Find information on thousands of medical conditions and prescription drugs.

Infant respiratory distress syndrome

Infant respiratory distress syndrome ("RDS", also called "Respiratory distress syndrome of newborn", previously called hyaline membrane disease), is a syndrome caused by developmental lack of surfactant and structural immaturity in the lungs of premature infants. RDS affects about 1% of newborn infants. The incidence decreases with advancing gestational age (length of pregnancy), from about 50% in babies born at 26-28 weeks, to about 25% at 30-31 weeks. The syndrome is more frequent in infants of diabetic mothers and in the second born of premature twins. more...

ICF syndrome
Ichthyosis vulgaris
Imperforate anus
Inborn error of metabolism
Incontinentia pigmenti
Infant respiratory...
Infantile spinal muscular...
Infective endocarditis
Inflammatory breast cancer
Inguinal hernia
Interstitial cystitis
Iodine deficiency
Irritable bowel syndrome

Clinical course

Respiratory distress begins shortly after birth, and is manifest by a whining noise, flaring of the nostrils and "sucking in" of the chest wall during breathing efforts. The baby may become cyanotic ("blue") from lack of oxygen in the blood. As the disease progresses, the baby may have respiratory failure, and prolonged cessations of breathing ("apnea"). If untreated, the baby's condition may worsen, and death may ensue. Complications include metabolic exhaustion (acidosis, low blood sugar), patent ductus arteriosus, low blood pressure, chronic lung changes, and intracranial hemorrhage.


The characteristic pathology seen in babies who die from RDS was the source of the name "hyaline membrane disease". These waxy-appearing layers line the collapsed tiny air sacs ("alveoli") of the lung. In addition, the lungs show bleeding, over-distention of airways and damage to the lining cells.


The lungs are developmentally deficient in a material called surfactant, which allows the alveoli to remain open throughout the normal cycle of inhalation and exhalation. Surfactant is a complex system of lipids, proteins and glycoproteins which are produced in specialized lung cells called Type II cells. The surfactant is packaged by the cell in structures called lamellar bodies, and extruded into the alveoli. The lamellar bodies then unfold into a complex lining of the alveoli. This layer serves the purpose of reducing the surface tension which would tend to cause the alveoli to collapse in the presence of gas. Without adequate amounts of surfactant, the alveoli collapse and are very difficult to expand. Microscopically, it is characterized by collapsed alveoli alternating with hyperaerated alveoli, vascular congestion and hyaline membranes (resulted from fibrin, cellular debris, red blood cells, rare neutrophils and macrophages). Hyaline membranes appear like an eosinophilic (pink), amorphous material, lining or filling the alveolar spaces and blocking the gases exchange . The blood (which normally receives oxygen from the alveolar gas and unloads carbon dioxide into the alveoli) passes through the lungs without this vital exchange. Blood oxygen levels fall, and carbon dioxide rises, resulting in rising blood acid levels. Structural immaturity, as manifest by low numbers of alveoli, also contributes to the disease process. It is also clear that the oxygen and breathing treatments used, while life-saving, can also damage the lung. The diagnosis is made by the clinical picture and the chest xray, which has a "ground-glass" appearance.


Most cases of hyaline membrane disease can be prevented if mothers who are about to deliver prematurely can be given a hormone-like substance called glucocorticoid. This speeds the maturation of the lungs and surfactant system. For very premature deliveries, glucocorticoid is given without testing the fetal lung maturity. In pregnancies of greater than 30 weeks, the fetal lung maturity may be tested by sampling the amount of lipid in the amniotic fluid, obtained by inserting a needle through the mother's abdomen and uterus. The maturity level is expressed as the lecithin-sphingomyelin (or "L/S") ratio. If this ratio is less than 2, the fetal lungs are probably immature, and glucocorticoid is given.


[List your site here Free!]

Adult respiratory distress syndrome due to blastomycosis during pregnancy
From CHEST, 12/1/90 by Diane MacDonald

A 23-year-old pregnant woman developed adult respiratory distress syndrome (ARDS) secondary to Blastomyces dermatitides. Early diagnosis and treatment with amphotericin B resulted in survival of both patient and fetus. Intrauterine transmission of blastomycosis appears to be possible, and treatment of infection during pregnancy is recommended.

