Diaphragmatic function in severely malnourished patients with anorexia nervosa. Effects of renutrition

Diaphragm and Lung Transplantation

Mutual interactions between the diaphragm and lung transplantation (LTx) are known to exist. Before LTx, many factors can exert notable impact on the diaphragmatic function, such as the underlying respiratory disease, the comorbidities, and the chronic treatments of the patient. In the post-LTx setting, even the surgical procedure itself can cause a stressful trauma to the diaphragm, potentially leading to morphological and functional alterations. Conversely, the diaphragm can significantly influence various aspects of the LTx process, ranging from graft-to-chest cavity size matching to the long-term postoperative respiratory performance of the recipient. Despite this, there are still no standard criteria for evaluating, defining, and managing diaphragmatic dysfunction in the context of LTx to date. This deficiency hampers the accurate assessment of those factors which affect the diaphragm and its reciprocal influence on LTx outcomes. The objective of this narrative review is to delve into the complex role the diaphragm plays in the different stages of LTx and into the modifications of this muscle following surgery.

Inpatient Rehabilitation during Intensive Refeeding in Severe Anorexia Nervosa

Severe forms of anorexia nervosa are responsible for weight loss and life-threatening consequences. Refeeding represents a real psychiatric and somatic challenge. Physical activities are usually not recommended during intensive refeeding in order to avoid energy expenditure. This study assessed the interest in an early return to controlled physical activities, during a hospitalization in a Physical Medicine and Rehabilitation (PMR) department, including continuous nasogastric refeeding and psychiatric care. A total of 37 subjects aged 32 ± 11 years old performed inpatient physical activities during nasogastric refeeding initiated after intensive care. The physical activity program was adapted according to the hyperactivity of the patients. Evaluation parameters were weight, body mass index (BMI), body composition (fat, lean, and bone masses), and function (strength, balance, walking, ventilation). Patient satisfaction, re-hospitalizations, and physical activities continuation were assessed at 12 months of follow-up. Weight, BMI, and body fat increased significantly (+2.7 ± 1.7 kg; +1.0 ± 0.6 kg/m²; +1.7 ± 2.5 kg, respectively). Muscle strength increased even if the lean mass did not. Walking distance, balance, and respiratory function were significantly improved. Weight and fat mass gains did not differ according to the presence or absence of hyperactivity. At 12 months, 46% of the patients continued to be physically active, but 21% of the patients had been re-hospitalized. The early return to controlled physical activities in PMR hospitalization does not compromise the efficiency of intensive refeeding in severe anorexia nervosa patients.

Evaluation of muscle-skeletal strength and peak expiratory flow in severely malnourished inpatients with anorexia nervosa: A pilot study

OBJECTIVES

Anorexia nervosa is a complex psychiatric disorder that can lead to specific somatic complications. Malnutrition is frequent and can involve a decrease of mobility, up to functional impotence, in individuals with extremely severe cases. The aim of this pilot study was to examine muscle strength and peak expiratory flow (PEF) in severely undernourished patients with anorexia nervosa at admission and after 5 wk of renutrition by tube feeding, and to find the clinical and biological correlates of muscle-strength impairment.

METHODS

A prospective observational study was conducted over 6 mo. Manual muscle testing, measures of PEF, and clinical and biologic assessments were performed at baseline and after 5 wk of renutrition.

RESULTS

Twenty-three extremely malnourished female participants (mean body mass index: 11.4 ± 1.3 kg/m²) were included. All participants had global impairment in muscle strength (manual muscle testing: 37.7 ± 7.7) and PEF (253.3 ± 60 mL/min) at admission. Muscle weakness was higher in axial than peripheral muscle groups (P < 0.01), with no significant difference between proximal and distal muscles (P > 0.05). Muscle strength at admission was significantly associated with severity of undernourishment (body mass index and albumin) and transaminitis (P < 0.05). At follow-up, musculoskeletal strength and PEF were significantly improved after partial weight recovery (P < 0.01).

CONCLUSIONS

Extremely undernourished people with anorexia nervosa present a decrease of PEF and musculoskeletal strength predominant on axial muscles. Both are associated with severity of malnutrition and liver damage. Partial recovery was observed after 5 wk of enteral nutrition.

Bladder and voiding dysfunction in adolescents with anorexia nervosa: a novel finding and potential causes

PURPOSE

This study aimed to investigate the bladder capacity (BC) and bladder dynamics of adolescents with anorexia nervosa (AN).

METHODS

The participants consisted of 15 adolescents newly diagnosed with AN according to the DSM 5 criteria and in the acute weight loss period who were questioned about the symptoms of lower urinary tract (LUT) dysfunction. Functional bladder capacity (FBC) and voided volume with uroflowmetry were measured for each subject; the larger volume of the two was chosen for the bladder capacity. Uroflowmetry was used to obtain uroflow curves for the participants whose patterns were labeled as pathologic if they were outside the bell-shape.

RESULTS

Fourteen (93.3%) of the patients exhibited at least one of the LUT dysfunction symptoms (pathologic voiding symptom/urinary incontinence/pathologic uroflow pattern). BC was observed to increase in 86.6% (n = 13) of the patients. Eighty% of the patients (n = 12) showed pathological uroflow patterns. In patients with pathological uroflow patterns, which showed insufficiency of bladder contraction, assistance of abdominal muscles was needed during voiding.

CONCLUSION

The novel findings presented in this study are the increase of BC in adolescents with AN, the presence of at least one type of voiding or bladder dysfunction, and the pathology of uroflow patterns of most patients show that the bladder dynamics is affected in AN. The most important contribution of this study to the literature is that impaired bladder dynamics was determined to be a medical complication of AN.

LEVEL OF EVIDENCE

Case-control analytic study, Level III.

Severe bronchiectasis and inflammatory lung disease in a patient with anorexia nervosa and severe and enduring malnutrition - a case report

BACKGROUND

Persistent structural changes of the lungs in anorexia nervosa (AN) patients are rarely described in contemporary medical literature. The objective of our paper is to report a rare case of severe bronchiectasis and inflammatory changes to the lungs resulting from chronic malnutrition in a AN patient.

CASE PRESENTATION

We describe a patient with severe inflammatory lung disease caused by malnutrition, resulting in persistent bronchiectasis accompanying AN. We performed an analysis of the patient's medical records including radiological findings and laboratory results. A review of available literature shows very little data available on this topic.

CONCLUSION

Bronchiectasis and other structural changes of the lungs are rare, but severe complications of severe, chronic malnutrition. As exemplified by our case report, they may require extensive differential diagnosis and pose a significant clinical challenge due to their non-reversible character. A successful treatment relies heavily on the patient's compliance and may be hard to achieve. Clinicians managing patients with anorexia nervosa should be wary of early respiratory tract dysfunction-related symptoms and always consider malnutrition bronchiectasis as a differential diagnosis option.

