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Minimum alveolar concentration of sevoflurane in rabbits with liver fibrosis
1Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, 610041, China.
Background:
Sevoflurane is widely used in patients undergoing surgical procedures, which could affect both the liver function and hepatic blood flow. However, the effects of liver fibrosis on minimum alveolar concentration (MAC) of sevoflurane are still unclear. Therefore, we designed this study to determine the MAC of sevoflurane in rabbits with liver fibrosis.
Methods:
Thirty male New Zealand white rabbits weighing approximately 2.5 kg were divided randomly into 2 groups: fibrosis (n = 20) and normal control group (n = 10). The rabbits in the fibrosis group were treated with 50% carbon tetrachloride for 12 weeks to induce liver fibrosis. The serum concentration of total protein, albumin, globulin, total bile acids, alanine aminotransferase, aspartame aminotransferase, alkaline phosphatase, γ-glutamyl transpeptidase, total bilirubin, direct bilirubin, and indirect bilirubin were measured before anesthesia. The anesthesia for animals that survived in both groups was induced and maintained with sevoflurane. A standard tail-clamp technique was used to determine the MAC of sevoflurane in spontaneously breathing rabbits. After anesthesia, animals were killed for liver pathologic examination.
Results:
Twelve weeks after 50% carbon tetrachloride administration, 14 of 20 rabbits survived in the fibrosis group, and 9 of 10 survived in the control group. All surviving animals in the fibrosis group had developed moderate to severe liver fibrosis. Three rabbits that survived after the fibrosis challenge were excluded for other diseases or no response to pain stimulation. The levels of globulin, aspartame aminotransferase, and γ-glutamyl transpeptidase significantly increased in fibrosis animals compared with controls. However, the albumin and alkaline phosphatase levels were significantly lower in the fibrosis group than in the control group. Mean arterial blood pressure, heart rate, end-tidal CO(2), and temperature were stable in both groups during sevoflurane anesthesia. The MAC of sevoflurane was significantly less in the fibrosis group than in the control group (3.52% vs 4.10%, P = 0.018).
Conclusion:
The MAC of sevoflurane decreased significantly in rabbits with liver fibrosis.
Insights
Liver fibrosis significantly reduces the minimum alveolar concentration (MAC) of sevoflurane, an anesthetic. This finding is crucial for adjusting anesthetic dosages in patients with liver disease.
Area of Science:
- Anesthesiology
- Hepatology
- Pharmacology
Background:
- Sevoflurane is a common anesthetic agent used in surgical procedures.
- Liver function and blood flow can be impacted by anesthesia.
- The effect of liver fibrosis on sevoflurane's minimum alveolar concentration (MAC) is not well understood.
Purpose of the Study:
- To investigate the impact of liver fibrosis on the MAC of sevoflurane.
- To determine if liver fibrosis alters the anesthetic requirements for sevoflurane.
Main Methods:
- Liver fibrosis was induced in New Zealand white rabbits using carbon tetrachloride.
- The MAC of sevoflurane was determined using a tail-clamp technique in rabbits with and without induced liver fibrosis.
- Serum biochemistry and liver pathology were assessed.
Main Results:
- Rabbits with induced liver fibrosis showed significant alterations in liver enzymes and protein levels.
- Vital signs remained stable during sevoflurane anesthesia in both groups.
- The MAC of sevoflurane was significantly lower in rabbits with liver fibrosis (3.52%) compared to controls (4.10%).
Conclusions:
- Liver fibrosis leads to a significant decrease in the MAC of sevoflurane.
- Anesthetic management may need adjustment in patients with liver fibrosis.
