Heroin Use Disorder

IV access first - Repeated injection leaves track marks along the superficial veins and makes conventional cannulation unreliable. Plan ultrasound-guided peripheral access from the start, with central access or a venous cutdown at the median basilic or long saphenous vein as the fallback. Establish it before induction, not after.

Inspect the injection sites - Cellulitis and abscess form where the needle went in. A tense, circumferential abscess can produce compartment syndrome. Needle fragments break off and stay embedded, or migrate proximally up the vein, so a plain film of the limb is worth having when the history suggests it.

Right-sided endocarditis - Left-sided infective endocarditis is far more common in general, but among people who inject drugs it is the tricuspid valve, and MRSA is the organism. Rates of tricuspid valve endocarditis have risen steeply since 2006.

What that buys preoperatively - Fever, a new murmur or an unexplained pulmonary infiltrate in someone who injects means blood cultures and an echocardiogram before an elective case. Right ventricular function and the degree of tricuspid regurgitation drive your volume and vasopressor plan. Septic emboli from a tricuspid vegetation land in the lung, so nodular infiltrates and cavitating lesions on the chest film are the disease, not a separate pneumonia.

Blood-borne infection - Shared needles transmit hepatitis B, hepatitis C and HIV. Get LFTs, coagulation studies and a platelet count before planning a neuraxial, and assume hepatic drug clearance may not be normal.

Noncardiogenic pulmonary edema - Severe, life-threatening pulmonary edema follows heroin overdose and comes from increased pulmonary vascular permeability rather than a failing ventricle. A hypoxic patient with a wet chest film after an overdose will not behave like cardiogenic edema; support oxygenation and ventilation rather than chasing it with diuresis.

Stated street dose is meaningless - Potency and concentration vary batch to batch, so the number the patient gives you is not a number. Titrate intraoperative opioid to effect and to respiratory rate, and reassess in PACU rather than front-loading.

Contaminated with what - Adulterants are diverse, frequently unknown to the user, and produce a conflicting exam. Carfentanil and its relatives do not appear on a routine urine drug screen and need gas chromatography-mass spectrometry. If a usual naloxone dose is not reversing what looks like an opioid overdose, a synthetic contaminant is the reason.

Naloxone, correctly - Airway control and rescue breathing come first; the toxicity is hypoxia from hypoventilation. Start at 0.4 to 0.8 mg IV, which reverses pure heroin quickly, and expect to need considerably more with fentanyl analogues. In a dependent patient naloxone precipitates withdrawal, so titrate to adequate ventilation rather than to consciousness.

Tolerance is uneven - Tolerance to respiratory depression develops more slowly than tolerance to euphoric effect. A patient who tolerates a large recreational dose is not protected against apnea from your opioids. Monitor ventilation in PACU for longer than the drug's duration alone suggests.

Withdrawal in the perioperative window - Muscle and joint pain, dilated pupils, piloerection, sweating, vomiting, diarrhea, insomnia and yawning. It is dehydrating and it will wreck your postoperative analgesia plan. Patients often present already volume-depleted, so have adequate access for fluids and repeat medication. Do not interrupt maintenance methadone or buprenorphine - see Opioid Withdrawal Syndrome.

Buprenorphine changes your intraoperative math - It is a partial mu agonist and kappa antagonist with higher affinity for the mu receptor than heroin itself. A patient on maintenance buprenorphine will not respond to a full agonist the way an opioid-naive patient does, so plan regional and non-opioid analgesia deliberately rather than escalating fentanyl.

Heroin (diacetylmorphine) is a prodrug more potent than morphine, and the danger is kinetic. Injected, it reaches the brain in 15 to 20 seconds, and 68% of an intravenous dose contacts central receptors against under 5% for intravenous morphine. Blood half-life is roughly 3 minutes; the active metabolite 6-acetylmorphine lasts about 30 minutes.

The illicit supply has no quality control. Users cannot know how much active drug is in a given sample, so the same apparent dose that produced euphoria yesterday is an overdose today, and adulterants such as carfentanil are not detected on routine drug screens.

Perioperatively the problems are route problems rather than opioid problems: destroyed peripheral access, injection-site infection, right-sided endocarditis and blood-borne viral disease. For opioid tolerance, hyperalgesia and maintenance therapy see Opioid Use Disorder and Opioid Withdrawal Syndrome.