Pertussis requiring intensive care

Risk factors for complications in hospitalized young infants presenting with uncomplicated pertussis

OBJECTIVE

We sought to identify risk factors for complications in hospitalized young infants with uncomplicated pertussis.

METHODS

Retrospective cohort study of hospitalized infants 0 to 6 months of age with confirmed pertussis from 2005 to 2009. Subjects presenting without complications or need for initial intensive care admission were deemed to have uncomplicated pertussis. Complications during hospitalization were defined as apnea, pneumonia, seizures, or encephalopathy. Univariate analysis was performed by estimating odds ratios (OR) and 95% confidence intervals (CI) for the association between each variable and the occurrence of complications. Multivariable analysis was performed using logistic regression. Clinical variables included demographics, historical, laboratory, and imaging data.

RESULTS

Of 126 study subjects, 46 (36.5%) developed complications in the hospital: 43 with apnea (two required endotracheal intubation), seven with pneumonia, and three with seizures; there were no cases of encephalopathy and no deaths. Age less than 60 days (OR, 2.71; 95% CI, 1.08-6.82), cough duration less than 7 days (OR, 5.38; 95% CI, 1.79-16.18), history of color change (OR, 5.24; 95% CI, 1.14-24.07), parental intervention (OR, 10.05; 95% CI, 1.67-60.39), and need for oxygen in the emergency department (OR. 3.94; 95% CI. 1.37-11.36) were associated with development of complications. The median duration of cough at the time of complication was 9 days (range 2-30 days). Initial complete blood cell count and radiographic findings were not associated with complications.

CONCLUSIONS

Infants with uncomplicated pertussis may be at low risk for developing respiratory failure or death. Historical information may assist practitioners in determining risk for serious complications.

The Collaborative Pediatric Critical Care Research Network Critical Pertussis Study: collaborative research in pediatric critical care medicine

OBJECTIVE

To provide an updated overview of critical pertussis to the pediatric critical care community and describe a study of critical pertussis recently undertaken.

SETTING

The six sites, seven hospitals of the Collaborative Pediatric Critical Care Research Network, and 17 outside sites at academic medical centers with pediatric intensive care units.

RESULTS

Despite high coverage for childhood vaccination, pertussis causes substantial morbidity and mortality in US children, especially among infants. In pediatric intensive care units, Bordetella pertussis is a community-acquired pathogen associated with critical illness and death. The incidence of medical and developmental sequelae in critical pertussis survivors remains unknown, and the appropriate strategies for treatment and support remain unclear. The Collaborative Pediatric Critical Care Research Network Critical Pertussis Study has begun to evaluate critical pertussis in a prospective cohort.

CONCLUSION

Research is urgently needed to provide an evidence base that might optimize management for critical pertussis, a serious, disabling, and too often fatal illness for U.S. children and those in the developing world.

Pertussis: should we improve intensive care management or vaccination strategies?

Bordetella pertussis, responsible for one of the oldest vaccine-preventable diseases in children, has resurged in North America, Europe, Latin America and many countries around the world. Despite new recommended vaccination strategies for adolescents, pregnant women and adults, mortality is still significant in developing and developed countries. For the critical care management of the infant with pertussis, strategies include conventional ventilation, high-frequency oscillatory ventilation, extracorporeal membrane oxygenation, inhaled nitric oxygen, exchange transfusion, plasmapheresis and, more recently, leukodepletion. The paper under evaluation describes the experience of UK investigators in the management of pertussis with rapid leukodepletion for infants with extreme leukocytosis. Using this strategy, a rapid fall in the number of leukocytes was observed in these patients. Their results suggest that rapid leukodepletion should be considered in severely ill infants with pertussis and severe leukocytosis.

Early blood exchange transfusion in malignant pertussis: a case report

OBJECTIVE

To report early blood exchange transfusion in malignant pertussis and a favorable clinical outcome.

SETTING

A pediatric intensive care unit in a tertiary hospital in Geneva, Switzerland.

DESIGN

A descriptive case report.

PATIENT

An 8-wk-old girl was diagnosed with malignant pertussis (extreme leukocytosis, seizures, pneumonia, and secondary severe hypoxic respiratory failure associated with pulmonary hypertension). After administration of a one-volume blood exchange transfusion, a rapid decrease in white blood cell count (from 119,000/mm(3) to 36,500/mm(3)) was observed and followed by clinical improvement and favorable outcome despite the initial presence of all described risk factors associated with a high mortality.

CONCLUSION

The use of exchange blood transfusion early in the course of the disease might help to prevent a fatal outcome of malignant pertussis.

Imaging of nonaccidental injury and the mimics: issues and controversies in the era of evidence-based medicine

Because of the controversy involving the determination of child abuse, or nonaccidental injury (NAI), radiologists must be familiar with the issues, literature, and principles of evidence-based medicine to understand the role of imaging. Children with suspected NAI must receive protective evaluation along with a timely and complete clinical and imaging work-up. Imaging findings cannot stand alone and must be correlated with clinical findings, laboratory testing, and pathologic and forensic examinations. Only the child protection investigation may provide the basis for inflicted injury in the context of supportive clinical, imaging, biomechanical, or pathology findings.

