37,000 patients a year receive an external ventricular drain (EVD) in the setting of acute hydrocephalus in the US, generating in-hospital charges of $151,672 per patient, or $5.6 billion dollars a year. There is great motivation in the neurointensive care unit for the optimization of EVD management to reduce infection rates, accurately determine need for permanent shunting, and to do so efficiently in order to minimize duration of drainage and length of stay (LOS). Risk factors for ventriculitis include EVD duration, cerebrospinal fluid (CSF) sampling frequency, presence of intraventricular hemorrhage (IVH), and insertion technique. Severe CSF disturbances in patients with IVH and EVDs limit the value of routine CSF analysis for ventriculitis prediction. And ventriculitis diagnosis is imprecise, with only a minority declaring culture positivity while all still demanding antibiotic treatment and delay of permanent shunt. This leads to unnecessary empiric antibiotic treatment and increased LOS (30.8 vs 22.6 days), with the associated cost ($30,335 more) and morbidity (e.g. Clostridium difficile infection, emergence of drug-resistant pathology). The process of determining permanent shunt dependence is variable between institutions, particularly around the decision of when to begin weaning the EVD or predicting delayed resolution. These decisions in the subacute period determine LOS and associated adverse events, exposure to radiography, and commitment to potentially unnecessary permanent foreign materials in the CNS, which then carry lifelong risks for infection and blockage. There is no accurate noninvasive test (that does not further introduce infection) to diagnose ventriculitis nor is there a timely method to predict need for permanent shunt after acute hydrocephalus. To fill this gap, we propose developing a quantitative model from intracranial pressure (ICP) waveform analysis to increase precision in the diagnosis of ventriculitis and accurately predict need for permanent shunt. In previous work, we were able to predict with good accuracy who would need permanent shunt placement using ICP waveform analysis collected during a 24 hour clamp trial. However, a complex model can only be justified if it achieves a diagnosis earlier or more accurately than traditional clinical methods. In preliminary work, we clustered raw ICP waveforms and found a pattern of waveforms specific for ventriculitis that appears 1 day before diagnostic cultures are sent. Our central hypothesis is that there is a temporal quantitative signal in ICP waveform reflective of intracranial dynamics that can be harvested to optimize acute hydrocephalus management. Impact and Significance: Noninvasive quantitative models based on ICP waveform analysis that diagnose ventriculitis and accurately predict need for permanent shunt would decrease the duration of EVD and the frequency of CSF sampling, two of the risk factors for ventriculitis, while also decreasing LOS, associated adverse events of ICU stay, and empiric antibiotics.
There is no accurate noninvasive test to diagnose ventriculitis nor is there a timely method to predict need for permanent shunt after acute hydrocephalus. To fill this gap, we propose developing a quantitative model from intracranial pressure waveform analysis to increase precision in the diagnosis of ventriculitis and accurately predict need for permanent shunt. Accurate noninvasive sequential machine learning models could decrease external ventricular drain duration and cerebrospinal fluid sampling frequency, two of the risk factors for ventriculitis, while also decreasing length of stay and empiric systemic antibiotics.
