Nonbronchoscopic bronchoalveolar lavage in mechanically ventilated infants: technique, efficacy, and applications

Prevalence and outcome of cytomegalovirus-associated pneumonia in relation to human immunodeficiency virus infection

AIM

To investigate the antemortem prevalence and outcome of cytomegalovirus (CMV)-associated pneumonia in African children.

METHODS

A total of 202 children (median age, 3.2 months; 124 human immunodeficiency virus [HIV]-infected, 62%; 87 severely malnourished, 43%) sequentially hospitalized for severe pneumonia were prospectively investigated. In addition to routine microbiologic investigations, respiratory tract secretions and blood were submitted for CMV culture and qualitative and quantitative CMV polymerase chain reaction.

RESULTS

CMV-associated pneumonia was common (28%, 47/169) and more prevalent in HIV-infected than uninfected children (36% vs. 15%; odds ratio [OR], 3.0; 95% confidence interval, 1.3-7.4). CMV-associated pneumonia was more common than Pneumocystis pneumonia (27%) and other viral-associated pneumonia (19%) in HIV-infected children. In-hospital mortality was 25% (51/202) with increased mortality in HIV-infected compared with uninfected children (43/124 [35%] vs. 8/76 [11%]; OR, 4.5; 1.9-11.8). Increased mortality occurred in HIV-infected children with CMV-associated pneumonia (OR, 2.5; 1.04-6.5) but this association was not evident after adjusting for CD4 <15% (adjusted OR, 1.78; 0.6-4.6).

CONCLUSIONS

CMV-associated pneumonia is common and associated with a poor outcome in children with advanced HIV disease. Improved diagnostic testing and increased access to antiviral therapy might improve the outcome of HIV-infected children with CMV-associated pneumonia.

The diagnostic dilemma of ventilator-associated pneumonia in critically ill children

OBJECTIVE

A review of the existing literature on ventilator-associated pneumonia in children with emphasis on problems in diagnosis.

DATA SOURCES

A systematic literature review from 1947 to 2010 using Ovid MEDLINE, PubMed, Cochrane Central Register of Controlled Trials, and ISI Web of Science using key words "ventilator associated pneumonia" and "children." Where pediatric data were lacking, appropriate adult studies were reviewed and similarly referenced.

STUDY SELECTION

Two hundred sixty-two pediatric articles were reviewed and data from 48 studies selected. Data from 61 adult articles were also included in this review.

DATA EXTRACTION AND SYNTHESIS

Ventilator-associated pneumonia is the second most common nosocomial infection and the most common reason for antibiotic use in the pediatric intensive care unit. Attributable mortality is uncertain but ventilator-associated pneumonia is associated with significant morbidity and cost. Diagnosis is problematic in that clinical, radiologic, and microbiologic criteria lack sensitivity and specificity relative to autopsy histopathology and culture. Qualitative tracheal aspirate cultures are commonly used in diagnosis but lack specificity. Quantitative tracheal aspirate cultures have sensitivity (31-69%) and specificity (55-100%) comparable to bronchoalveolar lavage (11-90% and 43-100%, respectively) but concordance for the same bacterial species when compared with autopsy lung culture was better for bronchoalveolar lavage (52-90% vs. 50-76% for quantitative tracheal aspirate). Staphylococcus aureus and Pseudomonas species are the most common organisms, but microbiologic flora change over time and with antibiotic use. Initial antibiotics should offer broad-spectrum coverage but should be narrowed as clinical response and cultures dictate.

CONCLUSIONS

Ventilator-associated pneumonia is an important nosocomial infection in the pediatric intensive care unit. Conclusions regarding epidemiology, treatment, and outcomes are greatly hampered by the inadequacies of current diagnostic methods. We recommend a more rigorous approach to diagnosis by using the Centers for Disease Control and Prevention algorithm. Given that ventilator-associated pneumonia is the most common reason for antibiotic use in the pediatric intensive care unit, more systematic studies are sorely needed.

CMV pneumonia in HIV-infected ventilated infants

BACKGROUND

The contributing role of cytomegalovirus (CMV) in infants treated for Pneumocystis jiroveci pneumonia (PJP) is unknown. High dose steroids used in the treatment of PJP may further immunocompromise these infants contributing to the development of CMV pneumonia.

