Routine vital signs not so routine: Next question? When does it matter?

Contrasting characters of quick methods to measure respiratory rate in a clinical setting

INTRODUCTION

Many medical professionals unofficially use quick methods for saving time. However, the evidence of such assessments is limited. The main aim of this article is verifying the agreement of these methods.

OBJECTIVES

Overall, 106 out-patients were simultaneously evaluated with respect to the respiratory time measurement (RTM; 60 divided by the single respiratory time), 15 seconds period quadruple respiratory rate (15secRR; 15 seconds respiratory rate multiplied by 4), and 1-min respiratory rate (1minRR; gold standard respiratory rate).

METHOD

We assessed the correlation, Bland-Altman plot, kappa value, and normalized root mean square error of the quick methods for the respiratory rate, with 1minRR as the gold standard.

RESULTS

The mean ± SD of 1minRR, RTM, and 15secRR are 20.4 ± 5.6, 19.1 ± 5.7, and 21.4 ± 6.5 breathes per minute, respectively. The correlation between RTM and 1minRR was 0.85 (95% confidence interval [95% CI]: 0.79-0.90), while that between 15secRR and 1minRR was 0.81 (95% CI: 0.74-0.87). The kappa coefficients between RTM and 1minRR, between 15secRR and 1minRR, and between RTM and 15secRR were 0.57 (95% CI: 0.41-0.72), 0.59 (95% CI: 0.43-0.74), and 0.37 (95% CI: 0.20-0.53), respectively. The normalized root mean square error between RTM and 1minRR was 16.9% and that between 15secRR and 1minRR was 15.0%. The Bland Altman plot demonstrated that RTM and 15secRR showed contrasting characteristics.

CONCLUSION

Compared to the gold standard, RTM tends to underestimate, while 15secRR tends to overestimate the respiratory rate. Therefore, health care professionals should be aware of this methodological tendency to assess vital signs properly.

Improving the Manchester Triage System for pediatric emergency care: an international multicenter study

Objectives

This multicenter study examines the performance of the Manchester Triage System (MTS) after changing discriminators, and with the addition use of abnormal vital sign in patients presenting to pediatric emergency departments (EDs).

Design

International multicenter study

Settings

EDs of two hospitals in The Netherlands (2006–2009), one in Portugal (November–December 2010), and one in UK (June–November 2010).

Patients

Children (<16years) triaged with the MTS who presented at the ED.

Methods

Changes to discriminators (MTS 1) and the value of including abnormal vital signs (MTS 2) were studied to test if this would decrease the number of incorrect assignment. Admission to hospital using the new MTS was compared with those in the original MTS. Likelihood ratios, diagnostic odds ratios (DORs), and c-statistics were calculated as measures for performance and compared with the original MTS. To calculate likelihood ratios and DORs, the MTS had to be dichotomized in low urgent and high urgent.

Results

60,375 patients were included, of whom 13% were admitted. When MTS 1 was used, admission to hospital increased from 25% to 29% for MTS ‘very urgent’ patients and remained similar in lower MTS urgency levels. The diagnostic odds ratio improved from 4.8 (95%CI 4.5–5.1) to 6.2 (95%CI 5.9–6.6) and the c-statistic remained 0.74. MTS 2 did not improve the performance of the MTS.

Conclusions

MTS 1 performed slightly better than the original MTS. The use of vital signs (MTS 2) did not improve the MTS performance.