Reliability of the Radial Arterial Pressure During Anesthesia: Is Wrist Compression a Possible Diagnostic Test?

doi:10.1378/chest.105.1.69

Chest

Volume 105, Issue 1, January 1994, Pages 69-75

https://doi.org/10.1378/chest.105.1.69 Get rights and content

Study objective

To evaluate wrist compression as a test to identify low radial from low systemic pressure and to see if the gradient found after cardipulmonary bypass is also present whenever hand vascular resistance may decrease.

Design

This was a prospective study.

Setting

Operating room area of a university medical center.

Participants

(1) Forty patients undergoing coronary bypass grafting studied at discontinuation of cardiopulmonary bypass. (2) Twenty-six patients received isoflurane anesthesia before major noncardiac operations. (3) Hydraulic model: a fluid container with a tube 66-cm long, 6- to 1.8-mm internal diameter, connected at its base.

Interventions

Before induction of anesthesia, the radial artery was cannulated and, in the first group, the aorta or femoral arteries as well. The radial pressure was compared consecutively with and without wrist compression. In the model, the pressure was recorded simultaneously at three sites along the tube while different flows ran through its distal end.

Measurements and results

Overall, wrist compression increased radial (p<0.001) systolic, diastolic, and mean arterial pressures. In the first group, compression reduced the femoral/aortic-radial mean pressure difference by 50 percent and never produced higher radial than central mean pressure. Plot of the pressure difference produced by wrist compression against the average of the (compared) radial pressures and considering increases ≥4 mm Hg as real, showed that, in the first group, systolic arterial pressure (SAP) increased 13 ± 1.4 mm Hg in 22 of 40 patients; diastolic arterial pressure (DAP) increased 7.8 ± 1.1 mm Hg in 4; and mean arterial pressure (MAP) increased 7.7 ± 1.6 mm Hg in 9 patients. In the second group, SAP increased 16.0 ± 1.7 mm Hg in 24 of 26 patients, DAP increased 6.0 ± 1.4 mm Hg in 5, and MAP increased 7.0 ± 0.7 mm Hg in 18 of 26 patients. In the model, base pressure at 94 mm Hg, the pressures were 1.2 to 28.1 mm Hg lower for flows ranging from 10 to 122 ml/min at the 54-cm distance (wrist equivalent).

Conclusion

The systemic-radial artery pressure gradient seen at the end of cardiopulmonary bypass seems to be a phenomenon common to patients with decreased hand vascular resistance. Wrist compression decreases or abolishes the gradient in most cases. It does not produce false positives, so an increase indicates a greater aortic than radial pressure. The difference is likely to be only temporary.

Section snippets

Clinical Measurements

With institutional approval and after obtaining written consent, we recorded the radial artery pressure with and without wrist compression in 40 patients, 38 men and 2 women (group 1), undergoing coronary artery bypass grafting. Patients with unequal bilateral arm cuff pressures determined oscillometrically were excluded, as well as those who exceeded the normal⁹ aorta/femoral radial MAP difference of 3 mm Hg or less measured before CPB. Fentanyl was the primary anesthetic and pancuronium, the

Clinical Observations

General characteristics of both groups are found in Table 1. All patients in the first group had documented obstructive coronary artery disease. The patients of the second group were ASA I-III; all had been in good health until minor symptoms or a routine examination uncovered their present pathologic state. The frequency response and damping coefficient of the pressure measuring system used in the second group were slightly higher than those in the first group, but they were not significantly

Discussion

In the first group of patients, wrist compression reproduced previous findings;³ ie, it significantly increased SAP, DAP, and MAP and reduced the magnitude and incidence of systemic radial MAP difference. As expected, wrist compression did not produce higher radial than systemic MAP, since this variable is not affected by alterations of wave reflections,¹⁴ which arterial compression will produce, nor by additional pressure from kinetic energy since flow velocity in the radial artery is

ACKNOWLEDGMENT

The authors wish to thank Robert James, biostatistician, Wilson Somerville, medical editor, and Vicky Cranfill, senior word processor, for their assistance in the preparation of this article.

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Cited by (19)

Ultrasound visual image-guided vs Doppler auditory-assisted radial artery cannulation in infants and small children by non-expert anaesthesiologists: a randomized prospective study
2013, British Journal of Anaesthesia
Citation Excerpt :
For example, the first-attempt success rate was more than three times higher in the US-guided group vs the Doppler-assisted group (15% vs 50%). The arterial vascular bed distal to a radial artery is typically vasodilated under general anaesthesia, which makes the radial artery collapsible and difficult to advance a catheter or guide wire into the arterial lumen during diastole.13–15 Further investigation is warranted if any haemodynamic manipulation (i.e. volume load or vasopressor administration) could enlarge the size of a radial artery and thus improve the success rate of cannulation.
Cannulation of the radial artery in infants and small children can be challenging, even for the most experienced providers. Utilizing Doppler to aid in radial artery cannulation has been well described. Recent studies have demonstrated the efficacy of ultrasound (US) image-guided vascular access techniques in the paediatric population. The utility of these two techniques, when used by non-expert personnel, has not been studied.
This is a randomized prospective study to compare the utility of two different radial arterial cannulation techniques in paediatric patients weighing <12 kg: US-guided technique (US group) vs Doppler-assisted technique (Doppler group) when used by trainees with limited experience. The primary objective was to compare the first-attempt success rate between each group. As a secondary objective, success rate within 10 min was compared.
The trial was prematurely terminated after 50% of paediatric patients (n=104) were included in the study and 52 of each were randomized to the US or Doppler group. A total of 12 anaesthesia trainees performed radial arterial cannulations. The first-attempt success rate was greater in the US group compared with the Doppler group [17/52 (33%) vs 8/52 (15%), P=0.039, odds ratio (OR): 2.67, confidence interval (CI): 1.03–6.91]. The overall success rate within 10 min was 34/52 (65%) in the US group and 24/52 (46%) in the Doppler group (P=0.048, OR: 2.20, CI: 1.00–4.85).
US-guided radial arterial cannulation in infants and small children provided a greater chance for success at the first attempt compared with the Doppler-assisted technique.
An intra-aortic balloon pump: An unusual cause of an arterial blood pressure discrepancy during cardiopulmonary bypass
1998, Journal of Cardiothoracic and Vascular Anesthesia
Invasive and concomitant noninvasive intraoperative blood pressure monitoring: Observed differences in measurements and associated therapeutic interventions
2011, Anesthesiology
Citation Excerpt :
Because maintaining adequate blood pressure at vital organs is the usual goal of therapy, central pressure should probably be of more interest than peripheral pressure. Although many practitioners may assume that radial artery pressure (our most common site of ABP monitoring) is an accurate measure of more central pressures, many investigators have found that radial pressure is often lower than femoral or aortic pressures.10–14 Thus, brachial pressure measured by NIBP cuff may be a better measure of central pressure when ABP indicates apparent hypotension.15
Noninvasive (NIBP) and intraarterial (ABP) blood pressure monitoring are used under different circumstances and may yield different values. The authors endeavored to characterize these differences and hypothesized that there could be differences in interventions associated with the use of ABP alone ([ABP]) versus ABP in combination with NIBP ([ABP+NIBP]).
Simultaneous measurements of ABP and NIBP made during noncardiac cases were extracted from electronic anesthesia records; the differences were subjected to regression analysis. Records of blood products, vasopressors, and antihypertensives administered were also extracted, and associations between the use of these therapies and monitoring strategy ([ABP] vs. [ABP+NIBP]) were tested using univariate, multivariate, and propensity score matched analyses.
Among 24,225 cases, 63% and 37% used [ABP+NIBP] and [ABP], respectively. Systolic NIBP was likely to be higher than ABP when ABP was less than 111 mmHg and lower than ABP otherwise. Among patients with hypotension, transfusion occurred in 27% versus 43% of patients in the [ABP+NIBP] versus [ABP] group, respectively (odds ratio = 0.4; 95% CI 0.35–0.46), and 7% versus 18% of patients in the [ABP+NIBP] versus [ABP] group received vasopressor infusions, respectively (P < 0.01). Among hypertensive patients, 12% versus 44% of those in the [ABP+NIBP] versus [ABP] group received antihypertensive agents, respectively (P < 0.01).
NIBP was generally higher than ABP during periods of hypotension and lower than ABP during periods of hypertension. The use of NIBP measurements to supplement ABP measurements was associated with decreased use of blood transfusions, vasopressor infusions, and antihypertensive medications compared with the use of ABP alone.
Can we trust radial artery pressure monitoring for cardiac surgery?
2022, Canadian Journal of Anesthesia
Determination of cardiac output from pulse pressure contour during intra-aortic balloon pumping in patients with low ejection fraction
2020, Journal of Clinical Monitoring and Computing
Risk Factors Involved in Central-To-Radial Arterial Pressure Gradient during Cardiac Surgery
2016, Anesthesia and Analgesia

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Chest

Clinical Investigations: Cardiology/Cardiovascular SurgeryReliability of the Radial Arterial Pressure During Anesthesia: Is Wrist Compression a Possible Diagnostic Test?

Study objective

Design

Setting

Participants

Interventions

Measurements and results

Conclusion

Section snippets

Clinical Measurements

Clinical Observations

Discussion

ACKNOWLEDGMENT

J Thorac Cardiovasc Surg

Br J Anaesth

Br J Anaesth

Br J Anaesth

Chest

Can we trust the direct radial artery pressure immediately following cardiopulmonary bypass?

Anesthesiology

Radial artery-to-aorta pressure difference after discontinuation of cardiopulmonary bypass

Anesthesiology

The cardiovascular effects of a new inhalational anesthetic, Forane, in human volunteers at constant arterial carbon dioxide tension

Anesthesiology

Nervous control of the cutaneous circulation

Br Med Bull

Clinical Investigations: Cardiology/Cardiovascular Surgery
Reliability of the Radial Arterial Pressure During Anesthesia: Is Wrist Compression a Possible Diagnostic Test?