use in adolescents.

METHODS

Adolescents aged 13-20 years undergoing elective surgery associated with an opioid prescription were prospectively recruited. Parent-adolescent dyads were surveyed preoperatively to assess sociodemographics, health literacy, and baseline substance use, and opioid use was measured at 30- and 90-days postoperatively. Medical records were reviewed to calculate cumulative opioid use during hospitalization. Inpatient and postoperative opioid use was converted to oral morphine equivalents. Adjusting for age, sex, race, health literacy, alcohol use, pain score, and surgery, multivariable linear regression identified factors associated with outpatient oral morphine equivalent use 90 days postoperatively.

RESULTS

Overall, 103 adolescents were enrolled. Median oral morphine equivalents used from 24 and 48 hours before discharge and throughout the hospitalization were 30.8 (interquartile range:11.7-45.0), 67.5 (interquartile range:37.5-94.3), and 97.5 (interquartile range:18.0-152.7), respectively. Regression analysis demonstrated that adolescent-reported pain at discharge (P = .028) and cumulative oral morphine equivalents used 24 hours (P < .001) and 48 hours (P = .003) before discharge were significantly associated with postoperative oral morphine equivalents use at home. Oral morphine equivalents consumption 24 hours before discharge estimated cumulative oral morphine equivalents use 90 days postoperatively at a 1-to-5 ratio in 94.1% of patients.

CONCLUSION

For adolescents undergoing surgery, patient-reported pain at discharge and oral morphine equivalents administered 24 hours before discharge are associated with cumulative outpatient opioid use. Tailoring outpatient prescriptions to total oral morphine equivalent consumption 24 hours before discharge could reduce excess opioid prescribing.

Understanding the epidemiology and perceived efficacy of cannabis use in patients with chronic musculoskeletal pain

BACKGROUND

The belief that cannabis has analgesic and anti-inflammatory properties continues to attract patients with chronic musculoskeletal (MSK) pain towards its use. However, the role that cannabis will play in the management of chronic MSK pain remains to be determined. This study examined 1) the rate, patterns of use, and self-reported efficacy of cannabis use among patients with chronic MSK pain and 2) the interest and potential barriers to cannabis use among patients with chronic MSK pain not currently using cannabis.

METHODS

Self-reported cannabis use and perceived efficacy were prospectively collected from chronic MSK pain patients presenting to the Orthopaedic Clinic at the University Health Network, Toronto, Canada. The primary dependent variable was current or past use of cannabis to manage chronic MSK pain; bivariate and multivariable logistic regression were used to identify patient characteristics independently associated with this outcome. Secondary outcomes were summarized descriptively, including self-perceived efficacy among cannabis users, and interest as well as barriers to cannabis use among cannabis non-users.

RESULTS

The sample included 629 patients presenting with chronic MSK pain (mean age: 56±15.7 years; 56% female). Overall, 144 (23%) reported past or present cannabis use to manage their MSK pain, with 63.7% perceiving cannabis as very or somewhat effective and 26.6% considering it as slightly effective. The strongest predictor of cannabis use in this study population was a history of recreational cannabis use (OR 12.7, p<0.001). Among cannabis non-users (N=489), 65% expressed interest in using cannabis to manage their chronic MSK pain, but common barriers to use included lack of knowledge regarding access, use and evidence, and stigma.

CONCLUSIONS

One in five patients presenting to an orthopaedic surgeon with chronic MSK pain are using or have used cannabis with the specific intent to manage their pain, and most report it to be effective. Among non-users, two-thirds reported an interest in using cannabis to manage their MSK pain, but common barriers to use existed. Future double-blind placebo-controlled trials are required to understand if this reported efficacy is accurate, and what role, if any, cannabis may play in the management of chronic MSK pain.

Cannabinoid Analgesia in Postoperative Pain Management: From Molecular Mechanisms to Clinical Reality

Postoperative pain (POP) is a challenging clinical phenomenon that affects the majority of surgical patients and demands effective management to mitigate adverse outcomes such as persistent pain. The primary goal of POP management is to alleviate suffering and facilitate a seamless return to normal function for the patient. Despite compelling evidence of its drawbacks, opioid analgesia remains the basis of POP treatment. Novel therapeutic approaches rely on multimodal analgesia, integrating different pharmacological strategies to optimize efficacy while minimizing adverse effects. The recognition of the imperative role of the endocannabinoid system in pain regulation has prompted the investigation of cannabinoid compounds as a new therapeutic avenue. Cannabinoids may serve as adjuvants, enhancing the analgesic effects of other drugs and potentially replacing or at least reducing the dependence on other long-term analgesics in pain management. This narrative review succinctly summarizes pertinent information on the molecular mechanisms, clinical therapeutic benefits, and considerations associated with the plausible use of various cannabinoid compounds in treating POP. According to the available evidence, cannabinoid compounds modulate specific molecular mechanisms intimately involved in POP. However, only two of the eleven clinical trials that evaluated the efficacy of different cannabinoid interventions showed positive results.

Cannabis smoking and abdominal wall reconstruction outcomes: a propensity score-matched analysis

PURPOSE

Despite increasing use of cannabis, literature on perioperative effects is lagging. We compared active cannabis-smokers versus non-smokers and postoperative wound morbidity and reoperations following open abdominal wall reconstruction (AWR).

METHODS

Patients who underwent open, clean, AWR with transversus abdominis release and retromuscular synthetic mesh placement at our institution between January 2014 and May 2022 were identified using the Abdominal Core Health Quality Collaborative database. Active cannabis-smokers were 1:3 propensity matched to non-smokers based on demographics and comorbidities. Wound complications, 30 day morbidity, pain (PROMIS 3a-Pain Intensity), and hernia-specific quality of life (HerQles) were compared.

RESULTS

Seventy-two cannabis-smokers were matched to 216 non-smokers. SSO (18% vs 17% p = 0.86), SSI (11.1% vs 9.3%, p = 0.65), SSOPI (12% vs 12%, p = 0.92), and all postoperative complications (46% vs 43%, p = 0.63) were similar between cannabis-smokers and non-smokers. Reoperations were more common in the cannabis-smoker group (8.3% vs 2.8%, p = 0.041), driven by major wound complications (6.9% vs 3.2%, p = 0.004). No mesh excisions occurred. HerQles scores were similar at baseline (22 [11, 41] vs 35 [14, 55], p = 0.06), and were worse for cannabis-smokers compared to non-smokers at 30 days (30 [12, 50] vs 38 [20, 67], p = 0.032), but not significantly different at 1 year postoperatively (72 [53, 90] vs 78 [57, 92], p = 0.39). Pain scores were worse for cannabis-smokers compared to non-smokers at 30 days postoperatively (52 [46, 58] vs 49 [44, 54], p = 0.01), but there were no differences at 6 months or 1 year postoperatively (p > 0.05 for all).

