Study on breathing

Roughly half of the infants experienced a "small increase" in respiratory rate post-immunization and Dr. Lussky admits he's not sure why but said "it wasn't related to temperature." In addition, 14% and 21% of infants, respectively, had an increased need for nebulizations and supplemental oxygen post-immunizations.

Based on this study, Dr. Lussky told Reuters Health that "premature infants should be immunized" according to current AAP guidelines." No Increase in Apnea/Bradycardia Spells Seen After Immunization in Preemies http://www.medscape.com/viewarticle/443394?mpid=5481

Reuters Health Information 2002. ) 2002 Reuters Ltd.

By Megan Rauscher

BOSTON (Reuters Health) Oct 21 - Results of a prospective study reported to the American Academy of Pediatrics National Conference this week do not support delaying immunizations in premature infants for fear of an increased risk of apnea and bradycardia (A&B).

In an interview with Reuters Health, lead researcher Dr. Richard C. Lussky of the Hennepin County Medical Center in Minneapolis said recent reports in the literature suggest that there may be an increase in the rate and/or severity of A&B spells in premature infants after their first set of immunizations.

"Many of these reports, which had methodological flaws, recommended that consideration be given to delaying immunizations in premature infants. This shocked me," Dr. Lussky said. "These are high-risk patients to begin with and we should not be even conjecturing about not immunizing them. And as a clinician, I wasn't seeing this increase in A&B spells," he added.

Currently, the American Academy of Pediatrics (AAP) recommends that premature infants be immunized as if they were full term. "Therefore, an infant born 4 months prematurely is immunized 2 months before their due date," Dr. Lussky noted.

He and his colleagues are evaluating the effects of inactivated polio vaccine, Haemophilus influenza B vaccine, pneumococcal vaccine, and diptheria-acellular pertussis-tetanus (DaPT) vaccine on A&B spells in an ongoing prospective study.

Data on roughly 30 premature infants evaluated thus far show no change in A&B spells or oxygenation status pre- and post-immunization.

Roughly half of the infants experienced a "small increase" in respiratory rate post-immunization and Dr. Lussky admits he's not sure why but said "it wasn't related to temperature." In addition, 14% and 21% of infants, respectively, had an increased need for nebulizations and supplemental oxygen post-immunizations.

Based on this study, Dr. Lussky told Reuters Health that "premature infants should be immunized" according to current AAP guidelines.

Only 30 subjects.....hmmmm, I am not all that mathematically minded, but I did learn in the mandatory stats class that in order to have valid results, you need at least 100 to populate your sample, and this does noy include the control group....and the more the better to get accurate results.

Also "roughly" has no place in a scientific experiment, they had "roughly 30 premature infants"? Can they not count? or is a preemie only "roughly" a person, and so therefore hey do not know how to count them? Then it goes on to say "roughly half" Well it is either half which would be "roughly" 15, or more than half which could be "roughly" 20-23, or less than half which would have been exactly 7-10. because that would have been a ruling supporting the status quo. Ugh, shoddy science is despicable.

Apnea and Bradycardia in Preterm Infants Following Routine Immunization (IMZ) Including Acellular Pertussis Containing Vaccines

Sven Schulzke, Hubert Fahnenstich. Neonatology, University Childrens Hospital, Basel, Switzerland.

BACKGROUND: The official recommendation in the US and various European countries is to vaccinate preterm infants (PT) at the same chronologic age as fullterm infants because PT are at an increased risk for vaccine-preventable diseases and produce satisfactory immune responses. However, apnea and bradycardia (A

B) in up to 12% of PT were observed in several studies after administration of whole-cell pertussis containing vaccines. Only preliminary data exists on the occurence of A

B after IMZ of PT with acellular pertussis containing vaccines.
OBJECTIVE: To determine the incidence and clinical significance of A

B in PT following diphteria (D) and tetanus (T) toxoids, acellular pertussis (Pa), Haemophilus influenzae type b (Hib), inactivated poliovirus (IPV) and hepatitis B virus (HBV) IMZ in the NICU.
DESIGN/METHODS: Medical records of PT receiving DTPa-IPV-Hib or DTPa-IPV-Hib-HBV IMZ between January 2000 and June 2003 were analyzed. For each infant, data was recorded for a 3-day period before and after the IMZ.
RESULTS: 60 PT (33 male/27 female) with a mean gestational age (GA) of 28 weeks and a mean birthweight (BW) of 1017 g were immunized; 7 infants (12%) temporarily showed an increase > 50% in A