A retrospective analysis of associations between BMI and days spent on mechanical ventilation in a level 1 trauma facility

OBJECTIVE

To examine whether BMI impacts the outcomes of mechanically ventilated patients.

METHODS

Data was collected retrospectively among patients involved in motor vehicle accidents in intensive care at a major trauma center in Atlanta, GA. Patients were categorized into five BMI groups: underweight (BMI < 18.5), normal weight (BMI of 18.5-24.9), overweight (BMI of 25-29.9), obese (BMI of 30-39.9), and morbidly obese (BMI of >40).

RESULTS

Among all patients (n=2,802), 3% of patients were underweight, 34% were of normal weight, 30% were overweight, 27% were obese, and 6% were morbidly obese. The mean number of ventilator days for normal weight patients was 4.6, whereas the mean number of ventilator days for underweight and morbidly obese patients were higher (10.3 and 7.4, respectively).

CONCLUSIONS

Underweight and morbidly obese populations may require additional interventions during their ICU stays to address the challenges presented by having an unhealthy BMI.

Differences in Respiratory Muscle Strength Measures in Well-Nourished and Malnourished Hospitalized Patients

BACKGROUND

Objective indicators of nutritional status are essential for accurate identification of malnutrition. Previous research has indicated an association between measures of respiratory muscle strength (RMS) and nutritional status. Measurement of RMS-including maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and sniff nasal inspiratory pressure (SNIP)-may provide evidence to support the assessment of nutritional status in hospitalized patients.

OBJECTIVE

The purpose of this study was to determine whether there was a difference in MIP, MEP, and SNIP between well-nourished and malnourished hospitalized patients.

DESIGN

A cross-sectional study was conducted.

PARTICIPANTS/SETTING

Patients were screened for eligibility criteria on admission by means of electronic medical records in general medical or surgical units at a tertiary care hospital in Chicago, IL, from January 2016 to January 2017. A total of 140 patients were included for analysis.

MAIN OUTCOMES MEASURED

The primary outcome was detection of differences in measures of RMS between malnourished and well-nourished hospitalized patients. Nutritional status was assessed using subjective global assessment and Academy of Nutrition and Dietetics/American Society for Parenteral and Enteral Nutrition (Academy/ASPEN) criteria recommended to identify malnutrition. The MIP, MEP, and SNIP measures were obtained and reported as absolute values (expressed in centimeters of water) and percent of predicted values.

STATISTICAL ANALYSIS

Independent t tests or Mann-Whitney U tests were used to determine differences in RMS measures between patients assessed as well nourished and those assessed as malnourished, depending on normality.

RESULTS

Compared with well-nourished patients, malnourished patients identified by subjective global assessment criteria had significantly lower absolute SNIP (73.7±28.7 vs 59.5±27.1 cm H₂O, P=0.004) and percent of predicted SNIP (78.6%±26.3% vs 64.8%± 30.0% predicted, P=0.006). Similarly, compared with well-nourished patients when Academy/ASPEN guidelines were used, malnourished individuals had significantly lower absolute SNIP (76.5±28.6 vs 58.3±26.3 cm H₂O, P<0.001), percent of predicted SNIP (81.4%±26.4% vs 63.5%±28.7% predicted, P<0.001), absolute MIP (83.5±34.6 vs 71.1±33.6 cm H₂O, P=0.05), and absolute MEP (108.7±36.6 vs 94.2±39.9 cm H₂O, P=0.04).

CONCLUSION

Differences in RMS between well-nourished and malnourished patients were observed when SNIP measures were used. However, there were no differences in MIP and MEP measures. Further research is needed to build on the findings from this study.

Diaphragmatic Palsy

The diaphragm is the primary muscle of respiration, and its weakness can lead to respiratory failure. Diaphragmatic palsy can be caused by various causes. Injury to the phrenic nerve during thoracic surgeries is the most common cause for diaphragmatic palsy. Depending on the cause, the symptoms of diaphragmatic palsies vary from completely asymptomatic to disabling dyspnea requiring mechanical ventilation. On pulmonary function tests, there will be a decrease in the maximum respiratory muscle power. Spirometry shows reduced lung functions and a significant drop of lung function in supine position is typical of diaphragmatic palsy. Diaphragmatic movements with respiration can be directly visualized by fluoroscopic examination. Currently, this test is being replaced by bedside thoracic ultrasound examination, looking at the diaphragmic excursion with deep breathing or sniffing. This test is found to be equally efficient, and without risks of ionizing radiation of fluoroscope. Treatment of diaphragmatic palsy depends on the cause. Surgical approach of repair of diaphragm or nonsurgical approach of noninvasive ventilation has been tried with good success. Overall prognosis of diaphragmatic palsy is good, except when it is related to neuromuscular degeneration conditions.

Acceleration sensors in abdominal wall position as a non-invasive approach to detect early breathing alterations induced by intolerance of increased airway resistance

BACKGROUND

Early detection of respiratory overload is crucial to mechanically ventilated patients, especially during phases of spontaneous breathing. Although a diversity of methods and indices has been established, there is no highly specific approach to predict respiratory failure. This study aimed to evaluate acceleration sensors in abdominal and thoracic wall positions to detect alterations in breathing excursions in a setting of gradual increasing airway resistance.

METHODS

Twenty-nine healthy volunteers were committed to a standardized protocol of a two-minutes step-down spontaneous breathing on a 5 mm, 4 mm and then 3 mm orally placed endotracheal tube. Accelerator sensors in thoracic and abdominal wall position monitored breathing excursions. 15 participants passed the breathing protocol ("completed" group), 14 individuals cancelled the protocol due to subjective intolerance to the increasing airway resistance ("abandoned" group).

RESULTS

Gradual increased respiratory workload led to a significant decrease of acceleration in abdominal wall position in the "abandoned" group compared to the "completed" group (p < 0.001), while these gradual accelerating changes were not observed in thoracic wall position (p = 0.484). Thoracic acceleration sensors did not detect any time- and group-specific changes (p = 0.746).

CONCLUSIONS

The abdominal wall position of the acceleration sensors may be a non-invasive, economical and practical approach to detect early breathing alterations prior to respiratory failure.

TRIAL REGISTRATION

EK 309-15; by the Ethics Committee of the Faculty of Medicine, RWTH Aachen, Aachen, Germany. Retrospectively registered 28th of December 2015.

