During laryngoscopy and endotracheal intubation or in response to painful surgical procedures, patients may experience severe hypertension and cardiac dysrhythmias. To prevent or treat these conditions, deepening anesthesia with intravenous or inhalation agents is advised. In cases of persistent hypertension, it may be necessary to administer vasodilators, such as hydralazine in 5 mg to 10 mg bolus doses or a continuous infusion of nitroglycerin, nicardipine, or clevidipine. However, the use of beta-blockers like metoprolol, propranolol, or esmolol is generally avoided due to the risk they pose in triggering unopposed alpha-adrenergic stimulation.
While enhancing anesthetic depth can help control hypertensive responses to surgical stress, it's important to note that the overall need for anesthesia can vary and may not necessarily increase. Additionally, the use of ketamine is discouraged because it could heighten the cardiovascular toxicity associated with cocaine or lead to myocardial depression, especially in patients who have suffered catecholamine depletion as a result of hemorrhagic shock.
Succinylcholine is also best avoided, particularly when early postoperative extubation is anticipated. Both succinylcholine and cocaine are metabolized by plasma cholinesterase, and administering succinylcholine can extend the duration of cocaine's effects and lead to prolonged neuromuscular blockade. Moreover, in the context of hyperthermia and rhabdomyolysis, succinylcholine could exacerbate hyperkalemia, thereby increasing the risk of life-threatening arrhythmias. As an alternative, rocuronium is recommended for achieving a more consistent neuromuscular blockade, offering a safer option in these clinical scenarios.
Cocaine intoxication can induce hyperthermia through mechanisms such as increased metabolic rate, psychomotor agitation, and peripheral vasoconstriction, which impedes the body's natural temperature regulation.
The management of a hyperthermic patient who is acutely intoxicated with cocaine during surgery poses unique challenges, making forced air cooling, ice packs, cooled intravenous fluids, and gastric lavage possible interventions.
Cocaine alters pain perception, leading to potentially lower pain thresholds. This may create challenges in analgesia administration, both intra-operatively and post-operatively.
Minimum alveolar concentration (MAC) is increased for volatile anesthetics, thus increasing the degree of myocardial depression and side effects associated with the volatile agents.
Chronic cocaine use also causes delayed gastric emptying. As a result, aspiration prevention is a crucial consideration preoperatively.
Chronic cocaine use is also associated with an increased incidence of dilated cardiomyopathy, both reversible and permanent. Due to cocaine’s effect on potassium and sodium blockade, the QRS and QTc may also be prolonged, contributing to ventricular dysrhythmias such as ventricular tachycardia, frequent premature ventricular contraction, or Torsade’s de Pointes.
| Agent or step | Role |
|---|---|
| Deepening anesthesia | First response to severe hypertension and cardiac dysrhythmias, using intravenous or inhalation agents |
| Hydralazine | 5 mg to 10 mg bolus doses for persistent hypertension |
| Nitroglycerin, nicardipine, clevidipine | Continuous infusion options for persistent hypertension |
| Beta-blockers (metoprolol, propranolol, esmolol) | Generally avoided — risk of triggering unopposed alpha-adrenergic stimulation |
| Ketamine | Discouraged — may heighten cocaine's cardiovascular toxicity or cause myocardial depression, especially with catecholamine depletion from hemorrhagic shock |
| Succinylcholine | Best avoided, particularly with early extubation planned — shares plasma cholinesterase metabolism with cocaine, prolonging both cocaine's effects and neuromuscular blockade, and can worsen hyperkalemia with hyperthermia and rhabdomyolysis |
| Rocuronium | Recommended alternative for more consistent neuromuscular blockade |
| Volatile anesthetics | Minimum alveolar concentration is increased, which increases myocardial depression and volatile-agent side effects — though overall anesthetic requirement can vary and may not necessarily increase |
