Hepatotoxicity and inhalation anesthetics: views in the era of isoflurane

Perioperative liver protection

PURPOSE OF REVIEW

This review presents important pathophysiological alterations associated with impaired liver function and discusses protective perioperative strategies and the various anaesthetic agents recommended.

RECENT FINDINGS

Perioperative liver impairment is a serious complication of anaesthesia and surgery. Unfortunately, clinicians are provided with only crude macrohaemodynamic monitoring devices to optimize their therapy. Technical improvements have revealed some complex mysteries of perioperative microcirculatory alterations and have disclosed a large heterogeneity between different vascular beds. The present review will critically discuss current clinical concepts of optimizing global haemodynamic variables and the often contrasting effects of vasoactive agents on the microcirculatory nutritional blood flow. Finally, promising protective experimental interventions of pharmacological or ischaemic preconditioning are presented and their often disillusioning transition into recent clinical trials is highlighted.

SUMMARY

Targeted perioperative liver protection still lacks adequate monitoring tools and is currently based on optimization of global haemodynamic variables. While there is currently no evidence suggesting a positive effect of ischaemic preconditioning, promising experimental results of pharmacological preconditioning and therapeutic hypothermia require further evaluation in larger randomized clinical trials.

Liver protection in the perioperative setting

With recent advances in surgical and anaesthetic management, clinical medicine has responded to societal expectations and the number of operations in patients with a high-risk of perioperative liver failure has increased over the last decades. This review will outline important pathophysiological alterations common in patients with pre-existing liver impairment and thus highlight the anaesthetic challenge to minimise perioperative liver insults. It will focus on the intraoperative balancing act to reduce blood loss while maintaining adequate liver perfusion, the various anaesthetic agents used and their specific effects on hepatic function, perfusion and toxicity. Furthermore, it will discuss advances in pharmacological and ischaemic preconditioning and summarise the results of recent clinical trials.

Acute cholestatic hepatitis after exposure to isoflurane

OBJECTIVE

To report a case of acute cholestatic hepatitis following exposure to the inhalational anesthetic isoflurane.

CASE SUMMARY

A 70-year-old healthy woman from Iraq developed acute cholestatic hepatitis 3 weeks following repair of the right rotator cuff under general anesthesia. There was no evidence for viral, autoimmune, or metabolic causes of hepatitis. No other medications were involved except for dipyrone for analgesia. The alanine aminotransferase was elevated to a peak concentration of 1533 U/L and the serum bilirubin reached a peak of 17.0 mg/dL. There was slow improvement over 4 months. Accidental reexposure by the patient to dipyrone was uneventful.

DISCUSSION

The clinical and histologic picture of this case resembles halothane hepatitis, which has a significant mortality rate.

CONCLUSIONS

Isoflurane, a common anesthetic agent, can cause severe cholestatic hepatitis.

Hepatotoxic effects in a child receiving valproate and carnitine

L-Carnitine supplementation has been recommended to prevent the fatal hepatotoxic effects associated with valproic acid. We report on a child with fatal valproate-related hepatotoxic effects despite this supplementation.

Postoperative elevation of serum transaminases following isoflurane anesthesia

Halogenated inhalational anesthetics have been implicated in hepatotoxicity. Halothane hepatitis results from the biotransformation of the drug to a metabolite that binds to liver proteins, which creates a hapten, which, in turn, causes an immunologic response in the liver. Case reports of hepatic injury resulting from isoflurane, which has a decreased biotransformation compared with that of halothane, have received much criticism. We describe a patient who had elevated liver enzymes and a positive trifluoroacetyl antibody titer following an anesthetic regimen that included isoflurane.