North American blastomycosis is caused by a thermal, dimorphic fungus, B dermatitides. The lungs are the primary source of infection and most cases are self-limited. To our knowledge, the case described herein is the first report of blastomycosis as a cause of ARDS in a pregnant patient. Early diagnosis and treatment were associated with survival of both patient and fetus.


A 23-year-old woman in her 33rd week of pregnancy was admitted to the hospital through the emergency department with a several-week history of cough and dyspnea. She had been intermittently ill throughout her pregnancy. Four months previously she had been treat with erythromycin for a "pneumonia." One month prior to hospital admission she developed progressive dyspnea, becoming associated with a productive cough a few days prior to admission. Additionally, she received topical steroids for herpes gestationis and two weeks prior to admission she had an episode of "gastroenteritis." Her pregnancy was otherwise unremarkable except for mild anemia and slightly increased blood glucose level. Pertinent travel history included trips to South America, Mexico, and Canada within the previous year.

Physical examination revealed a pregnant woman in moderate respiratory distress with a respiratory rate of 34/min and a pulse rate of 108 beats per minute. On lung examination, decreased breath sounds with bilateral crackles were noted. A diffuse, erythematous rash was noted on her upper and lower extremities and a 1-cm nontender lymph node was found in the right epitrochlear area. The fundal height was 31 cm and fetal heart tones were auscultated. White blood cell count was 16,800/cu mm with a normal differential count. Room air arterial blood gases revealed the following: pH, 7.50; [PO.sub.2], 75; [PCO.sub.2], 27; [CO.sub.2], 22.3 mmol/L. Chest roentgenographic examination revealed a diffuse, reticulonodular pattern throughout all lung fields.

On the following day, bronchoscopy was performed. Biopsy specimens from the right lower lobe demonstrated noncaseating granulomas with typical broad-based blastomycosis spores (Fig 1). Fungal serologic study showed a positive blastomycosis band on precipitation; biopsy specimens grew B dermatitides. Blood and urine cultures were negative, skin tests 5 U of PPD were negative as were the controls.

The patient was begun on a regimen of amphotericin B at 0.75 mg/kg, which was steadily increased to 1 mg/kg for a total daily dose of 55 mg. On the third hospital day, she developed increasing respiratory distress; she had labored respirations at 48/mn and was just able to maintain her oxygen saturation above 90 percent with 100 percent oxygen. Her arterial blood gases demonstrated a pH of 7.35; [PO.sub.2] of 70; [PCO.sub.2] of 34; and [CO.sub.2] of 21 mmol/L. On examination, the patient had no evidence of jugular venous distention, hepatojugular reflux, or peripheral edema. Auscultation of the chest revealed diffuse crackles that had progressed since the time of hospital admission. The cardiac examination demonstrated a regular rhythm of 120; there were no murmurs or extracardiac sounds. Her hemoglobin was 11.6 g/dl with a white blood count of 14,500/cu mm.

She was subsequently transferred to the intensive care unit, and because of her rapidly progressive respiratory failure, she was intubated and placed on a ventilator. Chest roentgenogram demonstrated alveolar infiltrates throughout all lung fields; right heart catheterization revealed a pulmonary capilary wedge pressure of 11 mm Hg; right ventricle was 38/6 mm Hg; and pulmonary artery was 38/16 mm Hg.

Because the patient's pregnancy was belived to be responsible for immunosuppression and the subsequent blastomycosis infection, an emergency cesarean section was performed that delivered a healthy male infant. Evaluation of the placenta demonstrated dimorphic fungal spores on both maternal and fetal sides (Fig 2); cultures were positive for B dermatitides. All cultures of the infant were negative.

After complicated hospital course, the patient was successfully weaned from the ventilator on day 19. Prior to her discharge from hospital, she received a total of 2 g of amphotericin B. At six months posthospitalization, her chest roentgenogram was normal and her pulmonary function tests showed small airway dysfunction with moderate impairment of diffusing capacity. The child remained healthy.


