Is the 1-Minute Sit-To-Stand Test a Good Tool to Evaluate Exertional Oxygen Desaturation in Chronic Obstructive Pulmonary Disease?

The 1-minute sit-to-stand test to evaluate fibrotic interstitial lung disease

INTRODUCTION

Fibrotic interstitial lung diseases (ILD) are a heterogeneous group of conditions. Progression criteria include clinical, imaging, and/or lung functional decline. Currently, the 6-minute walk test (6MWT) is considered the gold standard for assessing exercise-induced desaturation. The 1-minute sit-to-stand test (1STST) has the advantage of being easy to perform, making it feasible for use during clinical consultations. The aim of this study was to compare the 1STST with the 6MWT in patients with fibrotic ILD to detect exercise-induced desaturation.

METHODS

A multicenter cross-sectional involved patients with fibrotic ILDs from two centers. The 6MWT and 1STST were performed with a 30-minute rest period between the tests. The modified Borg scale was used to assess dyspnea and lower limb fatigue and continuous SpO2 and heart rate were monitored. Desaturation was defined as SpO2 < 90% or decline >3%.

RESULTS

Ninety patients were included. The median walking distance in the 6MWT was 432 meters and the median number of repetitions in the 1STST was 22, with a significant correlation (p<0.001, ρ=0.383). In addition, the minimum SpO2 and the desaturation levels recorded during the tests exhibited a moderate significant correlation (p<0.001, ρ=0.502 and p<0.001, ρ=0.537, respectively). There was a strong association between the increase in Borg score for dyspnea and a moderate association between the increase in Borg score for lower limb fatigue after both tests (p<0.001, ρ=0.706 and p<0.001, ρ=0.656, respectively).

CONCLUSIONS

This study demonstrates a significant correlation between the 6MWT and the 1STST in detecting exercise-induced desaturation.

The one-minute sit-to-stand test: A practical tool for assessing functional exercise capacity in patients with COPD in routine clinical practice

Background: Chronic obstructive pulmonary disease (COPD) is associated with a reduced exercise capacity. Although several field tests for exercise capacity have been modified for non-standard settings, i.e. outside the hospital clinic or pulmonary rehabilitation center, their uptake remains limited. Objectives: To assess the test-retest reliability, constuct validity and responsiveness of the one-minute sit-to-stand test (1'STST) adopted in clinical practice among patients with COPD and to confirm the earlier established minimal important difference (MID) of three repetitions. Methods: Patients with COPD performed two 1'STSTs, two 6-minute walk tests (6MWT), an isometric quadriceps force (QF) measurement, a cardiopulmonary exercise test (CPET), and a seven-day physical activity (PA) measurement before and after three months of pulmonary rehabilitation (PR). An Intraclass Correlation Coefficient (ICC) evaluated the agreement between two 1'STSTs. Pearson Correlation examined the association between the 1'STST and other physical measurements, and their changes following PR. A receiver operating characteristic (ROC) curve was constructed using a 30-meter increment in the 6MWT as cut-off to identify responders. Results: The 1'STST demonstrated good reliability (Δ0.9 ± 4.0 repetitions, p = .13; ICC = 0.79). The 1'STST was moderately correlated with the 6MWT (r = 0.57, p < .0001), VO2max (r = 0.50, p = .0006) and maximal work rate (r = 0.52, p = .0003). Weak correlations were observed with QF (r = 0.33, p = .03) and step count (r = 0.38, p = .013). The 1'STST improved after PR (∆ = 3.6 ± 6.4 repetitions, p = .0013) and changes correlated moderately with changes in the 6MWT (r = 0.57, p = .002), QF (r = 0.48, p = .003) and VO2max (r = 0.41, p = .014). A cut-off of three repetitions demonstrated a 71% accuracy in identifying responders to a rehabilitation program. Conclusion: The 1'STST is a valuable alternative to evaluate exercise capacity in patients with COPD when more expensive and time-consuming tests are unavailable.

