Conscious sedation is routinely used with patients so that they can tolerate procedures that may cause them discomfort, anxiety, or pain. Some of the tests and procedures conscious sedation may be used for are:

  • Breast biopsy
  • Dental prosthetic or reconstructive surgery
  • Minor bone fracture repair
  • Minor foot surgery
  • Minor skin surgery
  • Plastic or reconstructive surgery
  • Procedures to diagnose and treat some stomach (upper endoscopy), colon (colonoscopy), lung (bronchoscopy), and bladder (cystoscopy) conditions.

Conscious sedation may also be used with pediatric patients or adult patients who may have difficulty remaining still for certain tests and medical procedures.


Risks of over-sedation

Although procedures in which conscious sedation are used are generally safe for patients, the American Society of Anesthesiologists cautions that there are risks to over-sedating or under-sedating patients:

“At times, these sedation practices may result in cardiac or respiratory depression, which must be rapidly recognized and appropriately managed to avoid the risk of hypoxic brain damage, cardiac arrest, or death. Conversely, inadequate sedation analgesia may result in undue patient discomfort or patient injury because of lack of cooperation or adverse physiologic or psychological response to stress.”

White Memorial Medical Center in Los Angeles has experienced a “better than 50% reduction in calls of rapid responses”, according to Richard Kenney, MSM, RRT, NPS, ACCS, RCP (Director, Respiratory Care Services, White Memorial Medical Center).

To better understand what Adventist Health hospitals have done to reduce rapid response calls and improve patient safety and health outcomes, the Physician-Patient Alliance for Health & Safety (PPAHS) interviewed Mr. Kenney.

In this interview titled, “Avoiding Respiratory Depression During Conscious Sedation,” Mr. Kenney offered these 5 keys:


1. Recognize that each patient reacts differently to opioid dosages

Caregivers should be concerned about the risk of respiratory depression even during conscious sedation. Before commencing procedures that entail conscious sedation, be aware that each patient may react differently to the same opioid dosage. In the words of Mr. Kenney,

“We know that patients react differently to medications. Some react lightly and some have some pretty severe reactions to it. Opioids at certain dosages can lead to respiratory depression, as we know. If too depressed, the risk of respiratory failure could occur and jeopardize the patient’s health. If it goes unnoticed by those monitoring that patient, for example, the patient may appear to be OK at a simple glance, but when the respiratory rate drops, we’re now faced with a compromised patient. So, it’s important that we pay particular attention to those patients receiving opioids.”

As The Joint Commission advised in Sentinel Event Alert #49 “Safe use of opioids in hospitals,” patients should be screened for the risk of respiratory depression:

oversedation and respiratory depression


2. Don’t rely on pulse oximeter monitoring

Clinicians have cautioned against relying upon pulse oximeter monitoring and a breach of the 90% threshold level. As Paul Curry, MD wrote in “Improving the Safety of Post-Surgical Care”:

“…while effective in the OR, a 90% alarm threshold will leave hospital post-surgical floors much more error prone and ineffective by disallowing early detection of the common critical conditions that occur in those settings, including sepsis, pulmonary embolus, congestive heart failure, aspiration, and opioid-associated respiratory depression.”

From his 30 years experience as a respiratory therapist, Mr. Kenney also cautions against this over-reliance:

“Pulse oximetry is only designed to detect oxygen saturation and heart rate, not the ventilatory status of a patient. By the time oxygen saturation has dropped and the alarms are alarming, you’ve gotten beyond that threshold of the patient having a quick recovery from that.

I’ve always been and will always state that one should never rely on the use of pulse oximetry as the only means of monitoring a patient’s condition. Remember that monitors are only a tool to use, but the real monitoring is looking at the patient to see the readings that you’re looking at match the patient’s condition.”


3. Monitoring with capnography provides a more accurate assessment of patient’s ventilatory status

Mr. Kenney discussed the changes that his hospital has done, including monitoring patients undergoing conscious sedation with capnography:

“The Joint Commission has made recommendations to include end tidal CO2 monitoring during conscious sedation procedures. We use CO2 monitoring in the OR during cases, so why not use that at the same time during conscious sedation procedures.”

