Symptoms of hypovolemic shock during the induction of general anaesthesia in a patient with large vascular malformation--an adverse effect of propofol and sevoflurane?

BACKGROUND

Venous malformations are the second most common congenital vessel anomaly. In our hospital, we conduct up to 30 sclerotherapies with 1-3% aethoxysclerol annually in children of all ages. The procedure is invasive and painful and therefore requires general anaesthesia.

CASE REPORT: A 16-year-old girl underwent sclerotherapy of a vast vascular malformation of her left leg, pelvis, abdominal cavity and thorax. After induction of general anaesthesia and positioning for the procedure, she presented with hypotonic shock with sinus tachycardia and sudden decrease in her ETCO₂. Her skin became pale and cold. The venous malformation became distended. The incident was caused by redistribution of the blood to the malformation, which is believed to have been triggered by the volatile anaesthetic. After discontinuation of the sevoflurane, modification of anaesthesia and the administration of ephedrine and fluids, hypotonia was successfully treated. The patient's state was stabilised, her clinical measurements returned to normal, and the procedure was continued. Her later course was uneventful. Blood gas analysis in post-anaesthesia care unit revealed mild, compensated metabolic acidosis. No electrolyte abnormalities were present.

CONCLUSION

Volatile anaesthetics and propofol decrease the systemic vascular resistance and cause vasodilatation. Our patient presented with hypotonic shock due to the redistribution of blood to the dilated venous malformation, which developed after the use of standard concentration of sevoflurane. Intravenous anaesthetics were administered during induction and might have increased that effect. Although we found no similar reports, we believe that patients with vast venous malformations can experience such complications after the use of volatile anaesthetics, especially in high concentrations.