CONCLUSION

Cannabis smokers will likely experience similar complication rates after clean, open AWR, but should be counseled that despite similar wound complication rates, the severity of their wound complications may be greater than non-smokers.

Cannabis use in liver transplant candidates and recipients

The increasing legality and acceptance of cannabis sale and consumption across the United States has led to a measurable increase in cannabis use nationwide, including in liver transplant (LT) candidates and recipients. With over 75% of liver transplant recipients transplanted in states with legalized use of medicinal and/or recreational cannabis, liver transplant clinicians must have expertise in the assessment of cannabis use given its potential impact on clinical care. In this review, the authors provide an understanding of nomenclature and tools to assess cannabis use, highlight essential components to guide clinical policy development and implementation, and discuss the potential impacts of cannabis use on patients' transplant course.

Marijuana Use, Vaping, and Preoperative Anesthetic and Surgical Considerations in Clinical Practice

In recent years, marijuana and vaping have acquired widespread popularity, with millions of people using them for a variety of reasons, including recreational purposes. However, these practices have often overlooked the implications on surgery and the preoperative anesthesia considerations. Marijuana can influence a patient's response to anesthesia, alter postoperative pain management, and increase the risk of complications, whereas vaping can have negative effects on the respiratory system and hinder the body's ability to recover after surgery.

The Association of Cannabis Use After Discharge From Surgery With Opioid Consumption and Patient-reported Outcomes

OBJECTIVE

To compare outcomes of patients using versus not using cannabis as a treatment for pain after discharge from surgery.

BACKGROUND

Cannabis is increasingly available and is often taken by patients to relieve pain. However, it is unclear whether cannabis use for pain after surgery impacts opioid consumption and postoperative outcomes.

METHODS

Using Michigan Surgical Quality Collaborative registry data at 69 hospitals, we analyzed a cohort of patients undergoing 16 procedure types between January 1, 2021, and October 31, 2021. The key exposure was cannabis use for pain after surgery. Outcomes included postdischarge opioid consumption (primary) and patient-reported outcomes of pain, satisfaction, quality of life, and regret to undergo surgery (secondary).

RESULTS

Of 11,314 included patients (58% females, mean age: 55.1 years), 581 (5.1%) reported using cannabis to treat pain after surgery. In adjusted models, patients who used cannabis consumed an additional 1.0 (95% CI: 0.4-1.5) opioid pills after surgery. Patients who used cannabis were more likely to report moderate-to-severe surgical site pain at 1 week (adjusted odds ratio: 1.7, 95% CIL 1.4-2.1) and 1 month (adjusted odds ratio: 2.1, 95% CI: 1.7-2.7) after surgery. Patients who used cannabis were less likely to endorse high satisfaction (72.1% vs 82.6%), best quality of life (46.7% vs 63.0%), and no regret (87.6% vs 92.7%) (all P < 0.001).

CONCLUSIONS

Patient-reported cannabis use, to treat postoperative pain, was associated with increased opioid consumption after discharge from surgery that was of clinically insignificant amounts, but worse pain and other postoperative patient-reported outcomes.

Short-Term Pain Outcomes and Pain Medication Utilization Among Urine Toxicology-Identified Opioid and Marijuana Users After Elective Spine Surgery

BACKGROUND AND OBJECTIVES

Postoperative pain outcomes may be influenced by preoperative substance use, which is often underreported due to associated stigma. This study examined the impact of urine toxicology-identified preoperative opioid and marijuana use on pain outcomes after elective spinal surgery.

METHODS

Patients undergoing elective spinal surgery between September 2020 and May 2022 were recruited for this prospective cohort study. Detailed chart review was completed to collect demographic, urine toxicology, Visual Analog Scale (VAS), and pain medication data. Comparisons between self-reported and urine toxicology-identified substance use, preoperative/postoperative VAS ratings, and postoperative pain medication use were made using χ 2 tests, Student t -tests, and logistic regression, respectively. Models were adjusted for age, sex, and race.

RESULTS

Among 111 participants (mean age 58 years, 59% female, 95% with ≥1 comorbidity), urine toxicology overestimated drug use (47% vs 16%, P < .001) and underestimated alcohol use (16% vs 56%, P < .001) at preoperative baseline relative to patient reports. Two weeks postoperatively, participants with preoperative opioid metabolites reported no significant improvements in pain from baseline (6.67 preoperative vs 5.92 postoperative, P = .288) unlike nonusers (6.56 preoperative vs 4.61 postoperative, P < .001). They also had worse postoperative VAS (5.92 vs 4.61, P = .030) and heavier reliance on opioid medications (odds ratio = 3.09, 95% CI = 1.21-7.89, P = .019). Conversely, participants with preoperative marijuana reported similar improvements in pain from baseline (users: 6.88 preoperative vs 4.36 postoperative, P = .001; nonusers: 6.49 preoperative vs 5.07 postoperative, P = .001), similar postoperative pain (4.36 vs 5.07, P = .238), and similar postoperative reliance on opioid medications (odds ratio = 0.96, 95% CI = 0.38-2.44, P = .928). Trends were maintained among the 83 patients who returned for the 3-month follow-up.

CONCLUSION

Although urine toxicology-identified preoperative opioid use was associated with poor postoperative pain relief and reliance on postoperative opioids for pain management after elective spinal surgery, preoperative marijuana use was not. Preoperative marijuana use, hence, should not delay or be a contraindication to elective spinal surgery.

Cannabis Use Following Total Joint Arthroplasty is Associated With Increased Risks? A Meta-Analysis

BACKGROUND

With the increased legalization of cannabis, a new unknown emerges for orthopaedic surgeons and their patients. This systematic review aimed to (1) evaluate complications of cannabis use; (2) determine the effects of cannabis on pain and opioid consumption; and (3) evaluate healthcare utilizations associated with cannabis use among patients undergoing total joint arthroplasty (TJA).

METHODS

A systematic review was performed. A search of the literature was performed in 5 databases. We included studies between January 2012 and July 2022 reporting cannabis use and complications, pain management, opioid consumption, length of stay, costs, or functional outcomes following TJA. A meta-analysis of odds ratios (ORs) and continuous variables was performed. A total of 19 articles were included in our final analysis.

RESULTS

Cannabis use was associated with higher odds for deep vein thrombosis (DVT) (OR: 1.46, 95% Confidence Interval [CI]: 1.13 to 1.89) and revisions (OR: 1.47 [95% CI: 1.41 to 1.53]) in total knee arthroplasty (TKA). Cannabis use was associated with similar odds for DVT in total hip arthroplasty (THA) (OR: 1.30 [95% CI: 0.79 to 2.13]), pulmonary embolus in both TKA (OR: 1.29 [95% CI: 0.95 to 1.77]), THA (OR: 0.55 [95% CI: 0.09 to 3.28]), and cardiovascular complications in TKA (OR: 1.97 [95% Cl: 0.93 to 4.14]). Cannabis use did not alter pain scores, opioid consumption, or cost of care in THA (estimate: $2,550.51 [95% CI: $356.58 to $5,457.62]) but was associated with higher costs in TKA (estimate: $3,552.46 [95% CI: $1,729.71 to $5,375.22]). There was no difference in lengths of stay or functional outcomes; however, there may be a potentially increased risk for prosthetic complications, pneumonia, and cerebrovascular accidents among cannabis users.

CONCLUSION

Cannabis use may be associated with an increased risk of DVTs, revisions, pneumonia, cerebrovascular accidents, and cardiac complications after TJA. Higher-level studies are needed to ascertain the impact of cannabis use for patients undergoing TJA.

Cannabis Use Is Associated With Increased Use of Prescription Opioids Following Posterior Lumbar Spinal Fusion Surgery

STUDY DESIGN

Retrospective review.

OBJECTIVES

Cannabis is an antinociceptive which has been evaluated as a possible adjunct or substitute for opioid use in the treatment of acute pain. The aim of this study was to evaluate the association between preoperative cannabis usage and consumption of opioids for postoperative analgesia.

METHODS

Patients who underwent one- or two-level posterior lumbar fusion surgery were categorized as cannabis users or non-cannabis users based on preoperative diagnoses of cannabis use. Total morphine equivalent dose was calculated for both in-house opioid consumption and postoperative prescription opioid usage. Age, ASA, BMI, depression, tobacco use, estimated blood loss, OR time, LOS, disposition to rehab, 30-day readmission, in-house opioid consumption and postoperative prescription opioid usage were compared between groups using t-tests.

RESULTS

Of the 220 opioid naïve patients, 29 (13%) patients were identified as cannabis users while 191 (87%) were non-cannabis users. There were no significant associations between opioid naïve cannabis usage and ASA, BMI, tobacco use, EBL, OR time, LOS, disposition to rehab, or readmission. Opioid naïve cannabis users had greater association with depression (31.3% vs 13.7%, P=.017) and younger age (56.37 years vs 65.37 years, P<.001). Interestingly, cannabis use was associated with a lower Charlson Comorbidity Index (CCI), with 1.38 vs 2.49 (P=.002). Cannabis users were found to have increased postoperative prescription opioid usage (2545.41 POST-MED vs 1379.72 POST-MED, P=.019).

CONCLUSIONS

Cannabis usage is associated with increased usage of opioids postoperatively, both while in-patient and post-discharge, after posterior lumbar spinal fusion surgery.

Cannabis and Cannabinoids in the Perioperative Period

Cannabis use is increasingly common, and with a growing number of jurisdictions implementing legalization frameworks, it is likely that providers will encounter more patients who use cannabis. Therefore, it is important for providers to understand the implications of cannabis use and practical considerations for the perioperative period. Cannabis affects multiple organ systems and may influence intraoperative anesthesia, as well as postoperative pain management. The effects of cannabis and key anesthetic considerations are reviewed here.

Cannabis use in the intensive care setting: A scoping review

PURPOSE

Cannabis is the most used recreational drug worldwide, and is increasingly used for medicinal purposes, however little is known about its impact on patients in intensive care units (ICU). Our objective was to identify key themes in the literature surrounding cannabis in the ICU and identify future research priorities.

METHODS

Four databases were systematically searched for literature investigating the impact of cannabis, and evidence for its therapeutic use, in adult ICU patients.

RESULTS

Of 2589 articles screened, 22 articles were included for analysis. Cannabis-associated admissions were primarily related to an outbreak of vaping associated lung injury, and synthetic cannabinoid toxicity. Studies on the impact of cannabis use on outcomes were mostly limited to trauma and burns populations, with an inconsistent mortality benefit, and a trend towards increased pain scores and analgesic requirements found. There is minimal research on its therapeutic uses in ICU, with two trials investigating the use of a synthetic cannabinoid in patients with severe traumatic brain injury, with ultimately no significant effect on intracranial pressure found.

CONCLUSIONS

There is a paucity of studies investigating the impact of cannabinoids or their therapeutic uses in critically ill patients, with further research in this area needed.

Daily cannabis use may cause cannabis-induced hyperalgesia

BACKGROUND AND OBJECTIVES

Public opinion about cannabis as a medical treatment is generally favorable. As many as 35% of primary care patients report medical use of cannabis, most commonly for pain treatment. We designed a way to test whether cannabis helps chronic pain.

METHODS

A retrospective cohort study was conducted to explore whether daily long-term cannabis use was associated with increased pain sensitivity using the cold pressor test (CPT) to measure pain tolerance. Patients who used cannabis every day were compared to patients who inhaled tobacco and control patients who never used tobacco or cannabis. The effect of cannabis use on CPT was assessed using a generalized linear model.

RESULTS

Patients using cannabis daily had a median CPT of 46 s, similar to those who did not use cannabis but who inhaled tobacco (median CPT 45 s). Patients who used both cannabis and tobacco had the lowest CPT (median 26 s). The control group had a median CPT of 105 s. Cannabis use was associated with a significantly decreased pain tolerance (χ²(1)  = 8.0, p = .004). The effect of tobacco on CPT was only marginally significant (χ²(1)  = 3.8, p = .052).

CONCLUSION AND SCIENTIFIC SIGNIFICANCE

This suggests a phenomenon similar to opioid-induced hyperalgesia; a drug that reduces pain short term, induces pain long term-opponent process. Daily cannabis use may make chronic pain worse over time by reducing pain tolerance. In terms of risk/benefit, daily cannabis users risk addiction without any long-term benefit for chronic pain.

Unlocking the Healing Potential: Cannabinoids in Spine Surgery for Pain Relief and Recovery

» Cannabinoids, such as D9-tetrahydrocannabinol and cannabidiol, interact with endocannabinoid receptors in the central nervous system and immune system, potentially offering pain relief. The entourage effect, resulting from the interaction of multiple cannabis components, may enhance therapeutic impact and efficacy, making them promising candidates for exploring pain relief in spine operations, known to be among the most painful operative procedures.» The use of cannabinoids in pain management requires careful consideration of safety, including their cognitive and psychomotor effects, potential cardiovascular risks, risk of dependence, mental health implications, and drug interactions.» Few studies have analyzed cannabinoid use in relation to spine surgery, with variable results reported, indicating possible effects on reoperation rates, mortality, complications, postoperative opioid use, and length of hospital stay.» Current knowledge gaps exist in the understanding of cannabinoid effects on spine surgery, including the exploration of different administration routes, timing, dosage, and specific outcomes. In addition, mechanistic explanations for the observed results are lacking.» Ethical considerations related to informed consent, medical expertise, societal impact, and legal compliance must also be thoroughly addressed when considering the utilization of cannabinoids in spinal pathologies and back pain treatment.

