Circulation 122,210 • Volume 31, No. 1 • June 2016   Issue PDF

Use of Capnography during Moderate Sedation by Non-Anesthesia Personnel in Various Clinical Settings

Celestine Okwuone, MD

Letter to the Editor:

To the Editor:

Capnography is a waveform that shows evidence of breathing; it monitors the partial pressure of carbon dioxide (CO2) in the exhaled air, also known as end tidal CO2 expressed in a graphical pattern on the monitor. It is used quite extensively in anesthesia and critical care settings.

Capnography provides information of breath-to-breath ventilation, the EtCO2 can predict hyperventilation from inadequate analgesia or sedation, as well as hypoventilation from over-sedation or other potentially life-threatening causes. The diagnosis of respiratory difficulty from various obstructive mechanisms can be deduced from capnography. Capnography has been known to assist in predicting and averting impending respiratory arrest situations in hospitalized, critically ill patients who show significantly elevated CO2 levels (hypercapnia).

Moderate sedation is the use of sedative medications (anxiolytics­—midazolam, diazepam; opioids—morphine, fentanyl; anesthetic solutions—propofol, etomidate, ketamine) to provide patients with comfort, relaxation, amnesia, and analgesia in order to perform certain clinical procedures in various settings like cardiac catheterization laboratories, endoscopy suites, radiology, emergency rooms, ambulatory surgical centers, and doctors’ offices.

Anesthesia personnel usually provide moderate sedation for procedures and safe techniques are encouraged with capnography being of paramount importance alongside other standard monitoring techniques (pulse oximetry, blood pressure, EKG). Capnography during moderate and deep sedation was added by the American Society of Anesthesiologists as part of the Standards for Basic Anesthetic Monitoring, effective July 1, 2011.

Capnography use in 100% of moderate and deep sedation cases in hospitals should be encouraged. The monitoring of ventilation using capnography is vital to titrating sedatives for which different patients have variable levels of sensitivity. It will provide early warning signs of adverse respiratory events as well as assist in better patient care and outcomes.


Capnography should be a standard monitor in all situations of health care management in which moderate sedation is used, regardless of which health care provider is administering the sedation.

Celestine Okwuone, MD Brandywine Hospital Coatesville, PA