[A novel questionnaire to assess activity in patients after hip arthroplasties]

BACKGROUND

Until now, the activity of the lower limb could only be exactly measured with expensive electronic pedometers. The aim of this study was to develop a feasible questionnaire to measure the activity of patients after arthroplasty.

METHODS

The "Daily Activity Questionnaire" (DAQ) was developed in several steps and the evaluation was carried out in three groups of patients with osteoarthritis of the hip (160 patients and 855 investigated days). The psychometric characteristics were verified.

RESULTS

The retest reliability (ICC) of the DAQ is in a range comparable to the electronic pedometer StepWatch. The testing of the criterion validity showed high correlations between the StepWatch and the DAQ (r=0.743).

CONCLUSION

Because of its high correlations to the load changes actually performed, the DAQ is especially suited to answer arthroplasty-related questions. In all patient groups, projected load changes between 1.8 and 2.4 million per year were found, which by far exceed the generally accepted test standards for endoprostheses.

Multicenter study of surfactant (beractant) use in the treatment of term infants with severe respiratory failure. Survanta in Term Infants Study Group

OBJECTIVE

The purpose of this study was to determine whether surfactant (beractant) administration to term newborns in respiratory failure and at risk for requiring extracorporeal membrane oxygenation (ECMO) treatment would significantly reduce the incidence of severe complications through 28 days of age and the need for ECMO.

STUDY DESIGN

A multicenter (n = 44), randomized, double-blind, placebo-controlled trial was conducted. Infants weighing 2000 gm or more with gestational ages of 36 weeks or greater were stratified by diagnosis (meconium aspiration syndrome, sepsis, or idiopathic persistent pulmonary hypertension of the newborn) and oxygenation index (15 to 22, 23 to 30, 31 to 39) and then randomly assigned to receive four doses of beractant, 100 mg/kg (n = 167), or air placebo (n = 161) before ECMO treatment and four additional doses during ECMO, if ECMO was required. The incidence of untoward effects (including hemorrhagic, neurologic, pulmonary, renal, cardiovascular, infectious, metabolic, and technical complications) occurring before and after randomization and through 28 days of age or discharge were recorded.

RESULTS

The two treatment groups were comparable in baseline parameters, including birth weight, sex, gestational age, oxygenation index, and primary diagnosis. There was no difference in the incidence of severe complications. The need for ECMO therapy was significantly less in the surfactant group than in the placebo group (p = 0.038); this effect was greatest within the lowest oxygenation index stratum (15 to 22; p = 0.013).

CONCLUSIONS

Use of surfactant, particularly in the early phase of respiratory failure, significantly decreases the need for ECMO in the treatment of term newborns with respiratory failure, without increasing the risk of complications.

Surfactant content in children with inflammatory lung disease

OBJECTIVE

To determine surfactant profiles of tracheal secretions in mechanically ventilated children with respiratory failure secondary to bacterial pneumonia, viral pneumonitis, adult respiratory distress syndrome (ARDS), and cardiopulmonary bypass.

DESIGN

Prospective, cohort study.

SETTING

Tertiary, multidisciplinary, pediatric intensive care unit.

PATIENTS

One hundred twenty pediatric patients with respiratory failure requiring mechanical ventilation.

INTERVENTIONS

Routine tracheal aspirates were collected from children with bacterial pneumonia, viral pneumonitis, ARDS, postcardiopulmonary bypass, and a postsurgical control group. Samples were obtained on days 1, 2, 3, after every week of intubation and on the day of extubation.

