Experiences with high-frequency oscillatory ventilation in premature infants with respiratory distress syndrome

BACKGROUND: High-frequency oscillatory ventilation (HFOV) has been used in treating premature infants with respiratory distress syndrome who have a low incidence of ventilation-associated lung injury. Herein, we report our initial clinical experience in using HFOV to treat such infants. METHODS: From October 1996 to February 1997, 10 premature infants with severe respiratory distress syndrome treated with HFOV were retrospectively evaluated. Clinical course and laboratory data collected during treatment were analyzed. Parameters evaluated included patient survival rate, incidence of chronic lung disease and morbidity associated with HFOV usage. RESULTS: The mean gestational age was 29 +/- 2 weeks; mean birth weight, 1,182 +/- 342 g; and mean period of HFOV treatment, 3.4 +/- 1.9 days. One patient died of sepsis due to infective pancarditis. Two patients developed moderate chronic lung disease at 30 days post delivery and in one of these patients, the disease persisted at 36 weeks' of age. The overall survival rate was 90%. No patient developed air-leak syndrome during the course of treatment. CONCLUSIONS: Our initial experience demonstrated that using HFOV in treating premature infants with severe respiratory distress syndrome was safe and effective. The incidence of moderate to severe chronic lung disease or air-leak syndrome following HFOV was low.     

Acute respiratory distress syndrome: CT abnormalities at long-term follow-up

Photochemical thrombotic ischemia model was used to study the possible roles of excision repair cross-complementing group 6 (ERCC6), a DNA repair gene, in the neuroprotection of dextromethorphan (DM), a NMDA antagonist, in ischemic brain injury. The results showed that no obvious ERCC6 mRNA expression was found in the perifocal area of irradiated cerebral cortex before 24 h postischemia. Then, the number of ERCC6 mRNA positive cells gradually enhanced, and attained a peak value at 72 h after light irradiation, which followed a declined tendency at 7-day postlesion. These results suggest that DNA repair gene ERCC6 mRNA expression in the perifocal area may be involved in the pathophysiological processes following the photochemical thrombotic cerebral ischemia. By the administration of DM, we observed that it can significantly upregulate the expression of ERCC6 mRNA in the perifocal area at 48 h after ischemic event. The neuroprotective mechanisms of DM may be related to the upregulation of DNA repair gene ERCC6 mRNA.     

Adult respiratory distress syndrome

In this article the authors present a case of successful treatment of a 54-year old male patient with non-insulin dependent diabetes mellitus (NIDDM) and triple-vessel coronary artery disease who underwent surgical myocardial revascularization and was reoperated on the same day because of excessive bleeding. The patient was given cca 5000 mL of whole blood and cca 3000 mL of blood derivatives. The first postoperative chest X-ray showed radiological signs of ARDS. The therapy was based upon authors' experience and was consisted of controlled mechanical ventilation (respiratory volume 12-15 mL/kg, 10-14 cycles/min, I/E ratio 1:2, FIO2 0.6, PEEP 2-5 cm H2O), daily bronchoscopies with bronchoaspiration, aggressive diuresis, negative fluid balance, specific antibiotic therapy, and last but not least, of prostaglandin E1 (PGE1) 0.5-20 micrograms/kg/min combined with dopamine inotropic support (2-5 micrograms/kg/h). Simple but careful clinical observation still remains a milestone for all therapeutic measures taken in ARDS patients.     

Effect of surfactant replacement therapy on the outcome of premature infants with respiratory distress syndrome

Lung surfactant replacement has been tested clinically in recent years. In this study the outcome of 31 premature infants with moderate to severe neonatal respiratory distress syndrome (RDS) treated with surfactant was compared to that of 74 prematures with RDS treated conventionally by positive pressure ventilation and supportive care. The groups were well matched for gestational age, birthweight, sex, and Apgar scores at 1 and 5 min. Surfactant treatment resulted in a significant decrease in mortality--from 36.6% in the untreated group to 12.9% in the surfactant-treated group (P < 0.04). This improvement in survival was seen also in prematures with a birthweight < 1,000 g; in the untreated group mortality was 57.6% compared to 23.5% in the treated group (P < 0.05). The incidence of pneumothorax was lower in the treated group--42% vs. 13% (P < 0.01). Surfactant treatment resulted in a trend of more survivors without bronchopulmonary dysplasia or intraventricular hemorrhage, even though surfactant therapy did not change the incidence of either.     

