Epidemiology of Nosocomial Pneumonia in Infants After Cardiac Surgery

Association of Sugammadex or Neostigmine With Major Postoperative Pulmonary Complications in Children

BACKGROUND

Recent data in adult patients indicate that the use of sugammadex compared to neostigmine for reversal of neuromuscular block (NMB) was associated with a significant reduction in the risk of composite postoperative pulmonary complications. Despite the clinical significance of pulmonary complications in children, studies exploring the role of NMB reversal in the risk of these complications are currently unavailable.

METHOD

We performed a propensity score-matched retrospective study using the Pediatric Health Information System (PHIS) dataset spanning the years 2016 and 2020. We studied children <18 years who underwent elective, inpatient, noncardiac surgical procedures and received either neostigmine or sugammadex for reversal of NMB. Our primary outcome was major postoperative pulmonary complication, which we defined as the occurrence of either postoperative pneumonia or respiratory failure.

RESULTS

Our study included a study population of 33,819 children, of whom 23,312 (68.9%) received neostigmine and 10,507 (31.1%) received sugammadex. After propensity score matching (10,361 matched from each group), we found no evidence of a statistically significant association between the NMB reversal agent and the incidence of pulmonary complications (3.1% vs 3.1%; odds ratio [OR], 0.90; 95% confidence interval [CI], 0.78-1.05; P = .19). The components of pulmonary complications, including respiratory failure and pneumonia, were not statistically associated with the choice of NMB reversal agent.

CONCLUSIONS

Choice of NMB reversal agent does not appear to impact the incidence of major postoperative pulmonary complications. Further research is needed to determine whether our results carry forth across subpopulations defined by surgical specialty, the presence of complex chronic conditions, and anesthesia technique.

Post-cardiopulmonary bypass hypoxaemia in paediatric patients undergoing congenital heart disease surgery: risk factors, features, and postoperative pulmonary complications

Background

Hypoxemia after cardiopulmonary bypass (CPB) is the quantifiable manifestation of pulmonary dysfunction. This retrospective study was designed to investigate the risk factors for post-cardiopulmonary bypass hypoxaemia and the features of hypoxaemia and pulmonary complications in paediatric congenital heart disease surgery involving CPB.

Methods

Data including demographics, preoperative pulmonary or cardiac parameters, and intraoperative interventions were retrospectively collected from 318 paediatric patients who underwent radical surgery with CPB for congenital heart disease. Among them, the factors that were significant by univariate analysis were screened for multivariate Cox regression. The lowest ratio of arterial oxygen tension and the inspiratory oxygen fraction (PaO₂/FiO₂), hypoxaemia (PaO₂/FiO₂ ≤ 300) insult time, duration of hypoxaemia, extubation time, and pulmonary complications were also analysed postoperatively.

Results

The morbidity of post-cardiopulmonary bypass hypoxaemia was 48.4% (154/318). Months (6 < months ≤ 12, 12 < months ≤ 36 and 36 < months compared with 0 ≤ months ≤ 6: HR 0.582, 95% CI 0.388–0.873; HR 0.398, 95% CI 0.251–0.632; HR 0.336, 95% CI 0.197–0.574, respectively; p < 0.01), preoperative intracardiac right-to-left shunting (HR 1.729, 95% CI 1.200–2.493, p = 0.003) and intraoperative pleural cavity entry (HR 1.582, 95% CI 1.128–2.219, p = 0.008) were identified as independent risk factors for the development of post-cardiopulmonary bypass hypoxaemia. Most hypoxaemia cases (83.8%, 129/154) occurred within 2 h, and the rate of moderate hypoxaemia (100 < PaO₂/FiO₂ ≤ 200) was 60.4% (93/154).

Conclusion

The morbidity of post-cardiopulmonary bypass hypoxaemia in paediatric congenital heart disease surgery was considerably high. Most hypoxaemia cases were moderate and occurred in the early period after CPB. Scrupulous management should be employed for younger infants or children with preoperative intracardiac right-to-left shunting or intraoperative pleural cavity entry.

Outcomes After Bidirectional Glenn Shunt in a Tertiary-Care Pediatric Hospital in South Africa

OBJECTIVES

Large data sets have been published on short- and long-term outcomes following bidirectional Glenn surgery (BDG), or partial cavopulmonary connection, in high-income countries. Data from low-income and middle-income countries are few and often limited to the immediate postoperative period. The primary outcome was any in-hospital postoperative complication, assessed according to predefined criteria, in children who underwent BDG surgery at Red Cross War Memorial Children's Hospital.

DESIGN

A retrospective cohort study.

SETTING

A tertiary teaching hospital.

PARTICIPANTS

The study authors identified 61 children (<18 years of age) who underwent BDG over 8 years. The median age of patients undergoing BDG was 2.5 years (interquartile range, 1.4-5.5 years).

INTERVENTIONS

BDG surgery.

MEASUREMENTS AND MAIN RESULTS

Thirty-five patients (57.4%) had a postoperative complication, with some patients (17 of 61, 27.9%) having more than 1 complication. The most frequent complications were infective (29.5%). Univariate analysis found that postoperative complications were associated with the use of nitric oxide (p = 0.004) and a longer duration of anesthesia (p = 0.045) and surgery (p = 0.004). Patients with complications spent longer in the pediatric intensive care unit (ICU) (p < 0.001) and in the hospital (p < 0.012). On multivariate analysis, a priori risk factors based on previous studies were not found to be statistically significant. A total of 37.3% of patients completed their single-ventricle palliation, and 30.5% of patients were lost to follow-up.