Analysis of postoperative complications related to cannabis and tobacco usage in patients undergoing mandible facial fracture surgeries

BACKGROUND

Cannabis is the third most used controlled substance in the world. Despite its widespread use, minimal research investigates cannabis usage in patients undergoing facial fracture surgeries. This study aimed to evaluate patterns of postoperative complications related to cannabis and tobacco usage after mandible fracture surgeries.

MATERIALS AND METHODS

PearlDiver™, a commercially available healthcare database, was used to identify patients endorsing the use of cannabis, tobacco, or both who underwent mandible fracture surgeries for cross-sectional analysis. The study population was categorized into groups using the Classification of Diseases, 9th revision (ICD-9), ICD-10, and Current Procedural Terminology (CPT) codes. A chi-square analysis was performed to assess the influence of cannabis and tobacco use on postoperative complications.

RESULTS

A total of 8288 patients met the inclusion criteria, with 72 patients with cannabis-only usage, 914 patients with cannabis and tobacco usage, 3236 patients with tobacco-only usage, and 4066 in the control group. For patients using only cannabis, there was not an increased risk of developing postoperative complications compared with the control population. Patients with concurrent cannabis and tobacco usage and those with tobacco-only usage had an increased risk of surgical site infection, facial nonunion, facial abscess, debridement, and malocclusion after surgical repair of mandibular facial fracture.

CONCLUSION

Patients with tobacco-only as well as cannabis and tobacco usage had an increased risk of all postoperative complications, except malocclusion, compared with cannabis-only. Based on the results of this study, it is recommended that healthcare providers consider a patient's history of tobacco use when planning and performing surgical treatment for traumatic mandible fractures.

Cannabis and Pain Control After Total Hip and Knee Arthroplasty

Cannabis use among the elderly has increased over the previous 2 decades. This has translated to a greater proportion of orthopedic procedures being undertaken on these patients. This review provides clinicians with evidence-based information on the effects of cannabis on pain control in THA and TKA, to help counsel these patients and facilitate their perioperative management. The review specifically focuses on the following: origins of cannabis; biochemistry of cannabis; medical versus recreational cannabis; pharmacology of cannabis; effects of cannabis on bone metabolism; preoperative pain control; preoperative systemic considerations; intraoperative considerations; postoperative pain control, postoperative systemic considerations; and scope for future work.

[Does medicinal cannabis or cannabis consumption have an influence on the perioperative anesthesiological management?]

The greatly increasing use of medicinal cannabis products as well as the upcoming legalization of cannabis not only require a general re-evaluation of how these substances might be classified as illegal drugs, but also enforce a critical view on the possible consequences that cannabis consumption might have on the anesthesiological strategies applied for surgical procedures. Although high-quality clinical studies are still lacking, several clinical studies meanwhile indicate that an active preoperative cannabis consumption seems to be associated with relevant pathophysiological aspects. Patients who regularly consume high doses of cannabis show an increased risk of cardiovascular and respiratory complications as well as the postoperative nausea and vomitting (PONV) associated with anesthesia. This also applies to relatively young patients. Moreover, the requirements for general anesthetics and analgesics seem to be increased in the context of cannabis consumption, e.g., these patients may require additional efforts when it comes to monitoring the depth of anesthesia and providing a personalized multimodal postoperative pain therapy. It therefore appears to be meaningful to carefully assess and document the extent and duration of the preoperative cannabis consumption during the preoperative assessment. Furthermore, the possibility to perform a preoperative dose reduction of cannabis products in cases with high doses should at least be considered. As the consumption of cannabis is not only increasing in Germany but also worldwide, important future insights will offer a guide towards a safe handling of cannabis in perioperative medicine in the coming years.

Developing and validating a natural language processing algorithm to extract preoperative cannabis use status documentation from unstructured narrative clinical notes

OBJECTIVE

This study aimed to develop a natural language processing algorithm (NLP) using machine learning (ML) techniques to identify and classify documentation of preoperative cannabis use status.

MATERIALS AND METHODS

We developed and applied a keyword search strategy to identify documentation of preoperative cannabis use status in clinical documentation within 60 days of surgery. We manually reviewed matching notes to classify each documentation into 8 different categories based on context, time, and certainty of cannabis use documentation. We applied 2 conventional ML and 3 deep learning models against manual annotation. We externally validated our model using the MIMIC-III dataset.

RESULTS

The tested classifiers achieved classification results close to human performance with up to 93% and 94% precision and 95% recall of preoperative cannabis use status documentation. External validation showed consistent results with up to 94% precision and recall.

DISCUSSION

Our NLP model successfully replicated human annotation of preoperative cannabis use documentation, providing a baseline framework for identifying and classifying documentation of cannabis use. We add to NLP methods applied in healthcare for clinical concept extraction and classification, mainly concerning social determinants of health and substance use. Our systematically developed lexicon provides a comprehensive knowledge-based resource covering a wide range of cannabis-related concepts for future NLP applications.

CONCLUSION

We demonstrated that documentation of preoperative cannabis use status could be accurately identified using an NLP algorithm. This approach can be employed to identify comparison groups based on cannabis exposure for growing research efforts aiming to guide cannabis-related clinical practices and policies.

Cannabis use is associated with decreased opioid prescription fulfillment following single level anterior cervical discectomy and fusion (ACDF)

Background

Recently, there has been increasing legalization of marijuana within the United States, however data are mixed with respect to its efficacy in treating acute pain. Our goal was to identify a difference in opioid utilization in patients with known cannabis use before anterior cervical discectomy and fusion (ACDF) compared with those that report no cannabis use.

Methods

This study was a retrospective case-control design using PearlDiver. Patients who underwent a single level ACDF between January 2010 and October 2020, were included. Patients were placed in the study group if they had a previous diagnosis of cannabis use, dependence, or abuse. Patients were excluded if they were under the age of 18 or if they had filled an opioid prescription within 3 months of their procedure. A control group was then created using a propensity score match on age, gender, and Charleston comorbidity index (CCI), and had no diagnosis of cannabis use. The primary outcome was the number of morphine milliequivalents (MME) dispensed per prescription following surgery.

Results

A total of 1,339 patients were included in each group. The number of patients filling prescriptions was lower in the cannabis group than in the control group at 3 days postoperatively (p<.001). The average total MME per day as prescribed was lower in the cannabis group than the control group at 60 days post-op (48.5 vs. 59.4, respectively; p=.018).