Diaphragm Dysfunction: Diagnostic Approaches and Management Strategies

The diaphragm is the main inspiratory muscle, and its dysfunction can lead to significant adverse clinical consequences. The aim of this review is to provide clinicians with an overview of the main causes of uni- and bi-lateral diaphragm dysfunction, explore the clinical and physiological consequences of the disease on lung function, exercise physiology and sleep and review the available diagnostic tools used in the evaluation of diaphragm function. A particular emphasis is placed on the clinical significance of diaphragm weakness in the intensive care unit setting and the use of ultrasound to evaluate diaphragmatic action.

Exercise and physical therapy help restore body and self in clients with severe anorexia nervosa

Exercise in the context of anorexia nervosa is a multifaceted endeavour surrounded by controversy and uncertainty. A broader comprehension of this poorly understood phenomenon is required. Informed by the findings of a body examination of six individuals with anorexia nervosa, as well as exercise science, phenomenology and neurocognition, the purpose of this article is to elaborate on the potential role of exercise and physical therapy in the treatment of anorexia nervosa. The findings of the body assessment include constriction of posture, muscles and pattern of breathing. These bodily restraints are not necessarily merely associated with high levels of exercise, they may also reflect psychological strain accompanying the illness. The restricted breathing in particular is assumed to be associated with difficult thoughts and suppressed feelings. Based on the results of the body examination, as well as medical and psychological considerations accompanying the illness, it is suggested that interventions should focus on improving postural stability and restoring related muscular function. Integral to engaging in these activities, the potential to integrate proprioceptive information in this process may generate a more coherent experience of the body, as well as of the self, in these clients. Accordingly, constrictions of the body may have a vital role in constraining the experience of the self. As such, addressing bodily restraints in these clients may facilitate the experience of being the subject causing and controlling the movements. This is in marked contrast to clients' previous exercise experiences, which were associated with compulsion, rigidity and the absence of coherence and control.

Serum Albumin and Prealbumin in Calorically Restricted, Nondiseased Individuals: A Systematic Review

PURPOSE

Undernutrition is often suspected in patients when serum albumin or prealbumin levels are low. We asked whether these measures are indeed low in undernourished people if no inflammatory illness is present.

METHODS

We did a systematic review to identify otherwise healthy subjects who were severely nutrient-deprived due to poor access to food or unwillingness to eat. We excluded children and pregnant women. We tabulated available measures of nutrient intake, anthropometry, serum albumin and prealbumin, and, when available, changes in these measures during nutritional intervention.

RESULTS

In otherwise healthy subjects, serum albumin and prealbumin levels remained normal despite marked nutrient deprivation until the extremes of starvation, that is, body mass index <12 or more than 6 weeks of starvation.

CONCLUSIONS

In these otherwise healthy subjects, serum albumin and prealbumin levels are not "markers of nutritional status." The "markers" failed to identify subjects with severe protein-calorie malnutrition until extreme starvation. That is, they failed to identify healthy individuals who would benefit from nutrition support, becoming abnormal only when starvation was already obvious. In contrast, serum albumin and prealbumin levels are known to fall promptly with injury or illness regardless of nutrient intake. They are negative acute-phase reactants. When these measures are low in sick patients, this cannot be assumed to reflect nutritional deprivation. Decisions about nutrition support should be based on evidence of meaningful benefit from this treatment rather than on assessment of "nutritional markers."

Current status of the diagnosis and management of amyotrophic lateral sclerosis in Korea: a multi-center cross-sectional study

Background and Purpose

Recently published, evidence-based guidelines should alter the management of amyotrophic lateral sclerosis (ALS)/motor neuron disease (MND). However, the newest recommendations for ALS/MND therapy are not reflected in actual clinical practice. We sought to evaluate the current status of the diagnosis and management of ALS in Korea.

Methods

The Korean ALS/MND research group was organized in 2010, involving more than 50 neurologists from neuromuscular centers in Korea. Participating centers collected data from April to September 2010 on the diagnosis and management of patients with ALS. Data forms from the ALS patient care database, which is a component of the ALS clinical assessment, research, and education program (http://www.outcomes-umassmed.org/ALS/), were modified and used for data collection.

Results

In total, 373 sporadic ALS cases from 35 centers were enrolled. The demographic features and clinical findings were similar to those in previous reports from other countries. The mean age at onset was 50-60 years, and a slight male predominance was observed. The enrolled patients predominantly showed focal onset of cervical or lumbosacral symptoms. Only about one-half of the indicated patients (31.4%) received a physician's recommendation for a parenteral gastrostomy, and 18.1% underwent the procedure. Noninvasive ventilation was recommended in 23% of patients, but applied in only 9.5% of them. Tracheostomy was performed in 12.7% of patients.

Conclusions

The demographic and clinical features of the diagnosis and management of ALS in Korea are similar to those reported in other countries; however, supportive management, as recommended in evidence-based guidelines, are not yet widely recommended or performed for patients with ALS in Korea.

Monitoring of the respiratory muscles in the critically ill

Evidence has accumulated that respiratory muscle dysfunction develops in critically ill patients and contributes to prolonged weaning from mechanical ventilation. Accordingly, it seems highly appropriate to monitor the respiratory muscles in these patients. Today, we are only at the beginning of routinely monitoring respiratory muscle function. Indeed, most clinicians do not evaluate respiratory muscle function in critically ill patients at all. In our opinion, however, practical issues and the absence of sound scientific data for clinical benefit should not discourage clinicians from having a closer look at respiratory muscle function in critically ill patients. This perspective discusses the latest developments in the field of respiratory muscle monitoring and possible implications of monitoring respiratory muscle function in critically ill patients.

Respiratory functions in adolescents hospitalized for anorexia nervosa: a prospective study

OBJECTIVE

To examine the effects of malnourishment on the respiratory system of adolescents with anorexia nervosa (AN) hospitalized for medical stabilization.

METHOD

Prospective study.

STUDY GROUP

hospitalized adolescents with recent onset (<1 year) AN.

CONTROL GROUP

adolescents hospitalized for other diagnoses. Excluded: participants with lung disease.

