Pulmonary fat embolism: a distinct cause of severe acute chest syndrome in sickle cell anemia.

The etiology of most cases of acute chest syndrome (ACS) in sickle cell disease (SCD) is unknown. Although pulmonary fat embolism (PFE) is frequently found on autopsy, it is rarely considered in the differential diagnosis in pediatric patients. We conducted a study to determine if we could identify PFE in SCD patients with ACS, define the clinical and laboratory course of PFE, and determine if bronchoalveolar lavage is safe and useful in diagnosis of PFE. Twenty-seven SCD patients with ACS were evaluated and compared with 43 control patients. Serial tests (complete blood count, platelet count, nucleated red blood cells [NRBCs], chest x-ray, and oxygen saturations) were compared with steady-state results. Diagnosis of PFE was made by quantitative evaluation of pulmonary macrophages for intracellular fat. No serious complications from bronchoscopy were observed. In the SCD patients with ACS, 12 were PFE+ and 15 were PFE-. The clinical course of the two groups was quite different. All PFE+ patients experienced bone pain and 11 of 12 had chest pain. In contrast, only 6 of 15 of PFE- patients had bone or chest pain. Neurologic symptoms developed in 6 of 12 of the PFE+ group and in none of the PFE- group. Mean hospital days for PFE+ was 13 compared with 7 for PFE-. Laboratory studies in PFE+ showed a significant decrease in hemoglobin (-2 g, P < .05), platelet count (-293,000, P < .001), and an increase in NRBCs/100 white blood cells (+8.3, P < .001) compared with PFE-. These results indicate that when PFE is associated with ACS, it is characterized by a distinct clinical course, and that bronchial lavage is a safe and useful test in diagnosing PFE in patients with ACS.

Experience with a metered-dose inhaler with a spacer in the pediatric emergency department.

Studies of adults suggest that metered-dose inhalers with spacers are as effective as hand-held nebulizers for bronchodilator delivery. We studied 13 children with acute asthma. They received two puffs every 2 minutes from metered-dose inhalers with spacers (range, 4 to 14 puffs) titrated until improvement stopped. Peak expiratory flow increased 34% for metered-dose inhalers with spacers after the first 2 puffs and increased 87% for metered-dose inhalers with spacers after dose titration. After titration, respiratory rate decreased by 12%, heart rate increased by 2%, and breath sounds improved in 92% of the patients. We concluded that the metered-dose inhalers with spacers are an effective device for the treatment of asthma in the pediatric emergency department and that the use of metered-dose inhalers with spacers with titration can achieve significant bronchodilation in the treatment of patients with acute asthma.

Calibration of a heated transcutaneous carbon dioxide electrode to reflect arterial carbon dioxide.

The CO2 measured by a heated skin surface electrode is greater than arterial CO2. In this study we (1) determined the magnitude of this difference retrospectively, (2) adjusted the calibration of the heated transcutaneous CO2 electrode to reflect this difference, and (3) tested the validity of the calibration procedure prospectively. The retrospective study consisted of 252 simultaneous arterial and transcutaneous measurements on 38 infants and children (age range, 1 day to 6 yr). A linear regression analysis showed PtcCO2 = 1.61 X PaCO2 - 0.01 mmHg, r = 0.90 (p less than 0.0001). Because the intercept was virtually zero, we subsequently changed the calibration procedure by dividing the transcutaneous electrode reading by 1.61. The prospective study consisted of 269 more simultaneous arterial and transcutaneous measurements from 57 consecutive infants and children (age range, 1 day to 18 yr) using this calibration procedure. Regression analysis showed PtcCO2 = 1.02 X PaCO2 - 2.3 mmHg, r = 0.96 (p less than 0.0001). Thus, we found that the transcutaneous CO2 electrode, using this technique, reliably predicted the arterial CO2.

Congenital central alveolar hypoventilation syndrome in six infants.

Six infants with congenital alveolar hypoventilation syndrome (CCHS) were seen and observed over several years. Two had an association of CCHS with Hirchsprung's disease. All infants were treated by tracheostomy and mechanical ventilation. Three infants have survived (including one with CCHS and Hirchsprung's disease). However, all survivors have required frequent rehospitalization. The infant with the longest survival (now 4 years of age) has developed significant daytime problems involving the "behavioral control" of ventilation. One infant was considered as a "near miss for sudden infant death syndrome" and became significantly symptomatic after establishment of delta (stage 3-4 non-rapid eye movement) sleep, which normally develops between 2 and 4 months of age. CCHS involves autonomic nervous system dysfunction, and the question of a defect involving the integration of chemoreceptor information more than a direct defect of the central chemoreceptor is discussed.

Continuous transcutaneous oxygen and carbon dioxide monitoring in the pediatric ICU.

