Changes in airway configuration with different head and neck positions using magnetic resonance imaging of normal airways: a new concept with possible clinical applications.

BACKGROUND: The sniffing position is often considered optimal for direct laryngoscopy. Another concept of airway configuration involving a laryngeal vestibule axis and two curves has also been suggested. We investigated whether this theory can be supported mathematically and if it supports the sniffing position as being optimal for direct laryngoscopy. METHODS: Magnetic resonance imaging scans were performed in 42 normal adult volunteers. The airway passage was divided into two curves-primary (oro-pharyngeal curve) and secondary (pharyngo-glotto-tracheal curve). Airway configuration was evaluated in the neutral, extension, head lift, and sniffing positions. The airway passage, point of inflection (where the two curves meet), its tangent, and the line of sight were plotted on each scan. RESULTS: The point of inflection lay within the laryngeal vestibule in all positions. The head lift and sniffing positions caused the tangent to the point of inflection to approximate the horizontal plane. The sniffing, extension, and head lift positions caused a reduction in the area between the line of sight and the airway curve compared with the neutral position. CONCLUSIONS: A two-curve theory is proposed as a basis for explaining airway configuration. The changes in these curves with head and neck positioning support the sniffing position as optimal for direct laryngoscopy. Application of this new concept to other forms of laryngoscopy should be investigated.

A stable latent reservoir for HIV-1 in resting CD4(+) T lymphocytes in infected children.

HIV-1 persists in a latent state in resting CD4(+) T lymphocytes of infected adults despite prolonged highly active antiretroviral therapy (HAART). To determine whether a latent reservoir for HIV-1 exists in infected children, we performed a quantitative viral culture assay on highly purified resting CD4(+) T cells from 21 children with perinatally acquired infection. Replication-competent HIV-1 was recovered from all 18 children from whom sufficient cells were obtained. The frequency of latently infected resting CD4(+) T cells directly correlated with plasma virus levels, suggesting that in children with ongoing viral replication, most latently infected cells are in the labile preintegration state of latency. However, in each of 7 children who had suppression of viral replication to undetectable levels for 1-3 years on HAART, latent replication-competent HIV-1 persisted with little decay, owing to a stable reservoir of infected cells in the postintegration stage of latency. Drug-resistance mutations generated by previous nonsuppressive regimens persisted in this compartment despite more than 1 year of fully suppressive HAART, rendering untenable the idea of recycling drugs that were part of failed regimens. Thus the latent reservoir for HIV-1 in resting CD4(+) T cells will be a major obstacle to HIV-1 eradication in children.

Improved detection of Cryptococcus neoformans in the BACTEC NR 660 blood culture system.

To determine the impact of continuous agitation versus 24 hours agitation on the growth of Cryptococcus neoformans in the BACTEC NR 660 blood culture system, the authors compared recovery and detection time for 50 clinical isolates in Peds Plus, 26 Plus, and Fungal Medium bottles in paired simulated blood cultures. After 144 hours of continuous agitation, the Peds Plus bottle detected 96% of the isolates in an average of 82.5 hours, the 26 Plus bottle detected 96% in 79.5 hours, and the Fungal Medium detected 98% in 81.8 hours. For the bottles that were agitated only for the first 24 hours and incubated motionless for 120 hours (as recommended by the manufacturer), the Fungal Medium detected 82% of the isolates in 100.7 hours. However, the Peds Plus and 26 Plus bottles each detected only 38% of the isolates in an average of 112.4 hours and 109.9 hours, respectively. These results indicate that continuous agitation of BACTEC blood culture bottles for the full incubation time significantly improves (P < or = .0001) the detection and recovery of C neoformans.

Human immunodeficiency virus-specific IgA in infants born to human immunodeficiency virus-seropositive women.

OBJECTIVE: To determine the sensitivity and specificity of human immunodeficiency virus (HIV)-specific IgA for vertically transmitted HIV infection, particularly during the first month of life. DESIGN/SETTING/PATIENTS: Prospective cohort study of 140 infants born to HIV-seropositive women in a large urban teaching hospital and of 248 older infants and children referred for diagnosis and treatment of HIV infection. MAIN OUTCOME MEASURES: The HIV-specific IgA immunoblot results were compared with the infection status of patients as determined by Centers for Disease Control and Prevention (Atlanta, Ga) criteria or by sequential early diagnostic assays for HIV. Sensitivity, specificity, and predictive values were calculated for each age range. RESULTS: Among infants studied from birth, the rate of vertical transmission of HIV was 21.6% (25/116). The sensitivity of HIV-specific IgA for the first month of life was 8.0% (2/25), and the specificity was 90.1% (82/91). Sensitivity increased progressively during the first year of life, and the negative predictive value was 94.6% by 6 to 8 months of age. The positive predictive value of this assay was 18.2% for neonates but was 96% to 100% after the first month of life. CONCLUSIONS: False-positive test results for HIV-specific IgA occurred with diminishing frequency during the first 4 weeks of life, and the frequency of detectable HIV-specific IgA was similar among the HIV-infected and uninfected groups at this age. Beyond 1 month of age, detection of HIV-specific IgA is highly specific and is a useful serum-based assay for early diagnosis of HIV infection. These results suggest that maternal-fetal transfusion is common and support the hypothesis that the majority of maternal-fetal transmission of HIV occurs around the time of parturition.

