Changes in Pulmonary Function During the Early Years After Inpatient Rehabilitation in Persons With Spinal Cord Injury: A Prospective Cohort Study

Long-Term Pulmonary Function Postspinal Cord Injury

OBJECTIVE

To investigate mean values of pulmonary function tests (PFT) at specific time points to assess long-term progression in patients with spinal cord injury (SCI).

DESIGN

Retrospective cohort study from 1997-2022.

SETTING

National rehabilitation hospital, providing scheduled admission for potential SCI-related issues. Follow-up assessments are recommended annually, guiding the observation period into consecutive 1-year intervals.

PARTICIPANTS

This study included 1394 adult patients who were admitted at least twice to the National Rehabilitation Center between 1997 and 2022, selected from an initial pool of 1510. Overall, 116 patients were excluded owing to the absence of any PFT results.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Changes in PFT values over time, specifically assessing for a potential 2-phase pattern after injury. The hypothesis that PFT values would initially improve before declining was formulated based on existing literature.

RESULTS

Significant changes in pulmonary function were noted among 1394 adults with SCI. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) initially increased within the first 1-2 years after injury but declined to below baseline levels after 6 years. Pronounced changes occurred between <1 year and 1-2 years after injury (FVC: Δ=4.89, SE=0.87, P<.001; FEV1: Δ=4.28, SE=1.09, P=.002) and 1-2 years to >6 years (FVC: Δ= -5.83, SE=0.94, P<.001; FEV1: Δ= -6.49, SE=1.18, P<.001). No significant changes in the FEV1/FVC ratio. Motor completeness was significantly associated with the increase and decline phase, showing a steeper increase and less decline compared with the motor-incomplete group.

CONCLUSIONS

Pulmonary function in SCI initially increases but declines over time, falling below initial levels by 6 years. Further evaluation with more complete datasets is warranted to elucidate the factors influencing these changes.

Changes in respiratory structure and function after traumatic cervical spinal cord injury: observations from spinal cord and brain

Respiratory difficulties and mortality following severe cervical spinal cord injury (CSCI) result primarily from malfunctions of respiratory pathways and the paralyzed diaphragm. Nonetheless, individuals with CSCI can experience partial recovery of respiratory function through respiratory neuroplasticity. For decades, researchers have revealed the potential mechanism of respiratory nerve plasticity after CSCI, and have made progress in tissue healing and functional recovery. While most existing studies on respiratory plasticity after spinal cord injuries have focused on the cervical spinal cord, there is a paucity of research on respiratory-related brain structures following such injuries. Given the interconnectedness of the spinal cord and the brain, traumatic changes to the former can also impact the latter. Consequently, are there other potential therapeutic targets to consider? This review introduces the anatomy and physiology of typical respiratory centers, explores alterations in respiratory function following spinal cord injuries, and delves into the structural foundations of modified respiratory function in patients with CSCI. Additionally, we propose that magnetic resonance neuroimaging holds promise in the study of respiratory function post-CSCI. By studying respiratory plasticity in the brain and spinal cord after CSCI, we hope to guide future clinical work.

Improved pulmonary function is associated with reduced inflammation after hybrid whole-body exercise training in persons with spinal cord injury

NEW FINDINGS

What is the central question of this study? Does 12 weeks of functional electrical stimulation (FES) rowing exercise training lead to suppressed systemic inflammation and an improvement in pulmonary function in persons with sub-acute spinal cord injury (SCI)? What is the main finding and its importance? Twelve weeks of FES rowing exercise improves pulmonary function and the magnitude of improvement is associated with reductions in inflammatory biomarkers. Thus, interventions targeting inflammation may lead to better pulmonary outcomes for person with sub-acute SCI.