AIM

The aim of this study was to determine the role of CMV pneumonia in infants being ventilated for suspected PJP.

METHODS

In this prospective study HIV infected infants being treated with trimethoprim-sulfamethoxazole (TMP/SMX) and ventilated for suspected PJP were included if they had not responded to treatment. Open lung biopsy was performed if there was no improvement in ventilatory requirements.

RESULTS

Twenty-five HIV positive infants with a mean age of 3.3 months were included. Lung biopsy was performed in 17 (68%) and post-mortem lung tissue was obtained in 8 (32%). After evaluation of the histology, immunohistochemistry, and viral cultures from lung tissue, the most likely causes of pneumonia were: CMV and PJP dual infection 36% (n = 9), CMV pneumonia 36% (n = 9), and PJP 24% (n = 6). The pp65 test for CMV antigen was falsely negative in 24%. The mean blood CD4 count was 287/microl. There was an association between the CD4 lymphocyte status and the final diagnosis, with the CMV and PJP group (CD4 110/microl) having the lowest CD4 status (P = 0.0128). Pediatric Intensive Care Unit (PICU) mortality was 72% (n = 18) and in hospital mortality 88%.

CONCLUSION

Of the ventilated infants failing to respond to treatment, 72% had histologically confirmed CMV pneumonia, probably accounting for the high mortality in this cohort. The incidence of CMV disease in HIV infected infants being ventilated for severe pneumonia warrants that ganciclovir is used empirically until CMV disease is excluded. The role of lung biopsy in these circumstances needs to be researched.

Diagnosis of ventilator-associated pneumonia in children in resource-limited setting: a comparative study of bronchoscopic and nonbronchoscopic methods

OBJECTIVES

To compare the available methods for the diagnosis of ventilator-associated pneumonia in intubated pediatric patients and to suggest less costly diagnostic method for developing countries.

DESIGN

Prospective study.

SETTING

Pediatric intensive care unit of a tertiary care, multidisciplinary teaching hospital located in northern India.

PATIENTS

All consecutive patients on mechanical ventilation for >48 hrs were evaluated clinically for ventilator-associated pneumonia.

INTERVENTIONS

Four diagnostic procedures (tracheal aspiration, blind bronchial sampling, blind bronchoalveolar lavage, and bronchoscopic bronchoalveolar lavage) were performed in the same sequence within 12 hrs of clinical suspicion of ventilator-associated pneumonia. The bacterial density > or =104 colony-forming units/mL in a bronchoscopic bronchoalveolar lavage sample was taken as reference standard.

MEASUREMENTS AND MAIN RESULTS

Thirty patients with 40 episodes of ventilator-associated pneumonia were included in the study. Tracheal aspirate at the cutoff of > or =105 colony-forming units/mL was found to have sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 84%, 77%, 87.5%, 73%, and 80%, respectively. For blind bronchial sampling at > or =104 colony-forming units/mL cutoff, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 88%, 82%, 88%, 83%, and 87%, respectively; the most reliable results were obtained with blind bronchoalveolar lavage at the cutoff of > or =103 cfu/mL (sensitivity 96%, specificity 80%, positive predictive value 88%, negative predictive value 92%, and accuracy 90%). The area under the receiver operating characteristic curve of tracheal aspiration, blind bronchial sampling, and blind bronchoalveolar lavage was 0.87 +/- 0.06, 0.89 +/- 0.06, and 0.89 +/- 0.05, respectively. The cost of balloon-tip pressure catheter used for blind bronchoalveolar lavage was INR 1600.00 (US$40) whereas that for blind bronchial sampling was only INR 35.00 (<1 US$).

CONCLUSIONS

Blind bronchoalveolar lavage was the most reliable method followed closely by blind bronchial sampling for the diagnosis of ventilator-associated pneumonia. Considering the difference of the cost in the two procedures, blind bronchial sampling may be the preferred method in the pediatric intensive care unit of a developing country.

Surfactant phospholipids, surfactant proteins, and inflammatory markers during acute lung injury in children

OBJECTIVE

To explore the pathophysiology of acute lung injury in children.

DESIGN

Prospective cohort study.

