Changes in albuminuria during the spontaneous breathing trial: A prospective observational study.

BACKGROUND: We hypothesized urine albumin concentration may detect the early increasing cardiac load during the spontaneous breathing trial (SBT). The purpose of our study is to determine whether the changes in urine albumin concentration before and after the SBT correlate with SBT outcome. METHODS: This prospective observational study was conducted from January 2013 to September 2013. Patients receiving endotracheal tube intubation due to acute respiratory failure were included. Urine albumin concentration was measured upon admission to the intensive care unit, before and after the SBT. RESULTS: A total of 211 patients with respiratory failure were screened. Finally, 69 patients were included for analysis. Among the 69 patients received the SBT, 61 patients passed the SBT while 8 patients didn't. Urine albumin concentration upon admission was 251.00 ± 108.21 mg/g in the SBT success group and 260.87 ± 77.95 mg/g in the SBT failure group (p = 0.97). The mean percent change in urine albumin concentration during the SBT was significantly higher in the SBT failure group (+58.44%) than in the SBT success group (+13.11%) (p = 0.02). Univariable and multivariable logistic regression model showed that the difference of urine albumin concentration before and after the SBT correlated significantly with SBT failure (adjusted OR:1.04, p = 0.01). CONCLUSION: This open label pilot study demonstrates the significant association of the changes in urine albumin concentration with SBT outcome. Further study is warranted to investigate the predictive value of urine albumin concentration.

Effects of Sustained Inflation or Positive Pressure Ventilation on the Release of Adrenomedullin in Preterm Infants with Respiratory Failure at Birth.

OBJECTIVE: Delivery room (DR) management may play an important role in the development and prevention of lung injury. Therefore, in a cohort of low birth weight infants (LBW), we investigated the effects of two different lung recruitment maneuvers, such as positive pressure ventilation (PPV) and sustained inflation (SI) on adrenomedullin (AM), a well-established lung-specific vasoactive agent. STUDY DESIGN: This is a prospective case-control randomized study in 44 LBW infants spontaneously breathing with respiratory failure at birth requiring respiratory support. LBW were randomized to receive PPV (n = 22) or SI (n = 22) support. AM was measured from blood in samples collected at birth from arterial artery (BLT0) and at 1-hour (BLT1) and at 24-hour (BLT2) from peripheral venous site. AM assessment in urine samples was performed at 1-hour (URT1) and at 24-hour (URT2). RESULTS: No significant differences in AM (p > 0.05) blood (T0-T2) and urine (T1, T2) levels were observed between groups. CONCLUSION: The present data, showing the absence of any differences in AM blood and urine levels, suggest that PPV and SI are both feasible and equally effective DR maneuvers. The findings open the way to further studies evaluating the effects of PPV and SI on short-/long-term respiratory outcome through biomarkers assessment.

Microproteinuria Predicts Organ Failure in Patients Presenting with Acute Pancreatitis.

BACKGROUND AND AIMS: The disease course of acute pancreatitis (AP) ranges from mild and self-limiting to severe inflammation, associated with significant morbidity and mortality. At present, there are no universally accepted and reliable predictors for severity. Microproteinuria has been associated with the presence of systemic inflammatory response syndrome as well as trauma, although its association with AP is not well understood. The aim of this study was to investigate the value of microproteinuria to predict development of organ failure in AP. METHODS: Consecutive AP patients were prospectively enrolled. Urine samples were collected upon admission, 12-24 h after admission, and 3 months post-discharge for calculation of urine α1-microglobulin-, albumin-, IgG-, and IgM/creatinine ratios. Data regarding AP etiology, severity, and development of organ failure were registered. RESULTS: Overall, 92 AP patients were included (14 % with organ failure; 6 % with severe AP). The α1-microglobulin-, albumin-, and IgG/creatinine ratios correlated with high-sensitivity C-reactive protein 48 h after admission (r = 0.47-0.61, p < 0.001 for all). They were also significantly higher in patients with versus without organ failure (p < 0.05 for all). The α1-microglobulin/creatinine ratio upon admission predicted organ failure [adjusted odds ratio 1.286, 95 % confidence interval (CI) 1.024-1.614] with similar accuracy (AUROC 0.81, 95 % CI 0.69-0.94) as the more complex APACHE II score (AUROC 0.86, 95 % CI 0.70-1.00). CONCLUSION: The α1-microglobulin/creatinine ratio upon presentation with AP is related to inflammation and predicts development of organ failure. Further studies are warranted to evaluate its potential usefulness in predicting outcome for AP patients.