ABSTRACT

The current study was designed to test the hypotheses that (1) reducing systemic inflammation via a 12-week functional electrical stimulation rowing exercise training (FESRT) prescription results in augmented pulmonary function, and (2) the magnitude of improvement in pulmonary function is inversely associated with the magnitude of systemic inflammation suppression in persons with sub-acute (≤2 years) spinal cord injury (SCI). We conducted a retrospective analysis of a randomized controlled trial (NCT#02139436). Twenty-one participants were enrolled (standard of care (SOC; n = 9) or FESRT (n = 12)). The exercise prescription was three sessions/week at 70-85% of peak heart rate. A two-way analysis of covariance and regression analysis was used to assess group differences and associations between pulmonary function, log transformed high-sensitivity C-reactive protein (hsCRPlog ) and white blood cell count (WBC). Following FESRT, clinically significant improvements in forced expiratory volume in 1 s (FEV1 ; 0.25 (0.08-0.43) vs. -0.06 (-0.26 to 0.15) litres) and forced vital capacity (0.22 (0.04-0.39) vs. 0.08 (-0.29 to 0.12) litres) were noted and systemic WBC (-1.45 (-2.48 to -0.50) vs. 0.41 (-0.74 to 1.56) μl) levels were suppressed compared to SOC (mean change (95% confidence interval); P < 0.05). Additionally, both ΔhsCRPlog and ΔWBC were predictors of ΔFEV1 (r2  = 0.89 and 0.43, respectively; P < 0.05). Twelve weeks of FESRT improves pulmonary function and reduces WBC in persons with sub-acute SCI. The potency of FESRT to augment pulmonary function may depend on adequate suppression of systemic inflammation.

Spinal cord injury and degenerative cervical myelopathy

Spinal cord injury (SCI) often results in impaired respiratory function. Paresis or paralysis of inspiratory and expiratory muscles can lead to respiratory dysfunction depending on the level and severity of the injury, which can affect the management and care of SCI patients. Respiratory dysfunction after SCI is more severe in high cervical injuries, with vital capacity (VC) being an essential indicator of overall respiratory health. Respiratory complications include hypoventilation, a reduction in surfactant production, mucus plugging, atelectasis, and pneumonia. Respiratory management includes mechanical ventilation and tracheostomy in high cervical SCI, while noninvasive ventilation is more common in patients with lower cervical and thoracic injuries. Mechanical ventilation can negatively impact the function of the diaphragm and weaning should start as soon as possible. Patients can sometimes be weaned from mechanical ventilation with assistance of electrical stimulation of the phrenic nerve or the diaphragm. Respiratory muscle training regimens may also improve patients' inspiratory function following SCI. Despite the critical advances in preventing, diagnosing, and treating respiratory complications, they continue to significantly affect persons living with SCI. Additional studies of interventions to reduce respiratory complications are likely to further decrease the morbidity and mortality associated with these injuries.

Relationship of Exercise and Hospital Readmission After Spinal Cord Injury: A Secondary Analysis

IMPORTANCE

After spinal cord injury (SCI), as many as 45% of people experience at least one hospital readmission within 1 yr. Identification of feasible low-cost interventions to reduce hospital readmissions after SCI is needed.

OBJECTIVE

To explore whether a relationship exists between routine exercise and hospital readmission rates 1 yr after SCI.

DESIGN

We conducted a secondary analysis of data from the SCIRehab Project, a prospective cohort study.

SETTING

Five SCI inpatient rehabilitation facilities across the United States.

PARTICIPANTS

Participants were people age 12 yr and older who had sustained an SCI, were admitted to a participating inpatient rehabilitation facility, completed the 12-mo postinjury interview, and reported exercising either monthly or not at all since discharge (N = 520). Outcomes and Measures: The SCIRehab Project conducted 12-mo post-inpatient rehabilitation discharge interviews. As part of the interviews, self-reported hospital readmissions and exercise frequencies since discharge (self-reported number of months, average days per week, and average minutes per day of exercise participation) were collected and analyzed.

RESULTS

A χ2 analysis determined that a significant correlation (φ = -.091, p = .038) exists between monthly exercise and hospital readmissions 1 yr postinjury. Compared with those who did not exercise, participants who exercised monthly had 8.4% fewer hospital readmissions.

CONCLUSIONS AND RELEVANCE

A relationship exists between exercise and hospital readmission, but follow-up research is needed to determine whether regular exercise reduces hospital readmissions among this population. What This Article Adds: After discharge, 44% of the participants did not exercise during the first year after injury. Identifying or implementing accessible community exercise programs is an area of opportunity for occupational therapy practitioners and future researchers to explore.

Long-Term Mechanical Ventilation: Recommendations of the Swiss Society of Pulmonology

Long-term mechanical ventilation is a well-established treatment for chronic hypercapnic respiratory failure (CHRF). It is aimed at improving CHRF-related symptoms, health-related quality of life, survival, and decreasing hospital admissions. In Switzerland, long-term mechanical ventilation has been increasingly used since the 1980s in hospital and home care settings. Over the years, its application has considerably expanded with accumulating evidence of beneficial effects in a broad range of conditions associated with CHRF. Most frequent indications for long-term mechanical ventilation are chronic obstructive pulmonary disease, obesity hypoventilation syndrome, neuromuscular and chest wall diseases. In the current consensus document, the Special Interest Group of the Swiss Society of Pulmonology reviews the most recent scientific literature on long-term mechanical ventilation and provides recommendations adapted to the particular setting of the Swiss healthcare system with a focus on the practice of non-invasive and invasive home ventilation in adults.

