As cannabis use becomes more widespread, many individuals facing surgery wonder about its safety. Understanding how cannabis interacts with the body and medical procedures is important for patient safety. Cannabis can influence multiple physiological systems, potentially affecting the surgical process and recovery.
How Cannabis Affects the Body Systems
Cannabis impacts several key body systems. The cardiovascular system may experience changes in heart rate, such as tachycardia, and fluctuations in blood pressure, potentially leading to either hypotension or hypertension. These changes can complicate maintaining stable vital signs during surgery. Cannabis use can also increase the risk of heart attacks or strokes.
The respiratory system is also affected, especially with inhaled cannabis. Chronic smoking can lead to airway irritation, inflammation, and compromised lung function, including wheezing, coughing, and chronic bronchitis. This can make intubation and ventilation more challenging during anesthesia. For instance, smoking cannabis can cause swelling of the uvula, potentially obstructing the airway and making breathing tube placement difficult.
Cannabis also influences the central nervous system, altering pain perception, inducing sedation, and affecting cognitive functions. These effects can modify how the body responds to the stress of surgery.
Impact on Anesthesia
Cannabis use can significantly alter anesthetic requirements during surgery. Patients who regularly use cannabis may need higher doses of general or local anesthetic agents to achieve adequate sedation and pain control. Chronic cannabis users might require up to three times the amount of anesthesia compared to non-users to remain unconscious.
Cannabis use can also influence sedation levels and the emergence from anesthesia. Chronic use may lead to increased sedation or a delayed awakening after the procedure. Acute cannabis intoxication, characterized by symptoms like anxiety or paranoia, could even lead to a more violent emergence from anesthesia.
Furthermore, cannabis can exacerbate cardiovascular instability during the anesthetic process. It may cause sudden drops in blood pressure or irregular heartbeats, complicating the anesthesiologist’s efforts to maintain stable hemodynamics. Acute cannabis consumption can increase heart rate and myocardial oxygen demand, posing risks for patients with pre-existing heart conditions.
Recovery After Surgery
Cannabis use can significantly influence post-operative pain management. Patients who use cannabis, especially chronically, may experience higher pain scores and require greater quantities of opioid pain medications after surgery compared to non-users. One study indicated cannabis users experienced 14% more pain during the first 24 hours post-surgery and consumed 7% more opioids. This suggests a potential increase in tolerance to opioids, making pain control more challenging.
While cannabis has anti-emetic properties, its use can paradoxically influence post-operative nausea and vomiting (PONV). Some studies suggest that chronic cannabis use is associated with a small increase in the risk of PONV.
Respiratory complications are another concern in the post-operative period, particularly for those who smoke cannabis. Pre-existing airway irritation from inhaled cannabis can increase the risk of lung issues like pneumonia or bronchitis after surgery. Additionally, some studies suggest cannabis use can delay wound healing, potentially leading to infections and prolonged recovery times.
Essential Pre-Surgery Advice
Open and honest disclosure of all cannabis use to the surgical team is important for patient safety. This includes details about frequency, method of use (smoking, edibles, vaping), and amount, as it allows healthcare providers to make informed decisions and adjust care plans. Medical staff focus on patient safety, not judgment, when gathering this information.
Healthcare providers recommend specific cessation periods for cannabis before surgery. While general advice may suggest stopping at least 72 hours prior to surgery, some guidelines advise stopping inhaled cannabis within 72 hours due to its effects on heart rate. For chronic users, a longer cessation period, possibly several weeks, might be recommended, especially for inhaled forms. This helps mitigate risks like withdrawal symptoms during recovery.
Patients should always follow the specific advice given by their healthcare providers, as individual circumstances and the type of surgery can vary. Discussions with the anesthesiologist, surgeon, and other care team members are crucial for personalized instructions and optimal safety.