|LETTER TO EDITOR
|Year : 2016 | Volume
| Issue : 1 | Page : 32-33
“Zero” diastolic blood pressure
Deepak Choudhary1, Om Prakash Suthar2, Pradeep Kumar Bhatia1, Ghansham Biyani1
1 Department of Anesthesiology and Intensive Care, All India Institute of Medical Sciences, New Delhi, India
2 Department of Anesthesiology and Intensive Care, Dr. S N Medical College, Jodhpur, Rajasthan, India
|Date of Web Publication||17-Jun-2016|
Department of Anesthesiology and Intensive Care, 3rd Floor, OPD Block, All India Institute of Medical Sciences, Jodhpur, Rajasthan
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Choudhary D, Suthar OP, Bhatia PK, Biyani G. “Zero” diastolic blood pressure. Indian Anaesth Forum 2016;17:32-3
Multipara monitors are integral part of routine intensive and perioperative care. However, malfunctioning of these monitors may lead to wrong interpretation and faulty interventions. The overall anesthesia equipment failure rate is reported to be 0.1–0.4% and out of them, 30% is attributed to monitoring malfunction.,
A 40-year-old male patient with normal hemodynamics got admitted to our Intensive Care Unit (ICU) for postoperative observation. Multipara monitor was attached. It displayed noninvasive blood pressure (NIBP) of 130/0 mmHg [Figure 1]. On repeated measurements, diastolic blood pressure (DBP) was always reported to be zero while patient's systolic blood pressure (SBP) varied between 130 and 180 mmHg. NIBP was measured in the opposite arm which also showed zero DBP. On auscultatory measurement using mercury sphygmomanometer, patient's blood pressure (BP) was 140/70 mmHg. Similar values were recorded when a new multipara monitor was attached. This faulty monitor was attached to another patient and it displayed similar readings (zero) of DBP. The service engineer of the manufacturer was contacted, and the monitor was sent for service and repair.
Extremely low or zero DBP is a possibility in cases of severe hypotension, stiff arteries in elderly, diabetes, arteriovenous malformation, and aortic dissection. Our patient had no such history or findings suggestive of these medical conditions, and the manual BP measurement using mercury sphygmomanometer showed normal values. In addition, intraoperative records of the same patient revealed DBP within normal range. Hence, zero DBP was attributed to monitor malfunction.
Monitor malfunction can be due to faulty design, wear and tear, improper handling, and lack of regular service. Faulty measurement can be due to use of inappropriate size and improperly applied cuff (loose/tight/site). In routine practice, NIBP in ICU is measured by automated multipara monitors which work on oscillometric technique. It determines mean BP and calculates SBP and DBP, out of which DBP is the most unreliable of the three parameters. Various methods were used for validation, but only 74% of diastolic and 60% of mean and systolic measurements fall within 10% of actual values. Auscultatory method is considered to be the gold standard for NIBP monitoring against which oscillometric devices are validated. Manufacturers also recommend calibration of multipara monitors every year which was not done in our case and could be one of the reasons behind erroneous reading we encountered.
Multipara monitors help in continuous hemodynamic monitoring of patients in ICU and have significantly reduced morbidity and mortality by early detection of changes in hemodynamics. However, erroneous values displayed by the monitor which do not correlate with the patient's hemodynamics should be confirmed by alternative methods before taking any corrective measure.
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Conflicts of interest
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| References|| |
Fasting S, Gisvold SE. Equipment problems during anaesthesia – Are they a quality problem? Br J Anaesth 2002;89:825-31.
Cassidy CJ, Smith A, Arnot-Smith J. Critical incident reports concerning anaesthetic equipment: Analysis of the UK National Reporting and Learning System (NRLS) data from 2006-2008*. Anaesthesia 2011;66:879-88.
van Montfrans GA. Oscillometric blood pressure measurement: Progress and problems. Blood Press Monit 2001;6:287-90.
Mireles SA, Jaffe RA, Drover DR, Brock-Utne JG. A poor correlation exists between oscillometric and radial arterial blood pressure as measured by the Philips MP90 monitor. J Clin Monit Comput 2009;23:169-74.