Improvement in Pulmonary Function with Short-term Rehabilitation Treatment in Spinal Cord Injury Patients

Cervical and upper thoracic spinal cord injury causes impairments in respiratory muscle performance, leading to variable degrees of pulmonary dysfunction and rendering deep breathing difficult for affected individuals. In this retrospective study, we investigated the effects of self-directed respiratory muscle training in this context by assessing pulmonary function relative to spinal cord injury characteristics. A total of 104 spinal cord injury patients (tetraplegia/paraplegia; 65/39, acute/subacute/chronic; 14/42/48) were admitted for short-term (4–8 weeks) in-patient clinical rehabilitation. Initial evaluation revealed a compromised pulmonary function with a percentage of predicted value of 62.0 and 57.5 in forced vital capacity in supine and forced vital capacity in sitting positions, respectively. Tetraplegic patients had more compromised pulmonary function compared with paraplegic patients. At follow-up evaluation, the percentage of predicted value of forced vital capacity in supine and sitting position improved overall on average by 11.7% and 12.7%, respectively. The peak cough flow improved by 22.7%. All assessed pulmonary function parameters improved significantly in all subgroups, with the greatest improvements found in patients with tetraplegia and subacute spinal cord injury. Therefore, short-term self-directed respiratory muscle training should be incorporated into all spinal cord injury rehabilitation regimens, especially for patients with tetraplegia and subacute spinal cord injury, as well as those with chronic spinal cord injury.

Development and validation of models to predict respiratory function in persons with long-term spinal cord injury

STUDY DESIGN

Multicenter, cross-sectional study.

OBJECTIVES

To validate previously developed respiratory function prediction models for persons with long-term spinal cord injury (SCI) and if necessary develop and validate new models.

SETTING

Ten SCI rehabilitation centers.

METHODS

Five respiratory function parameters were measured in adults with chronic, traumatic, motor complete SCI (C4-T12). First, the models published in 2012 were validated using Bland-Altman plots. Then, new models were calculated using 80% of the dataset by multiple regression analysis with the candidate predictors gender, age, height, weight, time post injury (TPI), lesion level, and smoking. In a third step, the new models were validated using the other 20% of the dataset by Bland-Altman plots.

RESULTS

In total 613 participants were included. For persons with long-term SCI, the 2012 models were poorly predictive, especially for respiratory muscle strength (R2 = 0.4). Significant predictors for all respiratory function parameters in the new models (R2 = 0.7-0.8) were lesion level, gender and weight. Small effects on single outcome parameters were observed for TPI and age whereas smoking had no effect. For the new models the mean differences between measured and predicted values for respiratory muscle strength were 4.0 ± 36.0 cm H₂O and for lung function parameters -0.5 ± 1.2 L (FVC), -0.3 ± 0.9 L (FEV1) and -0.5 ± 2.0 L/s (PEF).

CONCLUSION

We did not find better models for lung function in long-term SCI but those for respiratory muscle strength showed better accuracy.

SPONSORSHIP

The content of this publication was developed under grant from Wings for Life, grant number WFL-CH-017/14.

Evaluation of a clinical implementation of a respiratory muscle training group during spinal cord injury rehabilitation

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To evaluate the clinical implementation of a respiratory muscle training group during rehabilitation of individuals with spinal cord injury.

SETTING

Spinal cord injury rehabilitation center.

METHODS

Individuals with complete or incomplete lesions during inpatient rehabilitation, level C4-T12.Ten or more training sessions of either an inspiratory or a combined in- and expiratory muscle training were performed in a group setting with respiratory function measurements before and after the training period.

RESULTS

Analysis of 79 persons. Inspiratory muscle training was performed for 7 weeks with a median of 3.1 training sessions per week. Median training intensity was at 33% of baseline PImax and 58 repetitions were performed per training session. Respiratory mucle strength parameters improved by 18-68% of baseline values and lung function parameters by 11-31% after inspiratory muscle training.The combined respiratory muscle training was performed for 13 weeks with a median of 2.8 sessions per week and 88 repetitions per training session. Median inspiratory training resistance was at 39% of baseline PImax and median expiratory training resistance was at 27% of baseline PEmax. Respiratory muscle strength parameters improved by 14-51% of baseline values and lung function parameters improved by 15-34% after the combined in- and expiratory muscle training.