B in the 3-day period after IMZ (group 1). Of the other 53 infants (group 2), 3 (5%) had an increase

50% and 50 (83%) the same or less occurrence of A

B in the 3 days after IMZ. 5/7 group 1 infants needed tactile stimulation, 3/7 infants required transient administration of oxygen, 1 infant needed brief bag and mask ventilation. Group 1 infants were more likely to have a maximal rectal temperature > 38

C after IMZ (p=0.009) and a lower mean weight at the time of IMZ than group 2 infants, the latter being of borderline statistical significance (2266g vs 2490g, p=0.055). The 2 groups did not differ in the mean BW (987g vs 1021g), GA (27,9wks vs 28,2wks), postmenstrual age (37,3wks vs 38,9wks) or median chronologic age at IMZ (66d vs 75d), history of A

B (all infants), median days on mechanical ventilation and/or CPAP (14d vs 18d), additional oxygen at the time of IMZ (0/7 vs 2/53), incidence of bronchopulmonary dysplasia (3/7 vs 13/53) or intraventricular haemorrhage (0/7 vs 12/53).
CONCLUSIONS: The incidence of temporarily increased A

B in PT receiving Pa containing vaccines is 7/60 (12%). Clinically significant A

B were seen in 5/7 infants. Monitoring of PT for 2 - 3 days after IMZ is recommended even in Pa containing vaccines.

First Author is a: Fellow

July 2004 • Volume 145 • Number 1

Original Articles
Safety of DTaP-based combined immunization in very-low-birth-weight premature infants: frequent but mostly benign cardiorespiratory events

Objective To evaluate the safety of diphtheria–tetanus–acellular pertussis–inactivated polio–Haemophilus influenzae type B (DTaP-IPV-HIB) immunization in premature infants.

Study design Observational study of 78 very low birth weight premature infants (mean gestational age, 28±2 weeks; mean birth weight, 1045±357 g) given DTaP-IPV-HIB vaccine before hospital discharge. Apnea, bradycardia, oxygen requirements and saturation, feeding practice, and medical interventions were assessed before and after immunization. The results were analyzed by the severity of the clinical condition and the persistence of prematurity-associated symptoms.

Results Administration of DTaP-IPV-HIB elicited resurgence or increase in cardiorespiratory events in 47% of infants (15% had apnea, 21% had bradycardia, 42% of desaturations). Most vaccine-triggered events resolved spontaneously or after brief stimulation. The relative risk was 5- to 8-fold higher in infants with a severe clinical course or persistence of cardiorespiratory symptoms at the time of immunization. Bag-mask respiratory support was given to 5 of 78 infants, and O2 requirements increased transiently in 4 of 21 infants with chronic lung disease, none requiring reventilation. Reintroduction of O2 supplementation, interruption of active oral feeding, or postponing of hospital discharge was not required.

Conclusions Cardiorespiratory events were frequently increased after DTaP-IPV-HIB immunization, requiring monitoring and appropriate intervention. However, these episodes did not have detrimental impact on the infants' clinical course. Timely immunization is warranted even in the most vulnerable preterm infants

http://www.medscape.com/viewarticle/571359

Apnea After Immunization Predictable in Some Hospitalized Neonates

By David Douglas

NEW YORK (Reuters Health) Mar 12 - Multiple factors, including severity of illness, predict apnea following immunization in hospitalized infants, researchers report in the March issue of Pediatrics. "This study," lead investigator Dr. Nicola P. Klein told Reuters Health, "can help physicians identify hospitalized premature infants in neonatal intensive care units who are at risk for developing apnea after receiving routine immunizations."

Dr. Klein of Kaiser Permanente, Oakland, California and colleagues, using data from that organization, identified more than 16,000 infants who were admitted to the NICU for at least 53 days. In all, 497 infants received 1 or more vaccines and met other entry criteria. All of the 27 infants who had apnea before immunization, and all but three of the 65 infants who had post-immunization apnea, had gestational ages of less than 31 weeks. The most important predictor of apnea after immunization was having apnea before immunization, but there were also associations with a higher 12-hour Score for Neonatal Acute Physiology II and an age that was less than the mean for the cohort (67 days).

Forty-nine infants without pre-immunization apnea and with one or more apnea predictors were discharged within 48 hours of immunization. Of these, two were subsequently readmitted because of apnea. Overall, concluded Dr. Klein, "focusing on these at-risk infants could result in improved vaccine safety because they would likely remain hospitalized for monitoring after immunization."

Pediatrics 2008;12:463-469.