Smoothing Effect in Vital Sign Recordings: Fact or Fiction? A Retrospective Cohort Analysis of Manual and Continuous Vital Sign Measurements to Assess Data Smoothing in Postoperative Care

Delay Between Actual Occurrence of Patient Vital Sign and the Nominal Appearance in the Electronic Health Record: Single-Center, Retrospective Study of PICU Data, 2014-2018

OBJECTIVES

Patient vital sign data charted in the electronic health record (EHR) are used for time-sensitive decisions, yet little is known about when these data become nominally available compared with when the vital sign was actually measured. The objective of this study was to determine the magnitude of any delay between when a vital sign was actually measured in a patient and when it nominally appears in the EHR.

DESIGN

We performed a single-center retrospective cohort study.

SETTING

Tertiary academic children's hospital.

PATIENTS

A total of 5,458 patients were admitted to a PICU from January 2014 to December 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We analyzed entry and display times of all vital signs entered in the EHR. The primary outcome measurement was time between vital sign occurrence and nominal timing of the vital sign in the EHR. An additional outcome measurement was the frequency of batch charting. A total of 9,818,901 vital sign recordings occurred during the study period. Across the entire cohort the median (interquartile range [IQR]) difference between time of occurrence and nominal time in the EHR was in hours:minutes:seconds, 00:41:58 (IQR 00:13:42-01:44:10). Lag in the first 24 hours of PICU admission was 00:47:34 (IQR 00:15:23-02:19:00), lag in the last 24 hours was 00:38:49 (IQR 00:13:09-01:29:22; p < 0.001). There were 1,892,143 occurrences of batch charting.

CONCLUSIONS

This retrospective study shows a lag between vital sign occurrence and its appearance in the EHR, as well as a frequent practice of batch charting. The magnitude of the delay-median ~40 minutes-suggests that vital signs available in the EHR for clinical review and incorporation into clinical alerts may be outdated by the time they are available.

Acute vital signs changes are underrepresented by a conventional electronic health record when compared with automatically acquired data in a single-center tertiary pediatric cardiac intensive care unit

OBJECTIVE

We sought to evaluate the fidelity with which the patient's clinical state is represented by the electronic health record (EHR) flow sheet vital signs data compared to a commercially available automated data aggregation platform in a pediatric cardiac intensive care unit (CICU).

METHODS

This is a retrospective observational study of heart rate (HR), systolic blood pressure (SBP), respiratory rate (RR), and pulse oximetry (SpO2) data archived in a conventional EHR and an automated data platform for 857 pediatric patients admitted postoperatively to a tertiary pediatric CICU. Automated data captured for 72 h after admission were analyzed for significant HR, SBP, RR, and SpO2 deviations from baseline (events). Missed events were identified when the EHR failed to reflect the events reflected in the automated platform.

RESULTS

Analysis of 132 054 622 data entries, including 264 966 (0.2%) EHR entries and 131 789 656 (99.8%) automated entries, identified 15 839 HR events, 5851 SBP events, 9648 RR events, and 2768 SpO2 events lasting 3-60 min; these events were missing in the EHR 48%, 58%, 50%, and 54% of the time, respectively. Subanalysis identified 329 physiologically implausible events (eg, likely operator or device error), of which 104 (32%) were nonetheless documented in the EHR.

CONCLUSION

In this single-center retrospective study of CICU patients, EHR vital sign documentation was incomplete compared to an automated data aggregation platform. Significant events were underrepresented by the conventional EHR, regardless of event duration. Enrichment of the EHR with automated data aggregation capabilities may improve representation of patient condition.