CONCLUSION

Respiratory resistance training improved respiratory function of individuals with acute spinal cord injury. Even if the combined respiratory muscle training was performed with more repetitions per training and nearly twice as long, relative improvements of respiratory function parameters were comparable with isolated inspiratory muscle training.

EFEITOS DA CANOAGEM ADAPTADA SOBRE O SISTEMA CARDIOPULMONAR DE PARAPLÉGICOS

RESUMO Introdução: As doenças cardiovasculares e pulmonares estão entre as principais causas de morbidade e mortalidade de indivíduos com lesão medular (LM). O treinamento físico pode ser uma alternativa terapêutica para prevenir ou amenizar complicações cardiopulmonares nessa população. Objetivo: Avaliar os efeitos do treinamento com canoagem adaptada, constituído por exercícios combinados (aeróbicos e de força), sobre variabilidade da frequência cardíaca (VFC), função pulmonar e força muscular respiratória de pessoas paraplégicas em decorrência da LM. Métodos: Participaram do estudo seis paraplégicos, cinco homens e uma mulher, média de idade de 31,50 ± 7,68 anos e índice de massa corporal médio de 24,00 ± 1,13 kg/m², nível de lesão de T4 a T9, que realizaram treinamento com canoagem adaptada por três meses. Os indivíduos foram avaliados por VFC, espirometria e manovacuometria antes e depois do treinamento. Resultados: Após o treinamento houve aumento não significativo de RR (12,7%), SDNN (24,3%), rMSSD (50,0%), pNN50 (478,6%), LF (ms²) (53,3%), HF (ms²) (158,8%), SD1 (50,6%), SD2 (23,2%) e SampEn (20,2%). Os índices HF (u.n) e LF/HF tiveram redução não significativa de 5,7 e 7,0%, respectivamente. Os maiores ganhos respiratórios foram para VVM (9,7%), Pimáx (8,5%) e Pemáx (11,0%), porém, não foram significativos. Conclusão: O protocolo proposto de três meses de canoagem adaptada não foi capaz de promover efeitos significativos sobre os parâmetros cardiopulmonares avaliados em indivíduos paraplégicos pós-LM, porém se observa uma tendência de melhora da maioria desses parâmetros. Nesse sentido, provavelmente, o estímulo de treinamento foi insuficiente.

Cardiovascular disease risk in people with spinal cord injury: is there a possible association between reduced lung function and increased risk of diabetes and hypertension?

STUDY DESIGN

Retrospective, descriptive study of medical files 253 patients with chronic traumatic spinal cord injury (SCI).

OBJECTIVES

To determine the frequency of cardiovascular disease (CVD) risk factors in SCI people, to estimate CVD risk in this population according to the Framingham Risk Score (FRS) and to determine whether reduced lung function parameters are significant predictors of diabetes mellitus (DM) and hypertension.

SETTING

Academic Rehabilitation Hospital.

METHODS

Demographic and clinical records of the patients and lung function parameters were obtained.

RESULTS

The FRS could not be calculated in 26 (10.3%) patients because this tool is designed for adults aged 20 years and older. According to the FRS guideline, ~6.7% of the SCI patients had high risk, 5.9% of them had intermediate risk and 77.1% of the study group had low risk for CVD. Regression analysis showed that impaired lung function parameters (FEV1, FVC and MVV) were significant predictors for the future development of hypertension (odds ratio (OR): 0.483 (0.258-0.903 95% confidence interval (CI)), OR: 0.549 (0.319-0.946 95% CI) and OR: 0.981 (0.965-0.998 95% CI), respectively) and DM (OR: 0.335 (0.140-0.801 95% CI), OR: 0.391 (0.183-0.839 95% CI) and OR: 0.970 (0.947-0.993 95% CI), respectively) in the SCI population.

CONCLUSION

This study showed that there might be a significant relationship between reduced lung function and the risk of DM and hypertension in people with SCI. Therefore, systematic measurement of these parameters should be performed in the routine clinical follow-up of SCI patients. Once reduced lung parameters are determined, the higher risk for developing hypertension and DM should be considered.

Long-term change in respiratory function following spinal cord injury

STUDY DESIGN

Retrospective study.