Longitudinal assessment of growth in children born to mothers with human immunodeficiency virus infection.

OBJECTIVES: To describe and to evaluate the longitudinal growth of children born to mothers with human immunodeficiency virus (HIV) infection. DESIGN: Measurements of weight, length (measured in infants in a recumbent position) and height (measured in older children in an upright position), and head circumference were documented and evaluated longitudinally using generalized estimating equations in a group of children born to HIV-infected mothers. Children infected with HIV were compared with uninfected children and with National Center for Health Statistics standards. SETTING: Primary care clinic in an urban hospital devoted to the medical care of children born to HIV-infected mothers. PATIENTS: One hundred nine children born to HIV-infected mothers, 59 HIV-infected and 50 uninfected, between birth and 70 months of age. RESULTS: The mean birth weights of both groups were below the 50th percentile. While the mean weight-for-age curve of uninfected children attained the 50th percentile by age 24 months, the mean birth weight-for-age curve of HIV-infected children remained below the 50th percentile. Weight gain became significantly different between the two groups by age 36 months. The mean birth length-for-age curves of HIV-infected and uninfected children was also below the 50th percentile. The mean height-for-age curve of uninfected children attained the 50th percentile by age 40 months, while that of HIV-infected children remained well below the 50th percentile. Linear growth between HIV-infected and uninfected children diverged earlier than weight, becoming significantly different by age 15 months. CONCLUSIONS: Although children born to HIV-infected mothers are born with weight and length below the 50th percentile, uninfected children catch up, while HIV-infected children remain below the 50th percentile and experience an earlier and more pronounced decrease in linear growth (height-for-age) than in weight-for-age.

Serum and plasma markers of nutritional status in children infected with the human immunodeficiency virus.

OBJECTIVE: To determine whether reduced serum or plasma protein and micronutrient levels are common in children infected with the human immunodeficiency virus (HIV) and whether these levels are different in children with growth retardation compared to those with normal growth. SUBJECTS: Children were separated into three groups: (a) HIV-infected with growth retardation (HIV + Gr); (b) HIV-infected with normal growth (HIV+); (c) HIV-uninfected with normal growth (HIV-). All children were afebrile and free of acute infection at the time of study. During a 24-hour stay in the Pediatric Clinical Research Unit, blood was drawn for analysis of total protein, albumin, zinc, selenium, and vitamin A levels; growth measurements were obtained; and dietary intake was assessed by 24-hour weighed food intake and 24-hour dietary recall. STATISTICAL ANALYSIS: Mean differences between groups were assessed by analysis of variance, and differences in the frequency of nutrient deficiency were determined by chi 2 analysis. RESULTS: Thirty-eight children between 2 and 11 years of age were studied: 10 HIV + Gr, 18 HIV+, and 10 HIV-. No statistically significantly differences were noted in mean levels of albumin, prealbumin, zinc, and selenium. Mean serum level of vitamin A was significantly higher in the HIV + Gr group than in the other two groups. There were no significant differences between groups in the frequency of deficiency for any nutrient studied. Mean energy and nutrient intake was similar among groups. APPLICATIONS/CONCLUSIONS: Abnormal serum or plasma protein or micronutrient levels were uncommon in this cohort of HIV-infected children, even in children with growth retardation. Routine monitoring of the level of proteins and micronutrients studied is unnecessary in the absence of specific clinical indicators of deficiency.

Whole body protein turnover in children with human immunodeficiency virus (HIV) infection.

