Hemedex: Features and Benefits of using the Bowman Perfusion Monitor in Neurocritical Care and Neurosurgery


Q: How does continuous monitoring of Cerebral Blood Flow at the bedside help to improve outcomes for your Neurocritical Care patients and reduce cost to your institution?  


A: Real-time monitoring provides the earliest possible detection of critical flow thus enabling the earliest possible intervention and opportunity to reduce the severity and extent of damage. Early, successful intervention improves patient outcomes and reduces costs associated with complications.


Compromised blood flow is a critical condition leading to organ dysfunction, infarction and often death. In the absence of continuous monitoring, critically low flow can occur unknowingly and cause injury prior to manifesting clinical signs. Frequently this injury is irreversible when it occurs in comatose, sedated or anesthetized patients who, being unconscious, do not complain of symptoms of ischemia (e.g.,  pain) and do not exhibit clinical signs (e.g.,  changes in cognitive function, speech, or movement) that clinicians would otherwise be able to detect in an awake patient.


Continuous perfusion monitoring in absolute physiological units enhances clinical management by providing real-time assessments of blood flow to detect critically low flow, and to assess patient responses to treatment interventions.   The Bowman Perfusion Monitor (BPM) is the only technology that continuously measures blood flow (tissue perfusion) in absolute physiologic units at the bedside (Hemedex, Inc., Cambridge, MA). 


Q: How does continuous monitoring of CBF with the BPM improve Clinical Insight, Work Flow, and Patient Care?


A: By providing information about critical parameters and allowing insight into administered therapies, all in real-time at the bedside.


By quantifying flow in absolute physiological units, the BPM accurately measures CBF for comparison with known thresholds for detecting critically low flow (i.e., Vasospasm: 15ml/100gm-min, Ischemia: 10ml/100gm-min)[i] or hyperemia . By monitoring flow in real-time at the bedside, the BPM provides continual vigilance so clinicians can Know the Flow ™ and have assurance when flow is adequate or have actionable information for treatment decisions if the flow is critical.


Q: How does continuous monitoring of CBF with the BPM provide an opportunity for better outcomes?


A: By providing the clinician with real-time information and alerting the clinician to changes in physiology sooner rather than later when damage associated with such changes may be irreversible.


Early detection of compromised blood flow enables early intervention and the opportunity to improve patient outcomes. Real-time assessment of the effectiveness of therapeutic interventions enhances clinical decision making. [ii]


Example applications include:


  • early detection of vasospasm in SAH patients[iii];
  • monitoring for changes in CBF with changes in ICP or brain swelling in TBI patients;
  • minimize re-bleeds by avoiding unnecessary therapeutic hypertension in SAH and TBI patients
  • measure the impact of arterial clamping on flow during aneurysm or bypass surgery[iv] ;
  • predict the maximal safe duration of Temporary Arterial Occlusion (TAO)[v]


Q: How could continuous monitoring of CBF with the BPM reduce health care costs at your institution?


  1. Reduce the use of an expensive alternative technology:  BPM monitoring is less expensive, more accurate, and easier to use than intermittent velocity assessments made by technicians using Transcranial Dopper (TCD) to detect vasospasm in SAH patients[vi]
  2. Improve selective use of more expensive assessments: Continuous bedside monitoring of CBF indicates when brain scans may be needed thus reducing the number of (cost of) unnecessary scans and improving the clinical utility of selected scans
  3. Reduce expenses associated with false detection of vasospam: Qualifying an elevated TCD in SAH patients by a quantitative CBF measurement reduces the risk and cost associated with mistakenly treating hyperemic patients with angiography (~$10K) and angioplasty (~$3-10K)
  4. Reduce risk of complications and their associated expenses: Early detection of compromised blood flow enables early intervention and the opportunity to avoid or mitigate complications
  5. Shortened ICU stays: Knowing when the flow is adequate reduces tendency for unnecessary therapeutic hypertension thus reducing re-bleeds and associated prolonged length of stay in SAH and TBI patients


In summary, BPM monitoring of CBF provides opportunity for a number of clinical and economical benefits. Please contact Hemedex (http://hemedex.com/contact/sales/) for additional information or to set up a clinical trial. To sign up for this webinar register here

[i] P. Vajkoczy, et al., Journal of Neurosurgery, 98(6): 1227-1234, 2003.

[ii] P. Vajkoczy, et al., Stroke, 32(2):498-505, 2001.

[iii] P. Vajkoczy, et al., Journal of Neurosurgery, 98(6): 1227-1234, 2003.

[iv] Thomé, et al, Journal of Neurosurgery, 95(3): 402-411, 2001.

[v] Ibid

[vi] P. Vajkoczy, et al., Journal of Neurosurgery, 98(6): 1227-1234, 2003.

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