Pulmonary Function in Renal Transplant Recipients and End-Stage Renal Disease Patients Undergoing Maintenance Dialysis

Follow-up evaluation of pulmonary function and computed tomography findings in chronic kidney disease patients after COVID-19 infection

Pulmonary complications are common after SARS-CoV2- infection. However, data on pulmonary sequelae of COVID-19 after recovery in dialysis patients are limited. We determined the prevalence of abnormal lung function tests and CT findings and investigate the association factors impacting pulmonary dysfunction. This prospective observational cohort study enrolled 100 patients with stage 5 chronic kidney disease (CKD) undergoing dialysis who had recovered from COVID-19 for ≥3 months. Pulmonary function test (PFT) and chest computed tomography (CT) were performed. Demographic data and laboratory results were recorded. The mean patient age was 55.15 ± 12.84 years. Twenty-one patients (21%) had severe COVID-19, requiring mechanical ventilation or oxygen supplementation. Pulmonary function tests revealed a restrictive pattern in 41% (95% confidence interval [CI], 31.73-50.78;) and an obstructive pattern in 7.29% (95% CI, 3.19-13.25) patients. The severe group showed PFT test results similar to the non-severe group, with three patients showing severe obstructive lung disease. The CT scan findings included reticulation (64%), multifocal parenchymal band (43%), ground glass opacities (32%), and bronchiectasis (28%). The median total CT score was 3 (interquartile range, 1-8.5). The CT score and PFT findings showed no association with pulmonary dysfunction extent, except in bronchiectasis. Lung function indices were associated with abnormal CT findings. Abnormal CT findings (bronchiectasis, reticulation, and ground-glass opacities) was associated with higher oxygen requirements than normal CT findings (p = 0.008, bronchiectasis; p = 0.041, reticulation; p = 0.032, ground-glass appearance). Aside from CT findings and CRP levels, no significant lung abnormalities were observed in severe and non-severe patients. Some patients had residual symptoms at follow-up. The findings indicate persistence of both radiological and physiological abnormalities in dialysis patients after COVID-19. However, the prevalence of these abnormalities was comparable to that in the normal population; few patients experienced ongoing symptoms. Follow-up observations and evaluations are warranted. Trial registration. Clinicaltrials.gov Identifier: NCT05348759.

Estimation of pulmonary artery systolic pressure in hemodialysis patients and its association with cardiorespiratory fitness and pulmonary function

PURPOSE

To evaluate the estimated pulmonary arterial systolic pressure (PASP) through transthoracic echocardiography in hemodialysis (HD) patients and associate it with cardiorespiratory fitness and pulmonary function.

METHODS

This study was a cross-sectional analysis of HD patients that performed evaluations of cardiac function, cardiorespiratory fitness, and pulmonary function, through transthoracic echocardiography, cardiopulmonary exercise test, spirometry, and manovacuometry, respectively. All patients underwent the evaluations on a non-dialysis day.

RESULTS

Thirty-five HD patients were evaluated and separated according to the presence of probable pulmonary hypertension (PH) (estimated PASP ≥ 35 mmHg) or not (estimated PASP < 35 mmHg). Those HD patients with probable PH had the worst cardiorespiratory fitness, evaluated by the peak oxygen consumption (VO_2peak) (17.11 ± 4.40 versus 12.90 ± 2.73 mL/kg/min; p = 0.011), and pulmonary function, evaluated by absolute and predicted of forced vital capacity (FVC) (85.52 ± 12.29 versus 71.38 ± 11.63%; p = 0.005) and absolute and predicted of forced expiratory volume in the first second (FEV₁) (83.37 ± 14.98 versus 69.21 ± 13.48%; p = 0.017). The secondary analysis showed that estimated PASP was correlated with VO_2peak (r = - 0.508; p = 0.002), FVC (r = - 0.450; p = 0.007), and FEV₁ (r = - 0.361; p = 0.033). Moreover, the adjusted odds ratio by HD vintage, dry weight and gender showed that increments in VO_2peak (OR 1.62; CI 95% 1.04-2.54; p = 0.034), FVC (OR 39.67; CI 95% 1.74-902.80; p = 0.021), and FEV₁ (OR 39.54; CI 95% 1.89-826.99; p = 0.018) were associated with 1-fold and 39-fold higher chance, respectively, for not having PH. However, all these associations were lost when age was included in the analysis.

CONCLUSIONS

The HD patients with probable PH had the worst cardiorespiratory fitness and pulmonary function. Exploratory analyses showed that greater cardiopulmonary fitness was associated with better cardiac function. Moreover, increments in cardiorespiratory fitness and pulmonary function may increase the chance of not having PH.

Effect of respiratory muscle training in patients with chronic kidney disease: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

This systematic review and meta-analysis aimed to evaluate the effect of respiratory muscle training on respiratory muscle strength, lung function, cardiopulmonary fitness, and quality of life for chronic kidney disease patients.

METHODS

PubMed, Embase, Web of Science Core Collection, and Cochrane Central Register of Controlled Trials published randomized controlled trials that evaluated the effect of respiratory muscle training for chronic kidney disease patients from inception to December 2021, and rerun on September 2022. The quality of included studies was evaluated according to the Cochrane Collaboration's risk of bias tool-2. The outcomes were analyzed as mean differences with a fixed/random effect model. The strength of evidence was evaluated with the Grading of Recommendation, Assessment, Development, and Evaluation approach.

RESULTS

Eleven randomized controlled trials were included. All but two of the studies were in hemodialysis patients. The follow-up time range was 4 to 12 weeks. Compared to controls, respiratory muscle training significantly improved maximal expiratory pressure (mean difference = 17.36, p = 0.013), maximal inspiratory pressure (mean difference = 18.26, p = 0.002), forced expiratory volume at 1 second (mean difference = 0.20, p= 0.020), forced vital capacity (mean difference = 0.26, p = 0.008), but not for 6-minute walk test (mean difference = 39.85, p= 0.138).

CONCLUSIONS

As a non-pharmacological therapy, respiratory muscle training can effectively improve maximal expiratory pressure, maximal inspiratory pressure, forced expiratory volume at 1 second, and forced vital capacity in patients with chronic kidney disease and is safe for such populations.

Influence of mild pulmonary congestion on diaphragmatic mobility and activities of daily living in chronic kidney disease: An experimental and clinical study

BACKGROUND

Pulmonary congestion is a strong predictor of mortality and cardiovascular events in chronic kidney disease (CKD); however, the effects of the mild form on functionality have not yet been investigated. The objective of this study was to assess the influence of mild pulmonary congestion on diaphragmatic mobility (DM) and activities of daily living (ADL) in hemodialysis (HD) subjects, as well as compare ADL behavior on dialysis and non-dialysis days. In parallel, experimentally induce CKD in mice and analyze the resulting pulmonary and functional repercussions.

METHODS

Thirty subjects in HD underwent thoracic and abdominal ultrasonography, anthropometric assessment, lung and kidney function, respiratory muscle strength assessment and symptoms analysis. To measure ADL a triaxial accelerometer was used over seven consecutive days. Twenty male mice were randomized in Control and CKD group. Thoracic ultrasonography, TNF-α analysis in kidney and lung tissue, exploratory behavior and functionality assessments were performed.

RESULTS

Mild pulmonary congestion caused a 26.1% decline in DM (R²=.261; P=.004) and 20% reduction in walking time (R²=.200; P=.01), indicating decreases of 2.23mm and 1.54min, respectively, for every unit increase in lung comet-tails. Regarding ADL, subjects exhibited statistically significant differences for standing (P=.002), walking (P=.034) and active time (P=.002), and number of steps taken (P=.01) on days with and without HD. In the experimental model, CKD resulted in increased levels of TNF-α on kidneys (P=.037) and lungs (P=.02), attenuation of exploratory behavior (P=.01) and significant decrease in traveled distance (P=.034). Thoracic ultrasonography of CKD mice showed presence of B-lines.

CONCLUSION

The mild pulmonary congestion reduced DM and walking time in subjects undergoing HD. Individuals were less active on dialysis days. Furthermore, the experimental model implies that the presence of pulmonary congestion and inflammation may play a decisive role in the low physical and exploratory performance of CKD mice.

Airflow Limitation, Fatigue, and Health-Related Quality of Life in Kidney Transplant Recipients

BACKGROUND AND OBJECTIVES

Many kidney transplant recipients suffer from fatigue and poor health-related quality of life. Airflow limitation may be an underappreciated comorbidity among kidney transplant recipients, which could contribute to fatigue and lower health-related quality of life in this population. In this study, we compared the prevalence of airflow limitation between kidney transplant recipients and healthy controls and investigated associations of airflow limitation with fatigue and health-related quality of life in kidney transplant recipients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data from the ongoing TransplantLines Biobank and Cohort study were used. Airflow limitation was defined as forced exhaled volume in 1 second less than the fifth percentile of the general population. Fatigue and health-related quality of life were assessed using checklist individual strength 20 revised (CIS20-R) and Short Form-36 (SF-36) questionnaires.

RESULTS

A total of 539 kidney transplant recipients (58% men; mean age 56±13 years) and 244 healthy controls (45% men; mean age 57±10 years) were included. Prevalence of airflow limitation was higher in kidney transplant recipients than in healthy controls (133 [25%] versus 25 [10%]). In multinomial regression models, airflow limitation was independently associated with fatigue severity (odds ratio moderate fatigue, 1.68; 95% confidence interval, 0.92 to 3.09 and odds ratio severe fatigue, 2.51; 95% confidence interval, 1.39 to 4.55; P=0.007) and lower physical health-related quality of life (-0.11 SDs; 95% confidence interval, -0.19 to -0.02; P=0.01) in kidney transplant recipients. In exploratory mediation analyses, fatigue accounted for 79% of the association of airflow limitation with physical health-related quality of life.

CONCLUSIONS

Airflow limitation is common among kidney transplant recipients. Its occurrence is associated with more than two times higher risk of severe fatigue, and it is associated with lower physical health-related quality of life. Mediation analyses suggest that airflow limitation causes fatigue, which in turn, decreases physical health-related quality of life.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

TransplantLines: The Transplantation Biobank, NCT03272841 PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2021_11_08_CJN06600521.mp3.

Acoustic Characteristics of Voice in Patients with Chronic Kidney Disease

Purpose

To investigate the multifactorial effects of chronic kidney disease (CKD) and hemodialysis (HD) on subjects' voices by examining correlations between laboratory investigations, respiratory function, and acoustic voice parameters.

Methods

This case-control study was conducted on 60 participants aged 18-50 years, divided equally into three groups: controls (no health problems or voice disorders), cCKD (stage 3-5, no HD HD]), HD, and CKD stage 5. The study took 21 months. All participants underwent general and otolaryngological examinations, followed by laboratory investigations (hemoglobin, uric acid, HCO₃, estimated glomerular filtration rate, urea, urea-reduction ratio, and creatinine), respiratory function tests, and acoustic voice analysis.

Results

There were significant differences between the control and HD groups for jitter, shimmer, and harmonic:noise (HNR) ratio (P=0 and between the control and CKD groups for shimmer and HNR (P=0), with no significant difference between HD and CKD. There were statistically significant correlations between duration of HD and HNR, jitter percentage, and shimmer percentage (P=0.

Conclusion

Systemic effects of CKD and HD were found to impair the acoustic characteristics of voice in both groups. Regression analysis revealed that hemoglobin, uric acid, and expiratory time were the most significant predictors of impaired acoustic characteristics.

Correlation between functional capacity and oxidative stress and inflammation in hemodialysis patients

INTRODUCTION

Patients with chronic kidney disease (CKD) may present impaired functional capacity due to peripheral muscle involvement. Oxidative stress and inflammation are probably involved in this pathophysiology. This study aimed to evaluate the association between functional capacity and biomarkers of oxidative stress as well as biomarkers of inflammation in patients under chronic hemodialysis therapy.

METHOD

Cross-sectional study including 41 patients from a single hemodialysis center. Functional capacity was assessed through the 6-min walk test (6MWT). The assessed blood biomarkers were: malondialdehyde (MDA) (oxidative stress, TBARS method) and angiopoietin-2 (Ang-2) (inflammation, ELISA). The influence of gender on impairment of functional capacity was further explored.

RESULTS

There was an inversely proportional correlation between the 6MWD and MDA (r = -,322 and p = 0.040) and Ang-2 (r = -, 376 and p = 0.016) values. 6MWD was 370.9 ± 101.2 m and 391.4 ± 108.2 m in women and men, respectively (p < 0.001), which means 29.3% and 34.3% reduction of the expected values for healthy individuals from the same age range.

CONCLUSION

Patients with CKD under hemodialysis, regardless of gender, presented impaired performance in 6MWT and this impairment was associated with oxidative stress and inflammation.

Duration of hemodialysis associated with cardio-respiratory dysfunction and breathlessness: a multicenter study

Background

Patients with hemodialysis suffer with protein-energy wasting and uremic myopathy lead to lack of physical activity and poor functional performance. However, ventilation abnormality in patients undergone hemodialysis remains controversial regarding the respiratory impairment. Therefore, the study aimed to determine the effect of duration of dialysis on respiratory function.

Methods

A multicenter study with cross-sectional study was designed in four hemodialysis outpatient clinics. Respiratory muscle strength (i.e., maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP)) pulmonary function test (i.e., forced vital capacity (FVC), forced expiratory volume in one second (FEV₁) and FEV₁/FVC ratio), functional capacity (6-minute walk test) and sensation of breathlessness were assessed prior to dialysis.

Results

A total of 100 hemodialysis patients were recruited with 38 females and 62 males. An average of duration of hemodialysis was 5.93± 4.96 years. Decreased MIP values, FEV₁ values, FVC values, %FEV₁ and %FVC were noted in patients with long duration of dialysis (defined as ≥ 5 years of dialysis) compared to those with short duration of dialysis (p_s < .05). In addition, increased sensation of breathlessness was observed in patients with long duration of dialysis (p < .05). Furthermore, participants with long duration of dialysis had an increased risk of ventilatory restriction (OR 6.093, p = .007).

Is whole body vibration an alternative physical training method for renal transplant recipients?

OBJECTIVE

To evaluate the effect of a 12-week whole-body vibration (WBV) training program on quadriceps muscle strength, quadriceps thickness, the 6-min walk test (6MWT), respiratory muscle strength and quality of life in adults with a kidney transplant.

METHOD

Five renal transplant recipients (age: 43-52 years; body mass: 67.1 kg; height: 1.60 m) were examined individually before and after a 12-week WBV program (two weekly sessions, 35 Hz frequency, 2-4 mm amplitude) using quadriceps strength, quadriceps thickness, 6-min walking test, inspiratory muscle strength and quality of life.

RESULTS

There were no complications during WBV protocol, and the program was considered safe. Two of the participants changed quadriceps muscle strength, and one increased muscle thickness. Inspiratory muscle strength improved in one participant. The distance covered on 6MWT increased for two participants. Most of the subjects (P3, P4 and P5) reported improved quality of life, mainly regarding pain and social aspects.

CONCLUSION

The protocol improved the physical function and quality of life in some of the patients. However, WBV training prescription should be adjusted according to individual needs. Thus, studying the use of WBV in this patient group is necessary to understand and apply the benefits for this population.

Is the peripheral muscle weakness a limitation to exercise on chronic kidney disease?

Abstract Introduction: Chronic kidney disease (CKD) is a global public health problem with systemic repercussions, compromising muscle function and making patients less exercise tolerant. Objective: To verify the contribution of peripheral muscle strength in the exercise capacity of patients in hemodialysis (HD), as well as to compare peripheral muscle strength and exercise capacity between renal patients and healthy individuals. Method: 50 patients with chronic kidney disease (CKD) who performed HD and 13 healthy subjects underwent anthropometric evaluation, evaluation of peripheral muscle strength, pulmonary function test and exercise capacity assessment. Results: Simple linear regression indicated that the peripheral muscle strength contributed 41.4% to the distance walked in the six-minute walk test (R2 0.414; p < 0.001), showing that for every 1 Kgf reduced in the right lower limb the patient it stops walking 0.5m while for every 1 Kgf reduced in the lower left limb the patient stops walking 0.8m. In addition, it was observed that patients with CKD had a reduction in right lower limb muscle strength (129.44 ± 48.05 vs. 169.36 ± 44.30, p = 0.002), left (136.12 ± 52, 08 vs 168.40 ± 43.35, p = 0.01) and exercise capacity (421.20 ± 98.07 vs. 611.28 ± 80.91, p < 0.001) when compared to healthy pairs. Conclusion: Peripheral muscle weakness is an important limiting factor for exercise in CKD and patients on HD experience a decline in peripheral muscle strength and exercise capacity when compared to healthy individuals.

Evaluation of the Renal Transplant Recipient in the Emergency Department

Renal transplants are becoming more and more frequent in the United States and worldwide. Studies demonstrate that these patients inevitably end up visiting an emergency department. In addition to typical medical and surgical problems encountered in the general population, this group of patients has unique problems arising from their immunocompromised state and also due to side effects of the medications required. This article discusses these risks and management decisions that the emergency department physician should be aware of in order to prevent adverse outcomes for the patient and transplanted kidney.

