Substance Abuse – Cocaine

Anesthesia Implications

Anesthesia Implications

Cancel Case – Depending on your facility, a positive drug screen for cocaine is reason to cancel an elective surgery

Positive test interpretation – Because the primary marker for cocaine can remain in the urine for 14 days after consumption, a positive test should not imply that the patient is acutely intoxicated. It should also be noted that the positive marker is not predictive of an increased risk of acute intraoperative complications.

False Positives – Amoxicillin and tonic water can create false positives

Intraop medications – Treated with labetolol in acute situations. Benzodiazepines or Magnesium Sulfate may reduce the cardiovascular effects of cocaine. Phenylephrine may be more effective than ephedrine to correct hypotension. Benzodiazepines and opioids are encouraged as pretreatment to avoid the intense sympathetic response sometimes seen during intubation. Abusers of cocaine require more analgesia than do nonusers. Nitrates and hydralazine will cause further increases in HR. Calcium entry-blocking agents can potentiate the toxic effects of cocaine.

Reactive airway risk – when the patient is smoking cocaine

Labile blood pressures – Cocaine positive patients are more likely to need pharmacological support for both hypertensive and hypotensive events during surgery

Combined substance abuse – Very likely to be abusing other substances (60-90% of cocaine users do). Synergistic side effects of cocaine are present when cocaine abuse is coupled with alcohol abuse.

OB:
Neuraxial anesthesia – early neuraxial anesthesia should be encouraged to reduce levels of circulating catecholamines
Causes placental abnormalities – specifically an increased risk of placental abruption.
Crosses the placenta – Cocaine and its active metabolites readily cross the placenta
Reduced uterine blood flow – Cocaine reduces uterine blood flow and increases uterine tone.
Fetal growth abnormalities – Anticipate SGA and LBW infants
Preeclampsia – Cocaine abuse can cause hemodynamics to mimic preeclampsia

Substance abuse (general considerations) – If necessary, get your urine/blood screen early. The urine screen will take 30 minutes and a serum screen will be closer to an hour. Almost all drug screens will return results for marijuana, amphetamines/methamphetamines, phencyclidine (PCP), cocaine, opioids, barbiturates, and benzodiazepines. Generally speaking, if the patient is acutely intoxicated, the case should be cancelled/delayed. Refer to your facility to get policies on cancellations/delays.

Pathophysiology

Cocaine causes an increase in presynaptic release of catecholamines. Cocaine also blocks reuptake of norepinephrine, dopamine, and serotonin. Reduces production of nitric oxide. These affects significantly increase sympathetic tone.

Side effects of cocaine:
1. Increase in BP, HR, temperature, ALT/AST, blood glucose, and cortisol
2. Reduced platelets
3. Pulmonary hypertension (reduced nitric oxide production)

Acute intoxication can lead to:
1. rhabdomyolysis
2. cardiac arrest
3. ischemic or hemorrhagic stroke
4. dysrhythmias
5. Aortic dissection
6. Sudden death

Chronic use of cocaine – leads to reactive airway (if smoked), cardiomyopathy, brain atrophy, renal failure

Possible procoagulant – Cocaine can have a procoagulant effect in small and large vessels

Additional Notes:

Benzoylecgonine is an inactive metabolite and the primary marker in the urine for testing positive for abuse.  This marker will typically remain in the urine for 1-2 weeks after consumption.

Hepatic metabolism.  Active metabolites include norcocaine and cocaethylene.

Half-life of cocaine is 1-1.5 hours

Acute intoxication can cause increased levels of CK along with myoglobinemia as a result of rhabdomyolysis and renal failure.

OB

Commonly abused during pregnancy.
Causes a shift of blood flow from the fetus to the mother.
A primary cause for fetal demise.
Associated with abnormal neonatal behavior and an increased incidence of gastrointestinal and genitourinary defects.

References

Barash. Clinical anesthesia. 7th edition. 2013.
Nagelhout. Nurse anesthesia. 5th edition. 2014.
Chestnut. Chestnut’s obstetric anesthesia principles and practice. 5th edition. 2014.
Baxter. Utility of Cocaine Drug Screens to Predict Safe Delivery of General Anesthesia for Elective Surgical Patients. AANA Journal. 2012.
Moran. Perioperative management in the patient with substance abuse. 2015.. web link