The diagnosis of cannabis use disorder for patients undergoing spinal surgery is associated with higher complication rates, including substantially increased risks of stroke and respiratory complications, according to a recent study published in the Spine journal.
The new research, which was conducted by Ankit Indravadan Mehta and colleagues from the University of Illinois (Chicago, USA), was designed to analyse the association between cannabis abuse and serious adverse events following elective spine surgery.
Mehta said: “Chronic cannabis use among patients undergoing spine surgery is associated with higher rates of inpatient neurovascular, thromboembolic, and pulmonary complications, and less favourable overall discharge disposition.
“The treatment of these patients is also associated with increased length of stay and cost of hospitalisation.”
Using a national hospital database (Nationwide Inpatient Sample), the researchers identified nearly 433,000 patients who underwent common elective spinal surgery procedures between 2012 and 2015. About 2,400 patients had a diagnosis of cannabis use disorder, defined as continued use of cannabis despite significant distress or impairment.
On initial analysis, there were some differences between patients with and without cannabis use disorder. Patients diagnosed with problematic cannabis use were younger, more likely to be male, and had lower rates of accompanying medical disorders (comorbidity).
Using propensity score matching, Mehta and colleagues created matched groups of 2,184 chronic cannabis users versus non-users with similar characteristics and comorbidities. A wide range of complications and other hospital outcomes of spinal surgery were compared between groups.
The study found that patients with cannabis use disorder were at increased risk for several types of complications after spinal surgery. The cannabis users were about twice as likely to develop respiratory and blood clot-related (thromboembolism) complications. They also had nearly a threefold increase in the risk of stroke and other neurologic complications. Risk of bloodstream infection (septicemia or sepsis) was increased by 50%.
There were also more myocardial infarctions among patients with cannabis use disorder. However, on further analysis, this was related to their much higher rate (71%) of tobacco use.
Patients with cannabis use disorder also spent nearly two more days in the hospital (about seven vs. five days) and had hospital costs nearly $15,000 higher. They were also more likely to be discharged to a nursing or rehabilitation facility and less likely to receive home health care.
The results come at a time when cannabis use becomes increasingly legalised and accepted in the US. Rates of cannabis use and cannabis use disorder have “increased drastically” in recent years, according to the authors.
The findings also have important implications for anaesthesia and surgical management in patients with cannabis use disorder, Mehta and colleagues believe. For example, such patients may need higher doses of opioid medications to achieve adequate pain management after spinal surgery. That may lead to slower recovery, requiring longer hospital stays and more intensive rehabilitation that cannot be done at home.
Mehta and his co-authors wrote: “This study reveals multiple aspects of perioperative care that are extremely complex and difficult in patients with cannabis use disorder.
“Their high-risk cardiorespiratory profiles combined with specialised anaesthetic considerations [before, during, and after surgery] necessitate very unique perioperative management. We hope this research will lead to future prospective trials for specific interventions that could improve outcomes in this specific population.”