MEASUREMENTS AND MAIN RESULTS

The tracheal aspirates were analyzed by high-performance liquid chromatography for lecithin/sphingomyelin rations and by enzyme-linked immunosorbent assay for surfactant proteins A and B. Lung compliance and the oxygenation index were measured on each day of sample collection. On day 1, patients with bacterial pneumonia, viral pneumonitis, and ARDS had decreased lecithin/sphingomyelin ration (p < .001), and those patients with bacterial pneumonia and viral pneumonitis had decreased surfactant protein A/protein concentration (p < .001). The lecithin/sphingomyelin ratios and surfactant protein A/protein concentration were significantly different among the groups (p < .001), with the bacterial pneumonia and viral pneumonitis groups having higher lecithin/sphingomyelin ratios and increased surfactant protein concentrations before extubation. Pulmonary compliance was lower and the oxygenation index was higher than controls (p < .001) in patients with bacterial pneumonia, viral pneumonitis, and ARDS. Pulmonary compliance was correlated weakly with lecithin/sphingomyelin ratio (r2 = .11, p < .001) and surfactant protein A/protein concentration (r2 = .03, p < .05). Surfactant protein B was similar in the diagnostic groups. Surfactant content in tracheal secretions from cardiopulmonary bypass patients was equivalent to controls.

CONCLUSION

Abnormal tracheal aspirate surfactant phospholipids and surfactant protein A were noted in children with bacterial pneumonia, viral pneumonitis, and ARDS, but not in children on cardiopulmonary bypass.

Serial lecithin/sphingomyelin ratios and surfactant/albumin ratios in tracheal aspirates from term infants with respiratory failure receiving extracorporeal membrane oxygenation

Serial tracheal aspirate samples were obtained for determination of lecithin/sphingomyelin (L/S) ratios from 47 term infants in respiratory failure. Phospholipids were extracted with Folch solution (chloroform:methanol, 2:1 by vol) and analyzed by HPLC with use of silica column and a mobile phase of acetonitrile:methanol:water (48:31:21, by vol). Surfactant/albumin (S/A) ratios were determined with the TDx Fetal Lung Maturity Assay (Abbott Labs). L/S ratios increased significantly over time in all patients (F = 19.42, P < 0.0001). The S/A ratio correlated with the L/S ratio (r = 0.554, P < 0.001). This study suggests that postnatal surfactant deficiency in term newborns with respiratory failure is a component of the newborn's lung injury.

Serial lecithin/sphingomyelin ratios and surfactant/albumin ratios in tracheal aspirates from term infants with respiratory failure receiving extracorporeal membrane oxygenation

Serial tracheal aspirate samples were obtained for determination of lecithin/sphingomyelin (L/S) ratios from 47 term infants in respiratory failure. Phospholipids were extracted with Folch solution (chloroform:methanol, 2:1 by vol) and analyzed by HPLC with use of silica column and a mobile phase of acetonitrile:methanol:water (48:31:21, by vol). Surfactant/albumin (S/A) ratios were determined with the TDx Fetal Lung Maturity Assay (Abbott Labs). L/S ratios increased significantly over time in all patients (F = 19.42, P &lt; 0.0001). The S/A ratio correlated with the L/S ratio (r = 0.554, P &lt; 0.001). This study suggests that postnatal surfactant deficiency in term newborns with respiratory failure is a component of the newborn's lung injury.

Surfactant (beractant) therapy for infants with congenital diaphragmatic hernia on ECMO: evidence of persistent surfactant deficiency

Infants with congenital diaphragmatic hernia (CDH) on extracorporeal membrane oxygenation (ECMO) can have initial lung atelectasis which, in survivors, gradually improves over time. To test the hypothesis that these patients could benefit from surfactant therapy, infants with CDH (born at > 34 weeks' gestation) on ECMO received either four doses of modified bovine lung surfactant extract (beractant) (surfactant group, n = 9) or an equal volume of air (control group, n = 8). Tracheal aspirate surfactant protein-A (SP-A) concentrations were initially low, and then increased over time in both CDH groups (P = .0021); however, levels remained low when compared with those of infants on ECMO who had other diagnoses (P = .04). Lung compliance (CL), time to extubation, time on oxygen, and total no. of hospital days were not different between the two groups. Infants with CDH had persistently elevated right ventricular pressure (RVP) at cessation of bypass when compared with non-CDH infants on ECMO (RVP = 53.25 mm Hg +/- 19.52 in the CDH group, 32.90 +/- 10.63 in the non-CDH group; P = .0121). The findings suggest that the postnatal surfactant deficiency may be more persistent in CDH infants than in non-CDH infants on ECMO. However, CDH remains a multifactorial condition, with delayed improvement, because of persistence of pulmonary hypertension, difficulties with vascular remodeling, degree of lung hypoplasia, or compromised respiratory mechanics.

