Four millimeters: a distance less than half an inch, approximately the length of a human fingernail and, according to regulators, the difference between life and death.

Trascheostomy tubes are used in surgical settings to maintain an airway through an opening in the trachea, allowing the patient to breath while surgeons clear the lungs.

However, while the device is intended to be life-saving, according to a Class I recall notice - a recall class reserved for potentially life-threatening or deadly defects - issued by the US Food and Drug Administration (FDA) on 22 July 2013, one device manufacturer's mix-up has the potential to cause permanent, even fatal damage to the youngest of patients.

The device in question is Bryan Medical's Tracoe Mini 3.0 Trascheostomy Tube, a device the company manufacturers in both pediatric and neonatal versions with the same 3.0mm-size internal diameter.

According to the recall notice, the company had accidentally packaged the pediatric version of the device in packaging intended to be used with the neonatal versions of the device. The problem, FDA explained, is that while the inner diameter is the same, the pediatric tube is actually 4.0mm wider, potentially causing permanent injury to the trachea and causing "adverse health consequences, including death."

FDA said Bryan Medical had initiated a recall of the devices in April 2013, just five days after the devices were initially distributed, but the agency had only just classified the severity of the recall, significantly upgrading its profile.

Read FDA's recall notice here.

Recall Notice of Bryan Medical