CONCLUSIONS

Important findings were the older age at which the BDG was performed compared to high-income countries, an acceptable mortality rate of 3.3%, infection being the most common complication, the association of a complication with increased ICU and hospital lengths of stay, and the high rate of patients lost to follow-up.

Risk Assessment for Postoperative Pneumonia in Children Living With Neurologic Impairments

BACKGROUND

Approximately one-third of all pediatric hospital charges are attributable to the care for children living with neurologic comorbidities. These children often require various surgical procedures and may have an elevated risk of lower respiratory infections because of poor neuromuscular coordination, poor cough, uncoordinated swallowing, and poor oral hygiene. Our objective was to evaluate the risk of pneumonia in children presenting with neurologic comorbidities.

METHODS

We performed a retrospective study of children (<18 years) who underwent inpatient surgery between 2012 and 2018 in hospitals participating in the National Surgical Quality Improvement Program. Our primary outcome was the time to incident pneumonia within the 30 days after surgery.

RESULTS

We identified 349 163 children, of whom 2191 developed pneumonia (30-day cumulative incidence: 0.6%). The presence of a preoperative neurologic comorbidity conferred approximately twofold higher risk of postoperative pneumonia (hazard ratio [HR]: 1.91, 95% confidence interval [CI]: 1.73-2.11). We explored the risk of pneumonia conferred by the components of neurologic comorbidity: cerebral palsy (HR: 3.92, 95% CI: 3.38-4.56), seizure disorder (HR: 2.93, 95% CI: 2.60-3.30), neuromuscular disorder (HR: 2.63, 95% CI: 2.32-2.99). The presence of a neurologic comorbidity was associated with a longer length of hospital stay (incidence rate ratio: 1.26, 95% CI: 1.25-1.28).

CONCLUSIONS

The risk of postoperative pneumonia was almost twofold higher in children with neurologic comorbidity. The magnitude of these associations underscores the need to identify areas of research and preventive strategies to reduce the excess risk of pneumonia in children with preoperative neurologic conditions.

Research on the economic loss of hospital-acquired pneumonia caused by Klebsiella pneumonia base on propensity score matching

BACKGROUND

Hospital-acquired pneumonia (HAP) caused by Klebsiella pneumonia (KP) is a common nosocomial infection (NI). However, the reports on the economic burden of hospital-acquired pneumonia caused by Klebsiella pneumonia (KP-HAP) were scarce. The study aims to study the direct economic loss caused by KP-HAP with the method of propensity score matching (PSM) to provide a basis for the cost accounting of NI and provide references for the formulation of infection control measures.

METHODS

A retrospective investigation was conducted on the hospitalization information of all patients discharged from a tertiary group hospital in Shenzhen, Guangdong province, China, from June 2016 to August 2019. According to the inclusion and exclusion criteria, patients were divided into the HAP group and noninfection group, the extended-spectrum beta-lactamases (ESBLs) positive KP infection group, and the ESBLs-negative KP infection group. After the baselines of each group were balanced with the PSM, length of stay (LOS) and hospital cost of each group were compared.

RESULTS

After the PSM, there were no differences in the baselines of each group. Compared with the noninfection group, the median LOS in the KP-HAP group increased by 15 days (2.14 times), and the median hospital costs increased by 7329 yuan (0.89 times). Compared with the ESBLs-negative KP-HAP group, the median LOS in the ESBLs-positive KP-HAP group increased by 7.5 days (0.39 times), and the median hospital costs increased by 22,424 yuan (1.90 times).

CONCLUSION

KP-HAP prolonged LOS and increased hospital costs, and HAP caused by ESBLs-positive KP had more economic losses than ESBLs-negative, which deserves our attention and should be controlled by practical measures.

Risk assessment of postoperative pneumonia among children undergoing otolaryngologic surgery: Derivation and validation of a preoperative risk profiling

BACKGROUND

Postoperative pneumonia is a serious complication because it may be associated with morbidity, mortality and substantially increased cost of surgical care. Risk of postoperative pneumonia varies across surgical specialties, although its incidence and risk factors in pediatric otolaryngology have not been comprehensively elucidated.

OBJECTIVE

To identify factors associated with postoperative pneumonia and determine whether a subset of children with a disproportionate risk of pneumonia can be identified.

METHODS

Using the National Surgical Quality Improvement- Pediatric (NSQIP-P) database, we first selected children (N = 17,776; age under 18 years) who underwent inpatient pediatric otolaryngology procedures between 2012 and 2017. Using a random subset of 80% of the study population (derivation cohort), we next developed a multivariable logistic regression model to identify independent risk factors for postoperative pneumonia. We then divided children into risk groups and evaluated whether the Pareto principle applied to distribution of postoperative pneumonia across the risk groups.