SETTING

Regional University Hospital, pediatric intensive care unit.

PATIENTS

Children without a preexisting lung injury who developed acute lung injury and were intubated were eligible for the study. Children without lung injury and intubated for minor surgical procedures acted as controls.

INTERVENTIONS

Bronchoalveolar lavage fluid and blood were collected on days 1 to 4, weekly, and immediately before extubation during acute lung injury. Molecular species compositions of phosphatidylcholine were determined by electrospray ionization mass spectrometry of lipid extracts of bronchoalveolar lavage fluid supernatants. Surfactant proteins A, B, and D and interleukin-8 were measured in bronchoalveolar lavage fluid and plasma by enzyme-linked immunosorbent assay and Western blotting.

MEASUREMENTS AND MAIN RESULTS

Eighteen children with acute lung injury were enrolled in the study and compared with eight controls. In children with acute lung injury, there were significant changes in the bronchoalveolar lavage fluid phosphatidylcholine species. Bronchoalveolar lavage fluid dipalmitoyl phosphatidylcholine (PC 16:0/16:0) and palmitoyl-myristoyl phosphatidylcholine (PC 16:0/14:0) significantly deceased during acute lung injury (p < .001 and p < .001, respectively), whereas oleoyl-linoleoyl PC (18:1/18:2), palmitoyl-linoleoyl PC (16:0/18:2) and stearoyl-linoleoyl PC (18:0/18:2) characteristic of plasma PC were significantly increased (p < .05, p < .02, and p < .05 respectively), as well as palmitoyl-oleoyl PC (16:0/18:1), and stearoyl-arachidonoyl PC (18:0/20:4) which are characteristic of cell membranes (p < .02, and p < .02, respectively). There were no significant changes to bronchoalveolar lavage fluid, surfactant protein A or B levels compared with controls during acute lung injury, whereas bronchoalveolar lavage fluid, surfactant protein D, and interleukin-8 levels significantly increased (p < .05 and p < .02, respectively). In plasma during acute lung injury, there were significant increases in surfactant proteins A, B, and D, and interleukin-8 (p < .001, p < .001, p < .05, and p < .001, respectively).

CONCLUSION

Changes to the phosphatidylcholine profile, surfactant proteins, and inflammatory markers of bronchoalveolar lavage fluid and plasma in children with acute lung injury are consistent with an alveolar/blood leakage and inflammatory cell membrane degradation products. These changes are due to alveolar capillary membrane damage and cellular infiltration.

Consensus among physiotherapists in the united kingdom on the use of normal saline instillation prior to endotracheal suction: a Delphi study

PURPOSE

To investigate whether physiotherapists consider normal saline instillation (NSI) useful before endotracheal suctioning and, if so, when.

METHODS

Sixty-eight respiratory physiotherapists recruited from the United Kingdom's Association of Chartered Physiotherapists in Respiratory Care agreed to participate in a Delphi study. Clinicians' opinion of when NSI should be used was established and developed into statements. Level of agreement with each statement was collated through three rounds of a questionnaire. Clinicians' experiences were also reported.

RESULTS

From the 52 responses to the third questionnaire, there was consensus that respiratory physiotherapists in the United Kingdom would use NSI when sputum retention is a problem, particularly when treatment options are limited (96%) and when sputum is obstructing the airway (92%). They agreed that non-bronchoscopic bronchoalveolar lavage can be used to resolve persistent atelectasis (70%). They would not use NSI for a test treatment during initial assessment without evidence of retained secretions (94%), when secretions are copious but can be cleared by alternative physiotherapy techniques (96%), to enhance a cough unless very strong evidence indicates retained secretions (81%), or to compensate for inadequate suction technique (90%).

CONCLUSION

This study provides clinicians' views about when NSI could be used.

