Table of Contents
Introduction
Exploratory interventions or other medical proceedings, if not instituted scrupulously and cautiously, could bring forth other health complications or other medical conditions. Thus, invoked health complications may warrant further interventions to reinstate healthy functioning. Iatrogenic disorders are the umbrella term that is customarily designated for such medical conditions prompted by medical intervention. It could be either an intricacy brought on by surgical approaches or diagnostic modalities. Iatrogenic pneumomediastinum is one such iatrogenic condition.
What Is Iatrogenic Pneumomediastinum?
Pneumomediastinum is a peculiar ailment where the air gets trapped and cornered into a specific chamber called mediastinum. The mediastinum is a chest receptacle bordered by the lungs on either of its sides. It lodges and accommodates the heart, food pipe, thymus gland, blood vessels, and a segment of the windpipe. In simple terms, it can be denoted as a chest cavity. In pneumomediastinum, air molecules somehow infiltrate and seep into the mediastinum. It is from the airway or digestive tract that these air molecules are drawn into the mediastinum.
Pneumomediastinum is cataloged into two distinctive subsidiaries - spontaneous pneumomediastinum and secondary pneumomediastinum. Spontaneous pneumomediastinum, as the name implies, is pulled off instantaneously with no specific risk quotient yielding the condition. It entails those pneumomediastinum cases that are not backed with reasonable etiology. Secondary pneumomediastinum is the collaborative term designated for all pneumomediastinum cases with conspicuous etiology.
What Are the Iatrogenic Causes of Pneumomediastinum?
Iatrogenic pneumomediastinum is a type of secondary pneumomediastinum where the air seepage into the chest cavity is pulled off by specific treatment interventions. Not all treatment interventions can bring in pneumomediastinum. Some apparent causes that could instigate iatrogenic pneumomediastinum are quoted below:
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Airway Endoscopy: An interventional modality where a thin tube is instituted to be driven through the airway tract. A small camera secured in the tube favors and capacitates visualization of the air passage as the tube wedges through. It holds the threat of inadvertent thumping of the endoscopy device into the lung lining. This impact could effectuate ruptures or abrasions on the lung lining, thereby instituting communication channels with the mediastinum.
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Upper Gastrointestinal Endoscopy: Endoscopic intervention employs a thin tube that incorporates a camera in it. In upper gastrointestinal endoscopy, this tube is driven through the food pipe (esophagus) into the gut and intestinal regions. Upper gastrointestinal endoscopy, otherwise quoted as esophageal endoscopies, can call forth iatrogenic pneumomediastinum. While driving in the endoscopic tube, one may confront incidental puncturing or piercing of the gut or intestinal wall. These punctures could bring forth iatrogenic mediastinum. Furthermore, in order to expedite the ingress of the endoscopic tube, the digestive tract is puffed up by instituting aeration. Aeration of the food tract may prompt the expulsion of air molecules into the mediastinum through the abrasions or punctures instigated by the endoscopic procedure. Thus, air molecules may break free into the chest cavity, bringing forth iatrogenic pneumomediastinum.
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Airway Intubation: Airway intubation is devised to import oxygen with machine assistance. It is instituted for retaining and sustaining the breathing patency in one with a collapsing airway. The oxygen dispensed through the intubation is often pressurized, which could instigate airway track puncture or abrasions. The air molecules may channel through the punctures and sweep into the chest cavity, setting off iatrogenic pneumomediastinum.
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Abdominal and Chest Surgeries: Surgical exploration of the chest region can bring in incidental and unintended punctures on the nearby structures. These punctures heighten the proclivity for iatrogenic pneumomediastinum.
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Central Vascular Access: Pneumomediastinum could be prompted by central vascular access modalities. These are procedures through which the central blood vessels are ingressed and accessed to dispense or withdraw fluids from the blood. The access is instituted by driving in medical catheters (flexible tubes devised for medical use). While driving in the catheter, particularly the subclavian vein (underneath the collarbone), there is scope for incidental venous punctures. These punctures can bring forth iatrogenic pneumomediastinum.
What Are the Radiological Interventions Advocated for Iatrogenic Pneumomediastinum?
Pneumomediastinum, be it spontaneous or secondary, is spotted and pinned down by imaging modalities. Chest X-ray is the customary advocated radiological modality for suspected pneumomediastinum owing to its aptness and competency in unmasking the air entrapment within the mediastinum. It precisely delineates the lucencies owing to the confined gas within the chest cavity.
The location of the gas entrapment within the chest cavity governs the form of radiographic findings by bringing in association with the heart, aorta, heart lining, and pulmonary arteries. In younger patients, particularly in newborns, a pronounced uplifting is encountered in the thymus gland’ position. The X-ray finding through which the thymus uplifting is exemplified is quoted as a “thymic sail”. “Double bronchial wall sign” is another hallmark observation expressed through chest X-ray. In pneumomediastinum, both bronchial wall margins are projected in chest X-ray, which is cited as a double bronchial wall sign. The ring-like lucency that encircles the right pulmonary artery (which streams blood to the lung from the right lower heart chamber) is expressed as a ring sign. Chest X-rays also unveil the cause that has pulled off iatrogenic pneumomediastinum.
Imaging through computed tomography ought to be instituted when a chest X-ray is unfair or incompetent to bring out confirmative observations. A computed tomography scan is more susceptive and sensitive to mediastinal air entrapment such that it can unmask even tiny air molecules. Ultrasounds are other imaging modalities instituted for pneumomediastinum suspected cases. The air gap sign is pneumomediastinum’s trademark observation revealed through ultrasound scans. Ultrasound scans work with sound waves; upon striking the air molecules, they rebound, which gets expressed as an air gap sign. However, ultrasounds are not habitually advocated for iatrogenic pneumomediastinum unless under exigency.
Conclusion:
Medical interventions hold the propensity to set off iatrogenic disorder, even though they ought to be instituted as treatment and diagnostic strategies. Iatrogenic pneumomediastinum is brought on by airway intubation, bronchoscopy (airway endoscopy), chest operations, subclavian vein access procedure, and esophageal endoscopies. Nevertheless, these interventions do not pull off pneumomediastinum in all instances. The restrictive accessibility of these procedures underscores and deepens the gravity of iatrogenic pneumomediastinum. Doctors’ expertise and other patient factors can govern and palliate the propensity for iatrogenic pneumomediastinum. Chest X-rays, ultrasound scans, and computed tomography are the radiological aids that can unmask iatrogenic pneumomediastinum. Chest X-ray expresses trademark attributes confirming air entrapment. It also unmasks the cause that has prompted iatrogenic pneumomediastinum. With prompt intervention, iatrogenic pneumomediastinum could be addressed with a noteworthy prognosis.