OBJECTIVES

To model the effect of time since injury on longitudinal respiratory function measures in spinal cord injured-individuals and to investigate the effect of patient characteristics.

SETTING

A total of 173 people who sustained a spinal cord injury between 1966 and April 2013 and who had previously participated in research or who underwent clinically indicated outpatient respiratory function tests at the Austin Hospital in Melbourne, Australia, were included in the study. At least two measurements over time were available for analysis in 59 patients.

METHODS

Longitudinal data analysis was performed using generalised linear regression models to determine changes in respiratory function following spinal cord injury from immediately post injury to many years later. Secondly, we explored whether injury severity, age, gender and body mass index (BMI) at injury altered the time-dependent change in respiratory function.

RESULTS

The generalised linear regression model showed no significant change (P=0.276) in respiratory function measured in (forced) vital capacity ((F)VC) after the spinal cord injury. However, significant (P<0.05) differences in respiratory function over time were found when categorising age and BMI.

CONCLUSION

This clinical cohort with long-term, repeated measurements of respiratory function showed no significant overall change in respiratory function over 23 years. However, a decline in respiratory function over time was observed in subgroups of individuals older than 30 years at the onset of injury and in those with a BMI>30 kg m(-2).

Does locomotor training improve pulmonary function in patients with spinal cord injury?

OBJECTIVES

The aim of this study was to compare the effects of a locomotor training (LT) combined rehabilitation program with a rehabilitation-only program on pulmonary function in spinal cord injury (SCI) patients by investigating spirometric analyses of the patients.

SETTING

Rehabilitation center in Ankara, Turkey.

METHODS

Fifty-two patients (40 male, 12 female) with SCI enrolled in the study. The subjects were divided into two groups: the first group (group A) received both LT and a rehabilitation program and the second group (group B) received only the rehabilitation program for 4 weeks. The LT program was prescribed as three 30-min sessions per week. Pulmonary function was evaluated spirometrically in both groups before and after the rehabilitation program.

RESULTS

The spirometric values of the SCI patients, including forced vital capacity, forced expiratory volume in 1 second, forced expiratory flow rate and vital capacity (VC) and VC%, increased significantly with LT in the first group (all P<0.05). Maximum voluntary ventilation values increased significantly in both groups (both P<0.05).

CONCLUSION

These findings suggest that LT is effective for improving pulmonary function in SCI patients. We also highlight the useful effects of LT, which are likely the result of erect posture, gait and neuroplastic changes that prevent potential complications in SCI patients.

Resistive inspiratory muscle training in people with spinal cord injury during inpatient rehabilitation: a randomized controlled trial

BACKGROUND

People with spinal cord injury (SCI) may benefit from resistive inspiratory muscle training (RIMT). Current evidence is weak, and little is known about the effect on functional outcomes and long-term effects.

OBJECTIVE

The purpose of this study was to assess immediate and long-term effects of RIMT in people with SCI.

DESIGN

This was a single-blinded randomized controlled trial.

SETTING

The study was conducted at 4 specialized SCI units in the Netherlands.

PATIENTS

The study participants were 40 people with SCI (15 with motor complete tetraplegia, 16 with incomplete tetraplegia, 8 with motor complete paraplegia, and 1 with incomplete paraplegia) who had impaired pulmonary function and were admitted for initial inpatient rehabilitation.

INTERVENTION

Study participants were randomized to an RIMT group or a control group. All participants received usual rehabilitation care. In addition, participants in the intervention group performed RIMT with a threshold trainer.

MEASUREMENTS

Measurements were performed at baseline, after 8 weeks of intervention, 8 weeks later, and 1 year after discharge from inpatient rehabilitation. Primary outcome measures were: respiratory muscle function, lung volumes and flows, and perceived respiratory function. Secondary outcome measures concerned patient functioning, which included health-related quality of life, limitations in daily life due to respiratory problems, and respiratory complications.

RESULTS

During the intervention period, maximum inspiratory pressure (MIP) improved more in the RIMT group than in the control group (11.7 cm H2O, 95% confidence interval=4.3 to 19.0). At follow-up, this effect was no longer significant. No effect on other primary or secondary outcome measures was found except for an immediate effect on mental health.

LIMITATIONS

The sample size was insufficient to study effects on respiratory complications.

CONCLUSIONS

Resistive inspiratory muscle training has a positive short-term effect on inspiratory muscle function in people with SCI who have impaired pulmonary function during inpatient rehabilitation.