Breathlessness and exercise performance to predict mortality in long-term oxygen therapy - The population-based DISCOVERY study

BACKGROUND

Patients with chronic respiratory failure treated with long-term oxygen therapy (LTOT) often have severe breathlessness, impaired exercise performance, and high but variable mortality that is difficult to predict. We aimed to evaluate breathlessness and exercise performance upon starting LTOT as predictors of overall and short-term mortality.

METHODS

This was a longitudinal, population-based study of patients who initiated LTOT between 2015-2018 in Sweden. Breathlessness was measured using the Dyspnea Exertion Scale, and exercise performance using the 30s-Sit-To-Stand test. Associations with overall and three-month mortality were analyzed using Cox-regression. Subgroup analyses were performed for patients with chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD) respectively. The predictive capacity of models was assessed using a C-statistic.

RESULTS

A total of 441 patients (57.6% female, aged 75.4 ± 8.3 years) were analyzed, of whom 141 (32%) died during a median follow-up of 260 (IQR 75-460) days. Both breathlessness and exercise performance were independently associated with overall mortality in the crude models, but only exercise performance remained independently associated with overall mortality when models were adjusted for other predictors, when short-term mortality was analyzed, or when breathlessness and exercise capacity were analyzed concurrently. The multivariable model including exercise performance but not breathlessness provided a relatively high predictive capacity for overall mortality, C-statistic 0.756 (95% CI 0.702-0.810). Similar results were seen in the COPD and ILD subgroups.

CONCLUSION

Exercise performance as measured by the 30s-STS may be useful to identify patients with higher mortality on LTOT for optimized management and follow-up.

Teamwork Management and Benefit of Telemedicine in COVID-19 Outbreak Control on an Offshore Vessel in the Gulf of Thailand, Songkhla Province, Thailand: A Case Report

In May 2021, there was a COVID-19 outbreak on board a construction support ship traveling from India to Thailand. Controlling the outbreak on this offshore vessel from 11 May to 2 June 2021 was applied. This case report describes the teamwork management of COVID-19 control on the vessel in the Gulf of Thailand. We summarized the COVID-19 outbreak control process on board, including active COVID-19-infected cases (CoIC) and close contacts (CoCC) identification, isolation, quarantine, treatment, and clinical monitoring using telemedicine to report their health measurements twice daily, including emergency conditions if they occurred. Active COVID-19 cases were identified by two rounds of reverse transcription polymerase chain reaction (RT-PCR) tests in all crew members, in which 7 of 29 (24.1%) showed positive results. Both the CoIC and CoCC were strictly and absolutely isolated and quarantined on the vessel. No serious medical conditions were reported during the monitoring. The third-round RT-PCR tests were conducted, and all tested negative one week later. Teamwork management in proactive COVID-19 case identification, isolation, comprehensive treatment, and close monitoring of health conditions using telemedicine devices is beneficial for controlling the COVID-19 outbreak on board.

In adults with advanced lung disease, the 1-minute sit-to-stand test underestimates exertional desaturation compared with the 6-minute walk test: an observational study

QUESTION

In adults with advanced lung disease, do the 6-minute walk test (6MWT) and 1-minute sit-to-stand test (1minSTS) elicit similar cardiorespiratory responses? Can the 6-minute walk distance (6MWD) be estimated from the 1minSTS result?

DESIGN

Prospective observational study using data collected during routine clinical practice.

PARTICIPANTS

Eighty adults (43 males) with advanced lung disease, a mean age of 64 years (SD 10) and a mean forced expiratory volume in 1 second of 1.65 L (SD 0.77).

OUTCOME MEASURES

Participants completed a 6MWT and a 1minSTS. During both tests, oxygen saturation (SpO2), pulse rate, dyspnoea and leg fatigue (Borg 0 to 10) were recorded.

