Arm and Finger Measurement for Blood Pressure Surveillance (ARMFIN)

Accurate blood pressure (BP) measurement is critical in peripartum care. The cuff and bladder sizes affects the accuracy of BP measurement. Current international BP measurement recommendations are based on mid-arm circumference (MAC). However, evidence have shown the discrepancies between these sizes, leading to inaccuracy of BP measurement. This study will measure arm and finger size of 300 parturients in third trimester to determine whether the MAC, finger measurement or body mass index (BMI) is the best clinical predictor for non-standard cuff sizes for BP measurement.

Study Overview

• Status: Active, not recruiting
• Conditions: Hypertension, Pregnancy-Induced
• Intervention / Treatment: Other: Physical measurement; Other: Cuff size fitting

Detailed Description

Accurate blood pressure (BP) measurement plays an important role in peripartum care as it is essential in detecting hypertensive disorders in pregnancy and medical decision making during the pregnancy. The cuff and bladder size have been highlighted as an important factor affecting the accuracy of BP measurement. Current international BP measurement recommendations are based on mid-arm circumference (MAC) assuming the arm is cylindrical in shape. However, evidence have shown a mismatch between these sizes, leading to BP overestimation or underestimation in obese patients. This is because the shape of the arm is a truncated cone instead of a cylinder, and the cuff will expand irregularly during inflation thus yielding inaccurate BP measurements. This is especially evident in Asian pregnant patients whereby no available guideline can recommend a suitable cuff for parturients with different MAC. Nexfin is a finger cuff device that can be a suitable alternative BP measurement device for such patients. In this study 300 parturients will be recruited in third trimester and undergoing nonemergent caesarean section in KKH. Patients' arm and finger sizes will be measured, and their user experience on current practices on BP measurement. The arm measurements will help to identify the proportion of women that may require non-standard cuff sizes for BP measurement. A conicity index will be determined whether the MAC, finger measurement or BMI is the best clinical predictor. The finger measurements will also help to determine the proportion of women that may require non-standard cuff sizes on the Nexfin device for BP measurement. The knowledge gathered in this pilot study will be used to design future studies in which the accuracy of Nexfin will be compared with standard BP measurement, which in turn will improve BP detection, subsequent patient monitoring and satisfaction.

• Study Type: Observational
• Enrollment (Actual): 300

Contacts and Locations

Study Locations

• Singapore
  • Singapore, Singapore, 229899
    • KK Women's and Children's Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 50 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

• Sampling Method: Non-Probability Sample

Study Population

Pregnant women in Singapore

Description

Inclusion Criteria:

• American Society of Anaesthesiologists physical status 1 or 2 (ASA 1 or 2) parturients at 32 or more weeks of gestation
• Multiparous or nulliparous;
• Age 21-50 years old;
• Undergoing Caesarean section in our institution.

Exclusion Criteria:

• Emergent Caesarean section such that consent and measurements cannot be taken.

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Pregnant cohort; Parturients of gestational age >= 32 weeks will have measurements of arm length, MAC, proximal arm circumference, distal arm circumference, finger circumference to generate the conicity index.	Other: Physical measurement; Parturients of gestational week >= 32 weeks will have their arms and fingers measured to generate the conicity index.; Other Names: Measurement of fingers and arms; Other: Cuff size fitting; Fit on arm cuff and finger cuff as selected by investigators based on the measurement.; Other Names: Cuff fitting for arm and finger

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Arm length (Left, Right)	The distance (cm) between the tip of the acromion process to the tip of the olecranon process on the posterior aspect of the arm, with the elbow in the flexed position.	During antenatal visit (1-2 hours). One visit only
Mid Arm circumference (MAC)(Left, Right)	The circumference (cm) of the arm at the mid-point of the arm length as measured above, with the arm hanging by the side.	During antenatal visit (1-2 hours). One visit only

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proximal arm circumference (Left, Right)	Arm circumference (cm) of the arm measured at the axilla, with the arm hanging by the side.	During antenatal visit (1-2 hours). One visit only
Distal arm circumference (Left, Right)	The circumference (cm) at the elbow above the elbow crease, with the arm hanging by the side.	During antenatal visit (1-2 hours). One visit only
Finger circumference (Left, Right)	The circumference (cm) of the mid-point of the middle phalanx of the middle finger will be measured with the hands placed flat on a table.	During antenatal visit (1-2 hours). One visit only
Feedback on experiences of previous BP measurement	Participants will also respond to a three-point rating scale (Never, sometimes, always) about their experience of the procedures for previous BP measurement during the current pregnancy, with questions such as the length of time taken to obtain a reading, the need to change a cuff when taking BP, the need to take BP on the leg and whether the arm felt uncomfortable when taking blood pressure.	During antenatal visit (1-2 hours). One visit only

Collaborators and Investigators

• Sponsor: KK Women's and Children's Hospital
• Investigators: Principal Investigator: Farida Ithnin, MMED (Anaes), KK Women's and Children's Hospital