A simple method of reducing complications of pediatric nonbronchoscopic bronchoalveolar lavage

Our objective was to determine whether a simple method of maintaining positive pressure ventilation during nonbronchoscopic bronchoalveolar lavage (NB-BAL) would successfully reduce the incidence and/or severity of desaturation events. Our design was a clinical trial with historical controls. Seventy ventilated pediatric patients undergoing diagnostic NB-BAL participated. Two NB-BAL techniques were compared: 1) the "unsealed" method, where the suction catheter was passed through an open system, maintaining oxygenation but not airway pressure; and 2) the "sealed" technique, which was identical except that the catheter was passed through a diaphragm, maintaining positive pressure ventilation throughout. NB-BAL was performed on 35 patients using the "unsealed" technique and 2 years later on 35 patients using the "sealed" method. Heart rate and oxyhemoglobin saturation (SaO(2)) were recorded before, during, and after NB-BAL. There was no difference between groups with regard to demographic data, oxygenation, or ventilatory requirements (P >or= 0.1). The "sealed" group experienced a median drop in SaO(2) of 6.0% (range, -6% to 44%), and the "unsealed" group a drop of 13.0% (-2% to 61%), during NB-BAL (P < 0.05). Patients with oxygenation index greater than 10 experienced the most severe desaturation events in both groups: 53.8% of patients in the "sealed" group with oxygenation index >10 desaturated to <80% vs. 91.6% in the "unsealed" group (P < 0.05). In conclusion, we describe a simple, inexpensive modification of the NB-BAL technique that reduces the incidence and severity of desaturation during NB-BAL.

Bronchoscopy in paediatric intensive care

Bronchoscopy is a highly versatile technique in the context of intensive care and has many potentially valuable indications. Safety is of paramount importance and the risks in critically unstable patients are correspondingly greater than in more stable children. The main contraindication to bronchoscopy is if it will provide no useful information. The procedure is obviously more risky in children with severe hypoxia, uncontrolled bleeding diathesis, cardiac failure or severe pulmonary hypertension. Monitoring should include at least oxygen saturation, blood pressure (ideally by continuous, invasive monitoring) and preferably capnography. Indications for bronchoscopy in paediatric intensive care include endobronchial toilet, sometimes instilling recombinant human DNAase even in children who do not have cystic fibrosis; checking tube patency and position; assisting in a difficult intubation or tube change; achieving the selective intubation of a main bronchus; the diagnosis and management of ventilator-associated pneumonia or the ventilated, immunocompromised host; the assessment of lobar collapse or focal hyperinflation; airway stent assessment; assessment of stridor on extubation and the diagnosis of any associated disease. New iatrogenic complications are also likely to be discovered. The procedure is very safe if performed by experienced operators with back-up from doctors skilled in airway management and the monitoring of sick children.

Bronchoscopy--how and when?

At the Royal Brompton Hospital, we perform over 200 flexible bronchoscopies per year in children. We will be presenting a series of five articles describing various aspects of our clinical and research practice. This first article is about the basics of how and when to perform flexible bronchoscopy. It highlights aspects of training, preparation of the patient and the equipment required. It discusses anaesthesia and gives practical details on how to actually use the bronchoscope, as well as detailing techniques of lavage, brushings and biopsy. Particular attention is paid to indications and contraindications, as well as potential complications.

Nosocomial pneumonia in pediatric patients: practical problems and rational solutions

Nosocomial pneumonia is a common hospital-acquired infection in children, and is often fatal. Risk factors for nosocomial pneumonia include admission to an intensive care unit, intubation, burns, surgery, and underlying chronic illness. Viruses, predominantly respiratory syncytial virus (RSV), are the most common cause of pediatric nosocomial respiratory tract infections. Gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa) are the predominant bacterial pathogens, and are associated with a high mortality rate. Staphylococcus aureus and Staphylococcus epidermidis are the most common Gram-positive bacteria causing nosocomial pneumonia; infections with these organisms have a better outcome than those with Gram-negative organisms. An increasing problem is the emergence of multiresistant Gram-positive and Gram-negative nosocomial pathogens. Distinguishing nosocomial pneumonia from other pulmonary processes may be difficult; diagnosis is based on clinical signs, radiological findings, and microbiological results. Recommended empiric therapy should consider factors such as the time of onset of illness, severity of disease, and specific risk factors for nosocomial pneumonia, including use of mechanical ventilation, underlying disease, or recent use of antibacterials. The resident local hospital flora should be considered when selecting therapy for nosocomial pneumonia. Early initiation of appropriate empiric therapy reduces morbidity and mortality. For empiric treatment of bacterial nosocomial pneumonia, an intravenous antibacterial regimen that includes coverage of Gram-negative bacilli and Gram-positive organisms should be used. A carbapenem or ureidopenicillin derivative (piperacillin) plus a beta-lactamase inhibitor should be used where extended spectrum beta-lactamase-producing Enterobacteriaceae are endemic. Therapy should be modified when a specific pathogen and its antimicrobial susceptibility are identified. Effective prevention of nosocomial pneumonia requires infection control measures that affect the environment, personnel, and patients. Of these, hand hygiene, appropriate infection control policies, and judicious use of antibacterials are essential.