RESULTS

Among the 12,443 children in the derivation cohort, 177 (1.4%) developed postoperative pneumonia. A multivariable risk model identified patients who developed postoperative pneumonia with good accuracy in both the derivation and validation cohorts. Stratification of patients into five mutually exclusive risk groups showed that 71% of postoperative pneumonia occurred in the highest risk group representing 20% the study cohort. Children who developed postoperative pneumonia were 18 times more likely to require an extended hospital length of stay (OR: 18.6; 95%CI: 12.3-28.2), and 7 times more likely to die compared to children without pneumonia (OR: 7.40, 95%CI: 3.53-15.48).

CONCLUSIONS

We identified key preoperative risk factors for postoperative pneumonia in children undergoing otolaryngology surgery. A small proportion (20%) of high-risk patients accounted for a large proportion (71%) of postoperative pneumonia indicating an underlying Pareto distribution and underscoring the need for targeted interventions for this "vital few". Postoperative pneumonia in pediatric otolaryngology surgical inpatients was associated with longer hospital stay and a higher risk of mortality.

CLINICAL TRIAL NUMBER AND REGISTRY

Not applicable.

Impact of Non-cardiac Comorbidities in Adults with Congenital Heart Disease: Management of Multisystem Complications

The prevalence and impact of non-cardiac comorbidities in adult patients with congenital heart disease increase over time, and these complications are often specifically a consequence of the long-term altered cardiovascular physiology or sequelae of previous therapies. For the ACHD patient admitted to the intensive care unit (ICU) for either surgical or medical treatment, an assessment of the burden of multisystem disease, as well as an understanding of the underlying cardiovascular pathophysiology, is essential for optimal management of these complex patients. This chapter takes an organ-system-based approach to reviewing common comorbidities in the ACHD patient, focusing on conditions that are directly related to ACHD status and may significantly impact ICU care.

IL-13 attenuates early local CXCL2-dependent neutrophil recruitment for Candida albicans clearance during a severe murine systemic infection

To investigate the role of IL-13 during a severe systemic Candida albicans infection, BALB/c control and IL-13^-/- mice were examined for colony forming units (CFU) in the kidneys and survival days after intravenous infection. Proinflammatory mediators and cell recruitment into the tissue were measured by quantitative real-time PCR, a multiple ELISA system, and morphological cell differentiation. The IL-13^-/- group exhibited a lower CFU number in the kidneys at 4 days and survived longer than the control mice, which was accompanied by significantly higher expression of C-X-C motif ligand 2 (CXCL2), IFN-γ, and polymorphonuclear neutrophils (PMNs) in the infected kidneys. By contrast, the expression of transforming growth factor β (TGF-β) and IL-17 A on day 10 were significantly higher in the control mice than in the IL-13^-/- group. When using an intratracheal infection model, the IL-13^-/- group recruited a greater number of PMNs in 6 h, with rapidly increased CXCL2 in the alveolar space. In vitro testing with cultured bone-marrow-derived cells demonstrated rapid CXCL2 mRNA upregulation at 3 h after contact with C. albicans, which decreased with recombinant IL-13 pretreatment, whereas rIL-13 retained TGF-β upregulation. In a murine model of Candida systemic infection, preexistent IL-13 limits both the rapid CXCL2 elevation and PMN aggregation in the target organ to suppress inflammatory mediators, which also attenuates local pathogen clearance within four days.

Risk factors for nosocomial infections after cardiac surgery in newborns with congenital heart disease

BACKGROUND

Congenital heart diseases are among the most common congenital malformations. Approximately 50% of the patients with congenital heart disease undergo cardiac surgery. Nosocomial infections (NIs) are the main complications and an important cause of increased morbidity and mortality associated with congenital heart diseases. This study's objective was to identify the risk factors associated with the development of NIs after cardiac surgery in newborns with congenital heart disease.

METHODS

This was a nested case-control study that included 112 newborns, including 56 cases (with NI) and 56 controls (without NI). Variables analyzed included perinatal history, associated congenital malformations, Risk-Adjusted Congenital Heart Surgery (RACHS-1) score, perioperative and postoperative factors, transfusions, length of central venous catheter, nutritional support, and mechanical ventilation.

STATISTICAL ANALYSIS

Differences were calculated with the Mann-Whitney-U test, Pearson X², or Fisher's exact test. A multivariate logistic regression was used to determine the independent risk factors.

RESULTS

Sepsis was the most common NI (37.5%), and the main causative microorganisms were gram-positive cocci. The independent risk factors associated with NI were non-cardiac congenital malformations (OR 6.1, CI 95% 1.3-29.4), central venous catheter indwelling time > 14 days (OR 3.7, CI 95% 1.3-11.0), duration of mechanical ventilation > 7 days (OR 6.6, CI 95% 2.1-20.1), and ≥5 transfusions of blood products (OR 3.1, CI 95% 1.3-8.5). Mortality attributed to NI was 17.8%.

CONCLUSION

Newborns with non-cardiac congenital malformations and with >7 days of mechanical ventilation were at higher risk for a postoperative NI. Efforts must focus on preventable infections, especially in bloodstream catheter-related infections, which account for 20.5% of all NIs.

Perioperative infections in congenital heart disease

BACKGROUND

Perioperative infections have significant consequences for children with congenital heart disease (CHD), which can manifest as acute or chronic infection followed by poor growth and progressive cardiac failure. The consequences include delayed or higher-risk surgery, and increased postoperative morbidity and mortality.

METHODS

A systematic search for studies evaluating the burden and interventions to reduce perioperative infections in children with CHD was undertaken using PubMed.

