Sedated Patient Apnea Management – Kathryn Hansen

Increasing prevalence for sleep apnea requires health professionals to implement a perioperative and periprocedure sleep apnea management program to reduce patient risk of experiencing an adverse event.2

What Happens When Someone has Sleep Apnea or is at Risk for Sleep Apnea?

Collapse of the upper airway is exacerbated during the perioperative and periprocedural care of a patient, especially if they receive premedication, general anesthesia, anxiolytics, antiemetics, and opioid analgesia.1,2,4,5 Decreased pharyngeal tone reduces ventilation and oxygenation causing hypoxia and hypercapnia, and inhibits the arousal response associated with each incident of apnea. As well, airway obstructions alter and strain heart and lung function.

For delivery of premedication with drugs such as benzodiazepines have muscle relaxing effects on the upper airway musculature, causing a reduction of the posterior pharyngeal airway. As a result, it creates a higher risk for hypoventilation, hypercapnia and hypoxemia necessitating monitoring of oxygenation and ventilation. There is a higher level of risk associated with premedications for procedures completed outside the operating theater as we often underestimate the need for monitoring cardiovascular changes in these patients. Capnography is a non-invasive alternative to ABGs and detects real time changes in carbon dioxide. Additionally, the procedures are performed on an outpatient basis and sent home to recover shortly after completion of the procedure. Readiness for discharge requires careful attention to defining risk factors for sleep apnea or sleep deprivation as a determinate of the readiness for discharge. Routine assessment of standardized discharge criteria will reduce the risk for adverse events at home.

Intra-operatively these patients routinely have more difficult intubations and extubations. They have more potential for adverse events due to hypoxemia, high or low blood pressure, cardiac arrythmias and aspiration pneumonias seen in the post anesthesia recovery unit (PACU). Delay in discharge from the PACU is more likely due to inability to maintain oxygenation at desirable levels for discharge, resulting in increased clinical care for nursing, anesthesiologists and respiratory therapy.

As well, due to the risk for cardiopulmonary arrest, they often require a discharge from PACU to a higher level of care for more intensive monitoring of their ventilation and increased sedation: telemetry, observation care for 7 hours or overnight, and even intensive care.1,2,5

Sleep patterns are changed significantly in patients recovering in a critical care unit. They have frequent interruptions that will increase the clinical effect from sleep deprivation, increasing the impact on sleep-disordered breathing. Hence, treatment with positive air pressure will improve the outcome of patients with cardiac and respiratory co-morbidities. The implications of this are significant, as sleep-disordered breathing is among the most common chronic diseases of middle-aged adults and is frequently undiagnosed and untreated.5

Anesthetics, analgesic and sedative drugs produce increased muscle relaxation of the throat and tongue, and in someone at risk for sleep apnea, may create a blockage of the airway. When administering anesthetics, the surgeon anesthesiologist may need to alter the type and dosages of medications received to protect the breathing responses. As well, management of pain after surgery may require adjustment of doses and pain medication to prevent decreased breathing. As a result, narcotic pain medication or sedation will be balanced to prevent respiratory depression.

Surgery of the upper abdomen, breast, chest, or upper airway exacerbate complications for the patient at risk for sleep apnea by causing increased discomfort when breathing. Respiration is shallow with these surgical procedures and increased pain adds to this discomfort when trying to breath.

When being cared for in a supine position, added risk occurs from the relaxation of the muscles in the posterior airway. Unless contraindicated, the head of the bed should be elevated 20–30 degrees to lessen some of the force placed on the posterior airway.

Use of positive air pressure may be required to support breathing after surgery or after a procedure requiring sedation or pain medication, if depressed respirations due to decreased ventilation become a risk.

Patient Sleep and Apnea Impact?

Patients at risk for sleep apnea have diminished capacity to maintain adequate time in the deep levels of sleep reducing the natural capacity to facilitate healing and pain control. If we are sleep-deprived or not getting adequate sleep, this process works less efficiently and less effectively.

Sleep is a diverse and complex process that includes two sleep states: NREM (non-rapid eye movement) and REM (rapid eye movement) sleep. Each sleep state performs a different type of function, both are important to overall daytime effectiveness.

Going to sleep is like descending a stairway. As brain activity slows we transition into NREM sleep until we reach deep sleep. When in deep sleep, pulse and respiratory slows, blood pressure drops, muscles relax, and growth hormone is released to facilitate physical healing, enhanced pain control, and physical rejuvenation.

About every 90 minutes we ascend out of deep sleep into REM sleep, a very active state of sleep.

REM sleep is very important since our breathing, blood pressure, pulse rate, and blood flow to the brain all increase during this phase. During REM sleep our peripheral muscles are atonic.

REM presents a challenge to sustain breathing, oxygenation, and cardiac stability in patients at risk for sleep apnea. The clinical functions all become more difficult to sustain: apneic events are longer during REM, oxygen desaturation is lower during REM, and more cardiac arrhythmias are noted during REM sleep. Since the longest REM period occurs in the early morning hours between 4:00 – 6:00 AM, we need to closely monitor our patients during this time to protect them from an adverse event.

Every hospital, outpatient surgery center and procedure clinic or practice that provides sedation for patient surgeries and procedures needs to implement sedation-related apnea management guidelines. This program will reduce patient risk, reduce medical liabilities and create additional sleep apnea patient disease management revenue streams for related health professionals.7

Kathryn Hansen, BS, REEGT,
CPC Senior
Advisor Sleep Center Management Institute

References

1. den Herder C, Risks of general anaesthesia in people with obstructive sleep apnea. BMJ 2004; 329: 955–959.

2. Estfan B, Respiratory function during parenteral opioid titration for cancer pain. Palliative Medicine. 2007; 21: 81–86.

3. Feinsilver SH, Asleeping giant: sleep-disordered breathing in the coronary care unit. Chest 2005; 127: 4–5.

4. Morgenthaler TI, Practice parameters for the use of autotitrating continuous positive airway pressure devices for titrating pressures and treating adult patients with obstructive sleep apnea syndrome: an update for 2007. An American Academy of Sleep Medicine report. Sleep. 2008 Jan 1; 31 (1): 141–147.

5. Practice Guidelines for the Perioperative Management of Patients with Obstructive Sleep Apnea. A report by the American Society of Anesthesiologists Task Force on Perioperative Management of Patients with Obstructive Sleep Apnea. Anesthesiology 2006; 104: 1081–1093.

6. Preventing and managing the impact of anesthesia awareness. Sentinel Event Alert Joint Commission on Accreditation of Healthcare Organizations October 6, 2004; Issue 32.

7. www.sedationrelatedapneamanagement.com

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