Impact of rapid leukodepletion on the outcome of severe clinical pertussis in young infants

OBJECTIVES

Bordetella pertussis is a common, underrecognized, and vaccine-preventable cause of critical illness with a high mortality in infants worldwide. Patients with severe cases present with extreme leukocytosis and develop refractory hypoxemia and pulmonary hypertension that is unresponsive to maximal intensive care. This may reflect a hyperviscosity syndrome from the raised white blood cell (WBC) count. Case reports suggest improved outcomes with exchange transfusion to reduce the WBC count. Our objective was to quantify possible benefits of aggressive leukodepletion.

METHODS

We, as a regional PICU and extracorporeal membrane oxygenation referral center, adopted a strategy of aggressive leukodepletion in January 2005. The impact of this strategy on crude and case mix-adjusted survival of all infants who were critically ill with B pertussis were compared with control subjects from January 2001 to December 2004 and Extracorporeal Life Support Organisation registry data.

RESULTS

Nineteen infants (7 [37%] boys) received intensive care for B pertussis from 2001 to 2009. Admission WBC counts were equivalent in 2 time periods: 2001-2004 (mean: 52,000/μL) and 2005-2009 (mean: 75,000/μL). In 2001-2004, 5 (55%) of 9 patients survived the ICU. Between 2005 and 2009, 9 (90%) of 10 patients survived. When case-mix adjustment for age, WBC count, and extracorporeal membrane oxygenation referral were considered, the 2001-2004 predicted survival (4.4 [49%] of 9.0) was equivalent to the observed mortality (4.0 [44%] of 9.0). Between 2005 and 2009, observed mortality (1.0 [10%] of 10.0) was significantly better than predicted (4.7 [47%] of 10.0).

CONCLUSIONS

Leukodepletion should be considered in critically ill infants with B pertussis and leukocytosis.

Fulminant pertussis: a multi-center study with new insights into the clinico-pathological mechanisms

Pertussis carries a high risk of mortality in very young infants. The mechanism of refractory cardio-respiratory failure is complex and not clearly delineated. We aimed to examine the clinico-pathological features and suggest how they may be related to outcome, by multi-center review of clinical records and post-mortem findings of 10 patients with fulminant pertussis (FP). All cases were less than 8 weeks of age, and required ventilation for worsening respiratory symptoms and inotropic support for severe hemodynamic compromise. All died or underwent extra corporeal membrane oxygenation (ECMO) within 1 week. All had increased leukocyte counts (from 54 to 132 x 10(9)/L) with prominent neutrophilia in 9/10. The post-mortem demonstrated necrotizing bronchitis and bronchiolitis with extensive areas of necrosis of the alveolar epithelium. Hyaline membranes were present in those cases with viral co-infection. Pulmonary blood vessels were filled with leukocytes without well-organized thrombi. Immunodepletion of the thymus, spleen, and lymph nodes was a common feature. Other organisms were isolated as follows; 2/10 cases Para influenza type 3, 2/10 Moraxella catarrhalis, 1/10 each with respiratory syncytial virus (RSV), a coliform organism, methicillin-resistant Staphylococcus aureus (MRSA), Haemophilus influenzae, Stenotrophomonas maltophilia, methicillin-sensitive Staphylococcus aureus (MSSA), and candida tropicalis. We postulate that severe hypoxemia and intractable cardiac failure may be due to the effects of pertussis toxin, necrotizing bronchiolitis, extensive damage to the alveolar epithelium, tenacious airway secretions, and possibly leukostasis with activation of the immunological cascade, all contributing to increased pulmonary vascular resistance. Cellular apoptosis appeared to underlay much of these changes. The secondary immuno-compromise may facilitate co-infection.

When to discharge children hospitalized with pertussis?

OBJECTIVE

It is difficult to know when children hospitalized with pertussis can be safely discharged. We sought to identify clinical features of children hospitalized with pertussis that are associated with readmission.

METHODS

A case series of 207 children hospitalized with pertussis was studied. The 33 children readmitted with pertussis were compared with the 174 who did not require readmission.

RESULTS

Demographic characteristics and immunization status of the children with pertussis requiring readmission did not differ from the children who were not readmitted. Median duration of initial hospital stay was 4 days for both groups (P=.11). The children who were readmitted had more cyanotic episodes per day (0.8 vs 0.0 episodes, P=.03) and on greater proportion of hospital days (0.5 vs 0.1, P=.01). On the last day of admission, the children subsequently readmitted had more coughing episodes (4 vs 0, P < .001), and a larger proportion had a cyanotic episode (30% vs 10%, P=.003). The risk of readmission was increased in children who had > or =1 cyanotic episode per day (relative risk [RR]=2.5, 95% confidence interval [95% CI] 1.3-4.6); cyanosis on > or =50% of days (RR=2.6, 95% CI 1.4-4.8);> or =2 coughing paroxysms on the last hospital day (RR=2.4, 95% CI 1.3-4.4); or any cyanosis on the last day (RR=2.9, 95% CI 1.5-5.2).

CONCLUSIONS

Paroxysmal cough and cyanosis are clinical signs that can be used in children hospitalized with pertussis to help decide when to discharge them from hospital.