A comparison of bronchodilator therapy delivered by nebulization and metered-dose inhaler in mechanically ventilated patients.

BACKGROUND: The optimal method of delivering bronchodilators in mechanically ventilated patients is unclear. The purpose of this study was to compare the pulmonary bioavailability of albuterol delivered by the nebulizer, the metered-dose inhaler (MDI) and spacer, and the right-angle MDI adaptor in ventilated patients using urinary analysis of drug levels. METHODS: Mechanically ventilated patients who had not received a bronchodilator in the previous 48 h and who had normal renal function were randomized to receive the following: (1) five puffs (450 microg) of albuterol delivered by the MDI with a small volume spacer; (2) five puffs of albuterol delivered by the MDI port on a right-angle adaptor; or (3) 2.5 mg albuterol delivered by a nebulizer. Urine was collected 6 h after the administration of the drug, and the amounts of albuterol and its sulfate conjugate were determined in the urine by a chromatographic assay. RESULTS: Thirty patients were studied, 10 in each group: their mean age and serum creatinine level were 62 years and 1.3 mg/dL, respectively. With the MDI and spacer, (mean +/- SD) 169+/-129 microg albuterol (38%) was recovered in the urine; with the nebulizer, 409+/-515 microg albuterol (16%) was recovered in the urine; and with the MDI port on the right-angle adaptor, 41+/-61 microg albuterol (9%) was recovered in the urine (p = 0.02 between groups). The level of albuterol in the urine was below the level of detection in four patients in whom the drug was delivered using the right-angle MDI adaptor. CONCLUSION: The three delivery systems varied markedly in their efficiency of drug delivery to the lung. As previous studies have confirmed, this study has demonstrated that using an MDI and spacer is an efficient method for delivering inhaled bronchodilators to the lung. The pulmonary bioavailability was poor with the right-angle MDI port. This port should not be used to deliver bronchodilators in mechanically ventilated patients.

Clearance of Clara cell secretory protein 16 (CC16) and surfactant proteins A and B from blood in acute respiratory failure.

Surfactant proteins A and B (SP-A and SP-B) enter the circulation in a manner that acutely reflects changes in pulmonary function in patients with acute respiratory failure (ARF). There is a small but significant gradient in SP-A and SP-B from arterial to mixed venous (A-V) blood, and since we have detected both proteins in urine, the kidney may be a major site of their systemic clearance. Clara cell secretory protein 16 (CC16), which leaks from the respiratory tract, is known to be freely eliminated by the kidney. Lung plasma protein levels will depend on the rates of both protein entry into and clearance from plasma. In order to study the limiting variable determining these levels, we compared plasma CC16, SP-A, and SP-B in matching A-V blood samples from 37 ARF patients with indices of lung dysfunction and glomerular filtration rate (GFR) (of plasma cystatin C and creatinine). Cystatin C, CC16, SP-A, and SP-B were reduced in mixed venous plasma (all p < 0.001) and their A-V gradients were directly related to their arterial levels (all p < 0.03). Whereas CC16, SP-A, and SP-B reflected blood oxygenation (all p < 0.05), only SP-A and SP-B were related to lung injury score (LIS) (both p < 0.05). In contrast, whereas the clearances of both CC16 and cystatin C were related to that of creatinine (p < 0.02 for both), the clearances of SP-A and SP-B were not. Our study confirms that all three lung proteins are acutely cleared from the circulation of patients with ARF (half-lives < 18 min), and we conclude that whereas the plasma concentration of CC16 depends on GFR, plasma concentrations of SP-A and SP-B reflect lung function independently of this variable.

Increased urinary loss of uric acid in adults with acute respiratory failure requiring mechanical ventilation.

INTRODUCTION: The purpose of this study was to test a hypothesis of increased urinary excretion of uric acid as an indicator of adenosine triphosphate (ATP) degradation in adult patients with acute respiratory failure, and to look for a correlation to the clinical outcome. STUDY DESIGN: Prospectively 31 patients with acute respiratory failure were studied. The patients were divided into two groups according to the clinical outcome: the need for solely supplemental oxygen (group 1), death or mechanical ventilation (group 2). METHODS: Uric acid was determined by spectrophotometry. RESULTS: Mean uric acid excretion was 39 mumol/kg (range, 7 to 92 mumol/kg) body weight/per 24 h in group 1 (16 patients) compared with 65 mumol/kg/24 h (range, 8 to 253 mumol/kg/24 h) in group 2 (13 patients were mechanically ventilated, and two patients died). The difference was highly significant (p less than 0.0001). CONCLUSION: Increased amount of urinary uric acid was related to the severity of acute respiratory failure in adults.

