Outcome of mechanical ventilation in children with acquired immunodeficiency syndrome

Behandlung von Patienten mit HIV-Infektion auf der Intensivstation

HIV-infizierte Patienten können aus einer Reihe von Indikationen heraus der Intensivbehandlung bedürfen (·Abb. 66.1; [7, 17, 19, 33, 41, 44, 51]). In 50–75% der Fälle stellt akutes respiratorisches Versagen die Indikation für die Behandlung HIV-Infizierter auf der Intensivstation dar [7, 17, 19, 33, 41, 44, 51]. Bei 55–90% dieser Patienten mit intensiv behandlungsbedürftigem respiratorischen Versagen stellt Pneumocystis carinii das für die Erkrankung verantwortliche Pathogen dar [7, 33, 44].

The etiology and outcome of pneumonia in human immunodeficiency virus-infected children admitted to intensive care in a developing country

In developing countries, many human immunodeficiency virus (HIV)-infected children require intensive care unit (ICU) resources for pneumonia, but there is little information on the etiology of pneumonia or the impact of ICU intervention. OBJECTIVE: To compare the etiology and outcome of pneumonia in HIV-positive and seronegative children admitted to ICU. DESIGN: Prospective study. SETTING: Two pediatric ICUs linked to the University of Cape Town, South Africa. PATIENTS: Consecutive children admitted for pneumonia during 1998. MEASUREMENTS AND MAIN RESULTS: Clinical, demographic, ventilatory, and laboratory data were collected. Blood for testing was obtained. Induced sputum or nondirected bronchoalveolar lavage was performed for culture and Pneumocystis carinii identification; gastric lavage (GL) provided specimens for mycobacterial culture. Seventy-six children (21 [27.6%, 95% confidence interval {CI} = 18-39.1] HIV-positive) were enrolled. At admission, HIV infection was diagnosed in 15 of the 21 (71.4% [47.8-88.7]) HIV-positive patients. P. carinii pneumonia occurred in eight HIV-positive children (38% of HIV-infected patients) and one HIV-negative child. It was the acquired immunodeficiency syndrome (AIDS)-defining illness in seven children (47%). The incidence of bacteremia (15.3%) was similar in HIV-positive (15.8%) and HIV-negative children (15.1%), p =.94; Streptococcus pneumoniae and Staphylococcus aureus were the predominant isolates. Bacterial and viral isolates from sputum or bronchoalveolar lavage, including Mycobacterium tuberculosis in six (8%) children, did not differ by HIV status. Intermittent positive pressure ventilation was used in 8 of 21 (38%) HIV-positive children and 28 of 55 (51%) HIV-negative children, p =.32. Median days of intermittent positive pressure ventilation (3 [2-6]), ICU (5 [3-9.5]), and hospital (11 [7.5-19]) did not vary by HIV status. The in-hospital mortality rate for HIV-positive children (6 of 21 [28.6%]) was double that for seronegative patients (8 of 55[14.5%], relative risk [RR] 1.96 [0.77-4.99], p =.16). CONCLUSION: More than a quarter of children admitted to ICU for pneumonia in this geographic area are HIV-positive; most are diagnosed with HIV at admission. P. carinii pneumonia is a common AIDS indicator disease. HIV-infected children admitted with pneumonia had a worse outcome than seronegative children, a difference that is rendered statistically insignificant by the small sample size.

Pneumocystis carinii pneumonia in South African children infected with human immunodeficiency virus

BACKGROUND

Pneumocystis carinii pneumonia (PCP) has been regarded as uncommon in HIV-infected patients in Africa, but diagnostic difficulties and geographic variability may partly account for this. There is little information on the incidence of PCP in HIV-infected children in Africa.

AIM

To investigate (1) the incidence and associated features of PCP in African HIV-infected children and (2) the usefulness of sputum induction and nasopharyngeal aspirates (NPAs) for diagnosis of PCP.

METHODS

HIV-infected children hospitalized with pneumonia were prospectively enrolled in a 1-year study in South Africa. History, examination, chest radiology and blood tests (including HIV testing) were performed. Sputum induction (5% NaCl nebulization) or nondirected bronchoalveolar lavage in intubated patients was performed for P. carinii identification using immunofluorescence and silver stain; immunofluorescence was also done on nasopharyngeal aspirates (NPAs).

