Forensic application of ESEM and XRF-EDS techniques to a fatal case of sodium phosphate enema intoxication

Toxicity of phosphate enemas - an updated review

INTRODUCTION

Enemas containing phosphate are widely prescribed and may cause important adverse effects. A systemic review published in 2007 reported the literature on the adverse effects of phosphate enemas from January 1957 to March 2007 and identified 12 deaths. These were thought due to electrolyte disturbances, heart failure and kidney injury. These data raised concerns about the use of phosphate enemas in routine practice. Newer osmotic-based enema alternatives are now available that do not contain absorbable ions. We sought to review the literature since this review and evaluate the latest data on the toxicity of phosphate-containing enemas. To gain a fuller picture we included case series and larger studies as well as case reports.

OBJECTIVES

To review the toxicity of phosphate enemas, particularly with respect to acute metabolic consequences and their associated clinical features. To identify risk factors for metabolic toxicity and consider whether phosphate enemas should be relatively contra-indicated in specific patient groups.

METHODS

A systematic literature review was conducted in PubMed, Google Scholar, and Cochrane Reviews (2005-2021) using the search terms 'phosphate enema or sodium phosphate enema' or 'phosphate-based enema' or (phosphate AND enema) or (Fleet AND enema) or 'sodium phosphate laxatives' or 'sodium phosphate catharsis' or 'sodium phosphate cathartic'. Relevant papers were read, and data were extracted.

RESULTS

The searches identified 489 papers of which 25 were relevant: seven papers were case reports or small case series of metabolic abnormalities from the use of phosphate enemas in nine children, six were case reports on 16 adults. Nine papers were large case series or clinical studies that included data on systemic metabolic effects, of varying size from 24 healthy volunteers to a cohort of 70,499 patients. Case reports identified seven adult deaths but none in children. Children most often presented with decreased consciousness (6/9), and tetany (4/9). In adults overall only five cases had clinical features reported, hypotension was seen in four and QT prolongation in two. Treatment was generally symptomatic, with intravenous fluid and calcium salts for electrolyte changes and hypocalcaemia, and vasopressors for severe hypotension. Haemodialysis was used in three children and peritoneal dialysis in one, all of whom survived. In adults, haemodialysis did not prevent death in two of four cases in whom it was used. Common factors underlying toxicity were inappropriately high phosphate dose, or enema retention, both resulting in greater absorption of phosphate. Associated pre-disposing conditions included Hirschsprung disease in children and co-morbidity and renal impairment (2/5) in older adults. Absolute reported changes in serum phosphate or calcium were not accurate indicators of outcome. Larger case series and clinical trials confirm an acute effect of phosphate enemas on serum phosphate, which was related to both dose and retention time. These effects were not seen with non-phosphate preparations. In these cases series, adverse events were rarely reported.

CONCLUSION

Phosphate enemas are potentially toxic, particularly in young children with Hirschsprung disease and in the elderly with co-morbidity. Raised awareness of the risk of phosphate enemas is still required. Other less toxic enema preparations are available and should be considered in patients at extremes of age. If phosphate enemas are the only clinical option careful monitoring of biochemical sequelae should be undertaken.

Histological microaggregates as a sign of systemic dissemination due to oral ingestion of povidone-iodine (Betadine®)

Povidone-iodine (PVP-I) in the formulation of Betadine® is widely used in several medical fields, whereas its suicidal ingestion is an unusual occurrence. Therefore, the biological signs of this fatal poisoning remain unclear and elusive, similarly to the histological lesions induced by PVP-I. In fact, there are no forensic articles concerning the histological signs of PVP-I acute poisoning. Specifically, this short communication reports the unique case of a man who ingested 125 ml of Betadine® 10% to commit suicide, for which he died three days later. The autopsy examination showed either local or systemic signs of caustic ingestion; moreover, the histological analysis showed both intra- and extra-cytoplasmic amorphous and brownish microaggregates in almost all the organs. Histological and histochemical techniques resulted to be negative for the detection of physiological and known pigments (e.g., formalin, lipofuscin, hemosiderin). Likewise, such pigments were not associated neither with the man's diseases nor with his medications. Therefore, the authors supposed that they were povidone-iodine microaggregates, which have been deposited in the organs through the blood circulation. In conclusion, the complete postmortem histological examination could allow the identification and the characterization of PVP-I microaggregates as evidence of systemic toxicity from Betadine®, when dealing with a forensic case of ingestion of povidone-iodine.