Conclusions

Patients who had a previous diagnosis of cannabis use, dependence or abuse filled fewer opioid prescriptions postoperatively (at 3 days postoperatively) and required lower doses (reduced average daily MME, at 60 days postoperatively) when compared with the control group.

Heterosynaptic long-term potentiation of non-nociceptive synapses requires endocannabinoids, NMDARs, CamKII, and PKCζ

Noxious stimuli or injury can trigger long-lasting sensitization to non-nociceptive stimuli (referred to as allodynia in mammals). Long-term potentiation (LTP) of nociceptive synapses has been shown to contribute to nociceptive sensitization (hyperalgesia) and there is even evidence of heterosynaptic spread of LTP contributing to this type of sensitization. This study will focus on how activation of nociceptors elicits heterosynaptic LTP (hetLTP) in non-nociceptive synapses. Previous studies in the medicinal leech (Hirudo verbana) have demonstrated that high-frequency stimulation (HFS) of nociceptors produces both homosynaptic LTP as well as hetLTP in non-nociceptive afferent synapses. This hetLTP involves endocannabinoid-mediated disinhibition of non-nociceptive synapses at the presynaptic level, but it is not clear if there are additional processes contributing to this synaptic potentiation. In this study, we found evidence for the involvement of postsynaptic level change and observed that postsynaptic N-methyl-d-aspartate (NMDA) receptors (NMDARs) were required for this potentiation. Next, Hirudo orthologs for known LTP signaling proteins, CamKII and PKCζ, were identified based on sequences from humans, mice, and the marine mollusk Aplysia. In electrophysiological experiments, inhibitors of CamKII (AIP) and PKCζ (ZIP) were found to interfere with hetLTP. Interestingly, CamKII was found to be necessary for both induction and maintenance of hetLTP, whereas PKCζ was only necessary for maintenance. These findings show that activation of nociceptors can elicit a potentiation of non-nociceptive synapses through a process that involves both endocannabinoid-mediated disinhibition and NMDAR-initiated signaling pathways.NEW & NOTEWORTHY Pain-related sensitization involves increases in signaling by non-nociceptive sensory neurons. This can allow non-nociceptive afferents to have access to nociceptive circuitry. In this study, we examine a form of synaptic potentiation in which nociceptor activity elicits increases in non-nociceptive synapses. This process involves endocannabinoids, "gating" the activation of NMDA receptors, which in turn activate CamKII and PKCζ. This study provides an important link in how nociceptive stimuli can enhance non-nociceptive signaling related to pain.

Cannabinoids as a Potential Alternative to Opioids in the Management of Various Pain Subtypes: Benefits, Limitations, and Risks

INTRODUCTION

Pain is a global phenomenon encompassing many subtypes that include neuropathic, musculoskeletal, acute postoperative, cancer, and geriatric pain. Traditionally, opioids have been a mainstay pharmacological agent for managing many types of pain. However, opioids have been a subject of controversy with increased addiction, fatality rates, and cost burden on the US healthcare system. Cannabinoids have emerged as a potentially favorable alternative or adjunctive treatment for various types of acute and chronic pain. This narrative review seeks to describe the efficacy, risks, and benefits of cannabinoids as an adjunct or even potential replacement for opioids in the treatment of various subtypes of pain.

METHODS

In June of 2022, we performed a comprehensive search across multiple databases for English-language studies related to the use of cannabinoids in the treatment of various types pain: neuropathic pain, musculoskeletal pain, acute postoperative pain, cancer pain, and geriatric pain. Data from meta-analyses, systematic reviews, and randomized control trials (RCTs) were prioritized for reporting. We sought to focus our reported analysis on more recent literature as well as include older relevant studies with particularly notable findings.

RESULTS

There is conflicting evidence for the use of cannabinoids in the management of pain. While cannabinoids have shown efficacy in treating specific chronic pain subtypes such as neuropathic pain, fibromyalgia pain, and geriatric pain, they do not show as clear benefit in acute postoperative and the majority of musculoskeletal pain syndromes. Data trends towards cannabinoids having a positive effect in treating cancer pain, but results are not as conclusive. To date, there is a paucity of data comparing cannabinoids directly to opioids for pain relief. Overall, the side effects of cannabinoids appear to be relatively mild. However, there is still potential for addiction, altered brain development, psychiatric comorbidities, and drug-drug interactions.

CONCLUSION

Cannabinoids may be effective in specific subtypes of pain, but current evidence and guidelines do not yet support its use as the first-line treatment for any type of acute or chronic pain. Rather, it may be considered a good adjunct or alternative for patients who have failed more typical or conservative measures. Additional studies are needed with standardized forms of cannabinoids, route of delivery, and dosing for greater-powered analysis. Providers must weigh the individualized patient risks, benefits, and concurrent medication list in order to determine whether cannabinoids are appropriate for a patient's pain treatment plan.

Alternative pain management via endocannabinoids in the time of the opioid epidemic: Peripheral neuromodulation and pharmacological interventions

The use of opioids in pain management is hampered by the emergence of analgesic tolerance, which leads to increased dosing and side effects, both of which have contributed to the opioid epidemic. One promising potential approach to limit opioid analgesic tolerance is activating the endocannabinoid system in the CNS, via activation of CB1 receptors in the descending pain inhibitory pathway. In this review, we first discuss preclinical and clinical evidence revealing the potential of pharmacological activation of CB1 receptors in modulating opioid tolerance, including activation by phytocannabinoids, synthetic CB1 receptor agonists, endocannabinoid degradation enzyme inhibitors, and recently discovered positive allosteric modulators of CB1 receptors. On the other hand, as non-pharmacological pain relief is advocated by the US-NIH to combat the opioid epidemic, we also discuss contributions of peripheral neuromodulation, involving the electrostimulation of peripheral nerves, in addressing chronic pain and opioid tolerance. The involvement of supraspinal endocannabinoid systems in peripheral neuromodulation-induced analgesia is also discussed. LINKED ARTICLES: This article is part of a themed issue on Advances in Opioid Pharmacology at the Time of the Opioid Epidemic. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v180.7/issuetoc.

ASRA Pain Medicine consensus guidelines on the management of the perioperative patient on cannabis and cannabinoids

BACKGROUND

The past two decades have seen an increase in cannabis use due to both regulatory changes and an interest in potential therapeutic effects of the substance, yet many aspects of the substance and their health implications remain controversial or unclear.

METHODS

In November 2020, the American Society of Regional Anesthesia and Pain Medicine charged the Cannabis Working Group to develop guidelines for the perioperative use of cannabis. The Perioperative Use of Cannabis and Cannabinoids Guidelines Committee was charged with drafting responses to the nine key questions using a modified Delphi method with the overall goal of producing a document focused on the safe management of surgical patients using cannabinoids. A consensus recommendation required ≥75% agreement.

