Subtle Heart Rates are Predictive of Neonatal Sepsis
Griffin MP, Lake DE, Bissonette EA, Harrell FE Jr, O'Shea TM, Moorman JR. Heart rate characteristics: Novel physiomarkers to predict neonatal infection and death. Pediatrics, 2005;116:1070-1074.
Serious infection in newborn infants is one cause of mortality in that age group. Although sepsis can be identified by culture and physical symptoms, there are times when the onset of sepsis is so sudden that efforts to combat it become futile. This study evaluated an algorithm that was developed to detect subtle changes in the heart rate of neonates before the onset of sepsis. The objective was to try to predict the development of neonatal sepsis so that interventions can begin earlier.
In order to evaluate the predictive equation, 1,022 neonates were studied over several years. It was determined that in these infants, there were 223 cases of sepsis, 108 urinary tract infections, and 48 deaths attributed to sepsis. Very low birth weight infants accounted for 30% of the cases. All infants were observed for heart rates by continuous monitored heart rate and a calculated heart rate index.
The findings revealed that subtle changes in the heart rate in the monitored infants showed up 12 hours prior to more serious symptoms of sepsis. These heart rate changes included decelerations and a loss of variability. The predictive rates of infection were considered to be high. Higher risk neonates, those who were premature or who had a low birth weight, were more likely to be identified as septic from these heart changes than were low-risk neonates.
The researchers proposed that this assessment of heart rates would help identify infants who later develop dangerous sepsis of the neonatal period. These assessments are easy to perform and have predictive value. Although there are other reasons why infants develop sepsis, and presumably other infectious illnesses that may not cause early heart rate changes, these researchers are hopeful that some infants can benefit from this new assessment tool.
Characteristics Differ According to Region in Rates of Low-Birth-Weight Infants
Thompson LA, Goodman DC, Chang CH, Stukel TA. Regional variation in rates of low birth weight. Pediatrics, 2005;116:1114-1121.
Low-birth-weight infants are born on a consistent basis in the United States despite considerable efforts at reduction in the numbers. Healthy People 2010 seeks to reduce low-birth-weight incidences to 5 per 100 live births by the year 2010; however, there appears to be no way that this goal can be met.
This research studied the regional characteristics of all infants born in the United States in 1998. There were 3,816,535 singleton, non-foreign births during that year. Data were collected on the following characteristics:
* Maternal age
* Race
* Hispanic ethnicity
* Completion of high school
* Martial status
* Live birth order
* Maternal weight gain
* Maternal birth place
* Tobacco and alcohol use
* Timing or prenatal care
* Maternal medical risk
* Region of the United States
The data revealed that the overall low-birth-weight rate in the United States in 1998 was 6.0 per 100 live births. The results also showed that low-birth-weight infants continued to be concentrated in black mothers (11.1/100), those who had gained less than 21 lb (10.9/100), those who smoked (10.5/100) and/or drank alcohol (12.9/100), teenage mothers (8.5/100), and those who had low household incomes (7.4/100). In addition, higher elevation (more than 6,500 ft; 7.7/100) was also linked to low birth weight. Regional differences were also found: Those in the west coast and northeastern part of the United States had lower rates of low birth weight, whereas the south and western mountain regions had higher rates.
The researchers stated that the findings show that low birth weight continues to be a problem in the United States and that many factors contribute to these statistics.