When kidneys and lungs suffer together

A significant interaction between kidneys and lungs has been shown in physiological and pathological conditions. The two organs can both be targets of the same systemic disease (eg., some vasculitides). Moreover, loss of normal function of either of them can induce direct and indirect dysregulation of the other one. Subjects suffering from COPD may have systemic inflammation, hypoxemia, endothelial dysfunction, increased sympathetic activation and increased aortic stiffness. As well as the exposure to nicotine, all the foresaid factors can induce a microvascular damage, albuminuria, and a worsening of renal function. Renal failure in COPD can be unrecognized since elderly and frail patients may have normal serum creatinine concentration. Lungs and kidneys participate in maintaining the acid-base balance. Compensatory role of the lungs rapidly expresses through an increase or reduction of ventilation. Renal compensation usually requires a few days as it is achieved through changes in bicarbonate reabsorption. Chronic kidney disease and end-stage renal diseases increase the risk of pneumonia. Vaccination against Streptococcus pneumonia and seasonal influenza is recommended for these patients. Vaccines against the last very virulent H1N1 influenza A strain are also available and effective. Acute lung injury and acute kidney injury are frequent complications in critical illnesses, associated with high morbidity and mortality. The concomitant failure of kidneys and lungs implies a multidisciplinary approach, both in terms of diagnostic processes and therapeutic management.

A study of pulmonary function in end-stage renal disease patients on hemodialysis: a cross-sectional study

BACKGROUND

The aim here was to study acute effects of hemodialysis among end-stage renal disease (ESRD) patients.

DESIGN AND SETTING

Prospective study in tertiary-level care center.

METHODS

Fifty ESRD patients undergoing hemodialysis were studied. Spirometric pulmonary function tests were performed before and after four-hour hemodialysis sessions.

RESULTS

The patients' average age was 45.8 ± 10.0 years; 64% were males and 64% had normal body mass index. Anemia (94%) and hypoalbuminemia (72%) were common. Diabetes mellitus (68%), hypertension (34%) and coronary artery disease (18%) were major comorbidities. Forty-five patients (90%) had been on hemodialysis for six months to three years. The patients' pre-dialysis mean forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) were below normal: 45.8 ± 24.9% and 43.5 ± 25.9% of predicted, respectively. After hemodialysis, these increased significantly, to 51.1 ± 23.4% and 49.3 ± 25.5% of predicted, respectively (P < 0.01). The increase in mean FEV1/FVC, from 97.8 ± 20.8% to 99.3 ± 20.1% of predicted, was not significant (P > 0.05). The pre-dialysis mean forced expiratory flow 25-75% was 50.1 ± 31% and increased significantly, to 56.3 ± 31.6% of predicted (P < 0.05). The mean peak expiratory flow was below normal (43.8 ± 30.7%) and increased significantly, to 49.1 ± 29.9% of predicted (P < 0.05). Males and females showed similar directions of change after hemodialysis.

CONCLUSIONS

Pulmonary function abnormalities are common among ESRD patients. Comparison of pre and post-hemodialysis parameters showed significant improvements, but normal predicted values were still not achieved.

Peripheral Muscle Strength Indicates Respiratory Function Testing in Renal Recipients

OBJECTIVES

Muscle wasting occurs in renal recipients due to decreased physical performance, and decreased respiratory muscle strength may occur due to changes in structure and function. Data are scarce regarding the roles of sarcopenia and nutritional status on respiratory muscle function in these patients. Here, we evaluated interactions among peripheral muscle strength, sarcopenia, nutritional parameters, and respiratory muscle function in renal transplant recipients.

MATERIALS AND METHODS

Ninety-nine patients were prospectively enrolled between September and April 2016 at Baskent University. Forced vital capacity values (via pulmonary function tests), respiratory muscle strength (via maximal static inspiratory and expiratory pressures), and peripheral muscle strength (via hand grip strength test) were recorded. Nutritional parameters, fat weight, arm circumference, waist circumference, and C-reactive protein levels were also recorded.

RESULTS

Of 99 patients, 68 were renal transplant recipients (43 men, mean age: 39.09 ± 10.70 y) and 31 were healthy participants (14 men, mean age: 34.94 ± 10.95 y). Forced vital capacity (P < .001, r = 0.65), maximal inspiratory (P = .002, r = 0.39) and expiratory (P < .001, r = 0.4) pressure, and hand grip strength showed significant relations in transplant recipients. Positive correlations were found between serum albumin levels and both hand grip strength (P = .16, r = 0.347) and forced vital capacity (P = .03, r = 0.436). Forced vital capacity was statistically different between renal recipients and healthy participants (P = .013), whereas maximal inspiratory and expiratory pressures were not (P > .05). No statistically significant relation was observed between biochemical parameters and maximal inspiratory and expiratory pressures (P ? .05).

CONCLUSIONS

Respiratory function and peripheral muscle strength were significantly related in renal transplant recipients, with significantly lower peripheral muscle strength suggesting the presence of inadequate respiratory function. Peripheral and respiratory muscle training and nutritional replacement strategies could help to improve postoperative respiratory function.

Inspiratory muscle training improves respiratory muscle strength, functional capacity and quality of life in patients with chronic kidney disease: a systematic review

QUESTION

Does inspiratory muscle training improve respiratory muscle strength, functional capacity, lung function and quality of life of patients with chronic kidney disease? Does inspiratory muscle training improve these outcomes more than breathing exercises?

DESIGN

Systematic review and meta-analysis of randomised trials.

PARTICIPANTS

People with chronic kidney disease undergoing dialysis treatment.

OUTCOME MEASURES

The primary outcomes were: maximal inspiratory pressure, maximal expiratory pressure, and distance covered on the 6-minute walk test. The secondary outcomes were: forced vital capacity, forced expiratory volume in the first second (FEV₁), and quality of life.