North American blastomycosis is a misnomer since the disease is recognized worldwide. Endemic areas in the United States include southeastern and southcentral states and areas bordering the Great Lakes. [1] The spores of the fungus, B dermatitides, are inhaled and deposit in the alveoli where they change to the yeast form and multiply by budding. Common extrapulmonary sites of infection include skin, bone, and the male genitourinary tract, and they are usually the result of dissemination from the lungs.

Six other well-documented cases of ARDS secondary to blastomycosis are reported in the English literature. [2-6] All patients had long prodmes of dyspnea, cough, pleuritic chest pain, and weight loss. Once hospitalized, all patients had rapidly deteriorating conditions; four patients died within five days of hospital admission. [2] Patients who survived had their conditions diagnosed and they were treated within a week of admission to the hospital; all survivors received a total of 2 g of amphotericin B.

Five other cases of blastomycosis during pregnancy have been reported; none of the five developed ARDS. [7-11] Pregnancy, with its well-documented association with depressed cell-mediated immunity, [12] may be the reason why these otherwise healthy women developed pulmonary blastomycosis. This possibility is supported by the anergy demonstrated by our patient who failed to react to a number of common skin tests. Unfortunately, skin testing was not repeated following her recovery.

Four of the pregnant patients were treated with amphotericin B and did well. However, one patient who received delayed treatment with ketoconazole following delivery gave birth to an infant that died suddenly at three weeks of age following a short episode of respiratory distress. [7] At autopsy, there was heavy colonization of the infant's alveoli with blastomycosis. Since the placenta was not examined, it is impossible to state whether this represented a case of intrauterine transmission of blastomycosis or infection acquired from the mother after birth. However, as demonstrated in the current case, blastomycosis can invade the fetal placenta, and therefore, intrauterine transmission remains a distinct possibility.

Adult respiratory distress syndrome is an unusual but highly lethal complication of blastomycosis; survival seems to be associated with early diagnosis and therapy. In pregnant patients, intrauterine transmission of blastomycosis to the fetus appears to be possible, and accordingly, a full course of amphotericin B is recommended.


[1] Klein BS, Vergeront JM, Davis JP. Epidemiological aspects of blastomycosis, the enigmatic systemic mycosis. Semin Respir Infect 1986; 1:29-39

[2] Evans ME, Haynes JB, Atkinson JB, Delvaux TC Jr, Kaiser AB. Blastomyces dermatitidis and the adult respiratory distress syndrome: case report and review of the literature. Am Rev Respir Dis 1982; 126:1099-1102

[3] Lockridge RS Jr, Glauser FL. Adult respiratory distress syndrome secondary to diffuse pulmonary blastomycosis. South Med J 1979; 72:235-36

[4] Skilrud DM, Douglass WW. Survival in adult respiratory distress syndrome caused by blastomycosis infection. Mayo Clin Proc 1985; 60:266-69

[5] Unger JM, Peters ME, Hinke ML. Chest case of the day. AJR 1986; 146:1080-86

[6] Thiele JS, Buechner HA, Deshotels SJ Jr. Blastomycosis and the adult respiratory distress syndrome. J La State Med Soc 1984; 136:38-40

[7] Watts, EA, Gard PD, Tuthill SW. First reported case of intrauterine transmission of blastomycosis. Pediatr Infect Dis 1983; 2:308-10

[8] Ismail MA, Lerner SA. Disseminated blastomycosis in a pregnant woman: a review of amphotericin B usage during pregnancy. Am Rev Respir Dis 1982; 126:350-53

[9] Hager H, Welt SI, Cardasis JP, Alvarez S. Disseminated blastomycosis in a pregnant woman successfully treated with amphotericin B: a case report. J Reprod Med 1988; 33:485-88

[10] Daniel L, Salit IE. Blastomycosis during pregnancy. Can Med Assoc J 1984; 131:759-61

[11] Neiberg AD, Mavromatis F, Dyke J, Fayyad A. Blastomycosis dermatitidis treated during pregnancy: a case report. Am J Obstet Gynecol 1977; 128:911-12

[12] Weinberg ED. Pregnancy-associated depression of cell-mediated immunity. Rev Infect Dis 1984; 6:814-31

COPYRIGHT 1990 American College of Chest Physicians
COPYRIGHT 2004 Gale Group

Return to Infant respiratory distress syndrome
Home Contact Resources Exchange Links ebay