RESULTS

Patients' characteristics (mean ± SD) for the AN (n = 16) and the control group (n = 13) on admission were: age: 15.0 ± 1.7 vs. 15.2 ± 1.4 years, p = 0.7; body mass index (BMI): 15.5 ± 2.3 vs. 19.8 ± 2.9 kg/m², p < 0.001; venous pH 7.34 ± 0.02 vs. 7.38 ± 0.03, p < 0.001; PCO₂ 53.3 ± 4.1 vs. 42.5 ± 3.1 mm Hg, p < 0.001; and HCO₃ 28.7 ± 2.0 vs. 25.3 ± 2.4 meq/L, p < 0.001, respectively. There were no significant differences in nocturnal respiratory rates, pulse-oximetry oxygen saturations, or end-tidal CO₂. Pulmonary function tests (PFTs) in adolescents with AN revealed no obstructive, restrictive, or significant pulmonary vascular disease except for lower peak expiratory flow rates (PEFRs). During hospitalization (12.3 ± 3.8 days), their weight, BMI, mean nocturnal heart rate, and respiratory rate increased significantly, while their venous PCO₂ and HCO₃ decreased significantly without significant changes in PFTs.

DISCUSSION

Adolescents with recent onset AN, admitted for medical stabilization, demonstrate hypercapnia despite normal PFTs, except for decreased PEFRs. These could result from decreased respiratory muscle strength and/or abnormal control of breathing.

Sudden death in eating disorders

Eating disorders are usually associated with an increased risk of premature death with a wide range of rates and causes of mortality. “Sudden death” has been defined as the abrupt and unexpected occurrence of fatality for which no satisfactory explanation of the cause can be ascertained. In many cases of sudden death, autopsies do not clarify the main cause. Cardiovascular complications are usually involved in these deaths. The purpose of this review was to report an update of the existing literature data on the main findings with respect to sudden death in eating disorders by means of a search conducted in PubMed. The most relevant conclusion of this review seems to be that the main causes of sudden death in eating disorders are those related to cardiovascular complications. The predictive value of the increased QT interval dispersion as a marker of sudden acute ventricular arrhythmia and death has been demonstrated. Eating disorder patients with severe cardiovascular symptoms should be hospitalized. In general, with respect to sudden death in eating disorders, some findings (eg, long-term eating disorders, chronic hypokalemia, chronically low plasma albumin, and QT intervals >600 milliseconds) must be taken into account, and it must be highlighted that during refeeding, the adverse effects of hypophosphatemia include cardiac failure. Monitoring vital signs and performing electrocardiograms and serial measurements of plasma potassium are relevant during the treatment of eating disorder patients.

Respiratory acidosis in adolescents with anorexia nervosa hospitalized for medical stabilization: a retrospective study

OBJECTIVE

To examine the effect of malnutrition due to anorexia nervosa (AN) on venous blood gases of adolescents with AN hospitalized for medical stabilization.

METHOD

This retrospective study included 45 adolescents with recent onset (<1 year) AN diagnosed by DSM-IV criteria and excluded subjects with a history of lung disease.

RESULTS

Mean (± SD) age at hospitalization was 15.0 ± 2.0 years; time from onset of symptoms was 6.8 ± 3.0 months; body mass index (BMI) was 15.2 ± 1.5 kg/m(2) ; and minimal nocturnal heart rate (MNHR) was 39.8 ± 7.2 beats/min. On admission, pH was 7.32 ± 0.02, pCO(2) was 53.8 ± 4.6 mm Hg, and HCO(3) was 28.1 ± 2.1 mEq/l. Significant changes (p < .001) occurred during the relatively short hospitalization (9.7 ± 5.1 days): venous pH increased, pCO(2) decreased, HCO(3) decreased, MNHR increased, and heart rate orthostasis decreased. Mild respiratory acidosis (pH < 7.35 and pCO(2) > 45 mm Hg) was observed in 78% of the patients on admission and only in 35% at discharge (p = .0003). Positive correlations were found between % of weight loss and pCO(2) on admission and between BMI on admission and the delta pCO(2) during hospitalization.

DISCUSSION

Mild respiratory acidosis is common in adolescents with recently diagnosed AN, hospitalized for medical stabilization. Respiratory acidosis improves with bed rest and refeeding. The clinical significance of these findings should be further evaluated.

Percutaneous endoscopic gastrostomy in amyotrophic lateral sclerosis: effect on survival

BACKGROUND

Percutaneous endoscopic gastrostomy (PEG) is offered to amyotrophic lateral sclerosis (ALS) patients with severe dysphagia. Immediate benefits of PEG are adequate food intake and weight stabilization. However, the impact of PEG on survival is still uncertain. In this work we retrospectively evaluated the effect of PEG on survival in a cohort of ALS patients followed in a tertiary referral centre.

METHODS

Between 2000 and 2007, 150 dysphagic ALS patients were followed until death or tracheostomy. PEG was placed in 76 patients who accepted the procedure and survival was analysed using the Kaplan-Meier life-table method.

RESULTS

In ALS patients submitted to PEG, no major complications were observed. Total median survival time from symptom onset was 38 months for PEG users as compared to 32 months for the remaining dysphagic patients who declined the procedure (p=0.05). Among bulbar-onset patients, PEG users showed a median survival time longer than those with no PEG (28 months vs. 25 months), even though the difference was not significant. Conversely, dysphagic spinal-onset patients with PEG lived significantly longer than those who refused this palliative care (44 months vs. 36 months, p=0.046). Survival in patients with PEG was not affected by the severity of the respiratory impairment, as measured by forced vital capacity.

CONCLUSIONS

This study demonstrates that PEG improves survival in dysphagic ALS patients, with few side effects. The procedure is safe and applicable even to patients with impaired respiratory function. PEG remains a milestone in palliative care in dysphagic ALS patients.

Sniff nasal inspiratory pressure versus IC/TLC ratio as predictors of mortality in COPD

BACKGROUND

Hyperinflation is a recognized adverse prognostic factor in COPD. As the sniff inspiratory nasal pressure (SnIP) principally reflects the severity of hyperinflation in COPD, we hypothesized that it might also be a predictor of mortality. We therefore compared the SnIP to the inspiratory capacity-to-total lung capacity (IC/TLC) ratio as predictors of mortality in advanced COPD.

METHODS

A retrospective mortality analysis of 110 patients with COPD (mean FEV(1) 1.01litres, 37% predicted; 66% male) was performed. All patients had SnIP and lung volume measurements performed. The power of each test to predict mortality was determined, and predicted survival curves were created for both the SnIP and IC/TLC ratio.

RESULTS

37 patients (34%) died during the study period (29 male, 8 female). Mortality rates were analysed with a Chi(2) test; there was a significant trend towards male death (mortality rate male vs. female; 39.7% vs. 21.6% respectively; chi(2)p=0.058, Chi 3.6). ROC curves demonstrated that both SnIP and IC/TLC ratio are predictors of mortality, but analysis by Cox proportional hazards suggested the SnIP has a stronger predictive power (SnIP vs. IC/TLC ratio; p=0.017 vs 0.525; HR 0.97 vs 0.99 respectively), and analysis of the area under ROC curves (AUC) suggest that SnIP is a better discriminator than IC/TLC ratio (AUC SnIP vs IC/TLC; 0.679 vs 0.618).

