Correlation of pulsatility index with intracranial pressure in traumatic brain injury

Abstract

AIm:In traumatic brain injury (TBI) patients, it is desired to monitor the intracranial pressure (ICP) to assess the cerebral haemodynamics and guide the therapy. The study was designed to see if the pulsatility index (PI) measured by transcranial Doppler ultrasonography (TCD) predicts information about ICP values. mAterIAl and methOds:In 52 TBI patients with Glasgow Coma Scale (GCS) score < 9, invasive intracranial monitoring and TCD ultrasonography for PI were performed through five days. ICP, cerebral perfusion pressure (CPP), PI values were recorded and calculated. The correlation and regression analysis between ICP, PI and CPP were investigated in the whole group and in patients with a Glasgow Outcome Score (GOS) of 3-5. results:The decline in ICP and PI values was significant through five days. The correlation between ICP and PI was strongly significant (p < 0.0001) on days 1, 3 and 5. In patients with a GOS of 3-5, correlation of ICP and PI was also observed. The only significant correlation observed between CPP and PI was on day 5. COnClusIOn:The strong correlation observed between ICP and PI through the management period of TBI patients can lead us to use TCD ultrasonography-derived PI as a guide if invasive monitoring is not available. BulGulAr: ICP ve PI değerlerindeki 5 gün boyunca olan azalma anlamlıdır. ICP ve PI arasındaki korelasyon 1, 3 ve 5. günlerde kuvvetli bir şekilde anlamlı bulunmuştur (p < 0,0001). Glasgow Outcome Skoru (GOS) 3-5 olan hastalarda da ICP ve PI değerlendirilmiştir. CPP ve PI arasındaki tek önemli korelasyon 5. günde tespit edilmiştir. sOnuÇ: ICP ve PI arasında bulunan güçlü korelasyon, tedavinin yönetilmesi için invaziv monitörizasyon yapmanın mümkün olmadığı hastalarda PI değerlerinin kullanılmasına yönlendirebilir.

Executive summary on the use of ultrasound in the critically ill: consensus report from the 3rd Course on Acute Care Ultrasound (CACU)

“…A PI > 1.4 correlates with an ICP > 15 mm Hg and a decreased CPP [10]. Although the formula 10.93 × PI) -1.28 has been suggested for ICP measurement, TCD remains more useful in the monitoring of ICP changes rather than providing an exact value [11,12]. Likewise, while TCD can screen for brain death, it is not definitive due to the inability to scan the posterior circulation.…”

Neurointensive Care Monitoring for Severe Traumatic Brain Injury

“…Similarly, assessing the intracranial vessels pulsation is made possible using transcranial doppler (TCD) and measuring the velocity of middle cerebral artery (MCA) and quoted as pulsatility (PI) or resistive index (RI). Researchers have found strong correlation between the RI or PI with raised ICP (Bellner et al, 2004;Gura et al, 2011;Voulgaris et al, 2005). Fig.…”

Posttraumatic vasospasm and intracranial hypertension after wartime traumatic brain injury

“…They concluded that the PI may provide guidance in those patients with suspected intracranial hypertension and that repeated measurements may be of use in the neurocritical care unit. There is significant evidence that independent of the type of intracranial pathology, a strong correlation between PI and ICP exists [12,[18][19][20]. A recent study indicated that TCD had 94% of sensitivity to identify high ICP/low CPP at admission and a negative predictive value of 95% to identify normal ICP at admission; the sensitivity to predict abnormal cerebral perfusion pressure was 80% [20].…”