FMGE 2018 — Forensic Medicine

Q: Confirmatory test of blood stain:

Spectroscopic test. ***Spectroscopic test*** - The **spectroscopic test** is considered a **confirmatory test** for bloodstains due to its ability to identify the characteristic **absorption spectrum of hemoglobin**. - It specifically detects the presence of **hemoglobin derivatives**, unequivocally confirming the presence of blood. *Kastle-Meyer test* - This is a **presumptive test** for blood, relying on the **peroxidase activity** of hemoglobin. - While sensitive, it can yield **false positives** due to other peroxidase-like substances (e.g., plant material, rust). *Benzidine test* - The **benzidine test** is also a **presumptive test** for blood based on peroxidase activity. - It is **highly sensitive** but has been largely replaced by other tests due to the **carcinogenic nature** of benzidine. *Orthotoluidine test* - Similar to the Kastle-Meyer and benzidine tests, the **orthotoluidine test** is a **presumptive test** that detects the peroxidase activity of hemoglobin. - It can also produce **false positive results** from various oxidizing agents or plant peroxidases. [Practice more Forensic Medicine PYQs on OnCourse]

Q: Gastric lavage is contraindicated in?

Hydrocarbons. ***Hydrocarbons*** - Gastric lavage is contraindicated in **hydrocarbon poisoning** due to the high risk of **aspiration** [2]. - Aspiration of hydrocarbons can lead to severe **chemical pneumonitis**, which is often more life-threatening than the systemic toxicity from ingestion [2]. *Bicarbonate* - Ingesting a large amount of bicarbonate can cause **alkalosis** and electrolyte imbalances. - While gastric lavage is not typically the primary treatment for mild bicarbonate overdose, it is not absolutely contraindicated in cases of massive ingestion where there is a clear benefit to removing unabsorbed substance, especially if performed with proper airway protection [1], [3]. *Organo-Phosphosphate poisoning* - Gastric lavage is generally recommended for **organophosphate poisoning** if the patient presents within 1-2 hours of ingestion and is awake with an intact gag reflex, or with a protected airway [2]. - This helps remove unabsorbed poison and can reduce the systemic absorption of these highly toxic compounds. *PCM toxicity* - For **paracetamol (PCM) toxicity**, gastric lavage can be considered if the patient presents within 1-2 hours of ingestion and has ingested a potentially toxic dose, especially when activated charcoal is not immediately available or contraindicated [4]. - The primary treatment for PCM toxicity involves **N-acetylcysteine (NAC)**, but gastric emptying can play a role in reducing initial absorption [4]. [Practice more Forensic Medicine PYQs on OnCourse]

Q: The most reliable criterion in Gustafson's criteria is:

Transparency of root. ***Transparency of root*** - This criterion, specifically **dentinal translucency**, is considered the most reliable age indicator in **Gustafson's criteria** due to its continuous and predictable increase with age. - The **translucency** results from the deposition of **secondary dentin** and obliteration of dentinal tubules, progressing from the apex towards the crown. *Attrition* - **Attrition** refers to the wear of tooth surfaces, which is highly variable and depends on diet, habits, and dental health, making it an unreliable age indicator. - While it generally increases with age, its rate is subject to many confounding factors. *Root resorption* - **Root resorption** is the progressive loss of tooth structure from the root and can be caused by various factors like trauma, infection, or orthodontic treatment, not solely age. - It is an unpredictable process and not a consistent age-related change. *Periodontosis* - **Periodontosis**, or **periodontal disease**, is inflammation and infection of the supporting structures around the teeth, influenced by oral hygiene and genetics. - While its prevalence may increase with age, it's not a direct and reliable physiological age marker for individuals. [Practice more Forensic Medicine PYQs on OnCourse]

3 Previous Year Questions with Answers & Explanations

Questions

Confirmatory test of blood stain:

Gastric lavage is contraindicated in?

The most reliable criterion in Gustafson's criteria is: