Anti-decubitus bed mattress may interfere with cerebrovascular pressure reactivity measures due to induced ICP and ABP cyclic peaks


Severe traumatic brain injury (TBI) patients are monitored with continuous arterial blood pressure (ABP) and intracranial pressure (ICP). The pressure reactivity index (PRx) is a frequently used correlation coefficient between ABP and ICP to inform clinicians at the bedside about trends in global cerebrovascular pressure regulation status. We present an unexpected influence of cyclic anti-decubitus mattress inflations and deflations on invasive ICP, ABP and PRx calculations in our TBI patients. This might affect autoregulation guided management. In our database, 23% (9/39) of the patients show recurrent peaks in the monitoring signals. We hypothesize that these peaks are caused by (a combination) of hydrostatic change, local (cervical) compression and/or incorrect sensor zeroing due to positional changes induced by the anti-decubitus mattress. This warrants further investigation by the manufacturer and exploration of data filters.

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The excellent medical and technical support of the medical and nursing staff of the intensive care unit at the Maastricht University Medical Center is gratefully acknowledged.

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Correspondence to Tas Jeanette.

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Conflict of interest

ICM+ software for brain monitoring ( is licensed by the University of Cambridge (Cambridge Enterprise Ltd, Cambridge, UK). Marek Czosnyka and Peter Smielewski have a financial interest in part of the licensing fee.

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Informed consent was obtained from all individual participants included in the study.

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Video S2. A 64 times speed up recording of a patient’s neck and upper body (written consent provided by the family). Three cycles of inflation and deflation are shown. The patient’s head and neck moves upwards and backwards and the lower body moves upwards. (MP4 59428 kb)


Figure S1. The ESRI 750 mattress has transverse alternating A and B cells, and a static head region covering the upper 30 centimetres. When the A cells deflate, the B-cells inflate (period I) until the A and B cells are on a similar level (starting position), Then both the A and B cells start to inflate to the maximum inflation (period II). During period III, both cells start deflating together to the starting position whereupon the A cells further deflate and the B-cells further inflate (period IV). A whole period of inflation and deflation is one bed mattress cycle. This bed mattress cycle repeats - depending on the bed mattress setting - every 10, 15 or 25 minutes. Combined period II and III, when A and B cells inflate and deflate in phase, is similar to the width of the peaks that we detected in our ICP signal (around 3.5 minute). (TIF 5222 kb)


Figure S3. A recording from a TBI patient showing cyclic ICP peaks. In the first part of the recording the ICP peaks are visible every 10 minutes. In the second period a hard plate is placed underneath the patient’s pillow covering the patient’s head and neck until the shoulders. The peaks are visibly dampened. ICP intracranial pressure. (TIF 306 kb)

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Jeanette, T., Melisa, B., Peter, S. et al. Anti-decubitus bed mattress may interfere with cerebrovascular pressure reactivity measures due to induced ICP and ABP cyclic peaks. J Clin Monit Comput 35, 423–425 (2021).

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  • Anti-decubitus bed mattress
  • ICP
  • Prx