Back to the Future - Part 2. Post-mortem assessment and evolutionary role of the bio-medicolegal sciences

Part 2 of the review "Back to the Future" is dedicated to the evolutionary role of the bio-medicolegal sciences, reporting the historical profiles, the state of the art, and prospects for future development of the main related techniques and methods of the ancillary disciplines that have risen to the role of "autonomous" sciences, namely, Genetics and Genomics, Toxicology, Radiology, and Imaging, involved in historic synergy in the "post-mortem assessment," together with the mother discipline Legal Medicine, by way of its primary fundament, universally denominated as Forensic Pathology. The evolution of the scientific research and the increased accuracy of the various disciplines will be oriented towards the elaboration of an "algorithm," able to weigh the value of "evidence" placed at the disposal of the "justice system" as real truth and proof.

Back to the Future - Part 1. The medico-legal autopsy from ancient civilization to the post-genomic era

Part 1 of the review "Back to the Future" examines the historical evolution of the medico-legal autopsy and microscopy techniques, from Ancient Civilization to the Post-Genomic Era. In the section focusing on "The Past", the study of historical sources concerning the origins and development of the medico-legal autopsy, from the Bronze Age until the Middle Ages, shows how, as early as 2000 BC, the performance of autopsies for medico-legal purposes was a known and widespread practice in some ancient civilizations in Egypt, the Far East and later in Europe. In the section focusing on "The Present", the improvement of autopsy techniques by Friedrich Albert Zenker and Rudolf Virchow and the contemporary development of optical microscopy techniques for forensic purposes during the 19th and 20th centuries are reported, emphasizing, the regulation of medico-legal autopsies in diverse nations around the world and the publication of international guidelines or best practices elaborated by International Scientific Societies. Finally, in "The Future" section, innovative robotized and advanced microscopy systems and techniques, including their possible use in the bio-medicolegal field, are reported, which should lead to the improvement and standardization of the autopsy methodology, thereby achieving a more precise identification of natural and traumatic pathologies.

Determining comparative elemental profile using handheld X-ray fluorescence in humans, elephants, dogs, and dolphins: Preliminary study for species identification

Species identification is a crucial step in forensic anthropological studies. The aim of this study was to determine elemental profiles in bones from four mammal species, to be used for species discrimination. Human, elephant, dog, and dolphin bones were scanned by X-ray fluorescence (XRF); the differences in elemental profiles between species were determined using discriminant analysis. Dogs had the greatest number of elements (23), followed by humans (22) and elephants (20). Dolphins had the lowest number of elements (16). The accuracy rate of species identification in humans, elephants, dogs, and dolphins was 98.7%, 100%, 94.9%, and 92.3%, respectively. We conclude that element profiles of bones based on XRF analyses can serve as a tool for determining species.

Release of metals from osteosynthesis implants as a method for identification: post-autopsy histopathological and ultrastructural forensic study

Metal structures--especially of stainless steel, titanium and their alloys (biomaterials)--are widely used in orthopaedic practice and the subject of constant study in bioengineering and preventive medicine. This study presents the first experience of forensic research into the presence of permanent tissue variations around metal implants in various bone structures for the purpose of identification, with particular reference to skeletal remains or severely decomposed corpses in the absence of other identifying elements. The evaluation was conducted on 12 corpses who had undergone osteosynthesis intra-vitam, whose implants were still in place or had been removed, in comparison with five controls who had never undergone osteosynthesis. Bone fragments taken during autopsy were subjected to histopathological and scanning electron microscope-energy dispersive electroscopy examination in order to reveal and characterise any metal particles originating from osteosynthesis. The study enabled the discovery of intra-bone metal particles in tissues treated by osteosynthesis even in bone areas where the implants had been removed and even where there were no longer any radiological signs of their application. These results are therefore of considerable forensic importance, especially in the area of identification, providing a valid means of recognition beyond that of the well-established use of in situ metal implants.