Repeatability of cellular constituents and cytokine concentration in fluid obtained by non-bronchoscopic bronchoalveolar lavage of infants receiving extracorporeal oxygenation

BACKGROUND

Since few studies have assessed the repeatability of non-bronchoscopic bronchoalveolar lavage (NB-BAL), we compared cellular counts and cytokine concentrations in fluid obtained by standardised NB-BAL from each side of 20 intubated infants receiving extracorporeal membrane oxygenation (ECMO).

METHODS

Total cell counts were obtained from 95 paired lavages and 77 pairs were suitable for differential counts and measurement of cytokine concentrations.

RESULTS

Moderate correlation was noted between the two sides for most cell types including total cell counts and percentages of neutrophils and macrophages (R=0.70-0.84) and for cytokine concentrations (IL-8 R=0.78, IL-6 R=0.75, TNF-alpha R=0.64, all p< or =0.001). Using Bland-Altman analysis the mean difference between the two sides approached zero for cellular constituents (total cell counts mean difference 1.7, limits of agreement -187.5 to +190.9 x 10(4)/ml; percentage neutrophils -3.9%, -41.5% to +33.6%; percentage macrophages 3.9%, -33.8% to +41.6%) but tended to be greater on the right for logarithmically transformed cytokine measurements (IL-8: left/right ratio 0.74, limits of agreement 0.12 to 5.45, IL-6: 0.93, 0.09 to 5.87, and TNF-alpha: 0.93, 0.27 to 3.16). Using linear regression with random effects to assess the variability, only the infant's age appeared to influence the cellular results but, for cytokines, only the volume retrieved affected the variability. The magnitude of the measurements, the underlying disease, the operator's experience, days on ECMO, or survival did not affect the variability.

CONCLUSION

Measurements obtained by NB-BAL need to be interpreted with caution and strongly suggest that normalisation for the dilutional effects of saline is essential.

Open lung biopsy in children with respiratory failure

OBJECTIVE

To evaluate benefits and risks of open lung biopsy in children with respiratory failure.

DESIGN

Retrospective chart review.

SETTING

A 36-bed pediatric critical care unit in a tertiary care, university-based hospital.

PATIENTS

We studied 31 patients with respiratory failure who underwent 33 open lung biopsies.

MEASUREMENTS AND MAIN RESULTS

The charts of all children in the critical care unit with respiratory failure who underwent an open lung biopsy over a 10-yr period (1989-98) were reviewed. Of 33 open lung biopsies performed, 76% (25 of 33) led to a relevant change in medical management. Complications were seen in 45% of patients, predominantly attributable to airleak (33%) without affecting respiratory function. An infectious agent was detected by open lung biopsy in ten patients; bronchoalveolar lavage performed before open lung biopsy failed to isolate the infection in eight of ten patients.

CONCLUSIONS

In children with undiagnosed or persisting respiratory failure, open lung biopsy is a useful diagnostic procedure that leads to significant changes in medical management and increases the diagnostic yield for infections. Despite the relatively high complication rate, open lung biopsy should be performed routinely in this group of patients.

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.

[Severe community-acquired pneumonia in immunocompetent children]

Severe community-acquired pneumonia (CAP) is still a serious disease with a high mortality rate, especially in developing countries. Children under 5 years are more prone to severe CAP. In this article, the authors review the definition and clinical criteria used in the initial evaluation and decision to hospitalize patients. The diagnosis approach requires only a limited number of laboratory tests before initiating the supportive measures and wide spectrum antimicrobial therapy. If the patient fails to respond favorably 48-72 hours after initiating therapy, more invasive investigations are indicated. After resolution, an immunological evaluation is warranted.

