Six minute walking distance in kyphoscoliosis patients with chronic respiratory failure

Abstract

Aim: To evaluate kyphoscoliosis patients with chronic hypercapnic respiratory failure (CHRF) using the six minute walk test (6MWT) distance (6MWD) and cardio-pulmonary function tests. Method: This prospective cross-sectional study was carried out in a tertiary training and research hospital in Turkey. Kyphoscoliosis patients with CHRF on home mechanical ventilation (HMV) followed in a respiratory intensive care unit (RICU) out-patient clinic were enrolled. Patients’ demographics were recorded as well as transthoracic echocardiography (ECHO), 6MWD, spirometry, arterial blood gas (ABG) values and high resolution chest computed tomography. 6MWT results were compared with other parameters. Results: Thirty four patients with kyphoscoliosis and chronic respiratory insufficiency admitted to our outpatient clinic were included in the study but 25 (17 M) patients underwent 6MWT (8 patients walked with oxygen supplement due to PaO2 < 60 mm Hg). The mean 6MWD was 274.4 ± 76.2 (median 270) m and median 6MWD predicted rate was 43.7% (inter quartile ratio, IQR, 37.6% to 47.7%). Median HMV use was 3 years (IQR 2-4). 6MWD predicted rate, body mass index (BMI), HMV duration were similar in male and female patients. 6MWD correlated well with age, BMI, dyspnea score for baseline 6MWT (r: - 0.59, p < 0.002, r: - 0.58, p < 0.003, r: - 0.55, p < 0.005 respectively) but modestly with forced expiratory volume in one second, pulse rate for baseline 6MWT, pulse saturation rate, fatigue and dyspnea score at end of 6MWT (r: - 0.44, p < 0.048; r: 0.44, p < 0.027; r: - 0.43, p < 0.031; r: - 0.42, p < 0.036; r: - 0.42, p < 0.034 respectively). 6MWD predicted rate was only correlated with dyspnea score at baseline (r: - 0.46, p < 0.022). The systolic pulmonary arterial pressure (PAPs) in 6 (24%) cases was more than 40mmHg, in whom mean PaO2/FiO2 was 301.4 ± 55.4 compared to 280.9 ± 50.2 in those with normal PAPs (p > 0.40). Conclusion: The 6MWT is an easy way to evaluate physical performance limitation in kyphoscoliosis patients with chronic hypercapnic respiratory failure using home mechanical ventilation. Nearly 275 m was the mean distance walked in the 6MWT, but rather than distance in meters, the 6MWD predicted rate according to gender and body mass index equation might be a better way for deciding about physical performance of these patients. Dyspnea score at baseline before the 6MWT may be the most important point that affects 6MWD in this patient population.

Six minute walking distance in kyphoscoliosis patients with chronic respiratory failure

“…In the present study we aimed to evaluate 6MWD and dyspnea perceptions (modified Borg scale) [ 13 ] and cardio-pulmonary function testing in patients with KS-CRF. Some data were presented at the 2009 ERS Congress as an abstract [ 14 ].…”

Intensive care and non-invasive mechanical ventilation in kyphoscoliosis: are new perspectives still needed?

“…However, in our previous study of 34 kyphoscoliosispatients, six (24%) with chronic respiratory failure had a PAP over 40 mmHg. Surprisingly, only two (33%) who had the higher PAP had a PaO 2 /FiO 2 less than 300 [9]. The majority of the patients (n = 28) who had abnormal PAP had hypoxemia (PaO 2 /FiO 2 < 300) [9].…”

“…Surprisingly, only two (33%) who had the higher PAP had a PaO 2 /FiO 2 less than 300 [9]. The majority of the patients (n = 28) who had abnormal PAP had hypoxemia (PaO 2 /FiO 2 < 300) [9]. The studies on pulmonary hypertension in patients with kyphoscoliosis are very limited [3,9].…”

Cardiac Functions and All-Cause Mortality in Kyphoscoliosis Patients with Chronic Respiratory Failure Using Non-invasive Ventilation

“…In addition, pulmonary hypertension, right heart failure, and cor pulmonale can also occur in many pulmonary diseases. There are limited studies in English based literature about the frequency of cardiovascular risk factors and especially, the frequency of pulmonary hypertension and cor pulmonale in kyphoscoliosis patients (3) . Furthermore, there is no study performed with transthoracic echocardiography investigating cardiac functions of kyphoscoliosis patients.…”

“…Hypercapnia and hypoxemia due to hypoventilation develop in time especially during night in kyphoscoliosis patients with severe chest deformity. Nocturnal non-invasive ventilation (NIV) and oxygen therapy have positive effects on quality of life and cognitive functions in these patients (1)(2)(3) .…”