Propofol adverse effects

Effects on respiration are similar to those of thiopental at usual anesthetic doses. However, propofol causes a marked decrease in systemic blood pressure during induction of anesthesia, primarily through decreased peripheral resistance. In addition, propofol has greater negative inotropic effects on the heart than etomidate and thiopental. Apnea and pain at the site of injection are common adverse effects of bolus administration. Muscle movements, hypotonus, and (rarely) tremors have also been reported following its use. Clinical infections due to bacterial contamination of the propofol emulsion have led to the addition of antimicrobial adjuvants (eg, ethylenediaminetetraacetic acid and metabisulfite). 

Subhypnotic doses of propofol (20 mg) given to 120 women receiving intrathecal morphine after cesarean section had no significant effect on pruritus (55). Higher success rates have been reported for propofol with non-obstetric patients, suggesting that labor-related factors may perpetuate this adverse effect. 

Intravenous nalbuphine 3 mg (n — 101) has been compared with intravenous propofol 20 mg (n = 90) in a double-blind, randomized study, to determine efficacy in the treatment of intrathecal morphine-induced pruritus after cesarean delivery 10 minutes after the drug was administered (6). Nalbuphine was significantly more effective, especially in cases of moderate but not severe pruritus. Adverse effects such as reduced analgesia and increased nausea, vomiting, sedation, and dizziness were not significantly different between the two groups. 

Propofol can cause severe pain on injection, especially when injected into a small vein (20) the incidence is 25-74% (21). Administration of the lipid solvent in which propofol dissolved has confirmed that the solvent is responsible for this adverse effect (22). 

This adverse effect has been reported many times with propofol in adults, but rarely in children. 

In an in vitro experiment using uterine muscle strips from 10 consenting parturients undergoing cesarean section, therapeutic concentrations of propofol had no effect on isometric tension developed during contraction of the muscle (68). However, higher than therapeutic concentrations did reduce the peak muscle tension that developed. These results confirm that propofol is free of this adverse effect, which is a known cause of postpartum bleeding after the use of volatile anesthetic drugs. 

In two randomized, double-blind, controlled comparisons of anesthetic techniques for extracorporeal shock wave lithotripsy remifentanil infusion had no advantage over the combination of fentanyl bolus plus propofol infusion, but caused more adverse effects (nausea and vomiting) (10). In another study remifentanil infusion provided comparable analgesia and caused less respiratory depression and fewer gastrointestinal symptoms than intravenous boluses of sufentanil (11). 

The respiratory depressant and gastrointestinal adverse effects of remifentanil have been observed in a randomized, single-blind study of 125 patients undergoing elective orthopedic and urological surgery under spinal or brachial plexus anesthesia (16). They were randomized to either remifentanil (a bolus of 0.5 micrograms/kg plus an infusion of 0.1 micrograms/kg/minute) or propofol... 

However, in one study 60 patients were given one of three treatments before induction of anaesthesia with propofol esmolol 1 mg/kg followed by an infusion of250 micrograms/kg per minute midazolam or placebo (sodium chloride 0.9%). No opioids were given. Esmolol and midazolam reduced the required induction doses of propofol by 25% and 45%, respectively. Esmolol reduced the mean heart rate by 7.6 bpm compared with placebo in the pre-induction period, and the only adverse effect noted was a transient episode of bradycardia (44 bpm) in one patient receiving esmolol. Esmolol reduces cardiac output by reduction of heart rate and stroke volume and this possibly reduces the required induction dose of propofol by changing its distribution."... 

Kosarek L, Hart SR, Schultz L, DiGiovanni N. Increase in venous complications associated with etomidate use during a propofol shortage an example of clinically important adverse effects related to dmg substitution. Ochsner J 2011 11(2) 143-6. 

Ketamine has been traditionally contraindicated in patients with increased ICP or reduced cerebral compliance because it increases CMR02, CBF and ICP. These deleterious effects can be antagonised by the concomitant administration of propofol, or thiopentone, and benzodiazepines. Furthermore, ketamine is an antagonist at the NMDA receptor. Nevertheless, ketamine can adversely affect neurological outcome in the presence of brain ischaemia. 

Propofol has a remarkably simple structure resembling that of phenol disinfectants. Because the substance is water-insoluble, an injectable emulsion is prepared by means of soy oil, phosphatide, and glycerol. The effect has a rapid onset and decays quickly, being experienced by the patient as fairly pleasant. The intensity of the effect can be well controlled during prolonged administration. Possible adverse reactions include hypotension and respiratory depression, and a potentially fatal syndrome of bronchospasm, hypotension, and erythema. 

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