RESULTS

Limited studies conducted in low- to middle-income countries demonstrated the large burden of perioperative infections among children with CHD. Most studies focussed on infections after surgery. Few studies evaluated strategies to prevent preoperative infection or the impact of infection on decision-making around the timing of surgery. Children with CHD have multiple risk factors for infections including delayed presentation, inadequate treatment of cardiac failure, and poor nutrition.

CONCLUSIONS

The burden of perioperative infections is high among children with CHD, and studies evaluating the effectiveness of interventions to reduce these infections are lacking. As good nutrition, early corrective surgery, and measures to reduce nosocomial infection are likely to play a role, practical steps can be taken to make surgery safer.

The respiratory system in pediatric chronic heart disease

Cardiovascular disease in the pediatric population closely affects the respiratory system inducing water retention in the lungs and pulmonary edema, airway compression by cardiovascular structures, restrictive pulmonary physiology as a result of hemodynamic changes and surgical repair, susceptibility to respiratory infections, development of pulmonary hypertension, thrombosis, or hemorrhage. Chronic heart failure and congenital heart disease are characterized by various respiratory manifestations and symptoms mimicking lung disease, which are frequently difficult to diagnose and treat. Pulmonary function is multiply affected in pediatric heart disease with mostly restrictive but also obstructive and diffusion abnormalities. Patients with Fontan circulation represent a separate group with slow, passive pulmonary blood flow and distinct pathophysiology with low cardiac output heart failure, restrictive lung pattern, increased thromboembolic complications and rare conditions such as protein losing enteropathy and plastic bronchitis. Distinguishing between cardiovascular and pulmonary symptoms may be challenging in the growing population of pediatric and adult survivors of congenital heart disease and understanding of the relationship of the two systems in heart disease is crucial for the optimal management of these patients.

Enterobacteriaceae producing extended-spectrum β-lactamases (ESBLs) colonization as a risk factor for developing ESBL infections in pediatric cardiac surgery patients: "retrospective cohort study"

Background

Children with cardiac defects need many hospitalizations and repetitive antibiotic therapies, with an increasing risk of colonization with multidrug-resistant bacteria (MDRB) such as extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) Post-operative infections with these bacteria in paediatric cardiac surgery are life threatening. This article aims to study the prevalence of ESBL colonization among paediatric cardiac surgery patients, and to compare occurrence of post-operative infections with and without ESBL colonization. We also aim to study the correlation between the onset of postoperative infection and other parameters such as age, length of stay and preoperative antibiotic therapy.

Methods

A retrospective cohort study included paediatric cardiac surgery patients in Cheikh Zaid hospital in Rabat, Morocco, between the 1st of January 2011 and 31 December 2014. A screening for ESBL colonization was requested for children who had a risk factor (previous hospitalization and/or taking antibiotics) at admission. Swabs were collected from three sites (throat, nose and anus). Two groups were compared – patients colonized and not colonized with ESBLs. Statistical analysis was performed using R software.

Results

ESBL colonization screening was performed in 111 patients. Positive colonization was detected in 17 cases (15%). Klebsiella pneumoniae (KP): 9 (53%) was the most frequently isolated species. Among the 17 patients, 23.5% (4/17) developed a postoperative infection due to ESBLs versus only one patient without colonization (1%).

There was a statically significant difference in terms of occurrence of postoperative infection between the two groups (p = 0.001). Relative risk of developing a postoperative infection with positive colonization was 22 (95% CI, 8.37–58.5).

Conclusions

The analysis of colonization with multidrug-resistant bacteria and the prevention of nosocomial infections appear to be important challenges for paediatric cardiac surgery. Systematic screening of ESBL colonization for cardiac surgery could have a significant contribution, on one hand to guide prophylactic antibiotic therapy of patients, and on the other, to prevent spread of those infections.

Avoidance of Hospital-Acquired Infections in Pediatric Cardiac Surgical Patients

OBJECTIVES

The objectives of this review are to discuss the prevalence and risk factors associated with the development of hospital-acquired infections in pediatric patients undergoing cardiac surgery and the published antimicrobial prophylaxis regimens and rational approaches to the diagnosis, prevention, and treatment of nosocomial infections in these patients.

DATA SOURCE

MEDLINE and PubMed.

CONCLUSION

Hospital-acquired infections remain a significant source of potentially preventable morbidity and mortality in pediatric cardiac surgical patients. Through improved understanding of these conditions and implementation of avoidance strategies, centers caring for these patients may improve outcomes in this vulnerable population.

Immunologic and Infectious Diseases in Pediatric Cardiac Critical Care: Proceedings of the 10th International Pediatric Cardiac Intensive Care Society Conference

Since the inception of the Pediatric Cardiac Intensive Care Society (PCICS) in 2003, remarkable advances in the care of children with critical cardiac disease have been developed. Specialized surgical approaches, anesthesiology practices, and intensive care management have all contributed to improved outcomes. However, significant morbidity often results from immunologic or infectious disease in the perioperative period or during a medical intensive care unit admission. The immunologic or infectious illness may lead to fever, which requires the attention and resources of the cardiac intensivist. Frequently, cardiopulmonary bypass leads to an inflammatory state that may present hemodynamic challenges or complicate postoperative care. However, inflammation unchecked by a compensatory anti-inflammatory response may also contribute to the development of capillary leak and lead to a complicated intensive care unit course. Any patient admitted to the intensive care unit is at risk for a hospital acquired infection, and no patients are at greater risk than the child treated with mechanical circulatory support. In summary, the prevention, diagnosis, and management of immunologic and infectious diseases in the pediatric cardiac intensive care unit is of paramount importance for the clinician. This review from the tenth PCICS International Conference will summarize the current knowledge in this important aspect of our field.

