Intensive care management of arterial carbon dioxide in acute intracerebral haemorrhage: Case report of influences on cerebral haemodynamics

Abstract

Intracerebral haemorrhage is relatively common and has devastating consequences. Furthermore, non-invasive and invasive strategies to manage raised intracranial pressure remain limited and associated with high morbidity and mortality. We report a case of a 72-year-old male with intracerebral haemorrhage with ventricular extension, hydrocephalus and intracranial hypertension, who was evaluated by transcranial Doppler ultrasound and optic nerve sheath diameter. This case demonstrates that beyond pharmacological and surgical interventions, simple manipulation of arterial carbon dioxide has the propensity to improve cerebral haemodynamic parameters. Our results demonstrate the negative effects of hypercapnia on cerebral autoregulation and the benefits of having transcranial Doppler ultrasound available in the intensive care unit point of care.

Keywords: Transcranial Doppler; cerebral autoregulation; optic nerve sheath diameter.

Figure 1.

Axial non-contrast computed tomography images demonstrating an acute haemorrhage in the temporal lobe which has spread to the lateral, third and fourth ventricles and associated right-to-left midline shift.

Figure 2.

Ultrasonographic image of abnormal optic nerve sheath diameter (ONSD) measurement. The probe was adjusted to give a suitable angle for displaying the entry of the optic nerve into the globe and measurement was performed at the depth of 3 mm behind the ocular globe (A). Right and left ONSD were measured in the transversal plane, with slight rotation of the probe to obtain optimal optic nerve visualization. Distance B (between the yellow crosses) is the ONSD (0.69 mm), suggestive of intracranial hypertension.

Figure 3.

Screen shot of transcranial Doppler showing the ultrasound spectrogram of cerebral blood flow velocity (CBFV) for the left (top left box) and right (top right box) MCAs, with the maximum velocity envelope represented by the white tracing. CBFV in the right MCA was reduced, compared to the left side due to the intracerebral hemorrhage in the right hemisphere. The bottom box allows comparison of the CBFV tracings (blue and red) with the ECG and the arterial blood pressure (BP) waveform (yellow tracing). Both BP and CBFV are needed to obtain estimates of the autoregulation index (ARI).

Figure 4.

Longitudinal changes in (a) end-tidal carbon dioxide (ETCO₂) and its effects on (b) cerebral blood flow velocity (CBFV) as a function of time; (c) normalized CBFV responses to a step change in blood pressure at admission to the ICU (continuous line) and at 24 hours (dashed line); and (d) normalized CBFV responses to a step change in blood pressure for assessments during manipulation of CO₂, low CO₂ (PaCO₂ < 30 mmHg, dashed line) and high CO_{2 (}PaCO₂ > 40 mmHg, continuous line).