Non-contact physiological monitoring of post-operative patients in the intensive care unit

Prolonged non-contact camera-based monitoring in critically ill patients presents unique challenges, but may facilitate safe recovery. A study was designed to evaluate the feasibility of introducing a non-contact video camera monitoring system into an acute clinical setting. We assessed the accuracy and robustness of the video camera-derived estimates of the vital signs against the electronically-recorded reference values in both day and night environments. We demonstrated non-contact monitoring of heart rate and respiratory rate for extended periods of time in 15 post-operative patients. Across day and night, heart rate was estimated for up to 53.2% (103.0 h) of the total valid camera data with a mean absolute error (MAE) of 2.5 beats/min in comparison to two reference sensors. We obtained respiratory rate estimates for 63.1% (119.8 h) of the total valid camera data with a MAE of 2.4 breaths/min against the reference value computed from the chest impedance pneumogram. Non-contact estimates detected relevant changes in the vital-sign values between routine clinical observations. Pivotal respiratory events in a post-operative patient could be identified from the analysis of video-derived respiratory information. Continuous vital-sign monitoring supported by non-contact video camera estimates could be used to track early signs of physiological deterioration during post-operative care.

Failure to detect ward hypoxaemia and hypotension: contributions of insufficient assessment frequency and patient arousal during nursing assessments

BACKGROUND

Postoperative hypotension and hypoxaemia are common and often unrecognised. With intermittent nursing vital signs, hypotensive or hypoxaemic episodes might be missed because they occur between scheduled measurements, or because the process of taking vital signs arouses patients and temporarily improves arterial blood pressure and ventilation. We therefore estimated the fraction of desaturation and hypotension episodes that did not overlap nursing assessments and would therefore usually be missed. We also evaluated the effect of taking vital signs on blood pressure and oxygen saturation.

METHODS

We estimated the fraction of desaturated episodes (arterial oxygen saturation <90% for at least 90% of the time within 30 continuous minutes) and hypotensive episodes (MAP <70 mm Hg for 15 continuous minutes) that did not overlap nursing assessments in patients recovering from noncardiac surgery. We also evaluated changes over time before and after nursing visits.

RESULTS

Among 782 patients, we identified 878 hypotensive episodes and 2893 desaturation episodes, of which 79% of the hypotensive episodes and 82% of the desaturation episodes did not occur within 10 min of a nursing assessment and would therefore usually be missed. Mean BP and oxygen saturation did not improve by clinically meaningful amounts during nursing vital sign assessments.

CONCLUSIONS

Hypotensive and desaturation episodes are mostly missed because vital sign assessments on surgical wards are sparse, rather than being falsely negative because the assessment process itself increases blood pressure and oxygen saturation. Continuous vital sign monitoring will detect more disturbances, potentially giving clinicians time to intervene before critical events occur.

Update on early warning scores

Early warning scores (EWS) have the objective to provide a preventive approach for detecting those patients in general wards at risk of deterioration before it begins. Well implemented and combined with a tiered response, the EWS expect to be a relevant tool for patient safety. Most of the evidence for their use has been published for the general EWS. Their strengths, such as objectivity and systematic response, health provider training, universal applicability and automatization potential need to be highlighted to counterbalance the weakness and limitations that have also been described. The near future will probably increase availability of EWS, reliability and predictive value through the spread and acceptability of continuous monitoring in general ward, its integration in decision support algorithms with automatic alerts and the elaboration of temporal vital signs patterns that will finally allow to perform a personal modelling depending on individual patient characteristics.

Reflections on vital sign measurement in nursing practice

Physiological observations or vital sign monitoring is a fundamental tenet of nursing care within an acute care setting. Surveillance of vital signs with algorithmic early warning frameworks aids the nurse in monitoring for early symptoms of clinical deterioration. The nurse must be cognizant of the factors that can influence the vital sign measurements because the framework score is only as reliable as the data inserted. Vital sign technology has made significant progress in its ability to objectify nursing subjective assessments. Early scientists have struggled with its relationship with subjectivity, claiming it has no relevance in true science. Quantitative measurements, regardless of how objectively they were created or obtained, need a subjective lens to interpret and act on the results. The skill of "making" the vital signs can be easily taught or done with technology, but it is the "taking" of the data for analysis of truth and action that requires a higher level of expertise. This paper will examine the truth of vital sign methodology and monitoring to explore the question, "Is true objectivity in the nursing practice of vital sign measurement possible?" The truth in vital sign recognition through a subjective lens will also be explored to challenge the philosophical scientific claims that objective data are the absolute truth.