Isoflurane renal effects are minimal, only 0.2% metabolites are excreted in the urine and fluoride excretion is minimal. In patients for renal transplantation where there is a risk of arrhythmias, due to alteration in plasma electrolyte concentration, release of renin and catecholamines; there is haemodynamic stability.
Skeletal muscle tone is reduced to a greater extent than with halothane. It is to be avoided in malignant hyperthermia susceptible individuals as there is a Ca-flux.
Also in Isoflurane renal effects , Hepatic function is not affected significantly because of better hepatic blood flow and minimal metabolism of drug compared to halothane.
Miller’s Anesthesia 7th Edition says the following about Isoflurane renal effects –
Higuchi and colleagues studied the effect of low-flow sevoflurane or isoflurane anesthesia (1 L/min) on 17 patients with stable moderate renal failure (serum creatinine >1.5 mg/dL). They found no difference in BUN or creatinine up to 14 days after exposure or in CCr at 7 days after exposure in either group for patient exposures less than 130 ppm-hours of compound A.
In a recent multicenter randomized controlled trial, Conzen and coworkers studied 116 patients with stable renal insufficiency (CCr >1.5 mg/dL) who were administered either low-flow (1 L/min) sevoflurane (n = 59) or isoflurane (n = 57) anesthesia.
Total exposure to sevoflurane was 201.3 ± 98 minutes, with an average total compound A exposure of 18.9 ± 7.6 ppm. Isoflurane exposure averaged 213.6 ± 83.4 minutes, and Baralyme was used as the carbon dioxide absorbent.
No significant changes above baseline values for serum creatinine, BUN, CCr, urine protein, or glucose were found at 24 or 72 hours after exposure to either anesthetic.