Investigation of the child with interstitial lung disease

Many disorders can affect the pulmonary interstitium in children. Although individual interstitial lung diseases are rare, the range of conditions encountered is wide. Interstitial disease is also seen increasingly as a consequence of the treatment of children having other primary problems including cancer, immunodeficiency and haemotological diseases, as well as in recipients of solid organ and bone marrow transplants. The management and prognosis of individual conditions is highly variable, thus it is essential to search for a precise diagnosis in every patient. High resolution computerised tomography (HRCT) and other less invasive investigations may be helpful in the management of patients. However, it is unusual to be able to make a firm diagnosis without a lung biopsy.

Blind protected specimen brush and bronchoalveolar lavage in ventilated children

OBJECTIVE

To determine whether nonbronchoscopic protected specimen brush (PSB) and bronchoalveolar lavage (BAL) are contributive for diagnosing ventilator-associated pneumonia in mechanically ventilated children.

DESIGN

Prospective study.

SETTING

Fifteen-bed pediatric intensive care unit in a university hospital.

PATIENTS

A total of 103 mechanically ventilated children, ranging in age from 7 days to 8.8 yrs, most with a high clinical suspicion for bacterial pneumonia.

INTERVENTIONS

All the children underwent nonbronchoscopic PSB and BAL. Nonbronchoscopic PSB was performed with a plugged double-sheathed brush and BAL with a double-lumen plugged catheter. Endotracheal secretions and blood cultures were also collected. Open-lung biopsy was performed for any child who died within 7 days after the inclusion in the study, according to the parental consent.

MEASUREMENTS AND MAIN RESULTS

The PSB specimens were submitted for bacteriologic quantitative culture (positive threshold, 10(3) colony-forming units [cfu]/mL). The BAL samples were processed for microscopic quantification of the polymorphonuclear cells containing intracellular bacteria (positive threshold, 1%) and quantitative culture (positive threshold, 10(4) cfu/mL). According to diagnostic categories based on clinical, biological, radiologic, and pathologic criteria, 29 children had bacterial pneumonia and 64 did not Ten children were classified as having an uncertain status. Of the 29 children with bacterial pneumonia, 26 (90%) met one of the following three criteria: a) PSB specimen culture, > or =10(3) cfu/mL; b) intracellular bacteria in cells retrieved by BAL, > or =1%; and c) BAL fluid culture, > or =10(4) cfu/mL. In contrast, 56 (88%) of the 64 patients without pneumonia did not.

CONCLUSION

The results of this study indicate the following: a) nonbronchoscopic PSB and BAL were feasible in a large population of mechanically ventilated children; b) nonbronchoscopic techniques were contributive for diagnosing ventilator-associated pneumonia in children; and c) a combined diagnostic approach, using nonbronchoscopic PSB and BAL, was superior to using either test alone.

Comparison of two methods of diagnostic lung lavage in ventilated infants with lung disease

The methods of nonbronchoscopic lung lavage used for collection of samples of epithelial lining fluid (ELF) in intubated patients are poorly standardized and incompletely validated. In infants with lung disease requiring ventilatory support, we evaluated two techniques of small volume saline lavage for the collection of a specimen suitable for pulmonary surfactant analysis. We aimed to compare apparent origin of the return fluid obtained by each method, equivalence and agreement of the estimates of measured pulmonary surfactant concentration, and the relative strength of association between surfactant indices and lung dysfunction. Fifty-three contemporaneous paired samples of lung lavage fluid suitable for surfactant analysis were collected from 31 infants using tracheal aspirate (TA, 4 x 0.5 ml saline), and then nonbronchoscopic bronchoalveolar lavage (NB-BAL, 3 x 1 ml/kg). Return fluid from TA had higher mean ELF concentration of total protein and IgA secretory component (SC), and a lower surfactant protein A (SP-A) concentration than NB-BAL, indicating that the TA lavage was sampling ELF more proximally in the tracheobronchial tree (protein: TA 7.7 versus NB-BAL 4.7 mg/ml; SC: 21 versus 1.8 microgram/ml; SP-A: 9.8 versus 19 microgram/ml; all p < 0.01). Mean concentration of surfactant indices in ELF differed only for SP-A, but for all indices, paired values showed poor agreement on Bland-Altman analysis, highlighting the potential imprecision associated with small volume lung lavage. TA return fluid yielded estimates of surfactant indices which were at least equivalent to NB-BAL in prediction of the severity of lung dysfunction. We conclude that NB-BAL return fluid has more distal origin, but analysis of TA fluid may have equal validity in the estimation of indices of pulmonary surfactant. The results of individual estimates of ELF constituents in a single sample of lavage fluid should be interpreted with caution, even when standardized sampling techniques are employed.

