Dexamethasone therapy for bronchopulmonary dysplasia: Improved respiratory mechanics without adrenal suppression

Abstract

The purpose of the present study was to examine the pattern of changes in respiratory system mechanics induced by dexamethasone (Dex) in infants with bronchopulmonary dysplasia (BPD) and to determine whether dosages that produce these changes induce adrenal suppression. We examined mechanics in seven ventilator-dependent premature infants (age, 33 +/- 4.8 days) with BPD, before and daily during Dex therapy. Dex (0.5 mg/kg/day) was given intravenously for 7 days unless complications necessitated early termination. Respiratory system resistance (Rrs) and compliance (Crs) were measured by the passive expiratory flow-volume technique during the course of dexamethasone therapy or until extubation. Adrenocorticotrophic hormone (ACTH) stimulation tests were done at baseline and following Dex therapy to evaluate adrenal function. Dex therapy caused a 77 +/- 18% increase in Crs (from 0.97 +/- 0.09 SEM mL/cmH2O to 1.6 +/- 0.16 mL/cmH2O; P less than 0.025) and a 33 +/- 5% decrease in Rrs (from 0.20 +/- 0.02 cmH2O/mL/s to 0.14 +/- 0.01 cmH2O/mL/s; P less than 0.01). Concurrently, ventilator rate, mean airway pressure, and FIO2 all decreased significantly (P less than 0.025). Extubation occurred later in infants with the lowest Crs and highest Rrs at baseline. At extubation, all Crs values were greater than 1.33 mL/cmH2O and Rrs values were less than 0.15 cmH2O/mL/s. Systolic blood pressure increased from 61 +/- 6.3 mmHg to 84 +/- 17 mmHg, 72-96 h after the start of Dex (P less than 0.025). There were no episodes of culture-positive sepsis. Neither basal nor ACTH-stimulated levels of cortisol were suppressed as a result of Dex therapy (P greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Dexamethasone for Pulmonary Interstitial Emphysema in Preterm Infants

“…However, these have not been reported with short courses of dexamethasone [15,20]. The survival of all infants who received 3 doses of dexamethasone (9/10 overall) is superior to the reported mortality rates of 50-80% in VLBW infants (Bsurfactant) with severe PIE [2,3,8,9].…”

Inhaled salbutamol and beclomethasone for preventing broncho-pulmonary dysplasia: a randomised double-blind study

“…In¯ammation of bronchial and lung tissue is seen as early as the 4th postnatal day and contributes to the genesis of BPD [1,10,23]. Several controlled studies have shown that dexamethasone therapy was associated with improved short-term pulmonary outcome, including a decrease in respiratory support requirements and an amelioration of pulmonary mechanics [5,11,13,19,26]. On the other hand, early onset of airway reactivity has been demonstrated in premature newborns [15].…”

Use of corticosteroids and the outcome of infants with bronchopulmonary dysplasia

“…However, after controlling for birth weight and gestational age in the stratified analysis, corticosteroid management did not affect the primary outcome measures in this study. Many studies have provided evidence of acute improvement in lung function -increase in dynamic lung compliance 10,15,18 and easier, earlier extubation 10,11,[13][14][15][16][17][18]26 -when corticosteroids were used.…”

“…Possible mechanisms of corticosteroid action include: stabilization of cell and lysosomal membranes 1 , increment of surfactant synthesis 2 , inhibition of prostaglandin and leukotriene synthesis 3 , decrease in polymorphonuclear cell recruitment to the lung 4,5 , enhancement of beta adrenergic activity 6 , reduction of pulmonary and bronchial interstitial fluid 7 . Several randomized clinical trials of postnatal corticosteroids in premature infants with bronchopulmonary dysplasia have been performed [8][9][10][11][12][13][14][15][16][17][18][19][20][21] . Despite a variety of study designs, some studies report that corticosteroids improve pulmonary compliance and facilitate extubation 10,11,15,18 , reduce the use of mechanical ventilation [8][9][10][11][12][13][14][15][16][17] and the length of oxygen therapy 11,13,14,16,19 .…”

“…Several randomized clinical trials of postnatal corticosteroids in premature infants with bronchopulmonary dysplasia have been performed [8][9][10][11][12][13][14][15][16][17][18][19][20][21] . Despite a variety of study designs, some studies report that corticosteroids improve pulmonary compliance and facilitate extubation 10,11,15,18 , reduce the use of mechanical ventilation [8][9][10][11][12][13][14][15][16][17] and the length of oxygen therapy 11,13,14,16,19 . Besides other adverse effects, reduced growth 13,15,17 has been described as a consequence of corticosteroid treatment.…”