RESULTS

The search identified four eligible studies. The sample consisted of 110 participants. The inspiratory muscle training used a Threshold^® or PowerBreathe^® device, with a load ranging from 30 to 60% of the maximal inspiratory pressure and lasting from 6 weeks to 6 months. The studies showed moderate to high risk of bias, and the quality of the evidence was rated low or very low, due to the studies' methodological limitations. The meta-analysis showed that inspiratory muscle training significantly improved maximal inspiratory pressure (MD 23 cmH₂O, 95% CI 16 to 29) and the 6-minute walk test distance (MD 80m, 95% CI 41 to 119) when compared with controls. Significant benefits in lung function and quality of life were also identified. When compared to breathing exercises, significant benefits were identified in maximal expiratory pressure (MD 6 cmH₂O, 95% CI 2 to 10) and FEV₁ (MD 0.24litres 95% CI 0.14 to 0.34), but not maximal inspiratory pressure or forced vital capacity.

CONCLUSION

In patients with chronic renal failure on dialysis, inspiratory muscle training with a fixed load significantly improves respiratory muscle strength, functional capacity, lung function and quality of life. The evidence for these benefits may be influenced by some sources of bias.

REGISTRATION

PROSPERO (CRD 42015029986). [de Medeiros AIC, Fuzari HKB, Rattesa C, Brandão DC, de Melo Marinho PÉ (2017) Inspiratory muscle training improves respiratory muscle strength, functional capacity and quality of life in patients with chronic kidney disease: a systematic review. Journal of Physiotherapy 63: 76-83].

Glomerular filtration rate affects interpretation of pulmonary function test in a Korean general population: results from the Korea National Health and Nutrition Examination Survey 2010 to 2012

BACKGROUND/AIMS

The pulmonary abnormalities (principally restrictive abnormalities) are characteristic of renal transplant recipients or those with end-stage renal disease. Our aim was to explore whether the prevalence of spirometric abnormalities was influenced by the estimated glomerular filtration rates (GFRs) in a Korean general population.

METHODS

We used data obtained during the 2010 to 2012 Korean National Health and Nutrition Examination Survey, a national cross-sectional survey. We analyzed data from subjects for whom spirometric assays and estimated GFRs were of acceptable quality.

RESULTS

A total of 8,809 subjects (3,868 male and 4,941 female) was included. In both males and females with GFR values < 60 mL/min/1.73 m², the linear trends toward the presence of obstructive and restrictive patterns were significant. However, the percent predicted forced vital capacity (FVC) decreased with a decline in the estimated GFR, but only in males (p for trend < 0.0031). Multivariate linear regression analysis showed a decline in the estimated GFR was independently associated with falls in the percent predicted FVC and the forced expiratory volume in 1 second/FVC ratio in both males and females. However, the percent predicted FVC was independently predictive only in males (p = 0.002).

CONCLUSIONS

Impaired pulmonary function was associated with a decline in the estimated GFR. The percent predicted FVC decrease paralleled the decline in estimated GFR in male only. Careful interpretation of pulmonary function test data is required in patients with decreased GFRs or impaired renal function, especially males.

Respiratory muscle impairment in dialysis patients: can minimal dose of exercise limit the damage? A Preliminary study in a sample of patients enrolled in the EXCITE trial

AIM

Skeletal muscle atrophy and dysfunction with associated weakness may involve the respiratory muscles of dialysis patients. We evaluated the effect of moderate-intensity exercise on lung function and respiratory muscle strength.

METHODS

Fifty-nine patients (25 F, aged 65 ± 13 years) from two centers participating in the multicenter randomized clinical trial EXerCise Introduction To Enhance Performance in Dialysis (EXCITE) were studied. Subjects were randomized into a prescribed exercise group (E), wherein subjects performed two 10-min walking sessions every second day at an intensity below the self-selected speed, or a control group (C) with usual care. Physical performance was assessed by the 6-min walk test (6MWT). Patient lung function and respiratory muscle strength were evaluated by spirometry and maximal inspiratory pressure (MIP), respectively.

RESULTS

Forty-two patients (14 F) completed the study. At baseline, the groups did not differ in any parameters. In total, 7 patients (4 in E; 3 in C) showed an obstructive pattern. The pulmonary function parameters were significantly correlated with 6MWT but not with any biochemical measurements. Group E safely performed the exercise program. At follow-up, the spirometry parameters did not change in either group. A deterioration of MIP (-7 %; p = 0.008) was observed in group C, but not in group E (+3.3 %, p = ns). In E, an increase of 6MWT was also found (+12 vs. 0 % in C; p = 0.038).

CONCLUSION

In dialysis patients, a minimal dose of structured exercise improved physical capacity and maintained a stable respiratory muscle function, in contrast to the control group where it worsened.

Functional capacity, pulmonary and respiratory muscle strength in individuals undergoing hemodialysis

Abstract Introduction: Individuals with chronic kidney disease (CKD) undergoing hemodialysis (HD) present low cardiorespiratory fitness and functional capacity. Metabolic changes, due to the disease, can result in a variety of pathophysiological conditions that favor the development of respiratory muscle weakness. However, very little is known about the performance of the respiratory muscles and the influence of HD on them. Aim: To evaluate and correlate pulmonary function, functional capacity and respiratory muscle strength in patients with CKD undergoing HD. Methods: Cross-sectional study comprising 23 patients with CKD, that met the following inclusion criteria: patients of both genders, who perform HD three times a week for a minimum period of three months. Respiratory muscle strength was evaluated using a respiratory pressure meter, lung function through spirometry and functional capacity through the 6-minute walk test (6MWT) before the HD session. Results: All patients were male and mean age was 50.2 ± 15.8 years. The median duration of HD was 3 (1.5 to 6.0) years. The mean values obtained in comparison to those predicted were MIP% 36.0 ± 13.6, MEP% 49.5 ± 15.8, FVC% 93.8 ± 21.1, FEV1% 93.7 ± 21.1, FVC/VEF1% 104.1 ± 10.3, and 6MWT% 66.33 ± 20.53. A statistically significant positive correlation was observed between the 6MWT and MIP (r = .63, p =.001) and MEP (r = .67, p < .001), between the MIP and MEP (r =.79, p < .001) and between the FEV1 and FVC (r = .91, p < .001). Conclusion: Patients with CKD undergoing HD present changes in respiratory muscle strength, with the predicted values decreasing for age and gender, as well as the distance covered in the 6MWT, although, with normal spirometric values. Functional capacity was dependent on respiratory muscle strength, as well as the values of MIP and MEP, and the values of FVC and FEV1.

