Comparison of Blood Pressure Measurements by Currently Available Multiparameter Monitors and Mercury Column Sphygmomanometer in Patients Admitted in Pediatric Intensive Care Unit.

Background: The multiparameter monitor (MPM) is replacing mercury column sphygmomanometers (MCS) in acute care settings. However, data on the former's accuracy in critically ill children are scarce and mostly extrapolated from adults. We compared non-invasive blood pressure (NIBP) measurements by MPMs with MCS in pediatric intensive care unit (PICU). Patients: Adequately sedated and hemodynamically stabilized children (age, 1-144 months) were prospectively enrolled. Materials and methods: Three NIBP measurements were obtained from MCS (Diamond®, India) and MPM (Intellivue MX800® or Ultraview SL®) in rapid succession in the upper limb resting in supine position. Respective three measurements were averaged to obtain a paired set of NIBP readings, one each from MCS and MPM. Such readings were obtained thrice a day. NIBP readings were then compared, and agreement was assessed. Results: From 39 children [median age (IQR), 30 (10-72) months], 1,690 sets of NIBP readings were obtained. A-third of readings were from infants and children >96 months, while 383 (22.6%) readings were from patients on inotropes. Multiparameter monitors gave significantly higher NIBP readings compared to MCS [median systolic blood pressure (SBP), 6.5 (6.4-6.7 mm Hg); diastolic blood pressure (DBP), 4.5 (4.3-4.6 mm Hg); mean arterial pressure (MAP), 5.3 (5.1-5.4 mm Hg); p < 0.05]. It was consistent across age, gender, and critical care characteristics. Multiparameter monitors overestimated SBP in 80% of readings beyond the maximal clinically acceptable difference (MCAD). Conclusions: Non-invasive blood pressure readings from MCS and MPMs are not interchangeable; SBP was 6-7 mm Hg higher with the latter. Overestimation beyond MCAD was overwhelming. Caution is required while classifying systolic hypotension with MPMs. Confirmation with auscultatory methods is advisable. More studies are required to evaluate currently available MPMs in different pediatric age groups. How to cite this article: Khan AA, Gupta PK, Baranwal AK, Jayashree M, Sahoo T. Comparison of Blood Pressure Measurements by Currently Available Multiparameter Monitors and Mercury Column Sphygmomanometer in Patients Admitted in Pediatric Intensive Care Unit. Indian J Crit Care Med 2023;27(3):212-221.

Deep learning-based automatic blood pressure measurement: evaluation of the effect of deep breathing, talking and arm movement.

Objectives: It is clinically important to evaluate the performance of a newly developed blood pressure (BP) measurement method under different measurement conditions. This study aims to evaluate the performance of using deep learning-based method to measure BPs and BP change under non-resting conditions.Materials and methods: Forty healthy subjects were studied. Systolic and diastolic BPs (SBPs and DBPs) were measured under four conditions using deep learning and manual auscultatory method. The agreement between BPs determined by the two methods were analysed under different conditions. The performance of using deep learning-based method to measure BP changes was finally evaluated.Results: There were no significant BPs differences between two methods under all measurement conditions (all p > .1). SBP and DBP measured by deep learning method changed significantly in comparison with the resting condition: decreased by 2.3 and 4.2 mmHg with deeper breathing (both p < .05), increased by 3.6 and 6.4 mmHg with talking, and increased by 5.9 and 5.8 mmHg with arm movement (all p < .05). There were no significant differences in BP changes measured by two methods (all p > .4, except for SBP change with deeper breathing).Conclusion: This study demonstrated that the deep learning method could achieve accurate BP measurement under both resting and non-resting conditions.Key messagesAccurate and reliable blood pressure measurement is clinically important. We evaluated the performance of our developed deep learning-based blood pressure measurement method under resting and non-resting measurement conditions.The deep learning-based method could achieve accurate BP measurement under both resting and non-resting measurement conditions.

A novel deep learning based automatic auscultatory method to measure blood pressure.

BACKGROUND: It is clinically important to develop innovative techniques that can accurately measure blood pressures (BP) automatically. OBJECTIVES: This study aimed to present and evaluate a novel automatic BP measurement method based on deep learning method, and to confirm the effects on measured BPs of the position and contact pressure of stethoscope. METHODS: 30 healthy subjects were recruited. 9 BP measurements (from three different stethoscope contact pressures and three repeats) were performed on each subject. The convolutional neural network (CNN) was designed and trained to identify the Korotkoff sounds at a beat-by-beat level. Next, a mapping algorithm was developed to relate the identified Korotkoff beats to the corresponding cuff pressures for systolic and diastolic BP (SBP and DBP) determinations. Its performance was evaluated by investigating the effects of the position and contact pressure of stethoscope on measured BPs in comparison with reference manual auscultatory method. RESULTS: The overall measurement errors of the proposed method were 1.4 ± 2.4 mmHg for SBP and 3.3 ± 2.9 mmHg for DBP from all the measurements. In addition, the method demonstrated that there were small SBP differences between the 2 stethoscope positions, respectively at the 3 stethoscope contact pressures, and that DBP from the stethoscope under the cuff was significantly lower than that from outside the cuff by 2.0 mmHg (P < 0.01). CONCLUSION: Our findings suggested that the deep learning based method was an effective technique to measure BP, and could be developed further to replace the current oscillometric based automatic blood pressure measurement method.