Necrotizing pneumonia following cardiac surgery in a neonate

In this report, we discuss the case of a male neonate who underwent surgical correction for coarctation of the aorta. The recovery of this patient was complicated by postsurgical necrotizing pneumonitis that resolved completely after a prolonged hospital stay with recurrent deterioration.

Pulmonary complications of congenital heart disease

Cardiac and pulmonary pathophysiologies are closely interdependent, which makes the management of patients with congenital heart disease (CHD) all the more complex. Pulmonary complications of CHD can be structural due to compression causing airway malacia or atelectasis of the lung. Surgical repair of CHD can also result in structural trauma to the respiratory system, e.g., chylothorax, subglottic stenosis, or diaphragmatic paralysis. Disruption of the Starling forces in the pulmonary vascular system in certain types of CHD lead to alveolar-capillary membrane damage and pulmonary oedema. This in turn results in poorly compliant lungs with a restrictive lung function pattern that can deteriorate to cause hypoxemia. The circulation post single ventricle palliative surgery (the so called "Fontan circulation") poses a unique spectrum of pulmonary pathophysiology with restrictive lung function and a low pulmonary blood flow state that predisposes to thromboembolic complications and plastic bronchitis. As the population of patients surviving post CHD repair increases, the incidence of pulmonary complications has also increased and presents a unique cohort in both the paediatric and adult clinics.

Bedside prediction rule for infections after pediatric cardiac surgery

Purpose

Infections after pediatric cardiac surgery are a common complication, occurring in up to 30% of cases. The purpose of this study was to develop a bedside prediction rule to estimate the risk of a postoperative infection.

Methods

All consecutive pediatric cardiac surgery procedures between April 2006 and May 2009 were retrospectively analyzed. The primary outcome variable was any postoperative infection, as defined by the Center of Disease Control (2008). All variables known to the clinician at the bedside at 48 h post cardiac surgery were included in the primary analysis, and multivariable logistic regression was used to construct a prediction rule.

Results

A total of 412 procedures were included, of which 102 (25%) were followed by an infection. Most infections were surgical site infections (26% of all infections) and bloodstream infections (25%). Three variables proved to be most predictive of an infection: age less than 6 months, postoperative pediatric intensive care unit (PICU) stay longer than 48 h, and open sternum for longer than 48 h. Translation into prediction rule points yielded 1, 4, and 1 point for each variable, respectively. Patients with a score of 0 had 6.6% risk of an infection, whereas those with a maximal score of 6 had a risk of 57%. The area under the receiver operating characteristic curve was 0.78 (95% confidence interval 0.72–0.83).

Conclusions

A simple bedside prediction rule designed for use at 48 h post cardiac surgery can discriminate between children at high and low risk for a subsequent infection.

Procalcitonin level as an aid for the diagnosis of bacterial infections following pediatric cardiac surgery

PURPOSE

The aim of the present study was to determine if blood procalcitonin can serve as an aid to differentiate between bacterial and nonbacterial cause of fever in children after cardiac surgery.

MATERIALS AND METHODS

A nested case-control study of children who underwent open cardiac surgery in critical care units of fourth-level pediatric hospital was performed. Blood samples for procalcitonin level were collected 1 day before operation; 1 hour postoperation; on postoperative days 1, 2, and 5; and on the day of fever, when it occurred.

RESULTS

Of 665 children who underwent cardiac bypass surgery, 126 had a febrile episode postoperatively, 47 children with a proven bacterial infection and 79 without bacterial infection. Among the 68 children in whom fever developed within the first 5 postoperative days, procalcitonin level at fever day was significantly higher in those with bacterial infection (n = 16) than in those without infection (n = 52). Similarly, among the 58 children in whom fever developed after day 5 postoperation, a significant difference was found in procalcitonin level at fever day between those with (n = 31) and without (n = 27) bacterial infection.

CONCLUSION

During the critical early and late periods after cardiac surgery in children, procalcitonin level may help to differentiate patients with bacterial infection from patients in whom the fever is secondary to nonbacterial infectious causes.

Ventilator-associated pneumonia in children after cardiac surgery in The Netherlands

PURPOSE

We conducted a retrospective cohort study in an academic tertiary care center to characterize ventilator-associated pneumonia (VAP) in pediatric patients after cardiac surgery in The Netherlands.

METHODS

All patients following cardiac surgery and mechanically ventilated for ≥24 h were included. The primary outcome was development of VAP. Secondary outcomes were duration of mechanical ventilation and length of ICU stay.

RESULTS

A total of 125 patients were enrolled. Their mean age was 16.5 months. The rate of VAP was 17.1/1,000 mechanical ventilation days. Frequently found organisms were Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus and Pseudomonas aeruginosa. Patients with VAP had longer duration of ventilation and longer ICU stay. Risk factors associated with the development of VAP were a PRISM III score of ≥10 and transfusion of fresh frozen plasma.