The purpose of this study was to determine the rate of whole body protein turnover (WBPT) in human immunodeficiency virus (HIV)-infected children, and to determine the relationship between WBPT and growth. The rate of WBPT was calculated from the cumulative excretion of labeled urinary ammonia after a single intravenous dose of 15N-glycine in three groups of children: 1) HIV+ with growth retardation (HIV+ Gr); 2) HIV+ with normal growth (HIV+); and 3) HIV-uninfected with normal growth (HIV-). Twenty-six children between 2 and 11 y of age were studied (10 HIV+ Gr, 12 HIV+, 4 HIV-). All children were afebrile and free of acute infection during the study. Rates of WBPT (mean +/- SD) for the study groups were: HIV+ Gr, 12.2 +/- 4.8; HIV+, 10.7 +/- 5.1; and HIV-, 8.6 +/- 2.1 g.protein.kg-1.d-1 (NS, P > 0.05). Although not statistically significant, mean WBPT was 42% greater in HIV+ Gr, and 24% greater in HIV+ compared to HIV-. Statistically significant correlations were found between WBPT and Z scores for height (r = -0.39, P = 0.05) and weight-for-age (r = -0.51, P = 0.01) and dietary intake of protein (r = 0.39, P = 0.05), and between protein balance (synthesis-catabolism) and intakes of energy (r = 0.47, P = 0.02) and protein (r = 0.40, P = 0.04). There was no statistically significant correlation between WBPT and resting energy expenditure (r = 0.27, P = 0.19), or CD4 cell number (r = 0.05, P = 0.82). These data suggest an association between increased rates of protein turnover and low weight and height-for-age Z scores, and that it may be possible to achieve positive protein balance given an adequate intake of nutrients.

Selenium deficiency and cardiomyopathy in acquired immunodeficiency syndrome.

Selenium deficiency is common in patients with human immunodeficiency virus infection and may contribute to the development of cardiomyopathy. A 5-year-old boy with congenital human immunodeficiency virus infection developed cardiomyopathy. Evaluation for reversible causes of cardiomyopathy was notable for the diagnosis of selenium deficiency. Cardiac function improved on selenium supplementation. The role of selenium in cardiac dysfunction and the need for nutritional evaluation and supplementation of malnourished patients with acquired immunodeficiency syndrome is discussed.

Surgical intervention in children with human immunodeficiency virus infection.

Twenty-one children with human immunodeficiency virus (HIV) infection required surgical intervention during the course of their disease. There were 11 females and 10 males (age range, 3 months to 6 years). The children underwent 54 operative procedures after diagnosis of their disease. These included placement of central venous catheter (23 patients), open lung biopsy (11), incision and drainage of perirectal abscess (4), incision and drainage of soft tissue abscess (5), myringotomy (2), diverting colostomy (3), Nissen fundoplication (1), and other (5). All 21 patients had clinical AIDS by the Centers for Disease Control CDC classification. To date, there have been 12 deaths in the 21 patients (57%) due to progressive deterioration with the patient's disease. Most procedures were adjuncts for diagnostic and therapeutic intervention in a population of children with a uniformly fatal disease. The knowledge of various high risk groups for AIDS must heighten the surgeon's awareness to the growing and significant pediatric segment of the HIV population, the complications of their disease, and the surgeon's limited role in treating these problems.

Children affected by HIV. Clinical experience and research findings.

This article describes the plight of HIV affected children, and the work of mental health professionals with HIV affected children and their families, and presents pertinent research findings on the topics. The concepts of prevention, resilience, and family and child development are applied to the organizing of mental health care for HIV affected children.

Care of HIV-risk infants: nursing outreach by PNPs.

In this prospective study, HIV-risk infants (infants born to women with a history of intravenous drug use, prostitution, or who is a sexual partner of an intravenous drug user) were followed during home visits by a pediatric nurse practitioner. Analysis of home visit records indicated that significant medical problems were detected in one out of every 12 visits, requiring referral of the infant for immediate medical attention. The most frequent problems/maternal concerns encountered during the home visits were infectious disease symptoms and skin conditions. The type of problems/maternal concerns did not differ by infant HIV status. With an increase in incidence of HIV infection in children, outreach by specialized nurses including PNPs is necessary to provide the intensive medical services required by these children.

Primary care for children with human immunodeficiency virus infection.

Pediatric human immunodeficiency virus (HIV) infection is now the seventh leading cause of death in U.S. children 1 to 14 years of age and the leading cause of death in children 2 to 5 years of age in many U.S. cities. The key to enhancing the quality and duration of life in HIV-infected children is to recognize and diagnose HIV infection as early as possible and to initiate prophylactic and antiretroviral therapies. Most of the medical treatment of these children can be conducted in a primary care setting if (a) primary care practitioners are informed of current treatment regimens and (b) adequate pediatric HIV consultation service is available. This article reviews the primary care of HIV-infected children including early diagnosis, current treatment options, and the complex psychosocial issues associated with caring for these children.

Disclosure of HIV diagnosis to children: when, where, why, and how.

Despite recent recommendations by the American Academy of Pediatrics that strongly encourage disclosure of human immunodeficiency virus (HIV) infection to school-age children, health care providers vary widely in their actual disclosure practices. Concrete guidelines for accomplishing disclosure are not currently available. Nondisclosure can result in a variety of problems, including anxiety, depression, phobias, and exclusion from peer support groups and medical camps. This article reviews the available literature on disclosure of HIV infection to children and describes the disclosure process used in a large, urban pediatric HIV clinic.