Auscultatory versus oscillometric blood pressure measurement in patients with atrial fibrillation and arterial hypertension.

BACKGROUND: The aim of our study was to investigate the reliability of automated oscillometric blood pressure (BP) monitoring in the presence and absence of atrial fibrillation (AF) in hypertensive patients. METHODS: BP was measured and compared in 71 randomly selected patients with AF and arterial hypertension diagnosis, 4 times each by auscultatory and oscillometric (Microlife BP A6 PC with AF detection system) methods. RESULTS: Study included 71 patients: 36 males (mean age 67.4 years) and 35 females (70.2 years). At the time of BP measuring procedure, 36 patients were in sinus rhythm (SR) and 35 in AF. In SR patients mean systolic blood pressure (SBP) was 132 ± 17.9 mmHg with auscultatory method (AM), 137.4 ± 19.4 mmHg with oscillometric method (OM); mean diastolic BP was 77.1 ± 10.9 mmHg (AM), 78.5 ± 12.2 mmHg (OM), in AF patients mean SBP was 127.5 ± 15.1 mmHg (AM), 133.6 ± 17.4 mmHg (OM); mean diastolic BP was 81.4 ± 9.9 mmHg (AM), 83.5 ± 11.8 mmHg (OM), p = 0.037. The averages of differences for SBP and DBP in sinus rhythm group were (-5.3 mmHg (95% limits of agreement -27.2 - 16.6)) and (-1.4 mmHg (95% limits of agreement -12.8 - 10.0)), respectively. In patients with AF the averages of differences for SBP and DBP were (-6.1 mmHg (95% limits of agreement -23.9 - 11.7)) and (-2.1 mmHg (95% limits of agreement -12.9 - 8.7)), respectively. CONCLUSIONS: The oscillometric device validated for patients with AF on average gives 5.3 mmHg higher systolic BP values for patients with SR and 6.3 mmHg higher BP values for patients with AF. However, the limits of agreement between two methods reveal wide range of random error rates which is a questionable topic in clinical practice, as it could possibly affect the treatment of arterial hypertension in patients with AF.

Reliability of pH measurement and the auscultatory method to confirm the position of a nasogastric tube.

BACKGROUND: Blind placement of a nasogastric feeding tube is a common nursing procedure. Confirmation of the correct position in the stomach is warranted to avoid serious complications such as misplacement in the lung. Testing pH of aspirate from a tube is one of the techniques to confirm the tip position. The purpose of this study was to evaluate the auscultatory method and pH measurement with a pH cut-off point of 5.5 after tube insertion and to compare this with the 'gold standard': an abdominal X-ray. Also the feasibility of the pH method was evaluated. MATERIALS AND METHODS: Large prospective observational study in a general hospital. In adult hospitalised patients, the positioning of 331 feeding tubes was tested using two different methods to predict tube position in the stomach. RESULTS: In 98.9% (n=178) of aspirate samples with a pH ≤ 5.5, the tube was located in the stomach. If an aspirate could be obtained, the results of pH measurements showed a sensitivity of 78.4% and a specificity of 85.7%. Obtaining aspirate initially after placement was possible in approximately half of cases but after taking additional measures (including administration of air into the tube, side-positioning of the patient and re-aspiration after one hour) this increased to 81.6%. The sensitivity of the auscultatory method was 79% while the specificity was 61%. CONCLUSIONS: A pH of ≤ 5.5 from tube aspirate is adequate to check the position of the tube in the stomach. Additional measures improve the success to obtain an aspirate from the tube. The auscultatory method is unreliable.

Study on difference of noninvasive blood pressure measurement method based on oscillometric and auscultatory / 医疗卫生装备

This paper introduces and compares several blood pressure measurements, among which two noninvasive blood pressure measurements based on oscillometric and auscultatory methods are mainly compared. It also analyses the characteristics and advantages of oscillometric method as well as introduces a noninvasive blood pressure measurement monitor based on oscillometric. By using this monitor and a common auscultory method, we conducted a public survey. The result for statistical data analysis showed that the difference between oscillometric and auscultatory methods are quite small, and the accuracy of them are both quite good .This paper also previews the future of the noninvasive blood pressure measurement

Development of Acquisition of Korotkoff's Sound Signal Device / 医疗卫生装备

Objective To design a device sampling Korotkoff's sound signal and acquiring blood pressure based on Korotkoff theory.Methods The author sampled Korotkoff's sound signal via microphone,and then according the cuff pressure corresponding to signal appearance and disappearance,the author acquired SBP and DBP.At last,the author validated the creditability by contrasting with the results of auscultatory method.Results The difference of SBP and DBP is near nonexistence,the blood pressure data using this device is creditable.Conclusion The blood pressure can be measured using this device,and it can be used to further study the auto-measurement of blood pressure base on Korotkoff's sound theory.