CONCLUSIONS

The SnIP conveys at least as much predictive power for mortality in COPD as hyperinflation determined by IC/TLC ratio. This test is cheaper, quicker and easier than measuring lung volumes by plethysmography.

[Lung function prediction equations in Tunisian children: taking into consideration pubertal stage]

OBJECTIVE

The purpose of this study was to set lung function prediction equations in Tunisian children with standing height and pubertal stage as the independent variables.

METHODS

Spirometric values were measured with a Minato portable Spirometer in 684 asymptomatic Tunisian children (351 boys and 333 girls), 8 to 16 years of age. The specific parameters of pulmonary function that were measured included Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 second (FEV(1)), Peak Expiratory Flow (PEF), Maximal Expiratory Flow at 50% of the vital capacity (MEF(50)), and Maximum Mild Expiratory Flow between 25 and 75% (MMEF(25-75)). The pubertal status was assessed for males and females according to the Tanner method.

RESULTS

A large variation was observed in the distribution of children's age and height by pubertal stages in both sexes. Multiple regression equations for FVC, FEV(1), MEF(50), MEF(25-75), and PEF for both sexes are presented with standing height and pubertal stage as the independent variables.

CONCLUSION

The establishment of validated reference values relevant to the ethnic group of the local population should significantly improve medical surveillance of respiratory diseases in Tunisian children.

A randomized trial on the efficacy of a 2-month tube feeding regimen in anorexia nervosa: A 1-year follow-up study

BACKGROUND & AIMS

Despite the high mortality rate in malnourished anorexia nervosa (AN) patients, very few trials have prospectively studied the efficacy of tube feeding.

METHODS

This open prospective study was conducted in malnourished AN patients, who were randomized in tube feeding (n=41) or control (n=40) groups during a 2-month period. Thereafter, body weight, body mass gain, energy intake, eating behavior and relapse rates were compared during a 1-year follow-up, using paired Student t-test and ANOVA.

RESULTS

At the end of the 2-months period, weight gain was 39% higher in the tube feeding group than in the control group (194+/-14 vs 126+/-19g/day; P<0.01). The fat-free mass gain was greater in the tube-feeding group: 109+/-14 vs 61+/-17g/day (P<0.01). Energy intake was higher in the tube feeding group than in the control group (P<0.05), as well as the decrease in bingeing episodes (P<0.01). Most patients thought that CEN improved their eating disorder. After discharge, the relapse-free period was longer in the CEN group than in the control one: 34.3+/-8.2 weeks vs 26.8+/-7.5 weeks (P<0.05).

CONCLUSION

CEN is helpful in malnourished AN patients for weight restoration, without hindrance on the eating behavior therapy nor inducing a more rapid relapse.

Neuromuscular disorders in critical illness

Neuromuscular disorders in the background of critical illness are under diagnosed. Standardized screening for weakness in the intensive care unit (ICU) setting is uncommon and persistent weakness as a sequel of critical illness is usually not recognized by physicians in the ICU for whom survival from acute illness is the primary outcome. The spectrum of illness ranges from isolated nerve entrapment with focal pain or weakness, to disuse muscle atrophy with mild weakness, and to severe myopathy or neuropathy with associated severe, prolonged weakness. This update focuses on neuromuscular disorders occurring in the critical care set up associated with diffuse and severe weakness.

Effects of undernutrition on respiratory mechanics and lung parenchyma remodeling

Undernutrition thwarts lung structure and function, but there are disagreements about the behavior of lung mechanics in malnourished animals. To clarify this issue, lung and chest wall mechanical properties were subdivided into their resistive, elastic, and viscoelastic properties in nutritionally deprived (ND) rats and correlated with the data gathered from histology (light and electron microscopy and elastic fiber content), and bronchoalveolar lavage fluid analysis (lipid and protein content). Twenty-four Wistar rats were assigned into two groups. In the control (Ctrl) group the animals received food ad libitum. In the ND group, rats received one-third of their usual daily food consumption until they lost 40% of their initial body weight. Lung static elastance, viscoelastic and resistive pressures (normalized by functional residual capacity), and chest wall pressures were higher in the ND group than in the Ctrl group. The ND group exhibited patchy atelectasis, areas of emphysema, interstitial edema, and reduced elastic fiber content. The amount of lipid and protein in bronchoalveolar lavage fluid was significantly reduced in the ND group. Electron microscopy showed 1) type II pneumocytes with a reduction in lamellar body content, multilamellated structures, membrane vesicles, granular debris, and structurally aberrant mitochondria; and 2) diaphragm and intercostals with atrophy, disarrangement of the myofibrils, and deposition of collagen type I fibers. In conclusion, undernutrition led to lung and chest wall mechanical changes that were the result from a balance among the following modifications: 1) distorted structure of diaphragm and intercostals, 2) surfactant content reduction, and 3) decrease in elastic fiber content.

Nutritional status is an important predictor of diaphragm strength in young patients with cystic fibrosis

BACKGROUND

The effect of nutritional status and lung disease progression on diaphragm strength in young patients with cystic fibrosis remains unclear.

OBJECTIVE

The aim of this study was to investigate the effect of nutritional status and airway obstruction on diaphragm strength.

DESIGN

Twitch transdiaphragmatic pressure (Tw Pdi) obtained by bilateral anterior magnetic phrenic nerve stimulation, body mass index (BMI) z score, fat mass, fat-free mass (FFM), arm muscle circumference (AMC), forced expiratory volume in 1 s (FEV(1)), and functional residual capacity (FRC) were measured in 20 patients aged 15.1 +/- 2.8 y (x +/- SD). Values were expressed as a percentage of predicted values.

RESULTS

Mean (+/-SD) Tw Pdi was 24.3 +/- 5.5 cm H(2)O. Univariate regression analysis showed positive correlations between Tw Pdi and nutrition scores (BMI z score: r = 0.63, P = 0.003; FFM: r = 0.47, P = 0.04; AMC: r = 0.45, P = 0.04), airway obstruction (FEV(1): r = 0.68, P = 0.001), and arterial oxygen partial pressure (r = 0.68, P = 0.001). Negative correlations were observed between Tw Pdi and dynamic hyperinflation (FRC: r = -0.65, P = 0.005) and arterial carbon dioxide pressure (r = -0.50, P = 0.03). Furthermore, stepwise regression analysis showed that Tw Pdi correlated with BMI z score (r = 0.75, P = 0.0002) and FEV(1) (r = 0.69, P = 0.001).

