External Ventricular Catheters: Is It Appropriate to Use an Open/Monitor Position to Adequately Trend Intracranial Pressure in a Neuroscience Critical Care Environment?

Abstract

Intracranial pressure (ICP) monitoring can be an important assessment tool in critically and acutely ill patients. An external ventricular drain offers a comprehensive way to monitor ICP and drain cerebrospinal fluid. The Monro-Kellie hypothesis, Pascal's principle, and fluid dynamics were used to formulate an assumption that an open/monitor position on the stopcock is an adequate trending measure for ICP monitoring while concurrently draining cerebrospinal fluid. Data were collected from 50 patients and totaled 1053 separate number sets. The open/monitor position was compared with the clamped position every hour. An order for "open to drain" was needed for appropriate measurement and nursing care. Results showed the absolute average differences between open/monitor and clamped positions at 1.6268 mm Hg. This finding suggests that it is appropriate to use an open/monitor position via an external ventricular drain for adequate trending of patients' ICP.

Nursing assistance in patient care with external ventricular drain: a scoping review

“…The nursing staff must monitor signs indicating infection, bleeding, document aspects of the drainage system, in addition to providing emotional support to patients' family (29) . Moreover, sometimes nurses perform CSF drainage as directed, to decrease CSF when elevated (30) .…”

Fluidic Considerations of Measuring Intracranial Pressure Using an Open External Ventricular Drain

“…One clinical study involving 50 patients being treated with EVD investigated the accuracy of pressure measurements made from the drainage line with concurrent flow and compared them to the standard of care: Traditional fluid-coupled measurements made by stopping flow [ 6 ]. These authors found that the error due to flow was on average 2.2 cmH 2 O (1.6 mmHg) and was less than 4 cmH 2 O (3 mmHg) 97% of the time, concluding that it was negligible.…”

“…1 1, 2 3, 4 5, 1, 6 1 Simultaneous drainage and ICP measurement has not been adopted clinically given concern for sources of error in these pressure measurements, however, the error has not been well-characterized. Proposed benefits of continuous monitoring include monitoring cerebrovascular autoregulation by pressure reactivity index without the need for an additional probe and rapid detection of CSF flow blockages and other emergencies that may place the patient at risk [6,7].…”

“…The typical method for making pressure measurements from an EVD is done by turning a stopcock at the T-connector to stop fluid flow and connect the catheter to an attached pressure transducer [ 5 ]. If drainage is needed, a healthcare worker manually closes the stopcock for each measurement and reopen it afterwards [ 6 ]. In many cases, this leads to a tradeoff between frequency of pressure measurements, drainage, and healthcare resources.…”

Perioperative Management of Adult Patients With External Ventricular and Lumbar Drains: Guidelines From the Society for Neuroscience in Anesthesiology and Critical Care

“…157,[165][166][167] This concern is relevant to transducers that are mounted externally and transducers placed within the tip of the drainage catheter. 166 Although a value for ICP can be trended while the device is simultaneously draining, 168 the EVD/LD should be closed for accurate measurement at least hourly. 166,168 In some situations such as an anesthetized patient with elevated ICP, it would be indicated to obtain accurate pressure measurements more frequently than hourly.…”