Patient-controlled analgesia (PCA) pumps are used extensively to help patients manage their pain. Mr. Kenney said that the PCA pumps used at White Memorial Medical Center have been integrated capnography monitoring. The benefits of having in one device both PCA and capnography monitoring are extensive, according to Mr. Kenney,

“In my last few years of my career with the introduction of the PCA pump and the ability to be able to self-dose with the same pump, we’ve received a lot of rapid response calls due to the changing condition of a patient. That’s very concerning. And so, our organization has provided us with a device—an end tidal CO2 monitoring device that attaches to that PCA pump—the patient controlled analgesia device…

With the use of the end tidal CO2 device, when those parameters are reached, this is indicating that the patient is overly sedated, and it will pause the pain control pump and it cannot be reactivated until a nurse or respiratory therapist has gone to the patient’s bedside and has physically evaluated that patient to make sure that they are awake and responsive and are able to answer questions appropriately.”


4. Ensure that nursing and respiratory therapists are working as a team

Patient safety is a team effort. Mr. Kenney emphasized the close working relationship between nurses and respiratory therapists at his hospital in ensuring optimal patient care:

“As you know, nurses are really kind of being inundated with so many things today with electronic documentation and so on and so forth, and the respiratory therapists want to do their part. So, we made an agreement with nursing group that respiratory therapists will be one hundred percent responsible for the application and monitoring of the end tidal CO2 devices, and we will round on those patients every four hours, as the nurses round every four hours as well. So, the patient is basically being seen every two hours. Respiratory will be responsible for the documentation in the electronic medical record of that rounding. At the same time, both the nurses and the respiratory therapists are there to educate the patient and the family on the precautions of using the pain pumps.”


5. Using capnography monitoring has reduced rapid response calls by more than 50%

The combination of using both capnography and pulse oximetry monitoring has delivered a huge win-win for Mr. Kenney’s hospital and for patient safety. As he describes,

“The combination of the two allows us to cover, if you will, our bases, meaning that we can monitor the respiratory rate, the heart rate, and cases of the pulse oximetry. It gives us a better reading knowing that their profusion status is good. What I think is even better today than just a few years ago, is that the end tidal CO2 device and the pulse oximetry were two separate machines that took up a lot of space on the patient’s bedside table with long cables running all over the place but, with today’s devices that we’re currently using have the pulse oximetry and the end tidal CO2 in one device. They have a built in algorithms that will let the respiratory therapist or the nurse taking care of that patient give them the advantage of knowing that something is starting to happen with this patient because these two parameters are not matching in a way that they should, and you need to come in and evaluate your patient. And so because of that, we can intervene much quicker for patient safety than we did in the past; so the combination of being able to monitor both oxygen and ventilatory status is a win-win for the patient.”

The result has been a significant reduction in rapid response calls

“since the implementation of this combination of monitoring the patient, the number of rapid responses to those areas where the patient comes out with that PCA pump have—I want to say—a better than 50% reduction in calls of rapid responses.”

Michael Wong, JD
Michael Wong, JD is the founder and Executive Director of the Physician-Patient Alliance for Health and Safety (PPAHS). He has been at the forefront in driving practical solutions that reduce healthcare costs, decrease medical errors, and improve patient health outcomes. He has been particularly active in these areas that most affect patient safety: • Improving patient adherence (i.e. helping patients to take their medications as prescribed by their physicians) • Enhancing patient access to healthcare • Reducing medical errors (PPAHS), is an advocacy group of physicians, patient advocates, and healthcare organizations. Supporters of and commenters for PPAHS include highly respected physicians and healthcare organizations, including the The Joint Commission, Anesthesia Patient Safety Foundation, Anesthesia Quality Institute, Johns Hopkins School of Medicine, Harvard Medical School, Stanford University School of Medicine, and the Cleveland Clinic.


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