CONCLUSIONS

Diaphragm strength is relatively well preserved in young patients with cystic fibrosis. However, the strength of the diaphragm decreases with the progression of malnutrition and airway obstruction.

Early Emphysema in Patients with Anorexia Nervosa

Postmortem studies of patients who died in the Warsaw Ghetto during World War II suggested that death from starvation was associated with pulmonary emphysema. This study re-examines this hypothesis in patients who are chronically malnourished because of anorexia nervosa. Age, smoking history, body mass index, and pulmonary function were measured in 21 subjects with anorexia nervosa and 16 control subjects. Computed tomography (CT) scans were obtained from three regions of the lung (at the level of the aortic arch, the carina, and the posterior position of the eighth rib) using a multislice scanner. The CT measurements of lung density, emphysema, and surface area-to-volume ratio were obtained using the X-ray attenuation values. CT measurements of emphysema were greater in the group that was anorexic than in historical control subjects (p < 0.001). Furthermore, there were significant correlations between the body mass index and the CT measures of emphysema for all the patients and between diffusing capacity and the CT measurements in the patients who were anorexic. A multiple linear regression analysis showed the diffusing capacity was predicted best by the percentage of lung voxels within the large emphysematous changes category. These data demonstrate that emphysema-like changes are present in the lungs of patients who are chronically malnourished.

Refeeding syndrome in patients with gastrointestinal fistula

OBJECTIVE

Although refeeding syndrome has been well documented in starved patients, obese patients, those with anorexia nervosa, malnourished elderly individuals, and certain postoperative patients, little is known about the presence and the importance of refeeding syndrome in patients with gastrointestinal fistula and insufficient nutrition support over the long term. The objective of this study was to estimate the morbidity of this syndrome in these patients, to assess the safety and efficacy of our graduated refeeding regimen, and to emphasize the importance of this syndrome.

METHODS

One hundred fifty-eight patients with gastrointestinal fistula during the past 2 y were reviewed.

RESULTS

Fifteen of these patients were diagnosed as having refeeding syndrome. They were started on the refeeding procedure according to our regimen, and changes in their serum levels of electrolytes were recorded. The symptoms and signs they presented were noted. All patients were successfully advanced to full nutrition support. During the refeeding procedure, patients presented with weakness, paralysis of limbs, slight dyspnea, paresthesia, tachycardia, edema, and diarrhea. Serum phosphorus concentration decreased in all patients within 24 h of refeeding, reaching a mean nadir after 3.3 +/- 1.5 d and another 6.1 +/- 2.1 d to return to above 0.70 mM/L upon phosphorus supplementation. Three patients treated with growth hormone presented more severe hypophosphatemia (<0.20 mM/L) than the others.

CONCLUSIONS

1) Refeeding syndrome occurs commonly in patients with malnutrition secondary to gastrointestinal fistula. 2) Alterations in phosphate metabolism are central to the refeeding syndrome. 3) Supplementation with electrolytes (including especially phosphate) and vitamins is the focal point of the treatment of this syndrome. 4) Growth hormone treatment may aggravate hypophosphatemia.

Function and bulk of respiratory and limb muscles in patients with cystic fibrosis

Inspiratory muscle weakness due to lung hyperinflation and muscle wasting may occur in cystic fibrosis. We therefore measured diaphragm function and bulk in 18 stable patients with cystic fibrosis and 15 matched control subjects; the abdominal and quadriceps muscles were studied for comparison. We assessed diaphragm mass, abdominal muscle thickness, twitch transdiaphragmatic and gastric pressures, quadriceps cross-section and isokinetic strength, and lean body mass. Lean body mass, quadriceps strength, and quadriceps cross-section were lower in patients with cystic fibrosis. Twitch transdiaphragmatic pressure was 23% lower and twitch gastric pressure was 22% greater in patients with cystic fibrosis than in control subjects, but diaphragm mass and abdominal muscle thickness were similar in the two groups. For any given lean body mass and quadriceps cross-section, patients with cystic fibrosis had greater diaphragm mass and abdominal muscle thickness. Diaphragm mass had greater intersubject variability in patients with cystic fibrosis than in control subjects. We conclude that diaphragm strength is decreased but abdominal muscle strength is increased in patients with cystic fibrosis. Diaphragm and abdominal muscle bulk are not affected by the general muscle wasting, which suggests that there may be a training effect of cystic fibrosis on respiratory muscles. However, the variability of diaphragm mass indicates that this beneficial response does not occur in all patients with cystic fibrosis.

Percutaneous endoscopic gastrostomy (PEG) in patients with ALS and bulbar dysfunction

OBJECTIVE

To compare characteristics of ALS patients with and without percutaneous endoscopic gastrostomy (PEG).

METHODS

Using the ALS Patient Care Database, data from patients with and without PEG with ALS Functional Rating Scale-bulbar subscale (ALSFRSb) scores < or = 5 were analyzed; follow-up data were also collected.

RESULTS

PEG use was markedly increased with declining ALSFRSb scores. Demographics did not differ, but ALSFRS composite scores and bulbar and arm subscale scores were lower (P<0.0001). PEG patients used significantly more assistive devices, multidisciplinary care, home care nurses and aides, had more frequent physician and emergency department visits and hospital admissions (P<0.0001), and had lower health status based on the mini-SIP scale (P=0.0047). PEG use varied greatly between ALS centers. In the follow-up study, positive impact of PEG was noted in 79 % of PEG patients but in only 37.5% of patients who received PEG later, based on a small number of patients. PEG use showed no survival benefit.

CONCLUSION

Patients did not receive PEG until bulbar function was severely reduced and overall ALS had markedly progressed. PEG may have been performed too late to demonstrate survival benefits. Aggressive proactive nutritional management appears essential in patients with ALS. To determine whether PEG provides benefits, it must be performed at earlier stages of the disease and prospectively studied.

