INTRODUCTION:

The Hamman’s syndrome is named after clinician Louis Virgil Hamman (1877-1946), who described it in 1939. He described pneumomediastinum in association with subcutaneous emphysema during pregnancy in 1945. It has been reported in all stages of labor but usually occurs in the second stage and often is clinically apparent only in the postpartum phase. It has also been seen in the prenatal phase, related to hyperemesis or self-induced vomiting. Previous reports have shown that nulliparity and excessive labor have been associated with this condition⁴.

DEFINITION:

Hamman's syndrome, also known as Macklin's syndrome, is a syndrome of spontaneous subcutaneous emphysema (air in the subcutaneous tissues of the skin) and pneumomediastinum (air in the mediastinum, the center of the chest cavity), sometimes associated with pain and, less commonly, dyspnea (difficulty breathing), dysphonia, and a low-grade fever².

Spontaneous pneumomediastinum is defined as the presence of free air in the mediastinum in the absence of an obvious precipitating cause. When associated with subcutaneous emphysema, it is called “Hamman’s syndrome”⁴

EPIDEMIOLOGY:

It is a rare entity most often encountered in young adults. It is a known entity peri- and postpartum5. Incidence is estimated at 1 in 100,000 deliveries¹. Approximately 200 such cases have been reported in literature worldwide¹.

CAUSES:

The cause of Hamman's syndrome is most commonly unknown (idiopathic).

There are many theories that attempt to explain the causes of Hamman’s syndrome.

· The most likely accepted one is the rupture of marginal pulmonary alveoli resulting from repetitive over inflations of the lungs and high intra-alveolar pressures during the second stage of labour. This can occur secondary to the Valsalva maneuvre as a result of continuous coughing, vomiting, screaming or pushing in labour.

· Prolonged labor

· During pregnancy (constipation, excessive vomiting and other causes of excessive straining)

· Hamman's is thus unsurprisingly occasionally known to be associated with asthma (i.e. frequent coughing), alcohol abuse (i.e. frequent vomiting) and inhalational illicit drug use (such as cocaine use).⁴

PATHOPHYSIOLOGY:

Maternal delivery efforts in second stage(ie, constant pushing, vulsalva maneuver etc)

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Development of pressure gradient ( Increased intra thoracic pressure, decreased vascular calibre)

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Repetative over inflation of lungs

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Rupture of alveoli

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Air dissection along broncho vascular sheath

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Spreading of air into mediastinum

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Air migration into subcutaneous and retroperitoneal tissues⁶

CLINICAL PRESENTATION:

The condition is most commonly asymptomatic. Presenting symptoms can include:⁶

· Non-Specific Chest Pain

· Dyspnea

· Dysphagia

· Dysphonia

· Subfebrile Temperature

· Hamman’s sign: Hamman’s sign is a crunching, rasping sound, synchronous with the heartbeat, heard over the precordium in spontaneous mediastinal emphysema. It is felt to result from the heart beating against air-filled tissues.

Clinical signs and Symptoms of Pregnancy-Associated SPM (Spontaneous Pneumomediastinum):

· Swelling andsubcutaneous emphysema(face, neck etc)

· Dyspnea

· Crepitus

· Chest pain

· Vomiting

· Tachy cardia

· Cough

DIAGNOSIS:

· Chest X-ray is the initial diagnostic modality.

· A CT scan provides more accurate information about extension of subcutaneous emphysema. CT is considered the gold standard for detecting mediastinal air, as it can detect small amounts which cannot be seen on a chest X-ray.

DIFFERENTIAL DIAGNOSIS:

Other aetiology of acute chest pain during or after labour are

· Amniotic fluid embolism

· Pulmonary Thrombus Embolism

· Myocardial Infarction

· Pneumothorax

· Aortic Dissection

· Boerhaave's Syndrome

· Interstitial Emphysema

· Pneumothorax,

· Pneumopericardium

· Toxic Effects Of Injected Drugs

· Cardiac Tamponade And

· Mediastinitis⁵

TREATMENT:

· Hamman's syndrome can resolve with bed rest or even with a conservative treatment within 2 weeks. Once other conditions have been ruled out and Hamman’s syndrome is diagnosed, reassurance and supportive measures with oxygen, sedatives, and analgesics are usually sufficient for treatment.

· Management includes avoidance of factors likely to exacerbate the condition such as active pushing, the use of nitric oxide and positive pressure ventilation, and attention to the reassurance and comfort of the patient. Regional anaesthesia is preferred for caesarean section, in order to avoid positive pressure ventilation⁷

REFERENCES:

1. Rajashree Chavan. Hamman’s syndrome in a parturient: a case report. Cited as :BJMP 2019;12(1):a007. http://www.bjmp.org/ content/hamman-s-syndrome-parturient-case-report

2. Hamman's syndrome. https://en.wikipedia.org/wiki/Hamman%27s_ syndrome#:~: text= Hamman's%20syndrome%2C%20also%20known%20as,%2C%20dyspnea%20(difficulty%20breathing)%2C

3. Miguel Marc Bonin. Hamman's syndrome (spontaneous pneumomediastinum) in a parturient: a case report. J Obstet Gynaecol Can; 2006 Feb;28(2):128-31. https://pubmed.ncbi.nlm.nih.gov/16643714/

4. Daniyeh Khurram, Brijesh Patel, and M. Waseem Farra^.Hamman’s Syndrome: a rare cause of chest pain in post partum patients. https://www.hindawi.com/journals /cripu /2015/201051/

5. Mostafa El-Feky and René Pfleger et al. Hamman syndrome. https://radiopaedia.org/articles/hamman-syndrome-2

6. Narcisse O Amine, Christine M Lomiguen, Asma Iftikhar, and Sonu Sahni.^.Pregnancy-associated Spontaneous Pneumomediastinum: A Contemporary Review. Cureus. 2018 Oct; 10(10): https://www.ncbi.nlm.nih.gov/pmc/articles /PMC6298626/

7. Mohamed Adnane Berdai,Said Benlamkadem, Smael Labib, and Mustapha Harandou. Spontaneous Pneumomediastinum in Labor https://www.ncbi.nlm.nih.gov /pmc/articles/PMC5339537/#: ~:text= Hamman's%20syndrome%20

8. Sabine Majer, Peter Graber. Postpartum pneumomediastinum (Hamman's syndrome) https://www.ncbi.nlm.nih.gov/pmc/articles/ PMC1896037/

Received on 09.02.2021 Modified on 10.04.2021

Int. J. Nur. Edu. and Research. 2021; 9(3):359-360.

DOI: 10.52711/2454-2660.2021.00082