[Physiopathological aspects of secondary hyperuricemia]. / Aspetti fisiopathologici delle iperuricemie secondarie.

Secondary hyperuricaemia expresses a heterogeneous group of clinical conditions generally classified according to the pathogenetic criteria. Hyperuricaemia can depend on an increased production, reduced renal excretion or on the combination of both. Myelo and lymphoproliferative diseases are clinically prevalent among the conditions accompanying this overproduction. The most frequent causes of reduced uric acid excretion are chronic renal failure and diuretic treatment. In recent years, several conditions of hyperuricaemia with mixed pathogenesis have revealed a common mechanism connected to the ATP cellular depletion.

[Effects of intermittent muscle stimulation on muscle catabolism in patients immobilized in the ICU]. / Effets des stimulations musculaires intermittentes sur le catabolisme musculaire des malades immobilisés en réanimation.

Are muscular contractions obtained by electrical stimulation able to reduce muscle catabolism in immobilized patients? Ten patients (65 to 79 yr old), hospitalized in an intensive care unit for postoperative failure or cerebral infarction, were studied during nine days. Artificial nutrition was the same for each patient during the study. Two periods of four days where defined and randomized for each patient, separated by one day; during the stimulation period (S), intermittent electrical stimulation of the muscles of the legs (external electrodes) was performed daily 2 X 30 min; during the non-stimulation period (NS), muscular stimulation was not performed. Urinary excretion of nitrogen (micro-Kjeldhal digestion and Nessler procedure), creatinine (Jaffé reaction) and 3-methylhistidine were measured every day. Results (X +/- SD) are as follows: the nitrogen balance (g/d) was -1.29 +/- 1.26 during the NS period and 1.43 +/- 1.10 during the S period (NS); 3-methylhistidine (mumol/kg/d) was 3.78 +/- 0.37 during the NS period and 3.15 +/- 0.32 during the S period (p less than 0.01); creatinine (mumol/kg/d) was 92.9 +/- 6.8 during the NS period and 72.9 +/- 25 during the S period (p less than 0.01). It is concluded that a significant decrease in 3-methylhistidine and creatinine excretions is observed during the S period. In intensive care unit patients, muscle protein breakdown may be influenced by intermittent electrical muscle stimulation.

[Urinary excretion of hydroxyproline in patients with chronic respiratory insufficiency (author's transl)]. / Excreción urinaria de hidroxiprolina en pacientes con insuficiencia respiratoria crónica.

The level of urinary excretion of hydroxyproline is considered as an index of the metabolic activity of the collagen. It increases in situations which include an increase in the osteoblastic activity or in the bone resorption. In respiratory insufficiency a series of conditions occur which are theoretically capable of modyfing this parameter. Twelve patients (9 males and 3 women) with chronic respiratory disease in a situation of respiratory insufficiency (hypoxemia and/or hypercapnia at rest) were studied. The urinary excretion of hydroxyproline in these patients was 15.30 +/- 8.16 mg/day/m2, significantly greater than that of a control group with similar characteristics which was 9.97 +/- 3.07 mg/day/m2 (p less than 0.05; Student's t test). The existence of a significant correlation between the urinary excretion of hydroxyproline and the degree of hypoxemia (r = 0.66; p less than 0.01) was likewise verified; in the same way, although to a lesser degree with the hypercapnia (r = 0.62; p less than 0.05). The different factors capable of influencing the bone metabolism in respiratory insufficiency are discussed, as well as the effects of the medications used by these patients. It is possible, on the other hand, that the increase of the urinary excretion of hydroxyproline does not depend only on alterations in the metabolic condition of the bone, but also on a reduction in the hepatic metabolism of the amino acid in relation with gasometric modifications.

Adrenocortical and somatotrophic secretions in acute and chronic respiratory insufficiency.

Adrenocortical function and plasma growth hormone pattern were investigated in 15 patients with chronic obstructive lung disease, in a period of acute respiratory failure and again after recovery. During the acute period, secretion rate and plasma concentrations of cortisol were markedly enhanced; urinary excretion of cortisol metabolites was only slightly increased, suggesting an alteration of the catabolism of cortisol under these conditions; adrenocortical sensitivity to corticotropin and capacity of maximal adrenal secretion were normal. The increase of cortisol secretion was probably due to hypoxemia and/or hypercapnia acting through the hypothalamo-pituitary axis. During the chronic phase of respiratory insufficiency, adrenocortical secretion and responsiveness were within the normal range. Finally, respiratory failure did not stimulate the secretion of growth hormone.