Hamman's Syndrome after Vaginal Delivery: A Case of Postpartum Spontaneous Pneumomediastinum with Subcutaneous Emphysema and Review of the Literature.

Hamman's syndrome is a rare condition that mostly affects young males, often with a predisposition to asthma. It includes the presence of free air in the mediastinum and subcutaneous emphysema with no other underlying cause such as trauma, infection, or administration of any sort of mask support with hyperpressure. It occurs spontaneously and often in association with a prolonged Valsalva maneuver. This might explain why there are some cases of Hamman's syndrome among young females giving birth. Here, we present a case report of a 24-year-old non-smoker primigravida with Hamman's syndrome. She presented with symptoms a few hours after an uncomplicated vaginal delivery at 40 + 1 weeks of pregnancy where the active phase of labor lasted for three hours with normal progress. The second stage lasted for 30 min, with no signs of distress on CTG. The symptoms (pain in the right ear, swelling and pain in the neck, chest tightness, shortness of breath, dysphagia, odynophagia, and pain in the upper thorax on the right side) and objective findings as subcutaneous crepitations in the neck, parasternal region, right axillary fossa, clavicle and over the chest resolved spontaneously after a few days of observation and conservative management. We also give a systemic review of reported cases since 2000 to provide an overview of the pathomechanism, symptoms, diagnostics, treatment, and management of this condition. Hamman's syndrome is a rare, usually benign, but potentially serious complication that can occur during the second stage of labor. Diagnostics include inquiring about typical symptoms, clinical examination, and chest x-ray or CT scan. Treatment is usually conservative with oxygen, bronchodilators, and pain relief. The recurrence rate is low and there is no contraindication to vaginal delivery in future pregnancies. However, it is suggested that physicians and midwives be cautious and consider a low threshold for instrumental delivery or cesarean section to avoid excessive Valsalva maneuvers.