RESULTS

Compared with the 6MWT, the 1minSTS resulted in higher nadir SpO2 (MD 4%, 95% CI 3 to 5), lower end-test pulse rate (MD -4 beats/minute, 95% CI -6 to -1), similar dyspnoea (MD -0.3, 95% CI -0.6 to 0.1) and greater leg fatigue (MD 1.1, 95% CI 0.6 to 1.6). Among the participants who demonstrated severe desaturation (SpO2 nadir < 85%) on the 6MWT (n = 18), five and ten participants were classified as moderate (nadir 85 to 89%) or mild desaturators (nadir ≥ 90%), respectively, on the 1minSTS. The relationship between the 6MWD and 1minSTS was: 6MWD (m) = 247 + (7 × number of transitions achieved during the 1minSTS) with poor predictive ability (r2 = 0.44).

CONCLUSION

The 1minSTS elicited less desaturation than the 6MWT and classified a smaller proportion of people as 'severe desaturators' on exertion. It is therefore inappropriate to use the nadir SpO2 recorded during a 1minSTS to make decisions about whether strategies are needed to prevent severe transient exertional desaturation during walking-based exercise. Further, the extent to which performance on the 1minSTS can estimate a person's 6MWD is poor. For these reasons, the 1minSTS is unlikely to be helpful when prescribing walking-based exercise.

The impact of seat height on 1-min sit-to-stand test performance in COPD: a randomised crossover trial

Study question

Is there a difference in the number of repetitions in the 1-minute sit-to-stand (1MSTS) test using an individually adapted seat height to 90° knee flexion (1MSTS_IND), compared with the commonly used standard chair seat height of 46 cm (1MSTS_STD), in people with COPD?

Methods

We conducted a single-centre, single-blinded, randomised crossover trial in people with COPD between August 2020 and March 2021 at a specialised rehabilitation clinic in Switzerland. After a learning 1MSTS test, all participants performed two 1MSTS tests in random order on consecutive days. Participants were blinded, as they did not receive detailed information on the testing protocols.

Results

49 individuals with COPD (47% female) participated. In a regression model adjusted for sequence period and subject, 1MSTS test performance was lower on 1MSTS_IND compared to 1MSTS_STD (−0.78 repetitions, 95% CI −1.47 to −0.11). In a second regression model additionally including the knee angle and an interaction term (1MSTS_IND×knee angle), the interaction term was significant: 0.18 (95% CI 0.05 to 0.30). The limits of agreement were between −5.5 and 4 repetitions.

Conclusion

Although we observed a statistically significant difference between 1MSTS_IND and 1MSTS_STD on a population level, the difference is negligible. Further studies may be needed to determine whether individual adaptation of seat height is needed for very tall or short people to ensure a valid assessment of 1MSTS test performance in COPD.

Performing the 1MSTS test on an individually adjusted chair versus a standard chair results in fewer repetitions (mean difference −0.78, 95% CI −1.47 to −0.11). However, the difference in repetitions is clinically negligible.https://bit.ly/3Oc8Rvp

Enhance Access to Pulmonary Rehabilitation with a Structured and Personalized Home-Based Program-reabilitAR: Protocol for Real-World Setting

Home-based models represent one of the solutions to respond to the poor accessibility of pulmonary rehabilitation (PR) services in patients with chronic respiratory disease (CRD). The main goal of this protocol is to present the implementation of the first nationwide home-based PR program—reabilitAR—in Portugal and the strategies to assess its benefits in patients with CRD. The program consists of 2 phases: a 12-week intensive phase and a 40-week maintenance phase (total: 52 weeks, 1 year). The intervention in both phases is composed of presential home visits and phone-call follow ups, including exercise training and the self-management educational program Living Well with COPD. Dyspnea, impact of the disease, emotional status, and level of dyspnea during activities of daily living are used as patient-reported outcomes measures. A one-minute sit-to-stand test is used as a functional outcome, and the number of steps as a measure of physical activity. To ensure safety, fall risk and the cognitive function are assessed. Data are collected at baseline, at 12 weeks, at 26 weeks and at 52 weeks. This is the first nationwide protocol on enhancing access to PR, providing appropriate responses to CRD patients’ needs through a structured and personalized home-based program in Portugal.