Rationale Published evidence indicates that mean arterial pressure (MAP) below a goal range (hypotension) is associated with worse outcomes, though MAP management failures are common.

Objectives Characterize hypotension occurrences in ICUs and consider the implications for MAP management.

Methods Observational study of three retrospective and one prospective cohorts of adult ICU patients during continuous vasopressor infusion. Three cohorts of general, mixed ICU patients; one cohort of acute spinal cord injury patients. Hypotension clusters were defined wherever ≥50% of MAP measurements were hypotensive with ≥10 minutes of total hypotension. Trend analysis was performed (predicting future MAP using 14 min of preceding MAP data) to understand which hypotension clusters could likely have been predicted by clinician awareness of MAP trends.

Measurements and Main Results In cohorts of 155, 66, 16, and 10 subjects, respectively, hypotension occurred 12.9%, 5.5%, 21.5%, and 3.9% of the time. Hypotension occurred overwhelmingly within temporal clusters. MAP trend analysis predicted most substantial hypotension clusters (range: 66.6% to 80.0% sensitivity) prior to continuous hypotension occurring, usually before the occurrence of any hypotension at all. When MAP trend analysis predicted hypotension, positive predictive value ranged from 56% to 77% (probability of subsequent temporal cluster of hypotension or vasopressor up-titration).

Conclusions Hypotension usually occurred in temporal clusters that can typically be predicted by extrapolation from trends. This implies that clinicians may be slow to identify incipient hypotension. In Cohort 4, analysis was performed in real-time, establishing a proof-of-principle for a computational tool with possible clinical utility.

Statement of Clinical Significance This analysis found that hypotension was relatively common in the bottom quartiles in each of four ICU cohorts, occurring in temporal clusters that could usually be predicted by trend extrapolation. This implies that clinicians may be slow to identify incipient hypotension in ICU patients. In one cohort, hypotension prediction was performed in real-time, establishing a proof-of-principle for future clinical usability.

The authors declare the following competing interests: Supported by and performed in collaboration with Nihon Kohden Corporation and the Nihon Kohden Innovation Center.

Supported by the Massachusetts Department of Public Health Spinal Cord Injury Cure Research Program, Mass General Brigham Innovations, and the Nihon Kohden Innovation Center. There were no sponsor restrictions on study design; in the collection, analysis, and interpretation of data; in the writing of the report; and in the decision to submit the report for publication.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Data collection and the associated research protocol for Cohort 1 were approved by the Institutional Review Boards of Beth Israel Deaconess Medical Center (Boston, MA) and the Massachusetts Institute of Technology (Cambridge, MA); these data were shared with the study authors after removal of protected health information. Data collection and associated research protocols for Cohort 2 and 4 were approved by the Institutional Review Board of the Massachusetts General Hospital and Mass General Brigham (Boston, MA). Data collection and associated protocols for Cohort 3 were approved by the Institutional Review Boards of the University of British Columbia Clinical Research Ethics Board (Vancouver, BC); these data were shared with the study authors under a data sharing agreement after removal of all protected health information except for time and date.

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Supported by the Massachusetts Department of Public Health Spinal Cord Injury Cure Research Program, Mass General Brigham Innovations, and the Nihon Kohden Innovation Center. There were no sponsor restrictions on study design; in the collection, analysis, and interpretation of data; in the writing of the report; and in the decision to submit the report for publication.

Dataset for Cohort 1 is publicly available (https://physionet.org). The datasets for Cohort 2 and 4 are available from the corresponding author on reasonable request, subject to our institution′s policies and approvals. The dataset for Cohort 3 was received under a data use agreement with the Vancouver General Hospital; the authors support sharing this dataset upon reasonable request, noting that additional permission from Vancouver General Hospital will be mandatory and additional restrictions may apply.

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