Influence of varying degrees of malnutrition on IGF-I expression in the rat diaphragm

This study evaluated the impact of varying degrees of prolonged malnutrition on the local insulin-like growth factor-I (IGF-I) system in the costal diaphragm muscle. Adult rats were provided with either 60 or 40% of usual food intake over 3 wk. Nutritionally deprived (ND) animals (i.e., ND60 and ND40) were compared with control (Ctl) rats fed ad libitum. Costal diaphragm fiber types and cross-sectional areas were determined histochemically. Costal diaphragm muscle IGF-I mRNA levels were determined by RT-PCR. Serum and muscle IGF-I peptide levels were determined by using a rat-specific radioimmunoassay. The body weights of Ctl rats increased by 5%, whereas those of ND60 and ND40 animals decreased by 16 and 26%, respectively. Diaphragm weights were reduced by 17 and 27% in ND60 and ND40 animals, respectively, compared with Ctl. Diaphragm fiber proportions were unaffected by either ND regimen. Significant atrophy of both type IIa and IIx fibers was noted in the ND60 group, whereas atrophy of all three fiber types was observed in the diaphragm of ND40 rats. Serum IGF-I levels were reduced by 62 and 79% in ND60 and ND40 rats, respectively, compared with Ctl. Diaphragm muscle IGF-I mRNA levels in both ND groups were similar to those noted in Ctl. In contrast, IGF-I concentrations were reduced by 36 and 42% in the diaphragm muscle of ND60 and ND40 groups, respectively, compared with Ctl. We conclude that the local (autocrine/paracrine) muscle IGF-I system is affected in our models of prolonged ND. We propose that this contributes to disordered muscle protein turnover and muscle cachexia with atrophy of muscle fibers. This is particularly so in view of recent data demonstrating the importance of the autocrine/paracrine system in muscle growth and maintenance of fiber size.

Respiratory muscle weakness and anorexia nervosa

BACKGROUND

Nutritional recovery in anorexia nervosa (AN) is associated with improved exercise tolerance.

METHOD

We describe the investigation of a male with AN. Despite nutritional recovery, he complained of impaired exercise tolerance.

RESULTS

Respiratory muscle weakness was demonstrated as the cause of the impaired exercise tolerance.

DISCUSSION

Weakness of the muscles of respiration results from prolonged malnutrition. The diaphragmatic muscle may be slower to recover than other muscles. This can cause impaired exercise tolerance due to shortness of breath on exertion, despite nutritional recovery.

Does undernutrition contribute to diaphragm weakness in patients with severe COPD?

BACKGROUND AND AIMS

The assumption that undernourishment contributes to diaphragm weakness in chronic obstructive pulmonary disease (COPD) remains unproven.

METHODS

We, therefore, studied diaphragm strength, measured as transdiaphragmatic pressure during a maximal voluntary sniff (Sn P(di)) and cervical magnetic stimulation (Tw P(di)), in two groups of 10 patients with severe COPD. The groups had equally severe COPD as judged by FEV(1) and thoracic gas volume (V(tg)). The malnourished group had a mean body mass index (BMI) of 17.3 kg/m(2) compared with 27 kg/m(2) for the normally nourished group (mean difference -9.7 kg/m(2); 95% confidence intervals -6.8 to -12.6 kg/m(2),P <0.0001).

RESULTS

There was no significant difference between Tw P(di) (mean difference 2.1 cm H(2)O; 95% CI-3 to + 7.4 cm H(2)O, P=0.39) or Sn P(di) (mean difference -2.4 cm H(2)O; 95% CI-21 cm H(2)O to +16 cm H(2)O,P =0.8).

CONCLUSION

We conclude that undernourishment of the severity studied does not contribute to diaphragm weakness in severe COPD.

Effect of prolonged undernutrition on rat diaphragm mitochondrial respiration

Previous studies have shown that undernutrition induces an impairment of the respiratory muscle function in patients with chronic lung disease. To explain this, we hypothesized that undernutrition could decrease oxidative metabolism in the diaphragm. We therefore examined the effect of prolonged undernutrition on diaphragm mitochondrial oxygen uptake with pyruvate and palmitate as substrates in adult rats. Ten rats served as controls (CTL). Ten nutritionally deprived rats (ND) received 40% of their estimated daily nutrition. Five weeks of undernutrition induced a 33% decrease in state 3 respiration with pyruvate plus malate as substrate (993 +/- 171 versus 1488 +/- 167 nmol atomic O/mg/min, P < 0.01) and a 39% decrease with palmitate plus malate (516 +/- 89 versus 850 +/- 165 nmol atomic O/mg/min, P < 0.05). With succinate plus rotenone, there was no significant difference in the respiratory rate between groups. In the ND group, we found a significant decrease in citrate synthase activity (P < 0.01), and also in reduced nicotinamine adenine dinucleotide (NADH) dehydrogenase activity (P < 0.05), which cannot alone induce such a state 3 respiratory decrease. This showed that undernutrition in rat diaphragm does not induce an alteration in protein complexes I, II, III, and IV, or the F complex containing the mitochondrial ATPase of the electron transport chain. In conclusion, the main result of this study was that prolonged undernutrition induced a decrease in mitochondrial respiration secondary to a significant reduction in NADH generation by the Krebs cycle, which may affect respiratory muscle function with implications for patient care.

Nutrition in chronic critical illness

Nutritional management of patients with respiratory failure can be a model of nutritional management in chronically critically ill patients. This model requires recognition of the differing metabolic states of starvation and hypermetabolism. Starvation can result in malnutrition, with adverse effect on respiratory muscle strength, ventilatory drive, and immune defense mechanisms. General nutritional goals include preservation of lean body mass by providing adequate energy and positive nitrogen balance. General nutritional prescriptions for both states include a substrate mix of 20% protein, 60% to 70% carbohydrates, and 20% to 30% fat. Positive nitrogen balance is difficult to attain in hypermetabolic patients and energy requirements are increased compared with starved patients. Enteral nutrition should be the mode of initial nutrient delivery unless the gastrointestinal tract is nonfunctional. Monitoring of nutritional support is essential. Complications of nutritional support are multiple. Nutritional hypercapnia is an important complication in a chronically critically ill patient. Outcomes of selected long-term acute patients are poor, with only 8% of patients fully functional 1 year after discharge. Appropriate nutritional therapy is one aspect of management of these patients that has the possibility of optimizing function and survival.

Changes in pulmonary hyperinflation and bronchial hyperresponsiveness following treatment with lansoprazole in children with cystic fibrosis

SUMMARY. In this prospective open study of 14 children with cystic fibrosis (CF), we evaluated the effect of 1 year adjuvant therapy with lansoprazole, a proton pump inhibitor (PPI), on growth, fecal fat loss, body composition and lung function. Only stable patients with pancreatic insufficiency were included, and their data were compared to those of a large Dutch pediatric normal reference population. During the use of the PPI, mean weight and height did not change significantly, while body mass index improved (P < 0.05). An immediate significant and persistent reduction of fecal acid steatocrit (P < 0.05) was demonstrated. Compared to normal Dutch children, the CF patients showed significantly decreased standard deviation scores (SDS) for total body fat (TBF, -0.966) and fat-free mass (FFM, -1.826). Under lansoprazole, TBF improved significantly (P < 0.05), while mean FFM remained unchanged. A significant improvement in total lung capacity (P < 0.05), residual volume (P = 0.055), and maximal inspiratory mouth pressure (P = 0.002) was also demonstrated. Hyperinflation tended to decrease during the use of a PPI. Daily recordings of peak expiratory flow (PEF) showed a maximal diurnal variability of 28% of recent best PEF and minimal morning PEF of 72% of recent best PEF, confirming that bronchial hyperresponsiveness is increased in CF. We conclude that adjuvant therapy with lansoprazole in young CF patients with persistent fat malabsorption, decreased fat losses and improved total body fat. Lung hyperinflation decreased, which may partly explain the improvement in inspiratory muscle performance. The simultaneous improvements in body composition and lung hyperinflation suggest a relationship between these two parameters. Further research is necessary to confirm such a relationship and to elucidate the mechanisms involved.