Decreased sodium ion absorption across nasal epithelium of very premature infants with respiratory distress syndrome

OBJECTIVE AND STUDY DESIGN: Successful adaptation to air breathing at birth depends on rapid absorption of fetal lung liquid that is mediated by activation of amiloride-sensitive sodium ion channels. To test the relationship between respiratory epithelial Na+ transport and development of respiratory distress syndrome (RDS), we measured nasal transepithelial potential difference (PD) in 31 very premature (< or = 30 weeks of gestation) newborn infants. Infants were retrospectively assigned to RDS (22 infants) and non-RDS (9 infants) groups on the basis of clinical and chest x-ray criteria. RESULTS: Maximal nasal epithelial PD increased with birth weight (-1.2 mV/100 gm) and was lower in infants with RDS (-16.5 +/- 0.6 mV) than in those without RDS (-22.0 +/- 1.3 mV). Infants without RDS had PD values similar to normal fullterm infants. Amiloride inhibition of PD, an index of Na+ absorption, was significantly lower, within the first 24 hours of life, in infants in whom RDS developed (3.8 +/- 0.2 mV; 29.5% +/- 0.8% inhibition) than in those without RDS (6.1 +/- 0.6 mV; 38.6% +/- 0.5% inhibition). Maximal and amiloride-sensitive PD returned to normal during the recovery phase of RDS. CONCLUSIONS: We conclude that Na+ absorption across nasal epithelium increases with increasing birth weight and that impairment of Na+ absorption across the respiratory epithelia of very premature infants may contribute to the pathogenesis of RDS.     

Traumatic adult respiratory distress syndrome

ARDS is the pulmonary manifestation of both direct and indirect insults to the lung. Trauma patients are at particular risk for ARDS from the direct effects of their injuries, as well as from complications that may occur during their hospital courses. ARDS prevention can be enhanced through diverse areas of medical focus. Public health issues addressing trauma prevention, improved understanding and treatment of trauma-related pathophysiology, as well as a better understanding of basic pathophysiology of this disease process will allow refinement and improvement of our management practices. Newer modes of mechanical ventilation may help us to avoid ventilator-induced exacerbation of lung injury. As we define the role of nonconventional therapies, such as anti-inflammatory and anticytokine therapies, our ability to actively interrupt and reverse the progression of the inflammatory cascade will be enhanced. As yet, ARDS continues to be a challenging disease process to both fully understand and successfully treat in our critically ill patients.     

Antenatal ambroxol treatment does not prevent the respiratory distress syndrome in premature infants

The effectiveness of ambroxol in the prevention of neonatal respiratory distress syndrome and in reducing the need for intermittent mandatory ventilation and oxygen therapy was studied in 88 mothers whose infants was born between 24 and 34 weeks of gestation and who were randomized either for treatment with ambroxol (group A = 42) or served as control (group B = 46). There were no significant differences in the mean gestational age, birth weight or Apgar score between the two groups. We found no significant differences in occurrence of respiratory distress syndrome (55% vs 45%), in support by intermittent mandatory ventilation (71% vs 72%) or oxygen therapy (74% vs 75%) at 12 h of age between groups A and B. CONCLUSION: This study does not suggest the efficacy of antenatal ambroxol treatment both for the prevention of neonatal respiratory distress syndrome and for the reduction of its severity.     

Acute respiratory distress syndrome in children

In 1991, the Dental Implant Clinical Research Group initiated a long-term clinical study in cooperation with the Department of Veterans Affairs to investigate the influence of implant design, application, and site of placement on clinical performance and crestal bone height. As part of this investigation, Periotest values for 2,212 root from implants were determined at second-stage surgery and during a 24-month follow-up period. Mean Periotest values decreased for implants placed in quality 1 and 2 bone, did not change for implants in quality 3 bone, and increased for implants in quality 4 bone. Implants in the posterior maxilla and single implants in the anterior maxilla had increasing mean Periotest values as compared with decreasing values for implants in other regions. Mean Periotest values for uncoated implants decreased gradually to approach those of hydroxyapatite-coated implants.     

Open-lung biopsy in patients with acute respiratory distress syndrome

Occupational exposures contribute to the morbidity and mortality of many diseases. However, occupational diseases continue to be underrecognized even though they are responsible for an estimated 860,000 illnesses and 60,300 deaths each year. Family physicians can play an important role in improving the recognition of occupational disease, preventing progressive illness and disability in their own patients, and contributing to the protection of other workers similarly exposed. This role can be maximized if physicians raise their level of suspicion for workplace disease, develop skills in taking occupational histories and establish routine access to occupational health resources.     