Surfactant protein levels in severe respiratory syncytial virus infection

Infection with respiratory syncytial virus (RSV) is a common cause of respiratory disease in infancy. Surfactant phospholipids have been shown to be reduced in severe RSV infection. Reduction in surfactant proteins might also contribute to the pathogenesis of this disease. We investigated daily levels of surfactant proteins in bronchoalveolar lavage (BAL) fluid from 18 ventilated infants with RSV infection (median age 3.1 mo) and in a control group of 16 ventilated surgical patients (median age 0.4 mo). Surfactant proteins were measured by ELISA, total protein by the Lowry method. Surfactant protein A (SP-A) was reduced in BAL fluid from children with RSV infection (median 5.6 micrograms/ml; range 0.6 to 151.9 micrograms/ml) compared with control samples (median 9.0 micrograms/ml; range 0.5 to 139.6 micrograms/ml, p = 0.0368). Surfactant protein B (SP-B) was lower in the RSV group (median 12.0 ng/ml; range 0 to 60. 8 ng/ml) than in control patients (median 118.1 ng/ml; range 0 to 778.2 ng/ml, p < 0.0000). Surfactant protein D (SP-D) was also reduced in the RSV group (median 130.3 ng/ml; range 0 to 1,486.0 ng/ml) versus median 600.4 ng/ml; range 0 to 1,869.0 ng/ml, p < 0. 0000. Total protein levels were higher in the RSV group (median 0.49 mg/ml; range 0.13 to 2.46 mg/ml versus median 0.36 mg/ml; range 0.07 to 1.65 mg/ml, p = 0.0079). The median value of SP-A was significantly lower in the initial sample (2.3 micrograms/ml) than in the final one (6.0 micrograms/ml). However, no significant correlation was found between surfactant protein concentrations and disease severity measured by arterial alveolar oxygen ratio. We conclude that alterations in surfactant protein concentrations are present in severe RSV infection and speculate that these may contribute to the abnormalities of lung function seen in this condition.

Bronchoalveolar lavage findings suggest two different forms of childhood asthma

BACKGROUND

It seems plausible that children with atopy and persistent asthma symptoms will, like their adult counterparts, have chronic airways inflammation. However, many young children with no other atopic features have episodic wheezing that is triggered solely by viral respiratory infections. Little is known as to whether airways inflammation occurs in these two asthma patterns during relatively asymptomatic periods.

METHODS

Using a non-bronchoscopic bronchoalveolar lavage (BAL) procedure on children presenting for an elective surgical procedure, this study has investigated the cellular constituents of BAL fluid in children with a history of atopic asthma (AA) non-asthmatic atopic children (NAA) or viral associated wheeze (VAW).

RESULTS

A total of 95 children was studied: 52 with atopic asthma (8.0 years, range 1.1-15.3, 36 male), 23 with non-asthmatic atopy (median age 8.3 years, range 1.7-13.6, 11 male) and 20 with VAW (3.1 years, range 1.0-8.2, 13 male). No complications were observed during the lavage procedure and no adverse events were noted post-operatively. Total lavage fluid recovered was similar in all groups and the total cell numbers were higher in the VAW group. Eosinophil (P < or = 0.005) and mast cell (P < or = 0.05) numbers were significantly elevated in the group with atopic asthma.

CONCLUSIONS

During relatively asymptomatic periods there is on-going airways inflammation, as demonstrated by eosinophil and mast cell recruitment, in children with asthma and atopy but not in children with viral associated wheeze or atopy alone. This strongly suggests that there are different underlying pathophysiological mechanisms in these two groups of children who wheeze.

