Air Force Cardiopulmonary Laboratory Technician

Close up of stethoscope
Martin Barraud

On the one hand, the human heart and lungs are two systems that go together like spaghetti and meatballs, so it's only natural to treat them together. On the other hand, they're both incredibly complex systems to get a handle on.

So it's no surprise that in the Air Force, enlisting in Air Force Specialty Code 4H to become a cardiopulmonary (CP) laboratory technician requires a sharp mind and extensive training, and that successful graduates earn a rewarding career with lucrative opportunities in the military and the civilian healthcare system.

Duties and Responsibilities

Don't let the word "laboratory" in this job title fool you: Cardiopulmonary work is about hands-on patient care, not beakers and bunsen burners.

Although they're technically enlisted assistants to commissioned medical professionals, CP lab techs do more than just grunt work. Here's a sampler of some duties and procedures they're involved in, according to the Air Force Enlisted Classification Manual:

  • Electrocardiograms: CP lab techs are instrumental in administering electrical diagnostics on the human heart. Like registered nurses, they're also expected to interpret the waveforms for signs of serious conditions, such as arrhythmias, conduction blocks, and heart attacks.
  • Invasive heart procedures: 4Hs are also present in the operating room, assisting cardiologists with invasive procedures including angiography (visualizing the blood vessels of the heart using dyes and x-ray) and life-saving procedures like balloon angioplasty and placing stents (unblocking clogged arteries around the heart, as in a heart attack.)
  • Respiratory therapies: These include simple measures like testing and maintaining lung function with external devices, as well as invasive procedures such as helping the doctor intubate a patient and caring for patients on mechanical ventilation.

Military Requirements

As you can imagine, cadets who want to work in the cardiopulmonary laboratory field need to be ready for some rigorous academics. Accordingly, the Air Force only accepts those with a high school diploma, and the Enlisted Classification Manual adds that "high school or college courses in algebra and chemistry [are] mandatory."

There's nothing else in the manual about entry requirements, although ​Rod Powers has discovered that a general aptitude (arithmetic reasoning and verbal expression) score of at least 44 is necessary when you take the Armed Services Vocational Aptitude Battery (ASVAB).


Following eight and a half weeks of Air Force basic training, be ready to switch gears to some high-octane academic work at the joint-service Medical Education and Training Campus (METC), located at Fort Sam Houston, Texas.

METC's Cardiopulmonary Program is divided into an academic and clinical phase. The first phase lays a ton of necessary groundwork in the classroom, covering fundamentals like "anatomy and physiology, chemistry, pharmacology, microbiology . . . [and] disease processes" as well as specific techniques for treating patients and using the wide variety of equipment at the CP lab tech's disposal, such as mechanical ventilators and electrocardiograms.

The second phase takes students out of the classroom and into the real world, assigning them to any one of the Air Force's many medical facilities across the country. Here, on-the-job training ensures that those who graduate the program are good at their jobs, not just taking written exams. But phase two is also an evaluation of whether these would-be techs can be trusted to "exercise judgment and accept responsibility . . . in the care of cardiopulmonary patients," according to the course description.

The Air Force recruiting website claims the course lasts a whopping 233 days, but those interested in the 4H field should plan on about a year, given that weekends, holidays, and individual course progress can stretch that number out. But at the other end of that long tunnel lies a challenging career with plenty of opportunities to make a difference for patients in dire need of assistance.