CONCLUSION

The mean VAP rate in this population is higher than that reported in general pediatric ICU populations. Children with VAP had a prolonged need for mechanical ventilation and a longer ICU stay.

Time-related increase of staphylococci, Enterobacteriaceae and yeasts in the oral cavities of comatose patients

BACKGROUND/PURPOSE

The composition of oral microbiota in comatose patients remains uncertain. Some pulmonary pathogens may be found in dental biofilms or as part of the saliva microbiota. It is supposed that some pneumopathogenic microorganisms may overgrow in the mouths of comatose patients and spread to their lungs.

METHODS

The oral colonization dynamics of staphylococci, Enterobacteriaceae and yeasts in nine comatose patients (group 1), and in 12 conscious patients that brushed their teeth at least twice a day (group 2) was evaluated. Both groups were followed up for 7 days after hospitalization. Daily samples of saliva were obtained, dispersed and plated on selective culture media and colony forming units of each microbial group were obtained.

RESULTS

For patients in group 1, the counts of total viable bacteria, staphylococci, Enterobacteriaceae and yeasts progressively increased in a time-dependant manner. For the conscious patients of group 2, there was no increase.

CONCLUSION

It would appear that concomitant consciousness and brushing teeth are determinants in controlling the selected pneumopathogen counts in resting saliva. The increase in microbial counts in comatose patients is understandable because these microorganisms could spread to the lungs.

Risk factors for healthcare-associated infection in pediatric intensive care units: a systematic review

A systematic review of observational studies on risk factors for healthcare-associated infection in pediatric Intensive Care Units (ICU) was carried out. Studies indexed in MEDLINE, LILACS, Cochrane, BDENF, CAPES databases published in English, French, Spanish or Portuguese between 1987 and 2006 were included and cross references added. Key words for search were 'cross infection' and 'Pediatric Intensive Care Units' with others sub-terms included. 11 studies were selected from 419 originally found: four studies had healthcare-associated infection as the main outcome without a specific site; three articles identified factors associated with lower respiratory tract infection (pneumonia or tracheitis); three articles were concerned with laboratory-confirmed bloodstream infection; and a single retrospective study analyzed urinary tract infection. The production of evidence on risk factors Paediatric ICU has not kept up the same pace of that on adult - there are few studies with adequate design and statistical analysis. The methodological diversity of the studies did not allow for a summarized measurement of risk factors.

Role of Ndt80p in sterol metabolism regulation and azole resistance in Candida albicans

The Ndt80p transcription factor modulates azole tolerance in Candida albicans by controlling the expression of the gene for the drug efflux pump Cdr1p. To date, the contribution of this transcriptional modulator to drug tolerance is not yet well understood. Here, we investigate the role of Ndt80p in mediating fluconazole tolerance by determining its genome-wide occupancy using chromatin immunoprecipitation coupled to high-density tiling arrays. Ndt80p was found to bind a large number of gene promoters with diverse biological functions. Gene ontology analysis of these Ndt80p targets revealed a significant enrichment in gene products related to the cell wall, carbohydrate metabolism, stress responses, hyphal development, multidrug transport, and the cell cycle. Ndt80p was found on the promoters of ergosterol biosynthesis genes, including on the azole target Erg11p. Additionally, expression profiling was used to identify fluconazole-responsive genes that require Ndt80p for their proper expression. We found that Ndt80p is crucial for the expression of numerous fluconazole-responsive genes, especially genes involved in ergosterol metabolism. Therefore, by combining genome-wide location and transcriptional profiling, we have characterized the Ndt80p fluconazole-dependent regulon and demonstrated the key role of this global transcriptional regulator in modulating sterol metabolism and drug resistance in C. albicans.

A Candida albicans early stage biofilm detachment event in rich medium

BACKGROUND

Dispersal from Candida albicans biofilms that colonize catheters is implicated as a primary factor in the link between contaminated catheters and life threatening blood stream infections (BSI). Appropriate in vitro C. albicans biofilm models are needed to probe factors that induce detachment events.

RESULTS

Using a flow through system to culture C. albicans biofilms we characterized a detachment process which culminates in dissociation of an entire early stage biofilm from a silicone elastomer surface. We analyzed the transcriptome response at time points that bracketed an abrupt transition in which a strong adhesive association with the surface is weakened in the initial stages of the process, and also compared batch and biofilm cultures at relevant time points. K means analysis of the time course array data revealed categories of genes with similar patterns of expression that were associated with adhesion, biofilm formation and glycoprotein biosynthesis. Compared to batch cultures the biofilm showed a pattern of expression of metabolic genes that was similar to the C. albicans response to hypoxia. However, the loss of strong adhesion was not obviously influenced by either the availability of oxygen in the medium or at the silicone elastomer surface. The detachment phenotype of mutant strains in which selected genes were either deleted or overexpressed was characterized. The microarray data indicated that changes associated with the detachment process were complex and, consistent with this assessment, we were unable to demonstrate that transcriptional regulation of any single gene was essential for loss of the strong adhesive association.

CONCLUSION

The massive dispersal of the early stage biofilm from a biomaterial surface that we observed is not orchestrated at the level of transcriptional regulation in an obvious manner, or is only regulated at this level by a small subpopulation of cells that mediate adhesion to the surface.

