title: Intracranial Pressure Values Are Highly Variable After Cerebral Spinal Fluid Drainage.
abstract: Intracranial pressure (ICP) is often obtained via external ventricular drain (EVD) placement and is discussed as a key vital sign in neuroscience. Nurses are most often delegated the task of observing, adjudicating, and documenting ICP. Cerebrospinal fluid drainage requires that the transducer connected to the EVD is open to drain, prohibiting ICP monitoring. There are no recent data to support an evidence-based standard for the period an ICP waveform should be observed, after the EVD is clamped, to be able to adjudicate a value that represents the patient's status. Therefore, the purpose of this study is to determine the optimal period for which an EVD should be closed to obtain an accurate ICP value. In a sample of 30 subjects who received continuous ICP monitoring for 15 minutes, there was no universal pattern to ICP after clamping an EVD. The conditional probability of observing a patient's highest ICP, if ICP is observed for 5 minutes, is 0.0181. The conditional probability increased to 0.0402 if ICP is observed for 10 minutes. There were no instances of ICP elevation requiring intervention. The results suggest that at least 5 minutes of ICP monitoring is safe and is required to provide an ICP value that reflects true ICP.
authors.affiliation: Michael Rogers, BSN RN CCRN, is Bedside Nurse, Neurointensive Care Unit, Zale-Lipshy Hospital, University of Texas Southwestern Medical Center, Dallas, TX. Sonja E. Stutzman, PhD, is Clinical Research Manager, University of Texas Southwestern Medical Center, Dallas, TX. Folefac D. Atem, PhD MS, is Assistant Professor of Biostatistics, University of Texas Southwestern Medical Center, Dallas, TX. Samarpita Sengupta, PhD, is Scientific Research Writer, University of Texas Southwestern Medical Center, Dallas, TX. Babu Welch, MD FAANS, is Associate Professor of Neurosurgery and Radiology, University of Texas Southwestern Medical Center, Dallas, TX. Questions or comments about this article may be directed to DaiWai M. Olson, PhD RN CCRN FNCS, at Daiwai.Olson@utsouthwestern.edu. He is an Associate Professor, Departments of Neurology and Neurotherapeutics and of Neurosurgery, University of Texas Southwestern Medical Center, Dallas, TX. The study was funded by the Agnes Marshal Walker Foundation and the Integra Foundation.
authors.forename: Michael
authors.initials: M
authors.lastname: Rogers
authors.forename: Sonja E
authors.initials: SE
authors.lastname: Stutzman
authors.forename: Folefac D
authors.initials: FD
authors.lastname: Atem
authors.forename: Samarpita
authors.initials: S
authors.lastname: Sengupta
authors.forename: Babu
authors.initials: B
authors.lastname: Welch
authors.forename: DaiWai M
authors.initials: DM
authors.lastname: Olson
mesh_terms: D001930:Brain Injuries / Q000134:cerebrospinal fluid; D064648:Critical Care Nursing; D004322:Drainage / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D019586:Intracranial Hypertension / Q000134:cerebrospinal fluid; D007427:Intracranial Pressure / Q000502:physiology*; D008991:Monitoring, Physiologic / Q000295:instrumentation* / Q000379:methods; D017410:Practice Guidelines as Topic; D013997:Time Factors