Tissue depletion and health related quality of life in patients with chronic obstructive pulmonary disease

The relationship between tissue depletion and decreased exercise performance has been well established in patients with COPD. In this study we investigated the influence of the pattern of tissue depletion on health related quality of life (HRQL) and their mutual relationship with exercise capacity and dyspnoea. Patients with low body weight and/or low fat-free mass (FFM; using bioelectrical impedance) were categorized in three groups according to type of tissue depletion: loss of both FFM and fat mass (FM), and loss of FFM or FM only. Handgrip strength (HGS) was used as a functional outcome measure of tissue depletion. Exercise performance was assessed by 12 min walking distance (12MWD) and dyspnoea by visual analogue scale (VAS). HRQL was measured with the St George's Respiratory Questionnaire (SGRQ) and the Medical Psychological Questionnaire for Lung diseases (MPQL). Patients with depletion of FFM irrespective of body weight showed greater impairment in 12MWD, HGS, the 'activity' and 'impact' scores of the SGRQ and the domain 'invalidity' of the MPQL, in comparison with depleted patients with relative preservation of FFM. Exercise performance and dyspnoea were also significantly related to these subscores of HRQL. In addition, dyspnoea related significantly to the domain 'symptoms' of the SGRQ. Tissue depletion pattern remained significantly related to SGRQ-scores and the domain 'invalidity' of the MPQL when dyspnoea and walking distance were added to the model as a covariates. Tissue depletion is an important determinant of HRQL independent of exercise capacity and dyspnoea.

Lung function study and diffusion capacity in anorexia nervosa

STUDY OBJECTIVES

In humans, malnutrition alters the respiratory system in different ways. It impairs the ventilatory drive, decreases respiratory muscle strength and reduces immune competence. In addition, typical emphysema-like changes were demonstrated in starved animals. The presence of emphysema has never been demonstrated in starved humans. Our objective was to investigate whether pulmonary emphysema occurs in anorexia nervosa by means of a pulmonary function study.

POPULATION AND METHOD

We examined 24 women aged between 14 and 38 years (nine smokers). We studied the lung function including lung volumes, ventilatory capacity, maximal respiratory pressures and transfer factor, as well as PaO2.

RESULTS

All respiratory tests were within normal limits with the exception of decreased maximal inspiratory (59% of predicted values) and expiratory pressures (35%), and increased residual volume (162%). Diffusion capacity (98.1 +/- 16.2%) and transfer coefficient (98.4 +/- 16.2%) were also normal. The diffusion coefficient was lower in current smokers than in those who had never smoked (P < 0.01), a difference similar to that calculated from existing reference values for transfer factor for smokers and nonsmokers.

CONCLUSION

In anorexia nervosa, pulmonary function tests are within normal limits with the exception of maximal pressures and residual volume. Diffusion capacity is not decreased. The present results within the limitations of the used method are not compatible with the hypothesis of starvation-induced pulmonary emphysema.

Treatment of cachexia with recombinant growth hormone in a patient before lung transplantation: a case report

OBJECTIVES

To describe the effects of recombinant human growth hormone (rhGH) in a severely malnourished patient before lung transplantation.

DESIGN

Case study.

SETTING

Intensive care unit.

PATIENTS

A 38-yr-old severely malnourished (body mass index, 15.1 kg/m2) woman (receiving prednisone) with bronchiolitis obliterans evolving during 10 yrs presented with end-stage lung disease and required continuous noninvasive mechanical ventilation.

INTERVENTIONS

Two courses of 35 days of 16 IU/day (0.42 IU/kg/day) rhGH administered subcutaneously, with an interruption of 5 wks between the two courses of rhGH.

MEASUREMENTS AND MAIN RESULTS

Weight gain of 14.7% and 12.8% fat-free mass, as measured by 50-kHz bioelectrical impedance analysis, during treatment during a 3.5-month period. Nitrogen excretion decreased from 23.7 g/day before treatment to 8.0 g/day while receiving rhGH. Improvement of pulmonary function was also noted and allowed discharge of the patient from the hospital after the second course of rhGH. She underwent successful lung transplantation 2 months later and reached 48.8 kg of body weight 6 months later.

CONCLUSIONS

rhGH treatment is a possible strategy that could be used with malnourished patients who are awaiting lung transplantation to improve the nutritional status and respiratory muscle function to prevent recurring respiratory infection and postoperative complications favored by malnutrition and possibly to decrease the length of hospital stay.

Assessment of respiratory muscle function and strength

Measurement of respiratory muscle strength is useful in order to detect respiratory muscle weakness and to quantify its severity. In patients with severe respiratory muscle weakness, vital capacity is reduced but is a non-specific and relatively insensitive measure. Conventionally, inspiratory and expiratory muscle strength has been assessed by maximal inspiratory and expiratory mouth pressures sustained for 1 s (PImax and PEmax) during maximal static manoeuvre against a closed shutter. However, PImax and PEmax are volitional tests, and are poorly reproducible with an average coefficient of variation of 25%. The sniff manoeuvre is natural and probably easier to perform. Sniff pressure, and sniff transdiaphragmatic pressure are more reproducible and useful measure of diaphragmatic strength. Nevertheless, the sniff manoeuvre is also volition-dependent, and submaximal efforts are most likely to occur in patients who are ill or breathless. Non-volitional tests include measurements of twitch oesophageal, gastric and transdiaphragmatic pressure during bilateral electrical and magnetic phrenic nerve stimulation. Electrical phrenic nerve stimulation is technically difficult and is also uncomfortable and painful. Magnetic phrenic nerve stimulation is less painful and transdiaphragmatic pressure is reproducible in normal subjects. It is a relatively easy test that has the potential to become a widely adopted method for the assessment of diaphragm strength. The development of a technique to measure diaphragmatic sound (phonomyogram) during magnetic phrenic nerve stimulation opens the way for noninvasive assessment of diaphragmatic function.