Impact of continuous positive airway pressure (CPAP) on the respiratory capacity of chronic kidney disease patients under hemodialysis treatment

PURPOSE

Chronic kidney disease (CKD) patients on long-term dialysis present changes in pulmonary function and respiratory muscle strength, negatively influencing physical capacity.

OBJECTIVE

To analyze the impact of a continuous positive airway pressure (CPAP) protocol on the respiratory capacity of CKD patients under hemodialysis.

METHODS

A randomized clinical trial was conducted involving 40 CKD patients 19-83 years old divided into two groups: control (n = 20) and CPAP (n = 20). Subjects were assessed on the respiratory muscle function test, maximal respiratory pressures, peak flow and 6-min walk test, at baseline and again at the 2-month follow-up. CPAP group patients were submitted to CPAP protocol (PEEP: 5 cm H2O, flow: 15 L/min, FiO2: 33 %) three times per week during hemodialysis sessions.

RESULTS

The CPAP group showed higher forced vital capacity, forced expiratory volume in one second, peak expiratory flow, maximal inspiratory pressure, peak flow, as well as lower systolic blood pressure, heart rate, respiratory rate and Borg scale, in addition to a longer distance travelled on the 6-min walk test, compared with the control group.

CONCLUSION

The introduction of a CPAP protocol during hemodialysis sessions had a positive impact on pulmonary function and physical capacity in CKD patients.

Long-term successful outcomes from kidney transplantation after lung and heart-lung transplantation

BACKGROUND

Renal dysfunction is common after lung and heart-lung transplantation (Tx), and it limits the recipient's survival and quality of life. This study analyzed the outcomes of simultaneous and late kidney Tx following lung and heart-lung Tx.

METHODS

From a single-center retrospective chart review of 1031 lung and heart-lung Tx recipients, we identified 13 simultaneous or late kidney Tx cases in 12 patients.

RESULTS

Three patients underwent simultaneous deceased donor lung and kidney Tx. Eight patients underwent lung and heart-lung Tx, followed by nine living donor kidney Tx (including one ABO-incompatible Tx). One additional patient underwent a late deceased donor kidney Tx following heart-lung Tx. The median time from lung and heart-lung Tx to later kidney Tx was 127 (interquartile range [IQR], 23 to 263) months. Three patients died, 1 of sepsis, 1 of multiple organ failure, and 1 of transplant coronary disease. At a median follow-up of 33 (IQR, 10 to 51) months, 9 patients are alive and well. Eight patients required dialysis before kidney Tx for a median time of 14 months (IQR, 5 to 49). Kidney graft loss occurred in 1 patient at 51 months. After kidney Tx, dialysis was necessary in association with acute allograft dysfunction in 2 patients. No acute kidney rejection has been detected in any patient. Treatable acute lung rejection was seen in 1 patient. Well-preserved pulmonary function was noted in recipients of late kidney Tx.

CONCLUSIONS

Simultaneous kidney Tx and late deceased donor kidney Tx have challenges in the setting of lung Tx. By contrast, late living related kidney Tx after lung Tx is associated with excellent long-term survival and acceptable kidney and lung allograft function.

Pulmonary hypertension in end-stage renal disease and post renal transplantation patients

BACKGROUND

Information regarding lung function parameters and functional capacity in renal failure and post renal transplantation patients with pulmonary hypertension (PH) is limited. The purpose of this study was to examine the clinical characteristics of patients with PH who were receiving hemodialysis (HD) or peritoneal dialysis (PD) or who had undergone renal transplantation.

METHODS

A prospective study was performed on 116 patients (HD =55, PD =17, and post renal transplantation =44) who underwent Doppler echocardiography. PH was defined as systolic pulmonary artery pressure (SPAP) ≥40 mmHg. Demographic information, clinical characteristics, pulmonary function tests (PFTs) and the six-minute walk test (6MWT) were collected and compared between the patients with and without PH.

RESULTS

Twelve (21.8%) patients receiving HD, four (23.5%) patients receiving PD, and eight (18.2%) post renal transplantation patients had PH. In the HD group, the physiological indicators (including pulmonary function test parameters, the final Borg score, and walking distance during the 6MWT) were all significantly lower in the patients with PH compared with those without PH (all P<0.0001). However, in the PD and post renal transplantation groups, no significant differences were noted in the demographic characteristics or in the physiological parameters when the PH patients were compared with those without PH (all P>0.05).

CONCLUSIONS

Among HD patients, marked aberrations in PFT results or walking distance may identify a subset of patients suffering from PH.