[Nosocomial infections in pediatric patients following cardiac surgery]

INTRODUCTION

Nosocomial infection (NI) is a possible complication in patients who undergo cardiac surgery, and represents an important cause of morbidity and mortality. This study was undertaken to determine the NI rate, main risk factors, and microbial spectrum in a paediatric intensive care unit (PICU) for this group of patients.

PATIENTS AND METHODS

A prospective review was performed, including all patients admitted to the PICU after cardiac surgery between December 2003 and November 2004. NI was defined according to Centers for Disease Control criteria.

RESULTS

Sixty-nine patients were included. Sixteen patients (23.2 %) acquired at least one episode of NI. The NI rate was 4.9 per 100 patient-days. The most common NI was pneumonia, followed by urinary tract infection. There were no episodes of sepsis. No patients died from infectious causes. The main aetiological organism was Haemophilus influenzae, associated with 41.6 % of pneumonias, and followed by Pseudomonas aeruginosa. No multiresistant organisms were isolated. There was a statistically significant association between the duration of use of external devices (mechanical ventilation, urinary and central venous catheterization) and development of NI.

CONCLUSIONS

Aggressive monitoring and support devices are the main risk factors for NI. Based on our data, we suggest early removal of these. Presumed NI should be diagnosed according standard criteria before starting antibiotic therapy, and treatment modified depending on culture results.

Perioperative risk factors for prolonged mechanical ventilation following cardiac surgery in neonates and young infants

BACKGROUND

Prolonged mechanical ventilation (PMV) after cardiac surgery in children is associated with a high postoperative morbidity and mortality, as well as increased ICU and hospital resource utilization. Little has been done to identify the predictors of PMV in neonates and young infants. This study was performed to evaluate the perioperative risk factors for PMV in neonates and young infants undergoing cardiac surgery.

METHODS

Clinical records of 172 consecutive children aged < or = 3 months were reviewed. PMV was defined as mechanical ventilation (MV) > or = 72 h following operation. After univariate analysis, a stepwise logistic regression analysis was used to evaluate the independent risk factors for PMV following cardiac surgery. The predictive ability of risk factors for PMV was assessed using an area under the receiver operating characteristic (ROC) curve.

RESULTS

Sixty-one patients required PMV after cardiac surgery. The median duration of MV was 150 h in PMV patients, while it was 28 h in non-PMV patients. The independent risk factors for PMV were risk adjustment for surgery for congenital heart disease (RACHS)-1 (p = 0.041), nosocomial pneumonia (p = 0.001), low cardiac output syndrome (LCOS) [p = 0.001], postoperative cumulative positive fluid balance (p = 0.032), and extubation failure (EF) [p = 0.027]. The value for the ROC curve was 0.940.

CONCLUSIONS

The present results strongly suggest that RACHS-1, nosocomial pneumonia, LCOS, fluid retention postoperatively, and EF are risk factors for PMV in neonates and young infants undergoing reparative surgery for congenital heart disease.

Factors prolonging length of stay in the cardiac intensive care unit following the arterial switch operation

The arterial switch operation has become the preferred procedure for surgical management of transposition, defined on the basis of concordant atrioventricular and discordant ventriculo-arterial connections. We conducted a retrospective evaluation of our experience in 61 infants with this segmental combination, seen from January, 1997, to July, 2003, in order to determine the factors that are associated with a prolonged postoperative course. Factors independently associated with a prolonged postoperative stay in the cardiac intensive care unit included prematurity, difficulty in feeding, capillary leak, need for preoperative inotropic support, and postoperative infectious complications. Future research is warranted designed to minimize the impact of capillary leak and postoperative infectious complications. In addition, based on these results, our practice has evolved to initiate enteral feedings in the preoperative period if feasible, with such enteral feedings resumed as soon as possible following surgery.

Frequent detection of multidrug-resistant pneumonia-causing bacteria in the pneumonia lung tissues of patients with hematological malignancies

Pneumonia is a critical issue during the agonal phase, and often becomes lethal in the absence of pathogen detection. Autopsy is a powerful tool for analyzing the cause of a patient's death, progression of the disease, and the therapeutic response. However, it is frequently limited to the identification of bacterial strains. To elucidate the pathogenesis during the agonal phase of pneumonia, intrapulmonary sputum was harvested by directly inserting a swab into a resected lung, and the bacterial composition was analyzed using both pathological and microbiological techniques from 15 patients with hematological malignancies, and the results were compared with those from 25 patients with other medical and surgical diseases. Among the 54 bacteria strains isolated from the 40 patients, multidrug-resistant strains were significantly more prevalent in hematological group than in other diseases (16/21 versus 11/33, P = .002). Enterococcus faecium was preferentially isolated from the hematological patients, whereas the methicillin-resistant Staphylococcus aureus was predominantly found in the nonhematological group. Two coagulase-negative Staphylococcus epidermidis strains in hematological diseases may be diagnosed as causative bacteria of pneumonia by both bacterial and pathological techniques. Although the results of this study may not be directly applicable for clinical diagnosis, this approach has a potential to become not only a diagnostic method for bacterial pneumonia, but may be also useful for the analysis of multidrug-resistant pathogens.