Improved pulmonary outcome after exogenous surfactant therapy for respiratory failure in term infants requiring extracorporeal membrane oxygenation

A blinded, randomized, controlled study was designed to test whether multiple-dose surfactant therapy would improve pulmonary outcome in term infants with respiratory failure, resulting in a shortened period of extracorporeal membrane oxygenation (ECMO). Infants > or = 34 weeks of gestational age in severe respiratory failure and receiving ECMO were stratified by diagnosis and then randomly assigned to the treatment or the control group. Four doses of modified bovine lung surfactant extract (beractant) were administered to the surfactant group (n = 28), and an equal volume of air was administered to the control group (n = 28). Lung compliance was initially low in both groups; after treatment, values were higher with time in the surfactant group (F = 5.40, p = 0.026). The ECMO treatment period was significantly shorter in the surfactant group (mean +/- SD: 107 +/- 33 hours vs 139 +/- 54 hours for the control group; U = 232, p = 0.023). Tracheal aspirate concentrations of surfactant protein A were low in both groups, and then increased steadily to a higher level in the surfactant group (F = 2.58, p = 0.04). The overall incidence of complications after ECMO was decreased in the surfactant group (18% vs 46% for the control group; chi-square value = 5.004, p = 0.025). Radiographic scores, echocardiographic findings, incidence of intracranial or pulmonary hemorrhage and bronchopulmonary dysplasia, time to extubation, duration of oxygen therapy, and duration of hospitalization did not differ between the two groups. Beractant in this population improved pulmonary mechanics, increased surfactant protein A content in tracheal aspirate, decreased time on ECMO duration, and reduced disease complications.

Extracorporeal membrane oxygenation therapy in neonates with septic shock

Neonatal septic shock has significant morbidity and mortality with current therapeutic measures. At Children's National Medical Center, from June 1984 to October 1986, 10 of 100 patients treated with venoarterial extracorporeal membrane oxygenation (ECMO) had a documented diagnosis of septic shock. All of these infants fulfilled criteria consistent with 80% mortality using conventional intensive medical management. However, the survival rate for the septic neonates in this study was 100%. Compared with other groups of infants treated with ECMO, these septic neonates required significantly more ventilatory support after ECMO and had a higher incidence of chronic lung disease (30% v 12%). The septic neonates were also at higher risk for intracranial hemorrhage than the other infants treated with ECMO (40% v 26%). The necessity for prolonged intubation after ECMO for patients with septic shock suggests that this condition may be associated with additional structural damage not seen with meconium aspiration syndrome or respiratory distress syndrome. Nevertheless, for neonatal patients with septic shock unresponsive to conventional medical management, ECMO must be considered a viable alternative treatment.

Surfactant protein A concentrations in tracheal aspirate fluid from infants requiring extracorporeal membrane oxygenation

To understand the lung abnormalities leading to respiratory failure in infants, we measured 35,000-dalton surfactant protein A concentrations in tracheal aspirate fluid collected daily from 25 infants receiving extracorporeal membrane oxygenation (ECMO). Surfactant protein A concentrations were standardized per milligrams of total protein present in the aspirate. Among the 23 survivors with complete data, the surfactant protein A concentration increased significantly with time (p less than 0.0001). Concurrent increases in lung compliance (p less than 0.0001) and radiographic scores (p less than 0.0001) were also observed. This increase in surfactant protein A content may reflect lung recovery from barotrauma and oxygen toxic effects or be a response to the primary pulmonary disease process. The two infants who did not survive extracorporeal membrane oxygenation failed to demonstrate these trends.

