**Question:** Hand over mouth technique was first described by

A. Henry Sigerist
B. Dr. Ewan Cameron
C. Dr. John Snow
D. Dr. William Osler

**Correct Answer:** C. Dr. John Snow

**Core Concept:** The hand over mouth technique is a method used in medical practice to determine if a patient has inhaled a foreign body, such as food or liquids. This technique involves placing the practitioner's hand over the patient's mouth while asking them to cough or breathe deeply. If the foreign body is present, the cough or breath will be obstructed, causing the patient to stop breathing or cough. This helps in identifying the potential foreign body and guiding further management.

**Why the Correct Answer is Right:** Dr. John Snow, a prominent physician and epidemiologist, popularized this technique in the late 19th century. He used it to diagnose aspiration pneumonia cases and to locate the source of cholera outbreaks in London's water supply. The hand over mouth technique has been widely adopted in clinical practice, allowing practitioners to efficiently assess for potential aspiration and guide appropriate interventions.

**Why Each Wrong Option is Incorrect:**

A. Henry Sigerist (1874-1957) was a Hungarian-born physician and historian who contributed to the development of public health and epidemiology. Although Sigerist was influential in the field of public health, he did not specifically describe the hand over mouth technique.

B. Dr. Ewan Cameron (1903-1991) was a Scottish physician known for his work in cardiology and the development of the Cameron classification of angina pectoris. He is not associated with the hand over mouth technique.

D. Dr. William Osler (1849-1919) was a Canadian physician widely regarded as the "Father of Modern Medicine." Although Osler made significant contributions to medicine, he is not directly linked to the hand over mouth technique.

**Clinical Pearl:** This technique is crucial for diagnosing and managing patients with suspected aspiration or respiratory distress. Practitioners must be familiar with the hand over mouth technique to effectively assess patients and ensure appropriate interventions for optimal patient care.