Zeroing a Transducer on an External Ventricular Drain.

Area of Science:

• Neurosurgery
• Critical Care Medicine
• Neuroscience

Background:

• External ventricular drains (EVDs) are vital for monitoring intracranial pressure in severe brain injury.
• Accurate intracranial pressure readings depend on proper transducer zeroing.
• Concerns exist regarding the accuracy of current EVD transducer zeroing techniques.

Purpose of the Study:

• To critically appraise whether zeroing an EVD transducer through its filter yields the same baseline as the open-to-air method.
• To evaluate the available evidence comparing closed (filter) and open (air) zeroing techniques for EVD transducers.

Main Methods:

• Conducted independent literature searches in CINAHL, PubMed, and Web of Science.
• Utilized keywords: "external ventricular drain* OR EVD AND transducer" and "zero AND transducer" AND "ventric."
• Appraised findings from observation studies and clinical practice guidelines.

Main Results:

• The literature search yielded one observation study and two clinical practice guidelines.
• The observation study provided no evidence supporting the equivalence of the two zeroing methods.
• Clinical practice guidelines and manufacturer instructions recommend the open-to-air method.

Conclusions:

• The current literature does not definitively answer whether filter zeroing is equivalent to open-air zeroing for EVD transducers.
• Evidence suggests the open-to-air method is preferable for ensuring accurate physiological values for treatment decisions.
• Further research is needed to establish the equivalence of different EVD transducer zeroing techniques.