Propofol (Diprivan)

Expiration - Expires 6 hours after drawn into a syringe, and 12 hours after being used as an infusion all remaining drug and tubing should be discarded and replaced. Pain - pain on injection can range from moderate to intense. The smaller the vein the higher the risk/intensity of pain. Some mix lidocaine with propofol, which tends to decrease pain on injection. However, the propofol label recommends against this - lidocaine additive greater than 20 mg in 200 mg of propofol results in instability, increased globule sizes over time, and a reduced anesthetic potency. Therefore, it is recommended to either give lidocaine prior to propofol, or if mixed, the mixture should happen just prior to administration and should not exceed 20 mg per 200 mg of propofol. Cardiovascular Affects - All of the following are reduced: Contractility, preload, SVR, and MAP. Heart rate minimally affected. Respiratory Affects - Profound respiratory depression, decreased upper airway reflexes. Cerebral Affects - reduces the following: cerebral blood flow, CMRO2 (for this reason it is also considered a cerebral vasoconstrictor), IOP, and ICP. Some studies suggest that propofol might be protective against ischemic brain injury for BRIEF ischemic events. PONV - propofol, in small doses, is useful for PONV prophylaxis/treatment. Epilepsy - Propofol causes burst suppression on the EEG and has been used successfully in stopping status epilepticus. HOWEVER, propofol administration to epilepsy patients increases the risks of a seizure in the recovery phase. Pregnancy - Propofol crosses the placenta and may be associated with neonatal depression. Propofol also crosses into breast milk. Affects of oral ingestion of propofol is unknown. Soy and Egg Allergies - Patients with soy allergy or egg allergy CAN receive propofol without any special precautions. Use - lower induction doses and slower maintenance rates should be used in the elderly, debilitated, and/or ASA III or IV patients. If high ICP is suspected, hyperventilation and hypocarbia should accompany a slower propofol administration to avoid significant decreases in cerebral perfusion pressure. Pediatric patients can get severe bradycardia when propofol is administered concomitantly with fentanyl.

Adult Induction of anesthesia - Adults: 2.0-2.5 mg/kg. Geriatric patients may require a smaller dose (generally 1.0-1.5 mg/kg). Use LEAN body weight in the obese. Pediatric Induction of anesthesia: 2.5mg/kg - 3.5 mg/kg PONV Prophylaxis - 0.5-1.0 mg/kg 15 minutes before the end of surgery. As little as 30 mg has been reported to be as effective as 10 mg of metoclopromide. Anxiolysis - 0.4 mg/kg

Adult Maintenance Infusion: 25-200 mcg/kg/min (typically the maintenance dose is > 100 mcg/kg/min). Obese - use TOTAL body weight Pediatric Maintenance Infusion: 80-360 mcg/kg/min (typically the maintenance dose is > 140 mcg/kg/min). The younger the patient, the higher the MEDIAN maintenance dose. Antiemetic Infusion: 16.7 mcg/kg/min.

Positive modulation of the inhibitory function of the neurotransmitter GABA through the ligand-gated GABAA receptors. Binding of these receptors in the hippocampus and prefrontal cortex reduces acetylcholine release which appears to contribute to the sedative effects. Propofol also inhibits NMDA receptors which contributes to the central effects.

Rapidly metabolized in the liver. Byproducts are glucuronide and sulphate. Clearance is faster than hepatic blood flow, which suggests additional metabolism elsewhere (lungs)

Excreted through the kidneys. Elimination half-life is 4-7 hours.

Propofol is a water-soluble, lipophillic weak acid (pKa of 11) and contains soybean oil, glycerol, and egg lecithin. Disodium edetate is added to reduce bacterial and fungal growth.