Stunned myocardium in an infant treated with extracorporeal membrane oxygenation

This report describes a case of postischemic myocardial dysfunction that was successfully treated with ECMO.

Steady-state dopamine clearance in critically ill infants and children

Little is known about dopamine pharmacokinetics in pediatric patients, especially in critically ill infants and children who often receive treatment with dopamine. Arterial plasma concentrations of dopamine were measured in 27 patients who were hemodynamically stable and received dopamine for at least one hour. The dopamine levels were measured using liquid chromatography with electrochemical detection. Dopamine clearance averaged 96.2 +/- 55.4 ml/kg.min in 13 patients in the neonatal ICU, and 58.8 +/- 51 ml/kg.min in 14 patients in the pediatric ICU. Six patients had renal (BUN greater than 25 mg/dl, or creatinine greater than 1.2 mg/dl) or hepatic (liver enzymes greater than 3 times normal) dysfunction. Dopamine clearance in these patients (25.1 +/- 17.2 ml/kg.min) was substantially lower than in the other patients (p less than .01). Neither postnatal nor gestational age correlated with dopamine clearance. Substantial interindividual variation was observed in steady-state dopamine clearance in critically ill infants and children, and plasma dopamine could not be predicted accurately from the dopamine infusion rate. Because of the more than three-fold prolongation of dopamine clearances in patients with hepatic or renal dysfunction, these patients may be more likely to suffer toxic effects of dopamine at the usual drug infusion rates.

Lung compliance as a measure of lung function in newborns with respiratory failure requiring extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) can now be used as an alternative mode of therapy for infants 2.0 kg or more with life-threatening respiratory failure. Current criteria for removal from ECMO are limited. We attempted to determine whether lung compliance (CL) could be used as a sensitive indicator of the neonates' lung improvement while they are on ECMO, as well as a predictor of their ability to tolerate removal from bypass. We obtained serial CL measurements in 13 infants, all of whom weaned successfully from ECMO. All had an initial CL on ECMO of 0.5 ml/cm H2O X kg or less (mean = 0.3), with a final CL of 0.8 ml/cm H2O X kg or more (mean = 1.7). The average change in CL from the initial to the final measurement was 0.6 ml/cm H2O X kg or more (mean = 1.5). CL findings correlated well with estimated bypass, expressed as a percent of cardiac output, and a radiographic score of pulmonary abnormality (r = -.66, p less than .0001, and r = -.52, p less than .0001, respectively). We conclude that CL measurements can be used to monitor clinical improvement in infants on ECMO, to predict their successful removal from bypass, and ultimately to shorten their total time spent on bypass.

Diffuse pulmonary opacification in infants undergoing extracorporeal membrane oxygenation: clinical and pathologic correlation

Diffuse pulmonary opacification is commonly seen on chest radiographs from infants with severe respiratory failure treated with extracorporeal membrane oxygenation (ECMO). The chest radiographs and clinical records of 18 such infants were reviewed to determine the correlation among degree of abnormality on chest radiograph (as determined by a radiographic score), clinical severity of disease (as measured by ECMO requirements [ECMO flow rate]), and dynamic lung compliance determinations. Increasing lung compliance and decreasing ECMO flow rates correlated well with decreasing (improving) radiographic score. Pathologic changes were mainly those associated with intensive respiratory support and the underlying pulmonary condition. One patient had diffuse pulmonary hemorrhage. Other than bleeding, no distinctive pathologic features could be attributed to therapy with ECMO. We conclude that the degree of pulmonary opacification seen in infants undergoing ECMO therapy is an accurate reflection of markedly decreased lung compliance and lung volumes caused by hyaline membrane formation, pulmonary edema, and atelectasis associated with the various causes of severe respiratory failure.