Publications and helpful links

General Publications

• Pickering TG, Hall JE, Appel LJ, Falkner BE, Graves J, Hill MN, Jones DW, Kurtz T, Sheps SG, Roccella EJ. Recommendations for blood pressure measurement in humans and experimental animals: part 1: blood pressure measurement in humans: a statement for professionals from the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research. Circulation. 2005 Feb 8;111(5):697-716. doi: 10.1161/01.CIR.0000154900.76284.F6.
• Brown MA, Lindheimer MD, de Swiet M, Van Assche A, Moutquin JM. The classification and diagnosis of the hypertensive disorders of pregnancy: statement from the International Society for the Study of Hypertension in Pregnancy (ISSHP). Hypertens Pregnancy. 2001;20(1):IX-XIV. doi: 10.1081/PRG-100104165. No abstract available.
• O'Brien E, Asmar R, Beilin L, Imai Y, Mallion JM, Mancia G, Mengden T, Myers M, Padfield P, Palatini P, Parati G, Pickering T, Redon J, Staessen J, Stergiou G, Verdecchia P; European Society of Hypertension Working Group on Blood Pressure Monitoring. European Society of Hypertension recommendations for conventional, ambulatory and home blood pressure measurement. J Hypertens. 2003 May;21(5):821-48. doi: 10.1097/00004872-200305000-00001. No abstract available.
• Perloff D, Grim C, Flack J, Frohlich ED, Hill M, McDonald M, Morgenstern BZ. Human blood pressure determination by sphygmomanometry. Circulation. 1993 Nov;88(5 Pt 1):2460-70. doi: 10.1161/01.cir.88.5.2460. No abstract available.
• Penaz J. Criteria for set point estimation in the volume clamp method of blood pressure measurement. Physiol Res. 1992;41(1):5-10.
• Palatini P, Parati G. Blood pressure measurement in very obese patients: a challenging problem. J Hypertens. 2011 Mar;29(3):425-9. doi: 10.1097/HJH.0b013e3283435b65. No abstract available.
• Fonseca-Reyes S, de Alba-Garcia JG, Parra-Carrillo JZ, Paczka-Zapata JA. Effect of standard cuff on blood pressure readings in patients with obese arms. How frequent are arms of a 'large circumference'? Blood Press Monit. 2003 Jun;8(3):101-6. doi: 10.1097/00126097-200306000-00002.
• Bonso E, Saladini F, Zanier A, Benetti E, Dorigatti F, Palatini P. Accuracy of a single rigid conical cuff with standard-size bladder coupled to an automatic oscillometric device over a wide range of arm circumferences. Hypertens Res. 2010 Nov;33(11):1186-91. doi: 10.1038/hr.2010.146. Epub 2010 Aug 5.
• Palatini P, Benetti E, Fania C, Malipiero G, Saladini F. Rectangular cuffs may overestimate blood pressure in individuals with large conical arms. J Hypertens. 2012 Mar;30(3):530-6. doi: 10.1097/HJH.0b013e32834f98a0.
• Kho CL, Brown MA, Ong SL, Mangos GJ. Blood pressure measurement in pregnancy: the effect of arm circumference and sphygmomanometer cuff size. Obstet Med. 2009 Sep;2(3):116-20. doi: 10.1258/om.2009.090017. Epub 2009 Sep 1.
• Eley VA, Roberts L, Rickards L, Pelecanos A, Blackie A, Zhang C, Christensen R, Barrett HL. Arm and finger measurements in the third trimester: Implications for blood pressure measurement. Pregnancy Hypertens. 2018 Oct;14:105-109. doi: 10.1016/j.preghy.2018.09.002. Epub 2018 Sep 5.
• Wang J, Thornton JC, Russell M, Burastero S, Heymsfield S, Pierson RN Jr. Asians have lower body mass index (BMI) but higher percent body fat than do whites: comparisons of anthropometric measurements. Am J Clin Nutr. 1994 Jul;60(1):23-8. doi: 10.1093/ajcn/60.1.23.
• Lim MJ, Tan CW, Tan HS, Sultana R, Eley V, Sng BL. Correlation of patient characteristics with arm and finger measurements in Asian parturients: a preliminary study. BMC Anesthesiol. 2020 Aug 31;20(1):218. doi: 10.1186/s12871-020-01131-6.

Study record dates

Study Major Dates

• Study Start (Actual): July 10, 2019
• Primary Completion (Actual): December 11, 2019
• Study Completion (Anticipated): December 31, 2024

Study Registration Dates

• First Submitted: May 27, 2019
• First Submitted That Met QC Criteria: July 4, 2019
• First Posted (Actual): July 9, 2019

Study Record Updates

• Last Update Posted (Actual): April 4, 2023
• Last Update Submitted That Met QC Criteria: April 2, 2023
• Last Verified: March 1, 2023

More Information

Terms related to this study

• Keywords: Blood pressure measurement; Conicity index; Mid arm circumference; Cuff size
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Pregnancy Complications; Hypertension; Hypertension, Pregnancy-Induced
• Other Study ID Numbers: ARMFIN; ANAESPRG19/012 (Other Identifier: SingHealth ANAES ACP)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No