Impact of hemodialysis on dyspnea and lung function in end stage kidney disease patients

Background. Respiratory symptoms are usually underestimated in patients with chronic kidney disease undergoing maintenance hemodialysis. Therefore, we set out to investigate the prevalence of patients chronic dyspnea and the relationship of the symptom to lung function indices. Methods. Twenty-five clinically stable hemodialysis patients were included. The mMRC dyspnea scale was applied before and after hemodialysis. Spirometry, single breath nitrogen test, arterial blood gases, static maximum inspiratory (P_imax⁡) and expiratory (P_emax⁡) muscle pressures, and mouth occlusion pressure (P_0.1) were also measured. Results. Despite normal spirometry, all patients (100%) reported mild to moderate degree of chronic dyspnea pre which was reduced after hemodialysis. The sole predictor of (Δ) mMRC was the (Δ) P_0.1 (r = 0.71, P < 0.001). The P_imax⁡ was reduced before and correlated with the duration of hemodialysis (r = 0.614, P < 0.001), whilst after the session it was significantly increased (P < 0.001). Finally (Δ) weight was correlated with the (Δ) P_imax⁡  %pred (r = 0.533, P = 0,006) and with the (Δ) CV (%pred) (r = 0.65, P < 0.001). Conclusion. We conclude that dyspnea is the major symptom among the CKD patients that improves after hemodialysis. The neuromechanical dissociation observed probably is one of the major pathophysiologic mechanisms of dyspnea.

Exercise limitation following transplantation

Organ transplantation is one of the medical miracles or the 20th century. It has the capacity to substantially improve exercise performance and quality of life in patients who are severely limited with chronic organ failure. We focus on the most commonly performed solid-organ transplants and describe peak exercise performance following recovery from transplantation. Across all of the common transplants, evaluated significant reduction in VO2peak is seen (typically renal and liver 65%-80% with heart and/or lung 50%-60% of predicted). Those with the lowest VO2peak pretransplant have the lowest VO2peak posttransplant. Overall very few patients have a VO2peak in the normal range. Investigation of the cause of the reduction of VO2peak has identified many factors pre- and posttransplant that may contribute. These include organ-specific factors in the otherwise well-functioning allograft (e.g., chronotropic incompetence in heart transplantation) as well as allograft dysfunction itself (e.g., chronic lung allograft dysfunction). However, looking across all transplants, a pattern emerges. A low muscle mass with qualitative change in large exercising skeletal muscle groups is seen pretransplant. Many factor posttransplant aggravate these changes or prevent them recovering, especially calcineurin antagonist drugs which are key immunosuppressing agents. This results in the reduction of VO2peak despite restoration of near normal function of the initially failing organ system. As such organ transplantation has provided an experiment of nature that has focused our attention on an important confounder of chronic organ failure-skeletal muscle dysfunction.

Avaliação da capacidade da Escala Internacional de Eficácia de Quedas em discriminar risco de quedas em pacientes com doença renal crônica submetidos à hemodiálise

O objetivo deste estudo foi avaliar a capacidade da Escala Internacional de Eficácia de quedas (FES-I), dos níveis séricos de paratormônio (PTH) e do tempo de tratamento hemodialítico (TTH) de discriminar pacientes com doença renal crônica (DRC) em tratamento hemodialítico caidores de não caidores. Foi realizado estudo transversal com 64 pacientes, com idade média de 44,2±14,8 anos. Foram coletados dados antropométricos, níveis séricos de PTH, histórico e risco de quedas (Escala Internacional de Eficácia de Quedas - FES-I), TTH e o nível de atividade física (Questionário Internacional de Atividade Física - IPAQ). Foram encontrados níveis séricos de PTH elevados em 64,1% dos pacientes, e 17,2% deles relataram histórico de queda no último ano. O tempo médio de TTH foi 50,3±37,5 meses. Nível de atividade física leve foi encontrado em 64,1%. Foi encontrada correlação positiva entre o PTH e o TTH (r=0,47; p<0,001). Não foram encontradas correlação entre o FES-I e o PTH (p<0,131), entre o FES-I e o TTH (p<0,153) nem entre o PTH (valor baixo/normal <450 pg/mL e valor elevado >450 pg/mL) e o risco de queda (caidores e não caidores) (p<0,158). No estudo, o instrumento FES-I mostrou-se capaz de discriminar hemodialíticos caidores de não caidores. Concluímos que a FES-I apresentou bom desempenho de avaliação entre caidores e não caidores, no entanto não foi observada associação entre caidores com os níveis séricos do PTH e com o TTH.

Respiratory biofeedback accuracy in chronic renal failure patients: a method comparison

Objective:

To analyse respiratory biofeedback effects on respiratory muscle strengthening in chronic renal failure patients.

Design:

Randomized controlled study.

Setting:

Nephrology and dialysis centre.

Subjects and intervention:

Forty-one end-stage renal patients on haemodialysis treatment were allocated into three groups: control ( n = 10), G-1 (inspiratory muscle training using Threshold IMT device; n = 16) and G-2 (biofeedback; n = 15) and given respiratory muscle training (three sessions/week for six weeks).

Main measures:

Forced vital capacity (FVC), expiratory volume in the first second (FEV1), FEV1/FVC ratio, maximal voluntary ventilation (MVV) and maximal inspiratory (MIP) and expiratory (MEP) pressures were measured before and after the respiratory muscle training programme.

Results:

Both training methods were efficient since we found an increase after training in the FVC in the G-1 group (from 2.45 ± 0.17 to 2.85 ± 0.16; P = 0.001) and in the G-2 group (from 2.35 ± 0.19 to 2.55 ± 0.19; P = 0.007), in the FEV1 in G-1 (from 2.18 ± 0.16 to 2.46 ± 0.14; P = 0.01) and in G-2 (from 1.97 ± 0.17 to 2.20 ± 0.15; P < 0.0001), MIP in G-1 (from 70.63 ± 4.03 to 108.75 ± 7.41; P < 0.0001) and in G-2 (from 67.67 ± 5.02 to 96.33 ± 8.30; P < 0.001) and MEP in G-1 (from 73.13 ± 5.10 to 82.50 ± 6.74; P = 0.007) and in G-2 (from 67.67 ± 5.41 to 76.00 ± 4.29; P = 0.002).

Conclusions:

Respiratory biofeedback is efficient as a respiratory muscle training modality for patients with chronic renal failure.

