Aspiration of Gastric Contents in Sudden Infant Death Syndrome Without Cardiopulmonary Resuscitation
Krous HF, Masoumi H, Haas EA, Chadwick AE, Stanley C, Thach BT
J Pediatr. 2007;150:241-246
Summary
This study attempted to shed light on whether gastric contents are likely to be found in infants who died of sudden infant death syndrome (SIDS). Previous pediatric literature had not been clear on this question, mostly because SIDS victims who had cardiopulmonary resuscitation (CPR) performed were included in previous case series. Infants who underwent CPR may have gastric contents reflux and enter the respiratory tract owing to chest compressions. Therefore, it has been unclear whether gastric contents found in the respiratory tract of SIDS victims were present as part of the primary event or as a result of the resuscitation attempts.
This study involved the review of 69 SIDS cases from one county in California, none of whom had CPR. The authors then compared the cases who had gastric contents found in the distal respiratory tract against those without gastric contents in the respiratory tract.
Two pathologists microscopically reviewed lung sections from each case in order to identify gastric contents; they found gastric contents in the respiratory tract of 10 cases (14%).
The infants with SIDS and gastric contents aspiration were similar to the other SIDS infants in all demographic and clinical characteristics, including age at time of death, sex (approx. 60% male), gestational age, and delivery mode.
Twenty percent of the SIDS infants with gastric aspiration had a history of gastroesophageal reflux compared with only 2% of the SIDS infants without aspiration, but this difference did not reach statistical significance. Less than 3% of either group had a history of apnea or bradycardia prior to death. When comparing sleep position, 83% of those with aspiration were placed prone to sleep compared with 57% of those who died without aspiration, but this difference was not statistically significant.
The authors concluded that gastric aspiration occurs in a notable percentage of infant SIDS cases.
Viewpoint
Interpreting the findings of this study is difficult. The authors admit this and review other literature suggesting that the emesis and aspiration that happened in these infants may be the result of agonal respirations and not the cause of the entire event that led to SIDS.
Although the comparisons found no statistically significant differences, it is difficult to put full faith in their findings because of the relatively low number of subjects. For example, the fact that 20% (vs 2%) of the SIDS cases with aspiration had a history of gastroesophageal reflux may have reached statistical significance with a larger cohort. Similarly, the disparity in sleep position may likely be significant in larger studies.
Even so, perhaps a history of gastroesophageal reflux and sleep position correlates with whether stomach contents are found in the lung at autopsy, but it does not provide guidance as to whether more aggressively treating reflux would have changed the outcome in those infants.
The take-home message might be that gastric aspiration occurs even without CPR attempts. Perhaps future trials will help delineate whether there is protective value in treating reflux, but we already know the value of supine sleep position vs prone position in reducing the rate of SIDS.
Reviewed by Ramaz Mitaishvili, MD