RESULTS

Of 151 HIV-infected children [47% female; median age, 9 (range, 3 to 23) months], 87 had been previously diagnosed with HIV whereas 64 (42.4%) were found to be HIV-positive at the time of admission. PCP occurred in 15 children (9.9%; 95% confidence interval, 5.9 to 15.5) and was the AIDS-defining infection in 13 of 64 (20.3%; 95% confidence interval, 11.8 to 31.5). Only 1 of 59 children receiving prophylaxis (1.7%) developed PCP compared with 14 of 92 (15.2%) not taking prophylaxis [relative risk, 0.11 (0.02 to 0.82), P = 0.007]. PCP-infected children were younger [3 (range, 3 to 4) vs. 10 (range, 4 to 24) months, P < 0.001] and presented with more severe pulmonary disease as indicated by a higher respiratory rate [63 (range, 60 to 73) vs. 50, (range, 40 to 60) P < 0.001], heart rate [160 (range, 136-180) vs. 140 (range, 120-152) P = 0.025] and a greater incidence of cyanosis (53% vs. 26%, P = 0.025). Clinical signs of HIV infection, occurring in 96% of children, were equally prevalent in both groups. High serum lactate dehydrogenase was the only laboratory investigation that distinguished PCP-infected from uninfected children [626 (range, 450 to 1098) vs. 307 (range, 243 to 465) units/l], P < 0.001. No radiologic features were found to be diagnostic of PCP. P. carinii was identified in 9 sputa and 6 bronchoalveolar lavage specimens, but all corresponding NPAs were negative. Seven of 15 (47%) children with PCP died while hospitalized compared with 24 of 136 (18%) without PCP [relative risk, 1.21 (range, 0.99 to 1.47), P = 0.008].

CONCLUSION

PCP is an important pathogen in HIV-infected infants in South Africa and is associated with a high mortality. Induced sputum is effective for obtaining lower respiratory tract secretions for diagnosis of PCP but an NPA is not useful.

Acute respiratory failure in the HIV-seropositive patient

Since approximately 40% to 65% of patients with AIDS will develop pulmonary disease, HIV-seropositive patients represent a large cohort of immunosuppressed individuals with the potential to progress to respiratory failure requiring mechanical ventilation and admission to the intensive care unit. This article reviews the cause, pathophysiology, diagnostic approach, and management of acute respiratory failure requiring mechanical ventilation in HIV-seropositive patients. Prognostic factors and survival rates for episodes of respiratory failure are also discussed. In addition, an overview of acute respiratory failure in pediatric AIDS patients is presented.

The pediatric pulmonary and cardiovascular complications of vertically transmitted human immunodeficiency virus (P2C2 HIV) infection study: design and methods. The P2C2 HIV Study Group

The P2C2 HIV Study is a prospective natural history study initiated by the National Heart, Lung, and Blood Institute in order to describe the types and incidence of cardiovascular and pulmonary disorders that occur in children with vertically transmitted HIV infection (i.e., transmitted from mother to child in utero or perinatally). This article describes the study design and methods. Patients were recruited from five clinical centers in the United States. The cohort is composed of 205 infants and children enrolled after 28 days of age (Group I) and 612 fetuses and infants of HIV-infected mothers, enrolled prenatally (73%) or postnatally at age < 28 days (Group II). The maternal-to-infant transmission rate in Group II was 17%. The HIV-negative infants in Group II (Group IIb) serves as a control group for the HIV-infected children (Group IIa). The cohort is followed at specified intervals for clinical examination, cardiac, pulmonary, immunologic, and infectious studies and for intercurrent illnesses. In Group IIa, the cumulative loss-to-follow-up rate at 3 years was 10.5%, and the 3-year cumulative mortality rate was 24.9%. The findings will be relevant to clinical and epidemiologic aspects of HIV infection in children.

Prospective, controlled study of the outcome of human immunodeficiency virus-1 antibody-positive children admitted to an intensive care unit

OBJECTIVE

Intensive care resources are both scarce and costly in South Africa. We set out to ascertain whether human immunodeficiency virus (HIV) status affects the spectrum of disease and the prognosis in children treated in pediatric intensive care units (ICUs).

DESIGN

A prospective, case-controlled study.

SETTING

The pediatric ICU at Kind Edward VIII Hospital, Durban, South Africa.

PATIENTS

HIV-positive cases were classified as "acquired immunodeficiency syndrome," "symptomatic HIV," and "HIV-unrelated diseases." Controls were matched for age, race, gender, severity of disease, and admitting diagnosis.