Peri-operative management of paediatric patients undergoing cardiac surgery--focus on respiratory aspects of care

Children requiring cardiac surgery present particular challenges in peri-operative respiratory management. The wide variety of conditions and operations and their varied impact on respiratory function makes dialogue with related medical staff essential. In most circumstances, cardiac performance is the main determinant of respiratory outcomes. Changing cardiologic and surgical approaches have combined to diminish the severity and frequency of pulmonary hypertensive issues and new treatment modalities are simplifying the intensive care approach. Patients with Down's syndrome and 22q11 deletion syndrome present particular issues related to anatomy, physiology and respiratory function. Certain conditions, including tetralogy of Fallot and cavopulmonary connections, present unique circumstances where respiratory management, sometimes including extubation, may assist in optimisation of cardiac performance. These and other conditions highlight the complexities of cardiopulmonary interactions. Cardiac performance remains the principal determinant of outcome after paediatric cardiac surgery and has the biggest impact on respiratory function.

Culture-independent analysis of bacterial diversity in a child-care facility

BACKGROUND

Child-care facilities appear to provide daily opportunities for exposure and transmission of bacteria and viruses. However, almost nothing is known about the diversity of microbial contamination in daycare facilities or its public health implications. Recent culture-independent molecular studies of bacterial diversity in indoor environments have revealed an astonishing diversity of microorganisms, including opportunistic pathogens and many uncultured bacteria. In this study, we used culture and culture-independent methods to determine the viability and diversity of bacteria in a child-care center over a six-month period.

RESULTS

We sampled surface contamination on toys and furniture using sterile cotton swabs in four daycare classrooms. Bacteria were isolated on nutrient and blood agar plates, and 16S rRNA gene sequences were obtained from unique (one of a kind) colony morphologies for species identification. We also extracted DNA directly from nine representative swab samples taken over the course of the study from both toy and furniture surfaces, and used "universal" 16S rRNA gene bacterial primers to create PCR-based clone libraries. The rRNA gene clones were sequenced, and the sequences were compared with related sequences in GenBank and subjected to phylogenetic analyses to determine their evolutionary relationships. Culturing methods identified viable bacteria on all toys and furniture surfaces sampled in the study. Bacillus spp. were the most commonly cultured bacteria, followed by Staphylococcus spp., and Microbacterium spp. Culture-independent methods based on 16S rRNA gene sequencing, on the other hand, revealed an entirely new dimension of microbial diversity, including an estimated 190 bacterial species from 15 bacterial divisions. Sequence comparisons and phylogenetic analyses determined that the clone libraries were dominated by a diverse set of sequences related to Pseudomonas spp., as well as uncultured bacteria originally identified on human vaginal epithelium. Other sequences were related to uncultured bacteria from wastewater sludge, and many human-associated bacteria including a number of pathogens and opportunistic pathogens. Our results suggest that the child-care facility provided an excellent habitat for slime-producing Pseudomonads, and that diaper changing contributed significantly to the bacterial contamination.

CONCLUSION

The combination of culture and culture-independent methods provided powerful means for determining both viability and diversity of bacteria in child-care facilities. Our results provided insight into the source of contamination and suggested ways in which sanitation might be improved. Although our study identified a remarkable array of microbial diversity present in a single daycare, it also revealed just how little we comprehend the true extent of microbial diversity in daycare centers or other indoor environments.

A probable case of aspiration pneumonia caused by Candida glabrata in a non-neutropenic patient with candidemia

Primary Candida pneumonia is rare, and detailed reports of Candida glabrata pneumonia have not been described. A 71-year-old woman had been treated for heart failure and developed aspiration pneumonia, which was refractory to antibacterial treatment. Antifungal treatment against C. glabrata resulted in resolution of pneumonia and candidemia. We report a probable case of C. glabrata pneumonia.

A simultaneous outbreak of Serratia marcescens and Klebsiella pneumoniae in a neonatal intensive care unit

We describe two concurrent outbreaks of Serratia marcescens and Klebsiella pneumoniae in a neonatal intensive care unit (NICU). Over a 16-month period, a total of 27 infants were either colonized (N=14) or infected (N=13). There were 15 cases of S. marcescens and 11 cases of K. pneumoniae. Both micro-organisms were involved in one fatal case. Seven preterm babies developed septicaemia, two had bacteraemia, three had respiratory infections and one had purulent conjunctivitis. The S. marcescens and K. pneumoniae isolates were investigated by three molecular methods: enterobacterial repetitive intergenic consensus polymerase chain reaction (PCR), arbitrary primed PCR with M13 primer, and random amplification of polymorphic DNA. Different patterns were found in the 16 S. marcescens epidemic isolates from 16 newborn infants. The major epidemic-involved genotype was linked to the first nine cases and this was subsequently replaced by different patterns. Eight different typing profiles were also determined for the 13 K. pneumoniae isolates from 12 newborn infants. Four K. pneumoniae bacteraemic strains proved to be identical. In conclusion, the typing results revealed that two different micro-organisms (S. marcescens and K. pneumoniae) were simultaneously involved in invasive nosocomial infections in preterm newborns. Two simultaneous clusters of cases were documented. Heterogeneous genotypes among both species were also demonstrated to be present in the NICU at the same time. A focal source for both micro-organisms was not identified but cross-transmission through handling was probably an important route in this outbreak. Strict adherence to handwashing policies, cohorting, isolation of colonized and infected patients, and rigorous environmental hygiene were crucial measures in the containment of the epidemic.