Phaeochromocytoma with adult respiratory distress syndrome mimicking septicaemic shock

Phaeochromocytomas are rare tumours that most commonly present with chronic sustained hypertension and hypertensive paroxysms or crises. We report a 49-year-old woman with unsuspected phaeochromocytoma who presented with sudden onset of profound hypotension and adult respiratory distress syndrome unresponsive to fluid and inotropic support. This case illustrates the diversity of presentations of phaeochromocytoma, depending on the type and amount of catecholamines secreted.     

A new view of pulmonary edema and acute respiratory distress syndrome

The old division of lung edema into two categories--cardiogenic (hydrostatic) and noncardiogenic (increased permeability)--is no longer adequate. For instance, it fails to distinguish between the capillary leak caused by acute respiratory distress syndrome from that caused by interleukin-2 treatment. Further, it fails to account for the capillary leak ('stress-failure') that may accompany edema. A modern view of edema must recognize the natural barriers to the formation and spread of edema. These barriers are the capillary endothelium and the alveolar epithelium. Varying degrees of damage to them can account for the varying radiographic and clinical manifestations of lung edema. Thus, interleukin-2 administration causes increased endothelial permeability without causing alveolar epithelial damage. The result is lung edema that is largely confined to the interstitium, causing little hypoxia and clearing rapidly. However, acute respiratory distress syndrome, which is characterized by extensive alveolar damage, causes air-space consolidation, severe hypoxia, and slow resolution. Thus, a reasonable classification of lung edema requires at least four categories: 1) hydrostatic edema; 2) acute respiratory distress syndrome (permeability edema caused by diffuse alveolar damage); 3) permeability edema without alveolar damage; and (4) mixed hydrostatic and permeability edema. The authors emphasize the importance of the barriers provided by the capillary endothelium and the alveolar epithelium in determining the clinical and radiographic manifestations of edema. In general, when the alveolar epithelium is intact, the radiographic manifestations are those of interstitial (not air-space) edema; this radiographic pattern predicts a mild clinical course and prompt resolution.     

Acute respiratory distress syndrome. Liquid ventilation

In summary, the use of partial liquid ventilation with perfluorocarbon seems to be safe in neonates, children, and adults with ALI or ARDS. Partial liquid ventilation can be used for the following goals: recruitment of lung volume; enhancement or uniformity of lung inflation; improved oxygenation; improved lung compliance; and prevention or minimization of lung damage induced by mechanical ventilation. Partial liquid ventilation improved gas exchange and lung mechanics in test subjects. Cardiopulmonary interaction and long-term safety require further study. Extrapolations from animal data, however, suggest that there are no long-term undesired effects. The current clinical data strongly suggest that close monitoring and adjustment of ventilator parameters during drug instillation are necessary to reduce hypoxia, bradycardia, and pneumothorax. Further studies are required to explore the efficacy of partial liquid ventilation with perfluorocarbon in ALI or ARDS subjects, in particular, to evaluate the safety and efficacy of smaller doses; mechanical ventilation strategies; and outcomes. Additional research including large randomized studies is clearly required to answer these and other questions.     

Surfactant treatment in the neonate with severe respiratory distress syndrome

Eighteen preterm infants severely ill with respiratory distress syndrome who required assisted ventilaton were given modified natural surfactant (Survanta) endotracheally. They had a mean +/- SEM gestational age of 31.2 +/- 0.4 weeks (range 28-34) and a mean +/- SEM birthweight of 1562 +/- 71 g (range 1160-2010). Average time of initial surfactant administration was 15 +/- 1.7 hour (range 5-24). No significant side effects were found during surfactant instillation. Post surfactant, the air entry was improved, oxygenation and arterial/alveolar gradients increased, and the levels of inspired oxygen could be reduced. Some of the radiological abnormalities were resolved. In 13 infants, patent ductus arteriosus became clinically evident, seven of whom received Indomethacin. There were 4 cases of pulmonary air leak, 5 cases of pulmonary hemorrhage and 8 cases of bronchopulmonary dysplasia. Four infants expired, two were due to severe asphyxia/shock and two died of unrelated causes. Among the 14 survivors who came for follow-up, two cases of retinopathy of prematurity had gradually regressed, one had cerebral palsy and delayed development. Surfactant rescue therapy is a supplemental beneficial treatment for severe respiratory distress syndrome while newborn intensive care concept is necessary for efficient diagnosis and treatment of RDS.     

Severe adult respiratory distress syndrome associated with transfusion of antileukocyte antibodies

The use of blood products is common in the period after cardiopulmonary bypass. A rare cause of adult respiratory distress syndrome is a reaction to antileukocyte antibodies. The plasma transfused may contain a potent leukocyte antibody that may cause severe problems in the intensive care unit.