Choking is blockage of internal airways usually between pharynx and bifurcation of trachea by foreign bodies, food boluses, blood clots, and laryngeal pathology, and it can cause sudden unexpected deaths (Saukko P. and Knight B. 2016). Deaths from choking occur due to hypoxic manifestation, neurogenic shock, or excess catecholamine release from the adrenal response. However, the rapidity of collapse highlights the dominant role of reflex vagal inhibition over mechanical airway obstruction (Byard R. 2018). Choking due to aspiration of gastric content is not common in previously healthy persons. However, neuropsychiatric conditions, alcohol intoxication, or sedative drugs can predispose an individual to end up in sudden death from choking consequent upon aspiration of food particles (Wick R. et al. 2006).
Gastric contents can be found in the airways in most of the decomposed bodies and occasionally in fresh bodies due to postmortem spillage and agonal aspiration. Differentiation between antemortem aspiration and postmortem spillage is a challenge for forensic pathologists (Saukko P. and Knight B. 2016). However, in our case, respiratory passage including trachea and bronchi showed mildly inflamed mucosa, and body was well preserved until autopsy examination. In postmortem spillage, gastric contents do not reach beyond the secondary bronchus (Agarwal S. et al. 2010). In the deceased of our case, gastric contents had reached well beyond the secondary bronchus, and a significant number of inflammatory cells had infiltrated the bronchiolar lumen. Expanded alveoli along with broken septa, as seen in this patient, may be caused due to forced expiratory effect against closed airways (Agarwal S. et al. 2010).
In this presented case, petechial hemorrhages were not seen over the epicardial surface and pleural surface. However, asphyxial signs are nonspecific findings as those may be absent in undoubted hypoxic deaths and might be present in some non-hypoxic deaths (Saukko P. and Knight B. 2016). The factors increasing the risk of aspiration associated with pregnancy include the gravid uterus, progesterone-mediated lower esophageal sphincter relaxation, lower gastric pH, and delayed gastric emptying (UK Obstetric Surveillance System 2016). Most of the above risk factors cease with the termination of pregnancy, but some residual effects persist in the immediate and early postpartum period, and these effects may contribute to gastric content aspiration (Thélin C. and Richter J. 2020) similar to our case.
A large amount of gastric contents, gastroesophageal reflux disease and hiatal hernia also contribute to gastric content aspiration (Brodsky J. and Lemmens H. 2011). In this patient, no history or postmortem evidences suggestive of gastroesophageal reflux disease and hiatal hernia were found. However, physiological sphincter action of the lower esophagus cannot be assessed during the autopsy. According to the recent clinical records, she had not suffered from gastroesophageal reflux disease. Effects of labor and opioid drugs are known to cause delayed gastric emptying in puerperium (Gin T. et al. 1991). It is possible that opioids and effects of labor have contributed to delayed gastric emptying in this patient. Based on the history and recent clinical records, she had not suffered from any neurological impairment, and there were no gross and microscopic abnormalities of the central nervous system. Extensive neuro-pathological examination may warrant identifying rare causes of aspiration, and such facilities are not available where this autopsy was conducted.
Postpartum hemorrhage and amniotic fluid embolism are known to cause sudden death in postpartum mothers, which can present as obstetric shock (Steiner, P. E., & Lushbaugh, C. C. 1986). However, in this case, such causes can be excluded since her immediate postpartum period was uneventful.
When considering sudden cardiac deaths, which contribute to a majority of sudden deaths, autopsy findings play a major role in ascertaining the cause of death. Coronary artery diseases and noncoronary artery diseases such as rheumatic heart disease, syphilis, hypertensive heart disease, myocarditis, acute aortic dissection, and cardiomyopathy show features of such conditions in gross examination and histological examinations to support the diagnoses (Sessa et al. 2021 and Banner et al. 2021).
Similar sudden death in pregnancy can occur with conditions like arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVCD). In such cases, fibro-fatty changes in the myocardium with associated inflammatory cell infiltration will be expected to see at the autopsy (Lynch M. and Noel W. 2008). However, in this patient, there was no demonstrable macroscopic or microscopic and toxicological evidence to explain the sudden death except the presence of gastric content throughout the large and small airways with microscopic evidence of inflammation. Evidence of inflammation excludes the postmortem spillage and agonal aspiration. Presences of inflammatory cells further exclude the immediate death by neurogenic shock in choking. History of sudden onset of breathing difficulty, risk factors of early postpartum period, and recent heavy meal were supportive for antemortem gastric content aspiration.
Majority of sudden deaths during the puerperium results from cardiovascular and gynecological conditions and holds medicolegal significance particularly if associated with criminal abortion or medical negligence (Vadysinghe A. et al. 2017). However, it should not be forgotten that physiological changes in pregnancy itself can predispose an individual to be ended up in a sudden death. As in this case, gastric content aspiration can present as an asymptomatic silent killer particularly in peripartum mothers given their increased risk induced by physiological changes in pregnancy. Even though there are no well-established screening programs for such case identification, prevention of gastric content reflux can be done by simply following conservative measures such as lifestyle and dietary modifications (Vazquez J. 2015).
This case shows how the involvement of various disciplines would facilitate the investigation of a complex case (Ferrara M. 2019). Inputs from neurohistopathology and cardiachistopathology would have positively influenced the diagnostic procedure, and lacking of such involvement is a shortcoming in this case.