Morbidity and mortality of open lung biopsy in children

OBJECTIVE

In patients with diffuse pulmonary infiltrates, when empiric therapy or less-invasive diagnostic procedures fail, physicians frequently resort to open lung biopsy (OLB) to provide a definite diagnosis and to help redirect therapeutic treatment. OLB is still widely regarded as a safe diagnostic procedure, even in the critically ill child. The objective of this study is to evaluate the accuracy of this view with regard to children with acute respiratory failure (ARF) and, for this purpose, compares the mortality and morbidity of such patients with those without ARF.

DESIGN

Retrospective chart review.

SETTING

University hospital.

PATIENTS

Forty-two patients (mean age, 6.6 years) underwent 47 OLBs for undiagnosed diffuse pulmonary infiltrates between July 1984 and December 1994. Twenty-six patients (55%) were in ARF. Fifteen of these patients were intubated and receiving mechanical ventilatory support before the OLB procedure.

RESULTS

The overall incidence of serious complications associated with the OLB procedure was 51%. Of the patients with ARF, 17 (65%) had at least one major complication compared with 3 (14%) of the patients without ARF. Pleural air complications (62% of the total) occurred only in patients with ARF: pneumothoraces and/or prolonged air leaks developed in 10 (38%) after their OLBs; 9 of these patients died, and 7 had pneumothorax complicating their chest tube removal, which required replacement chest tubes. All patients with ARF preoperatively required prolonged ventilatory support after the OLB procedure, whereas 90% of the patients without ARF could be extubated within 24 hours. Overall, 10 patients (24%) died after the OLB procedure. All deaths occurred in patients with ARF. Both ARF preoperatively and the presence of postoperative complications were significantly associated with decreased survival.

CONCLUSIONS

The morbidity and mortality rates of children with ARF undergoing OLB for diffuse pulmonary infiltrates differ considerably from those of children without ARF. For children with ARF, OLB is associated with the risk of prolonged ventilatory support, recurrent pneumothoraces, and air leaks. These complications may be attributable to such patients' having diseased lungs with poor healing. Moreover, these complications may, in turn, contribute to the patients' poor outcomes.

Pneumocystis carinii pneumonia in preterm infants: report of two cases successfully diagnosed by non-bronchoscopic bronchoalveolar lavage

We present two cases of Pneumocystis carinii pneumonia in apparently immunocompetent preterm infants presenting with unexplained respiratory distress associated with a predominantly interstitial process on the chest radiograph. Definite diagnosis was promptly established on the detection of cyst forms in the lung fluid obtained by non-bronchoscopic bronchoalveolar lavage, and a favourable outcome was achieved.

New approaches in the diagnosis of nosocomial pneumonia

We have presented a review of the present literature on new modalities to diagnose nosocomial pneumonia. Procedures are now available that, when correctly used, can establish a diagnosis of pneumonia with a high degree of reliability. In our institution, reliance on bronchoscopic modalities has simplified management of patients with suspected VAP, by eliminating confusion and rationalizing antibiotic treatment. Invasive procedures, however, should be performed only if the results of cultures are consistently applied to treatment. As this field rapidly evolves, we hope that this review will provide the reader with a foundation to understand new developments.

Unsuspected Pneumocystis carinii pneumonia and vertically acquired HIV infection in infants requiring intensive care

When an infant develops acute respiratory failure of sufficient severity to necessitate supportive mechanical ventilation a cause should always be sought. A chest radiograph showing predominantly interstitial lung disease and an infant's failure to respond to standard antibiotic treatment are indications for non-bronchoscopic bronchoalveolar lavage. If P carinii pneumonia is diagnosed a congenital immunodeficiency should be sought and the parents counselled about HIV infection. Earlier investigation may be indicated by features of immunodeficiency when taking a history, performing a general examination, or analysing the results of basic haematological testing.

Review--neonatal bronchoscopy

Neonatologists are increasingly exploring the airways with rigid and flexible bronchoscopes. Each instrument has particular advantages; the rigid endoscope mainly for therapy, including balloon dilatation of acquired strictures, and the fibrescope mainly for inspection of the airway for diagnostic purposes. Before using either technique, it is essential to ensure that the information will be really useful and cannot be obtained using less invasive methods.