The transcutaneous partial pressures of carbon dioxide (PtcCO2) and oxygen (PtcO2) were measured with heated electrodes in 18 hemodynamically stable pediatric ICU patients and these data were compared to simultaneously measured arterial oxygen and carbon dioxide tensions. There was a significant degree of correlation (p less than 0.001) between the skin surface CO2 and O2 and their corresponding arterial tensions. These data defined values for PtcCO2 and PtcO2 indices in the pediatric patient without cardiovascular complications as PtcCO2 index = 1.6 +/- 0.2 and the PtcO2 index = 0.84 +/- 0.18 (PtcCO2 index = PtcCO2/PaCO2 and PtcO2 index = PtcO2/PaO2). The authors found the monitoring of skin surface gases a reliable technique to monitor arterial gas tension in hemodynamically stable patients.

Transcutaneous measurements of carbon dioxide partial pressure in sick neonates.

The authors measured the partial pressure of carbon dioxide transcutaneously (PtcCO2) in 15 sick newborns and compared the PtcCO2 to simultaneously measured partial pressure of arterial carbon dioxide (PaCO2). The PtcCO2 values reflected changes in the PaCO2 values. A linear regression on 106 paired PtcCO2 and PaCO2 values produced a correlation coefficient of 4 = 0.91 with a slope of 1.89 and a y-intercept of --9.4. The authors found the measurement of PtcCO2 to be a clinically useful method of continuously following the trend of PaCO2.

Acid-fast actinomyces in a child with pulmonary actinomycosis.

Open-lung biopsy in a child with chronic pneumonia revealed branched gram-positive acid-fast organisms, later identified as Actinomyces israelii. Like Nocardia asteroides, A israelii can be acid fast by the commonly used Putt stain. The pneumonia was cured with 12 weeks of penicillin treatment.

Experimental murine candidiasis: pathological and immune responses in T-lymphocyte-depleted mice.

Mice depleted of T-lymphocytes by thymectomy and irradiation (TXB) and immunologically competent mice were compared for gross and histological pathology as well as immune responses after cutaneous and/or intravenous challenge with Candida albicans. In response to a first cutaneous inoculation with viable Candida, TXB, sham-operated (SXB), and unmanipulated (normal) mice, all developed lesions of comparable size, duration, and histopathology. When challenged a second time cutaneously, normal and SXB mice developed lesions which were greatly increased in size when compared with those produced by a first cutaneous infection, whereas TXB mice developed lesions comparable in size to those initiated by the first infection. Histologically, the first and second lesions in all animals were acute abscesses predominantly comprised of polymorphonuclear leukocytes. The larger second lesions in SXB and normal mice were accompanied by detectable circulating antibody and by delayed hypersensitivity. Neither circulating antibody nor delayed hypersensitivity were stimulated in the TXB mice. When challenged intravenously, all previously uninfected mice, regardless of T-cell status, were equally susceptible to C. albicans. Contrary to SXB or normal mice, however, TXB mice which had been infected cutaneously were not more resistant to a subsequent intravenous challenge as judged by 6-week survival. The results suggest that T-cells do not play a significant role in innate resistance of mice to systemic candidiasis, but that such cells are important in the development of acquired resistance.

Malignant cystosarcoma phylloides. Treatment and prognosis.

Twenty-six cases of malignant cystosarcoma phylloides treated at The Charity Hospital of Louisiana were reviewed. No metastases to axillary lymph nodes was observed. The lesion appears to metastasize seldom, if ever, to lymphatics, and axillary dissection is seldom required. Local recurrence was common, however, and justifies wide resection of the primary. Mortality was related more to the size of the lesion than to other findings such as skin or muscle involvement. No lesion with less than three mitoses per ten high power fields and minimal stromal atypia proved fatal. Associated neoplasia was common, particularly in the opposite breast.

Experimental murine candidiasis: pathological and immune responses to cutaneous inoculation with Candida albicans.

Cutaneous infection of mice with Candida albicans elicited a predominantly acute inflammatory response, stimulated the production of precipitating antibodies, and conferred protection against subsequent intravenous challenge with the same organism. The acute inflammatory skin reaction seen after cutaneous infection suggested a predominantly humoral response to Candida. Animals infected cutaneously a second time with viable C. albicans developed larger skin lesions than animals infected only once, and the twice-infected animals were more resistant to an intravenous challenge as well. The cutaneous inoculation of mice with heat-killed C. albicans was less effective in stimulating antibody production, in eliciting the inflammatory response, and in inducing a protective response demonstrable by intravenous challenge with viable Candida. This model of experimental candidiasis represents a reproducible means of studying a protective immune response to the organism.

Benign liver tumors: what is their relationship to oral contraceptives?

A series of eight cases of benign hepatocellular tumors from the New Orleans area is presented. Clinical and histological features of these unusual tumors are discussed. Also, a series of 56 similar cases reported in the literature is reviewed. We conclude that these tumors have shown definite evidence of hormonal sensitivity and there is strong circumstantial evidence that oral contraceptive medications have contributed to their recent increased incidence. Although the risk of this problem in the overall population of women taking oral contraceptives seems to be quite small, further clinical and experimental research on this problem is clearly indicated.