Noninvasive estimation of raised intracranial pressure using ocular ultrasonography in liver transplant recipients with acute liver failure -A report of two cases-

Abstract

Intracranial pressure (ICP) monitoring is an important issue for liver transplant recipients, since increased ICP is associated with advanced hepatic encephalopathy or graft reperfusion during liver transplantation. Invasive monitoring of ICP is known as a gold standard method, but it can provoke bleeding and infection; thus, its use is a controversial issue. Studies have shown that optic nerve sheath diameter > 5 mm by ocular ultrasonography is useful for evaluating ICP > 20 mmHg noninvasively in many clinical settings. In this case report, we present experiences of using ocular ultrasound as a diagnostic tool that could detect changes in ICP noninvasively during liver transplantation.

Keywords: Intracranial pressure; Liver transplantation; Ocular ultrasonography.

Fig. 1

Optic nerve sheath diameter (ONSD, dash line) measured at 3 mm behind the optic globe using ocular ultrasonography (A) and cerebral blood flow velocity measured at the left middle cerebral artery using transcranial Doppler (B) in a liver transplant patient with acute-on-chronic liver failure (case 1). Note that the ONSD (6.4 mm) is dilated, suggesting increased intracranial pressure (ICP). Also, note that the second systolic peak (Windkessel effect) is lost, the systolic peak is sharp and narrow, and the diastolic cerebral blood flow velocity is low, suggesting a high ICP.

Fig. 2

Changes in optic nerve sheath diameters (ONSD, dash line) (A) before induction of general anesthesia, (B) 5 min, and (C) 30 min after graft reperfusion in a liver transplant recipient with acute liver failure (A: 4.8 mm, B: 5.7 mm, C: 5.1 mm) (case 2). Note that the dilated ONSD > 5 mm after reperfusion decreases 30 min after reperfusion.