Priapism as a complication of long-term intravenous nutrition

Systematic review of clinical adverse events reported after acute intravenous lipid emulsion administration

BACKGROUND

Intravenous lipid emulsions (ILEs) were initially developed to provide parenteral nutrition. In recent years, ILE has emerged as a treatment for poisoning by local anesthetics and various other drugs. The dosing regimen for the clinical toxicology indications differs significantly from those used for parenteral nutrition. The evidence on the efficacy of ILE to reverse acute toxicity of diverse substances consists mainly of case reports and animal experiments. Adverse events to ILE are important to consider when clinicians need to make a risk/benefit analysis for this therapy.

METHODS

Multiple publication databases were searched to identify reports of adverse effects associated with acute ILE administration for either treatment of acute poisoning or parenteral nutrition. Articles were selected based on pre-defined criteria to reflect acute use of ILE. Experimental studies and reports of adverse effects as a complication of long-term therapy exceeding 14 days were excluded.

RESULTS

The search identified 789 full-text articles, of which 114 met the study criteria. 27 were animal studies, and 87 were human studies. The adverse effects associated with acute ILE administration included acute kidney injury, cardiac arrest, ventilation perfusion mismatch, acute lung injury, venous thromboembolism, hypersensitivity, fat embolism, fat overload syndrome, pancreatitis, extracorporeal circulation machine circuit obstruction, allergic reaction, and increased susceptibility to infection.

CONCLUSION

The emerging use of ILE administration in clinical toxicology warrants careful attention to its potential adverse effects. The dosing regimen and context of administration leading to the adverse events documented in this review are not generalizable to all clinical toxicology scenarios. Adverse effects seem to be proportional to the rate of infusion as well as total dose received. Further safety studies in humans and reporting of adverse events associated with ILE administration at the doses advocated in current clinical toxicology literature are needed.

Propofol-Induced Priapism, a Case Confirmed with Rechallenge

Objective:

To report a case of propofol-induced priapism.

Case Summary:

A 17-year-old male receiving propofol for induction of anesthesia during a cardiac ablation procedure developed priapism that required medical intervention and discontinuation of propofol. The priapism developed after a total propofol dose of 550 mg, lasted for 2 hours, and resolved immediately following medical intervention. The following day, the patient underwent a transesophageal echocardiogram and received a total propofol dose of 40 mg throughout the procedure. He again developed priapism, which resolved within one hour without medical intervention.

Discussion:

Priapism experienced by this patient is considered to be drug-induced because of the temporal relationship, recurrence with rechallenge, and dose–response relationship. Using the Naranjo probability scale, we determined that propofol was a highly probable causative agent of priapism in this patient.

Conclusions:

Although, as of April 4, 2006, this adverse effect has not been previously reported, there is a strong correlation of propofol to priapism in this patient. Clinicians should be aware of this adverse effect.

Priapism in a patient treated with total parenteral nutrition

Venous thrombosis is a common complication of total parenteral nutrition. We report a case of priapism in a 40-year-old man after administration of total parenteral nutrition for chronic idiopathic intestinal pseudo-obstruction. The patient received glucose, amino acids, and 20% fat emulsion; 12 hours after administration, the patient complained of a persistent, painful penile erection lasting 5 hours. Bilateral corpora cavernosa spongiosum shunts achieved immediate and sustained detumescence, but the patient remained impotent. There was no history of penile or pelvic trauma, hemoglobinopathy, coagulopathy, venous thrombosis, or leukemia. The medical literature describes seven other cases of priapism related to total parenteral nutrition. All of the patients received 20% fat emulsion; two patients developed priapism during the weekly infusion of fat emulsion. Among the multiple factors that can favor thrombosis and therefore priapism during total parenteral nutrition, fat infusion appears to be the most important. Three different mechanisms have been postulated: increase in blood coagulability, effects on red blood cells, and fat embolism. In this patient, platelet function was estimated in vivo by the levels of antiheparin platelet factor 4 and beta-thromboglobulin. These two parameters were both elevated before 20% lipid emulsion and were even higher after the 20% fat-emulsion infusion. Therefore, even if a direct thromboplastic effect is possible, 20% fat emulsion increases platelet activity, which was already high in our patient, and thereby favors priapism.

Priapism in patients treated with total parenteral nutrition

Three patients who developed priapism associated with total parenteral nutrition are reported. To reduce the risk of priapism in such patients it is suggested that fat emulsions stronger than 10% should not be administered.

Priapism associated with the use of intravenous fat emulsion: case reports and postulated pathogenesis

During the 8 years since inception of a home total parenteral nutrition program in 35 male patients 2 suffered priapism related temporally to the weekly intravenous infusion of 20 per cent fat emulsion. Fat emulsions have been shown to cause hypercoagulability, capillary thrombosis and fat embolus in in vivo and in vitro experiments. Autopsies of patients treated with intravenous fat emulsion have revealed capillary engorgement and fat embolus with associated organ infarction. We postulate that fat emulsions may cause priapism in these patients. Because of the more frequent occurrence of priapism in this small subset of patients we now recommend that 1) patients be informed of this potential complication before hyperalimentation is begun, 2) the less concentrated 10 per cent emulsion should be used twice weekly, rather than the 20 per cent emulsion weekly, and should be infused during at least 4 hours, and 3) the fat emulsion should be added to other components of the intravenous regimen, when possible, to dilute the fat and prolong its administration time.

Priapism — A complication of home parenteral nutrition?

A case of priapism in a patient receiving home parenteral nutrition is reported. To our knowledge this is the first such case to occur in a patient receiving home parenteral nutrition. The literature is reviewed and the possible aetiology discussed.