Força muscular respiratória e capacidade funcional na insuficiência renal terminal

OBJETIVO: Verificar a associação da força muscular respiratória com a capacidade funcional, força proximal de membros inferiores e variáveis bioquímicas em pacientes em hemodiálise (HD). MÉTODOS: Participaram deste estudo 30 indivíduos (18 homens), com 53,4 ± 12,9 anos e tempo de HD de 41,1 ± 55,7 meses. Foram avaliados pressão inspiratória máxima (PImax), pressão expiratória máxima (PEmax), distância percorrida no teste de caminhada de seis minutos (6MWT), número de repetições no teste de sentar-e-levantar em 30 segundos (TSL) e registrados os exames bioquímicos de rotina no serviço. RESULTADOS: Houve diminuição da PEmax em relação aos valores preditos (p = 0,015) e redução na distância percorrida no 6MWT quando comparados com equações de predição (p < 0,001). O logPImax e o logPEmax correlacionaram-se com o número de repetições no TSL (r = 0,476, p = 0,008; r = 0,540, p = 0,002, respectivamente), e com os níveis séricos de fósforo (r = 0,422, p = 0,020; r = 0,639, p < 0,001, respectivamente). A distância no 6MWT correlacionou-se com o logPEmax (r = 0,511; p = 0,004) e com o número de repetições no TSL (r = 0,561; p = 0,001). CONCLUSÃO: A redução da PEmax em pacientes com IRT em HD está associada à capacidade funcional, força proximal de membros inferiores e níveis de fósforo sérico, podendo representar, pelo menos em parte, o baixo desempenho físico-funcional desses pacientes.

Função pulmonar e força muscular respiratória em pacientes com doença renal crônica submetidos à hemodiálise

OBJETIVO: Avaliar a função pulmonar e a força muscular respiratória de pacientes com doença renal crônica e correlacioná-las com a variação de peso ligada à realização de hemodiálise; estudar a correlação entre o tempo de hemodiálise e possíveis alterações respiratórias. MÉTODOS: Foram avaliados 17 pacientes (mediana de idade, 47 anos; intervalo interquartílico, 41-52 anos) submetidos a três sessões semanais de hemodiálise (mediana de tempo, 27 meses; intervalo interquartílico, 14-55). Doze eram do sexo masculino. Realizaram espirometria e mensuração das pressões máximas inspiratória (PImáx) e expiratória (PEmáx) antes e após a primeira sessão semanal de hemodiálise. O peso corporal foi quantificado antes e após as três sessões semanais. RESULTADOS: Oito pacientes apresentaram distúrbio restritivo leve antes da primeira sessão de hemodiálise. Desses, 2 normalizaram após a sessão. Houve aumento da capacidade vital forçada (p = 0,02) e diminuição de peso (p = 0,0001) ao final da primeira sessão semanal. A variação de peso durante três dias sem hemodiálise tendeu a se correlacionar com a variação da capacidade vital forçada na primeira sessão (r = 0,47; p = 0,055). O tempo de hemodiálise correlacionou-se com os valores da porcentagem do predito da PImáx (r = -0,53; p = 0,03) e com a PEmáx (r = -0,63; p = 0,006) pré-diálise. CONCLUSÕES: O maior ganho de peso no período interdialítico está associado com a piora da função pulmonar, que pode ser quase totalmente revertida com hemodiálise. Além disso, o maior tempo de hemodiálise está associado à diminuição da força muscular respiratória.

Pulmonary complaints and lung function after pediatric kidney transplantation

Recently four of 38 children with a kidney transplant were diagnosed with bronchiectasis. The aim of the current study was to identify patients with increased risk for pulmonary damage. In this cross-sectional observational study, children with a functioning kidney graft in the Netherlands and Antwerp, Belgium, were screened with the use of a symptom checklist and spirometry. Maximum score for upper airway complaints was 21 (normal: <8), for lower airway complaints 28 (<10). Results of FVC, FEV(1) and MEF(25) were expressed as percentage predicted for height and sex. One hundred and thirty-five patients completed the interview (122) and/or spirometry (103); 91 did both. Lower airways symptoms were above acceptable levels in 18 (14%) patients. Forty-nine patients (48%) had an abnormal lung function test: in 12 concerning FVC%, in 11 FEV(1)%, in 24 MEF(25)% and in 36 FEV(1)/FVC. Of correlations between symptomatology or spirometry data, and clinical parameters, only that between GFR and MEF(25)% was statistically significant. Children with a kidney transplant are at increased risk for obstructive lung disease. We recommend to monitor lung function during the follow-up after renal transplantation.

Study of the effect of renal transplantation on methacholine challenge test in patients with end-stage renal failure in Shahid Doctor Labafinejad Hospital in Tehran, Iran

Pulmonary complications are common in patients with chronic renal failure (CRF). The objective of this study was determine the effect of renal transplantation on pulmonary function, using a methacholine challenge test. This interventional study included 14 CRF patients on maintenance dialysis who underwent serial spirometry and astography before and after renal transplantation. None of them was known to have clinically important pulmonary or heart disease. The results of spirometry, astography, echocardiography, and chest X-ray were normal. Five patients were men and all others were women. The overall age range was 15 to 45 years (mean age = 28.6 +/- 10.9). For every patient four times astography was done. The mean values of spirometric and astography indices before and after renal transplantation were within normal limit. But by repeated measure analysis of variance, the results actually showed improved airway responsiveness (although within normal limits). The most common pathological lung condition in CRF is pulmonary edema, usually due to a combination of fluid overload and abnormal permeability of the pulmonary microcirculation. However, our patients had no symptomatic pulmonary edema, but minor degrees of fluid retention are virtually impossible to detect clinically and could not be excluded. Therefore, it seems that disappearance of subclinical pulmonary edema was the likeliest cause of an increase in minimum dose of methacholine, and therefore improvement in airway responsiveness after renal transplantation.