Higher Rates of Respiratory Support Needed in Patients Admitted With RSV

A higher risk of a complex hospital course and higher rates of respiratory support were found in patients admitted to the hospital for respiratory syncytial virus (RSV) compared with patients who were admitted to the hospital for influenza in children 2 years and younger, according to a study published in Pediatric Pulmonology.

The most common cause of hospital admissions in American children younger than 2 years is lower respiratory tract infections (LRTI), comprising bronchiolitis, viral pneumonia, and reactive airway disease when they are triggered by a virus. RSV and influenza can cause severe respiratory disease in young children. This study aimed to “examine the associations between RSV and influenza LRTI and the risk of complex hospital course in admitted children.”

The retrospective cohort study was conducted from January 2016 to December 2019. All children who were younger than 2 years with an admission to the hospital for LRTI and received viral testing within 7 days for RSV and influenza were included. The unit of analysis for this study was the number of admissions.

Children were excluded if they tested negative for RSV and influenza, tested positive for both viruses, or met Feudtner’s Chronic Complex conditions. All data were extracted from electronic health records and manual chart review. The primary outcome was whether the patient participated in a complex hospital course, with the primary exposure of interest being RSV or influenza.

There were 1228 admissions included in this study, 89% of which were RSV diagnoses and 11%, influenza. Patients who were admitted with RSV were younger vs influenza admissions (median age 165 vs 336 days). The groups were similar in sex, age, race/ethnicity, and insurance and had the same vaccination rate for influenza. However, patients who were admitted with influenza were more likely to be have a diagnosis of viral pneumonia (77.6%) whereas RSV admissions more often had a bronchiolitis diagnosis (98.6%).

RSV infections were less likely to have fever (18.9% vs 27.6%) and abnormal heart rate for age (73.5% vs 84.3%), but more likely to receive albuterol (29.6% vs 14.9%).

A total of 44.7% of the admissions met the criteria for a complex hospital course, with RSV admissions more likely to meet this end point vs those admitted for influenza (odds ratio [OR], 3.4; 95% CI, 2.2-5.3). Association between RSV infection and complex hospital course was similar and significant after adjustment (OR, 3.5; 95% CI, 2.2-5.6).

Increased odds of respiratory support (OR, 4.1; 95% CI, 2.4-6.9), pediatric intensive care unit (PICU) admission (OR, 2.4; 95% CI, 1.4-4.2), and length of stay (IRR, 1.3; 95% CI, 1.1-1.5) were all associated with RSV infection. Nasogastric tube feeding (OR, 2.3; 95% CI, 0.7-8.0) and death were not significantly associated with RSV infection.

RSV infection was associated with a large increase in odds for a complex hospital course in children younger than 1 year (OR, 5.5; 95% CI, 2.8-11.0), but these odds was smaller in children older than 1 year (OR, 2.3; 95% CI, 1.2-4.3).

A total of 36.4% of admissions needed respiratory support, with RSV admissions more likely to require this compared with influenza (39.2% vs 13.4%). Admissions with RSV also had a higher rate of required respiratory support compared with people with influenza (HR, 3.3; 95% CI, 2.1-5.3), which remained significant after adjustment (HR, 3.2; 95% CI, 2.0-5.2).

Children younger than 1 year had an increased risk of respiratory support compared with older children. A significant risk increase was seen in children younger than 1 year who had RSV compared with influenza (HR, 5.6; 95% CI, 2.5-12.8. HR, 5.8; 95% CI, 2.5-13.6). This was smaller in children who were older than 1 year.

The study only took place at a single center, limiting its generalizability. In addition, the electronic health record was the only place from which information was retrieved, and administrative billing codes limited study inclusion.

Patients who are admitted to the hospital for RSV were more likely to need a complex hospital course, respiratory support, PICU admission, and longer hospital stay, the study authors concluded.

Reference

Tang KM, Hametz P, Southern W. RSV causes more severe respiratory illness than influenza in admitted children under 2-years-old. Pediatr Pulmonol. Published online April 4, 2023. doi:10.1002/ppul.26394