Forearm Loss Caused by Automated Non-Invasive Blood Pressure Cuff Malfunction: A Hearsay Report

Failure of an automated blood pressure cuff to deflate when a patient is under general anesthesia can lead to catastrophic consequences if unnoticed for more than three hours [1]. We present this as a hearsay case in which an automated blood pressure cuff of the Spacelabs Ultraview Clinical Workstation monitor (model No. 90385) applied pressure for about five hours resulting in limb thrombosis. In order to analyze this catastrophe, simulation scenarios were tested to elucidate the possible errors and malfunctions that may have led to this injury. We present the analysis of the advantages and validity of the hearsay case report. We also include our proposed criteria that should be required when a hearsay case is considered for publication.

Effects of Continuous Non-Invasive Blood Pressure Monitoring on Intraoperative Hemodynamics and Postoperative Myocardial Injury in Craniotomy:Comparison Between Groups Based on Self-Control and Propensity Score Matching

Objective:To explore the effect of continuous non-invasive blood pressure monitoring on intraoperative hemodynamics and postoperative myocardial injury in craniotomy.Methods:120 cases of elective craniotomy were divided into the self-control group(continuous non-invasive blood pressure monitoring and intermittent cuff non-invasive blood pressure monitoring,CNAP group)and propensity score matching group(only intermittent cuff non-invasive blood pressure measurement in previous craniotomy,PSM group);Goal-directed hemodynamic management in CNAP group included heart rate(HR),blood pressure(BP),stroke volume(SV),stroke variability(SVV),and systemic vascular resistance index(SVRI).The main index is to compare the troponin level within 72 hours after operation between the CNAP group and the PSM group;The secondary indicators are the comparison of the hemodynamic conditions between the CNAP group and the PSM at 10 specific time points.Results:The incidence of postoperative myocardial injury in the CNAP group was significantly lower than that in the PSM group(12%vs.30%,P=0.01);in the CNAP group hypotensive episodes(6 vs.3,P=0.01),positive balance of fluid therapy(700 vs.500 mL,P<0.001),more use of vasoactive drugs(29 vs.18,P=0.04),more stable hemodynamics medical status(P=0.03)were recorded.Conclusion:The hemodynamic management strategy based on continuous non-invasive blood pressure monitoring can reduce the incidence of myocardial injury after elective craniotomy and maintain a more stable hemodynamic state.

A Deep Learning-Based Continuous Blood Pressure Measurement by Dual Photoplethysmography Signals

This study proposed a measurement platform for continuous blood pressure estimation based on dual photoplethysmography(PPG)sensors and a deep learning(DL)that can be used for continuous and rapid measurement of blood pressure and analysis of cardiovascular-related indicators.The proposed platform measured the signal changes in PPG and converted them into physiological indicators,such as pulse transit time(PTT),pulse wave velocity(PWV),perfusion index(PI)and heart rate(HR);these indicators were then fed into the DL to calculate blood pressure.The hardware of the experiment comprised 2 PPG components(i.e.,Raspberry Pi 3 Model B and analog-todigital converter[MCP3008]),which were connected using a serial peripheral interface.The DL algorithm converted the stable dual PPG signals acquired from the strictly standardized experimental process into various physiological indicators as input parameters and finally obtained the systolic blood pressure(SBP),diastolic blood pressure(DBP)and mean arterial pressure(MAP).To increase the robustness of the DL model,this study input data of 100 Asian participants into the training database,including those with and without cardiovascular disease,each with a proportion of approximately 50%.The experimental results revealed that the mean absolute error and standard deviation of SBP was 0.17±0.46 mmHg.The mean absolute error and standard deviation of DBP was 0.27±0.52 mmHg.The mean absolute error and standard deviation of MAP was 0.16±0.40 mmHg.

Most patients with non-hypertensive diseases at a critical care resuscitation unit require arterial pressure monitoring: a prospective observational study

BACKGROUND:Blood pressure(BP)monitoring is essential for patient care.Invasive arterial BP(IABP)is more accurate than non-invasive BP(NIBP),although the clinical signifi cance of this diff erence is unknown.We hypothesized that IABP would result in a change of management(COM)among patients with non-hypertensive diseases in the acute phase of resuscitation.METHODS:This prospective study included adults admitted to the Critical Care Resuscitation Unit(CCRU)with non-hypertensive disease from February 1,2019,to May 31,2021.Management plans to maintain a mean arterial pressure>65 mmHg(1 mmHg=0.133 kPa)were recorded in real time for both NIBP and IABP measurements.A COM was defined as a discrepancy between IABP and NIBP that resulted in an increase/decrease or addition/discontinuation of a medication/infusion.Classification and regression tree analysis identified significant variables associated with a COM and assigned relative variable importance(RVI)values.RESULTS:Among the 206 patients analyzed,a COM occurred in 94(45.6%[94/206])patients.The most common COM was an increase in current infusion dosages(40 patients,19.4%).Patients receiving norepinephrine at arterial cannulation were more likely to have a COM compared with those without(45[47.9%]vs.32[28.6%],P=0.004).Receiving norepinephrine(relative variable importance[RVI]100%)was the most signifi cant factor associated with a COM.No complications were identifi ed with IABP use.CONCLUSION:A COM occurred in 94(45.6%)non-hypertensive patients in the CCRU.Receiving vasopressors was the greatest factor associated with COM.Clinicians should consider IABP monitoring more often in non-hypertensive patients requiring norepinephrine in the acute resuscitation phase.Further studies are necessary to confi rm the risk-to-benefi t ratios of IABP among these high-risk patients.

床旁监护仪无创血压测量的原理与检验校准

本文在介绍多参数监护仪无创血压参数测量原理的基础上,简述应用美国FLUKE公司的BP-Pump2无创血压测试仪对监护仪无创血压监护参数检测校准的方法。通过对动态无创血压的检测校准,可以最大限度地保障临床使用的安全、准确、可靠。