RESULTS

Nine questions were selected, with 100% consensus achieved on third-round voting. Topics addressed included perioperative screening, postponement of elective surgery, concomitant use of opioid and cannabis perioperatively, implications for parturients, adjustment in anesthetic and analgesics intraoperatively, postoperative monitoring, cannabis use disorder, and postoperative concerns. Surgical patients using cannabinoids are at potential increased risk for negative perioperative outcomes.

CONCLUSIONS

Specific clinical recommendations for perioperative management of cannabis and cannabinoids were successfully created.

Cannabis use disorder is associated with shorter length of stay and increased home discharge after primary total joint arthroplasty: a propensity-weighted analysis

INTRODUCTION

Increased legalization of cannabis use across the United States has been correlated with increased cannabis use in the clinical setting. However, little is known regarding the characteristics and postoperative outcomes after primary joint arthroplasty (TJA) for patients with cannabis use disorder (CUD).

METHODS

This retrospective cohort study used data from the National Inpatient Sample of patients undergoing primary TJA between 2006 to 2015. Patients were grouped based on presence of concomitant CUD. Patient demographic characteristics and outcome data between groups were analyzed. Propensity score methodology was used to compare immediate in-hospital complications and economic outcomes.

RESULTS

A total of 8,740,798 TJAs were included. The prevalence of CUD increased nearly five-fold from 0.05% to 0.26% during this time (P < 0.0001). CUD patients were significantly younger, more likely to be male, most frequently of non-Hispanic Black race, and had higher rates of Medicaid insurance. Patients with CUD had a significantly shorter length of hospital stay (3.04 vs. 3.24 days, P = 0.0297), while incurring significantly higher daily ($22,614 vs. $17,955, P < 0.0001) and total charges during admission ($58,507 vs. $50,924, P < 0.0001), compared to patients without CUD. When compared with the control group, CUD was associated with significantly greater odds of home discharge (odds ratio (OR): 1.45, P = 0.0007), and significantly lower odds of rehab discharge (OR: 0.70, P = 0.0013). There were no differences in overall complication profile or in the vast majority of individual in-hospital complications between groups.

CONCLUSION

While CUD is correlated to shorter length of stay and increased home discharge after TJA, it does not show a strong effect on complications in an inpatient postoperative setting. It is important for clinicians to appreciate the demographic profile and expected clinical and economic outcomes for patients with CUD undergoing TJA, particularly in the context of evolving laws surrounding cannabis use.

Real-world data and evidence in pain research: a qualitative systematic review of methods in current practice

The use of routinely collected health data (real-world data, RWD) to generate real-world evidence (RWE) for research purposes is a growing field. Computerized search methods, large electronic databases, and the development of novel statistical methods allow for valid analysis of data outside its primary clinical purpose. Here, we systematically reviewed the methodology used for RWE studies in pain research. We searched 3 databases (PubMed, EMBASE, and Web of Science) for studies using retrospective data sources comparing multiple groups or treatments. The protocol was registered under the DOI:10.17605/OSF.IO/KGVRM. A total of 65 studies were included. Of those, only 4 compared pharmacological interventions, whereas 49 investigated differences in surgical procedures, with the remaining studying alternative or psychological interventions or epidemiological factors. Most 39 studies reported significant results in their primary comparison, and an additional 12 reported comparable effectiveness. Fifty-eight studies used propensity scores to account for group differences, 38 of them using 1:1 case:control matching. Only 17 of 65 studies provided sensitivity analyses to show robustness of their findings, and only 4 studies provided links to publicly accessible protocols. RWE is a relevant construct that can provide evidence complementary to randomized controlled trials (RCTs), especially in scenarios where RCTs are difficult to conduct. The high proportion of studies reporting significant differences between groups or comparable effectiveness could imply a relevant degree of publication bias. RWD provides a potentially important resource to expand high-quality evidence beyond clinical trials, but rigorous quality standards need to be set to maximize the validity of RWE studies.

Preoperative Cannabis Use Associated With an Increased Rate of Reoperation and Postoperative Opioid Use Following Anterior Cervical Decompression and Fusion

Objectives The objective of this retrospective cohort study was to evaluate the associations among preoperative cannabis use, postoperative opioid use, and postoperative outcomes following elective anterior cervical decompression and fusion (ACDF). Methods Patients who underwent one- or two-level ACDF were characterized preoperatively as active cannabis users, former users, or nonusers. Patients were also classified based on history of preoperative opioid use as chronic users, acute users, or nonusers. Groups were compared based on outcomes including the rate of emergency department visits six months postoperatively, rate of readmissions one year postoperatively, rate of reoperation two years postoperatively, and daily postoperative opioid use measured in milligram morphine equivalents (MMEs) at 0-6 months and 6-12 months postoperatively.  Results Of the 198 patients included in this study, 13 (6.6%) were active cannabis users, 11 (5.6%) were former users, and 174 (87.8%) were nonusers. The rate of reoperation within two years was 23.1% for active cannabis users, 0% for former users, and 4.0% for nonusers (p=0.0075). The average daily opioid use in MMEs 6-12 months postoperatively was 49.4 for active cannabis users, 4.1 for former users, and 13.3 for nonusers (p=0.0014). For chronic opioid users, acute users, and nonusers, the average daily opioid use in MMEs 6-12 months postoperatively was 39.9, 18.4, and 5.7, respectively (p<.0001). Conclusions History of cannabis use is associated with increased postoperative opioid use and increased rate of reoperation following elective ACDF.

Self-Reported Cannabis Use Is Associated With a Lower Rate of Persistent Opioid Use After Total Joint Arthroplasty

Background

Legalization of cannabis, along with concern over prescription opiate use, has garnered interest in cannabis for adjuvant pain control. This study examines the relationship between cannabis and opioid consumption after total hip (THA) or knee (TKA) arthroplasty.

Methods

Patients undergoing primary THA or TKA with minimum 6-month follow-up who self-reported cannabis use were retrospectively reviewed. A total of 210 patients (128 TKAs and 82 THAs) were matched by age; gender; type of arthroplasty; Charlson Comorbidity Index; and use of nicotine, antidepressants, or benzodiazepines to patients who did not self-report cannabis use. Patients receiving an opioid prescription after 90 days postoperatively were classified as persistent opioid users (POUs). Duration of opioid use (DOU) was calculated for non-POU patients as the time between surgery and their last opioid prescription. Differences in inpatient morphine milligram equivalents (MMEs), outpatient MMEs, POU, and DOU were analyzed.

