American Sleep Apnea Association Archives - The anesthesia consultant

Author
Recent Posts

Physician anesthesiologist at Stanford at Associated Anesthesiologists Medical Group

Richard Novak, MD is a Stanford physician board certified in anesthesiology and internal medicine.Dr. Novak is an Adjunct Clinical Professor in the Department of Anesthesiology, Perioperative and Pain Medicine at Stanford University, the Medical Director at Waverley Surgery Center in Palo Alto, California, and a member of the Associated Anesthesiologists Medical Group in Palo Alto, California.
emailrjnov@yahoo.com

Latest posts by THE ANESTHESIA CONSULTANT (see all)

STANFORD EMERGENCY MANUAL POCKET VERSION - 28 Sep 2023
CALL FROM THE JAILHOUSE REVIEW: “I LOVED HOW THE BOOK WAS CRAFTED.” - 15 Sep 2023
CONTINUOUS FINGER-CUFF BLOOD PRESSURE MONITORING - 28 Aug 2023

This week I filmed a 26-minute question and answer video for the American Sleep Apnea Association regarding the topic of sleep apnea and surgery. The video provides answers to individuals who have obstructive sleep apnea and are contemplating surgery and anesthesia. The link to this video is HERE.

Obstructive sleep apnea (OSA) is a common medical condition which affects 17% of males aged 50 to 70 years, and 9% of females in the same age group. Patients with OSA frequently present for surgery, and all anesthesia professionals must be aware of the risks involved with anesthetizing OSA patient. This video takes the opposite viewpoint and is directed toward patients with OSA, with the goals that they may understand their risks during anesthesia and surgery, and they may understand a physician anesthesiologist’s role in providing state of the art medical care to them before, during, and after surgery.

To simplify your search for information within the lecture, the outline for the questions presented in the video is as follows:

I. PREOPOPERATIVE CARE:

Let’s talk about the diagnosed sleep apnea patient and pre-operative assessment for upcoming surgery: The diagnosis of OSA is based on the presence of symptoms, such as disturbed sleep, snoring, hypertension, and also the frequency of sleep-related respiratory events during a sleep study or home sleep apnea testing. OSA is characterized by “recurrent upper airway collapse during sleep that leads too reduced or complete cessation of airflow, despite ongoing breathing efforts.”

The severity of OSA is typically characterized by the apnea-hypopnea index (AHI). The AHI is the number of apneic and hypopneic episodes the patient has per hour of sleep. Hypopnea means abnormally slow or shallow breathing. Apnea means a period of no breathing. (See the question on sleep studies below.)

How/why is it important to talk to all doctors involved about all your preexisting health conditions? And disclosure of meds? The medical history is critical in the preoperative assessment of patients. For OSA patients, pertinent comorbidities include hypertension, obesity, heart disease, lung disease, and a list of prescription medications including sedatives or pain relievers.

Preoperative sleep study results matter to the anesthesiologist. Most sleep centers use an AHI between 5 and 10 events per hour as a normal limit.

The OSA disease classifications are as follows:

Mild Disease: AHI of 5 to 15 events per hour

Moderate Disease: AHI of 15 to 30 events per hour

Severe Disease: AHI of greater than 30 events per hour

STOP-BANG questionnaires. Many patients who present for surgery do not have a diagnosis of OSA, and most patients do not have a preoperative sleep study. A STOP-BANG questionnaire contains 8 questions, and the answers to these questions help us screen for probable OSA. A patient is at high risk for OSA if they answer 5 questions positively, and re at intermediate risk if they answer 3-4 questions positively. The 8 questions include the presence of preoperative:

SNORING

CHRONIC TIREDNESS

OBSERVED EPISODES OF STOPPED BREATHING DURING SLEEP

HYPERTENSION

A BODY MASS INDEX (BMI) OF > 35

AGE> 50

NECK CIRCUMFERENCE > 15¾ INCHES

MALE GENDER.

What about other treatments for apnea, oral appliance, maxillary distractors, implants, positional devices, etc….

II. INTRAOPERATVE CARE:

What’s happening now with COVID and surgeries, and CPAP (Continuous Positive Airway Pressure) units?

Risks of anesthesia and the OSA patient? All anesthesia care follows the priorities of Airway-Breathing-Circulation, or A B C. Many patients with OSA are at an increased risk for complications during airway management. For the anesthesiologist, mask ventilation, direct laryngoscopy, endotracheal intubation, and fiberoptic visualization of the airway can be more difficult in patients with OSA. Patients with OSA are at increased operative risk during and after surgery.

Type of surgery: non-airway surgery vs. airway surgery to treat OSA. Many OSA patients present for non-airway procedures such as orthopedic surgeries, abdominal surgeries, or endoscopies and colonoscopies. Other OSA patients present for procedures designed to improve their sleep apnea. These procedures involve surgical modification of the upper airway. These airway surgery patients require a different set of intraoperative and postoperative standards and concerns for the anesthesiologist. Commonly performed airway procedures for OSA include uvulopalatopharyngoplasty (UPPP), uvulopalatal flap surgery, tonsillectomy and adenoidectomy, genioglossus advancement, and maxillomandibular advancement. My Stanford surgical colleagues Dr. Nelson Powell and Dr. Robert Riley began to develop new surgical procedures for OSA in the 1980s. Drs. Powell and Riley were educated both as MDs and as dentists, and believed that the tongue base, not previously identified as a potential area of obstruction, was partially responsible for failures of the UPPP procedure to cure OSA. They pioneered the procedure of maxillary (upper jaw) and mandibular (lower jaw) advancement to increase the diameter of the upper airway.

Are sleep apnea patients monitored differently?

Apnea is a breathing disorder. Do the medicines you use effect apnea patients differently?

III. POSTOPERATIVE CARE:

Are sleep apnea patients monitored differently in the Post Anesthesia Care Unit?

Can apnea patients use their CPAP units during surgery/ in recovery?

If you cannot use your CPAP in recovery, how do medical professionals monitor my breathing?

Are OSA patients discharged home after surgery, or are they kept in the hospital?

The answers to these four questions are discussed, with the caveat that for surgery involving surgical modification of the upper airway, postoperative patients require a different set of intraoperative and postoperative standards and concerns for the anesthesiologist, often including postoperative hospitalization to monitor for potential acute airway complications.