MEASUREMENTS AND MAIN RESULTS

THe clinician was blinded to the serostatus of patients. Informed consent and Ethics Committee approval were obtained for HIV testing and the study. Outcome measures were the duration of intermittent positive-pressure ventilation and ICU stay, maximum ventilatory requirements, infectious complications, and mortality. There were 11 cases of acquired immune deficiency (AIDS), 24 cases of symptomatic HIV, and 13 cases of HIV-unrelated diseases. Mortality rates for the three groups were as follows: 100% in patients with AIDS compared with 55% in their controls (p<.01); 38% in patients with symptomatic HIV and 46% in controls. Cytomegalovirus and Pneumocystis carinii infections were significantly increased (p<.01, p<.002, respectively) in patients with AIDS as compared with controls. Outcome measures were similar in those patients with symptomatic HIV and those patients with HIV-unrelated diseases, as compared with their respective controls.

CONCLUSIONS

Outcome in children with AIDS admitted to the pediatric ICU was significantly worse than the outcome in HIV-uninfected children. However, the number of AIDS patients studied was small. HIV antibody-positive children without AIDS do as well as uninfected controls. Ethics committees in resource-constrained countries may be assisted by such data when making difficult decisions on the admissions of HIV-infected patients to pediatric ICU facilities.

Improved outcome for young children with AIDS, Pneumocystis carinii pneumonia, and acute respiratory failure

OBJECTIVE

To describe the clinical course of children with acquired immunodeficiency syndrome, requiring mechanical ventilation secondary to Pneumocystis carinii pneumonia, with respect to intensive care unit outcome, long-term survival after intensive care unit discharge, and possible predictors of outcome.

DESIGN

Retrospective case series.

SETTING

Multidisciplinary, tertiary, pediatric intensive care unit.

PATIENTS

Thirteen consecutive patients accounting for 15 admissions to the intensive care unit, from September 1986 through December 1991, with the diagnoses of acquired immunodeficiency syndrome, P. carinii pneumonia, and acute respiratory failure requiring mechanical ventilation.

RESULTS

All patients were less than 2 years of age and acquired human immunodeficiency virus infection perinatally. Survival after 15 admissions to the intensive care unit was 60%. Mean (+/- SD) and median long-term survival for the nine intensive care unit survivors was 30 +/- 12.9 months and 27 months, respectively. Maximum oxygenation index and minimum partial pressure of arterial oxygen to fraction of inspired oxygen ratio were significantly different between survivors and nonsurvivors.

CONCLUSIONS

Young children with acquired immunodeficiency syndrome who develop acute respiratory failure secondary to P. carinii pneumonia and who require mechanical ventilation may have a better acute outcome and long-term survival than previously reported.

Pulmonary manifestations of HIV infection in children

We retrospectively reviewed the spectrum, course, and outcome of pulmonary diseases in 66 children with AIDS, hospitalized between 1982 and 1988, prior to the use of zidovudine. Fifty-two of the 66 (79%) patients developed pulmonary problems. In fifty-two percent of all patients, a pulmonary problem was the first symptom of HIV infection. The most common respiratory illness requiring hospitalization was an episode of respiratory distress with normal PaO2 and unchanged X-ray with a 9.7 +/- 6.8 days mean duration of hospitalization. Bacterial pneumonia, Pneumocystis carinii pneumonia (PCP) and pulmonary lymphoid hyperplasia/lymphoid interstitial pneumonia occurred in 30%, 32% and 22% of the patients, respectively. Bacterial pneumonia and PCP were associated with a high mortality rate. Sixty-eight percent of the patients died within 24 months of the onset of pulmonary disease. In 50% of the children, pulmonary disease was a primary cause of death. The results of this study can be useful in developing prospective studies for the prevention and treatment of pulmonary complications of HIV infection.

Pneumocystis carinii pneumonia in young children with AIDS

We present our experience with 54 episodes of Pneumocystis carinii pneumonia in 50 young children with AIDS, all but one representing congenitally acquired infection. Findings at history and physical examination are not helpful in suggesting the diagnosis. The diagnosis is suggested by marked hypoxemia, diffuse disease on chest radiograph, and elevated serum LDH level. Because important aspects of the history may be withheld, a high index of suspicion may be necessary for the correct diagnosis. The mortality rate for ventilated patients was 50%.