Results

Cannabis users required equivalent inpatient and outpatient MMEs. There was no difference in DOU. There was a significant difference in POU between cannabis users and matched controls (1.4% [n = 3] vs 9.5% [n = 20], P < .001, respectively). Grouping patients by TKA or THA, there remained a difference in POU for TKA (1.5% [n = 2] vs 10.9% [n = 14], P = .002) and THA (1.2% [n = 1] vs 7.3% [n = 6], P = .04). There was no difference in inpatient or outpatient MMEs or DOU for THA and TKA patients.

Conclusions

There is a reduced rate of POU in patients who self-report perioperative cannabis use. Prospective studies are needed to clarify the role of cannabis as an adjunct to perioperative pain control.

Preoperative cannabis use does not increase opioid utilization following primary total hip arthroplasty in a propensity matched analysis

PURPOSE

The recreational and medical use of cannabis is being legalized worldwide. Its use has been linked to an increased risk of developing opioid use disorders. As opioids continue to be prescribed after total hip arthroplasty (THA), the influence that preoperative cannabis use may have on postoperative opioid consumption remains unknown. The purpose of this study was to assess the relationship between preoperative cannabis use and opioid utilization following primary THA.

METHODS

We identified all patients over the age of 18 who underwent unilateral, primary THA for a diagnosis of osteoarthritis at a single institution from February 2019 to April 2021. Our cohort was grouped into current cannabis users (within 6 months of surgery) and those who reported never using cannabis. One hundred and fifty-six current users were propensity score matched 1:6 with 936 never users based on age, sex, BMI, history of chronic pain, smoking status, history of anxiety/depression, ASA classification and type of anesthesia. Outcomes included inpatient and postdischarge opioid use in morphine milligram equivalents.

RESULTS

Total inpatient opioid utilization, opioids refilled, and total opioids used within 90 postoperative days were similar between the groups.

CONCLUSION

In propensity score matched analyses, preoperative cannabis use was not independently associated with an increase in inpatient or outpatient, 90-days opioid consumption following elective THA.

Modification of Behavioral Habits in Prehabilitation Programs

OBJECTIVES

To review the evidence supporting the modification of behavioral habits and substance use management during cancer treatment and how to implement them as part of a multimodal optimization intervention.

DATA SOURCES

A literature review of the association between cancer and behavioral habits, their impact on oncological treatment outcomes, and substance use management guidelines.

CONCLUSION

There is an association between harmful habits, such as smoking and alcohol consumption, and cancer. The continuation of poor behavioral habits throughout oncological treatments is associated with poor oncological outcomes and increased complications. Prehabilitation could be an ideal setting to screen, assess, and modify these harmful habits. Prehabilitation programs should be equipped with professionals and resources to help patients achieve harmful habit cessation.

IMPLICATIONS FOR NURSING PRACTICE

This review puts into manifest the importance of a multidisciplinary approach to substance use management. It can serve as a framework to develop a harmful habit cessation intervention in the context of multimodal prehabilitation to improve surgical and oncological outcomes in the cancer population.

Cannabis, cannabinoids, and cannabis-based medicines: future research directions for analgesia

The use of cannabis spans thousands of years and encompasses almost all dimensions of the human experience, including consumption for recreational, religious, social, and medicinal purposes. Its use in the management of pain has been anecdotally described for millennia. However, an evidence base has only developed over the last 100 years, with an explosion in research occurring in the last 20-30 years, as more states in the USA as well as countries worldwide have legalized and encouraged its use in pain management. Pain remains one of the most common reasons for individuals deciding to use cannabis medicinally. However, cannabis remains illegal at the federal level in the USA and in most countries of the world, making it difficult to advance quality research on its efficacy for pain treatment. Nonetheless, new products derived both from the cannabis plant and the chemistry laboratory are being developed for use as analgesics. This review examines the current landscape of cannabinoids research and future research directions in the management of pain.

Prevalence of Cannabinoid (CBD) Use in Orthopaedic Sports Medicine Patients

Background:

Although there is some evidence that cannabinoid (CBD) products may provide a therapeutic effect for musculoskeletal pain, little is known about the usage patterns or their prevalence of use in orthopaedic sports medicine patients.

Purpose:

To report the prevalence and perceived self-efficacy of CBD products in patients evaluated in an orthopaedic sports medicine clinic.

Study Design:

Descriptive epidemiology study. Level of evidence, 2.

Methods:

The study population consisted of new patients who visited an orthopaedic surgery sports medicine clinic at a large academic center for consultation with a surgeon between August 2020 and March 2021. All patients were asked to complete a survey that assessed perceived pain and effectiveness of CBD products and other nonsurgical treatment modalities using the Single Assessment Numeric Evaluation score (range, 0-100) and the Numeric Pain Rating Scale (NRS). Descriptive factors were collected via chart review. Descriptive statistics were used to characterize the data.

Results:

Overall, 823 patients completed the survey (45.4% female; mean age, 51 years [range, 18-87 years]; mean body mass index, 28.9 [range, 17.2-58.4]). Body areas involved included 285 shoulders, 44 elbows, 76 hips, 276 knees, 58 ankles, and 77 other. Of these patients, 19% (152/823) endorsed the use of CBD products before their initial evaluation. The mean NRS for pain was significantly different between non-CBD users and CBD users (5.6 vs 6.1; P = .029). CBD users were significantly more likely to have tried other nonoperative modalities compared with nonusers, including nonsteroidal anti-inflammatory drugs (79.6% vs 69.8%; P = .032), bracing (44.7% vs 34.6%; P = .024), steroid injections (38.8% vs 21.6%; P < .001), and physical therapy (54% vs 36.1%; P < .001). In addition, 30.9% of CBD utilizers reported marijuana use compared with 2.8% of non-CBD users ( P < .001) for management of their pain.

Conclusion:

In the current study, 19% of patients had used CBD products to manage joint-related issues. Sports medicine providers should be aware of this high incidence of usage and the potential interactions CBD products may have with other treatment modalities. Further studies are needed to assess the effectiveness of CBD as a therapeutic agent and the specific interactions it has with other drugs and other forms of treatment.

Cannabis Use Disorder in the Setting of Primary Total Hip Arthroplasty: Understanding the Epidemiology, Demographic Characteristics, and Inpatient Postoperative Outcomes

INTRODUCTION

Cannabis use is expected to increase in the context of its decriminalization and legalization in several states. The purpose of this study was to report on the epidemiologic and demographic characteristics and inpatient postoperative outcomes of patients with cannabis use disorder (CUD) undergoing primary total hip arthroplasty (THA).

METHODS

The National Inpatient Sample registry was used to identify patients undergoing THA between 2006 and 2015. Patients were stratified into groups with and without CUD. Epidemiology, comorbidity, and outcomes data were comparatively analyzed between these two groups.

RESULTS

A total of 2,838,742 THAs were performed during the study period. The prevalence of CUD significantly increased from 0.10% in 2006 to 0.39% in 2015 (P < 0.0001). Patients with CUD were significantly younger, more likely to be male, had higher rates of Medicaid insurance and were more likely to be non-Hispanic Black and less likely to be non-Hispanic White when compared with the control group. When comparing patients with and without CUD, there was no significant difference in the composite any complication variable and no significant difference in seven of eight individual in-hospital complications assessed, with the exception being higher genitourinary complications in the CUD group. There were no significant differences in discharge disposition or length of stay.

DISCUSSION

Although CUD is significantly associated with various demographic, comorbidity, and hospital characteristics, it is not significantly associated with in-hospital complications, discharge disposition, and length of stay outcomes in the immediate in-hospital, postoperative period. It is critical for clinicians and public health professionals to understand the characteristics and expected inpatient outcomes of this evolving population of patients with CUD undergoing THA, particularly in the context of widespread legalization.

LEVEL OF EVIDENCE

Level III.

Marijuana in Orthopaedics: Effects on Bone Health, Wound-Healing, Surgical Complications, and Pain Management

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Marijuana use is on the rise in the United States, and there is a paucity of information on the effects of cannabis and its chemical constituents on bone health, wound-healing, surgical complications, and pain management.

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Current evidence suggests that cannabidiol (CBD) may enhance bone health and metabolism, while Δ9-tetrahydrocannabinol (Δ9-THC), the major psychoactive component in marijuana, has an inhibitory effect.

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Marijuana users are at higher risk for delayed bone-healing, demonstrate lower bone mineral density, are at increased risk for fracture, and may experience postoperative complications such as increased opioid use and hyperemesis.

The Effectiveness of Cannabis and Cannabis Derivatives in Treating Lower Back Pain in the Aged Population: A Systematic Review

BACKGROUND/AIMS

Cannabis is increasingly used in the management of pain, though minimal research exists to support its use since approval. Reduction in stigma has led to a growing interest in pharmaceutical cannabinoids as a possible treatment for lower back pain (LBP). The objective of this review was to assess the role and efficacy of cannabis and its derivatives in the management of LBP and compile global data related to the role of cannabis in the management of LBP in an aging population.

METHODS

A systematic review was conducted using predetermined keywords by 3 independent researchers. Predetermined inclusion and exclusion criteria were applied, and 23 articles were selected for further analysis.

RESULTS

Studies identified both significant and insignificant impacts of cannabis on LBP. Contradicting evidence was noted on the role of cannabis in the management of anxiety and insomnia, 2 common comorbidities with LBP. The existing literature suggests that cannabis may be used in the management of LBP and comorbid symptoms.

CONCLUSIONS

Further research is needed to consider cannabis as an independent management option. There is a lack of evidence pertaining to the benefits of cannabis in an aged population, and thus, additional research is warranted to support its use in the aged population.

Minimizing opioid consumption by eliminating patient-controlled analgesia after penile inversion vaginoplasty with enhanced recovery after surgery (ERAS) protocol

BACKGROUND

Genital-based gender affirmation surgery is a physically demanding procedure requiring extensive postoperative pain management. However, perioperative opioid use for these procedures is relatively understudied.

OBJECTIVES

This study analyzes whether intravenous patient-controlled analgesia (PCA) enhances pain control after penile inversion vaginoplasty (PIV) in the setting of enhanced recovery after surgery (ERAS) protocols, and whether non-PCA (NCA)-based regimens could reduce postoperative opioid use.

METHODS

All patients undergoing PIV with ERAS protocols by a single provider from December 2018 to November 2020 were retrospectively reviewed. Patient demographics, comorbid conditions, pain scores, length of stay (LOS), and opioid usage during their hospitalization were collected. Postoperative opioid use and pain scores were compared between PCA and NCA patient cohorts.

RESULTS

A total of 61 patients were included. 30 patients received intravenous PCA postoperatively, and 31 patients used NCA-based narcotic pain control. All patients underwent ERAS protocol perioperatively. Average patient age was 34.5 years (SD 11.9) in the PCA cohort and 37.6 years (SD 11.9) in the NCA cohort (p = 0.242). Average total postoperative opioid use during hospital stay was reduced by 53.7% in the NCA cohort, with an average use of 501.6 morphine milligram equivalents (MME) (SD 410.3) among PCA patients and an average use of 232.0 MME (SD 216.5) among NCA patients (p = 0.003). Daily average pain scores for postoperative days 1 to 6 did not differ between the PCA and NCA patient groups (p > 0.05). Average hospital LOS was shorter among NCA patients, 6.2 days (SD 1.0) versus 7.3 days (SD 1.4), respectively, (p < 0.001).

DISCUSSION

In combination with an ERAS non-narcotic pain control protocol, it may be possible to reduce opioid use by more than 50% and shorten length of postoperative hospital stay among patients by implementing NCA pain management protocols.

CONCLUSION

Minimizing postoperative opioid consumption after PIV will benefit patients and their sustained well-being.

Preoperative Considerations for Teenagers Undergoing Orthopaedic Surgery: VTE Prevention, Mental Health Assessment, Vaping, and Drug Addiction

INTRODUCTION

Adolescents undergoing pediatric orthopaedic surgery typically experience an uncomplicated postoperative course. However, adolescence represents a unique transition period from pediatric to adult physiology. As a result, the astute pediatric orthopaedic surgeon will be aware of unique medical and social scenarios which are relevant to adolescents during the perioperative course including the risk of venous thromboembolism (VTE), prevalence of mental health conditions, and rising use of electronic cigarettes or "vaping" to consume nicotine and cannibas.

DISCUSSION

Adolescents are at a greater risk of VTE after pediatric orthopaedic surgery. In particular, adolescent females with a family history of blood clotting disorders and those with a change in mobility after surgery should be considered for prophylaxis. The prevalence of adolescent mental health conditions including anxiety, depression, and behavioral issues is increasing in the United States. Higher levels of preoperative anxiety and the presence of mental health pathology are associated with slower recovery, higher levels of postoperative pain, and the increased likelihood for chronic pain. Several quick screening instruments are available to assess adolescents for preoperative anxiety risk, including the Visual Analogue Scale for Anxiety or the Amsterdam Perioperative Anxiety Information Scale. Unfortunately, electronic cigarettes have become increasingly popular for the consumption of nicotine and cannabis among adolescents. Preoperative use of combustive cigarettes (nicotine/cannabis) represents perioperative risks for induction/anesthesia, postoperative pain, and analgesia requirements and issues with delayed wound and fracture healing.

CONCLUSIONS

VTE, underlying mental health conditions, and usage of nicotine and cannabis are clear detriments to the recovery and healing of adolescent patients following orthopaedic surgery. Therefore, standardized screening for adolescents before orthopaedic surgery is indicated to identify perioperative risk factors which have negative impacts on functional outcomes.