QUEEN’S UNIVERSITY

DEPARTMENT OF ANESTHESIOLOGY

SUBJECT: Guidelines for the Perioperative Care of Adult Obstructive Sleep Apnea Patients APPROVED BY: Department of Anesthesiology

PAGE 1 of 4 ORIGINAL ISSUE 2001 October REVISION 2007 January

Introduction:

Patients with Obstructive sleep apnea (OSA) are at increased risk of complications including:

· Morbid obesity and other co-morbid diseases

· Hypertension, hypoxemia, hypercarbia, polycythemia, and cor pulmonale

· Increased risk of difficult intubation

· Increased sensitivity to sedative and analgesic medications

· At risk for postoperative apnea, desaturation, and cardiac dysrhythmias

Guidelines:

1. Preoperative Management of Adult Sleep Apnea Patients:

1.1 The Pre-Surgical Screening (PSS) nursing staff will include screening questions about sleep apnea in their preoperative evaluation.

1.2 Patients with symptoms of sleep apnea syndrome (snoring, witnessed apnea, daytime hypersomnolence, morning headache, BMI > 35) that have not had a sleep study should be assessed by an anesthesiologist preoperatively to determine if a sleep study is required prior to surgery.

1.3 If a patient has been diagnosed with OSA, a copy of the most recent sleep study should be included in the PSS package.

1.4 The PSS nurses will notify the surgeon and the OR booking office of OSA patients scheduled for surgery so appropriate arrangements can be made for their postoperative care.

1.5 OSA patients should use their CPAP regularly in the preoperative period.

Note: Whenever possible, surgery should be scheduled at Hotel Dieu Hospital (HDH) to avoid occupying monitored beds at Kingston General Hospital (KGH).

2. Perioperative Management of Adult Sleep Apnea Patients:

2.1 Surgical patients using nasal CPAP must bring their machine with them to the hospital on the day of surgery.

2.2 Most patients with OSA having surgical procedures will require admission postoperatively.

2.3 The anesthesiologist should anticipate the possibility of a difficult airway for patients diagnosed with OSA.

2.4 The use of local anesthesia, peripheral nerve blocks, and neuraxial anesthesia and non-opioid analgesics should be considered.

2.5 Ventilation should be monitored using capnography if moderate or deep sedation is required.

2.6 Patients should be extubated in the sitting position.

2.7 The supine position should be avoided during recovery if possible.

2.8 CPAP should be administered as soon as feasible after surgery and used as continuously as possible for at least 24 hrs.

2.9 The patient’s perioperative risk should be determined based on the severity of OSA, the invasiveness of surgical procedure, and the need for postoperative opioid analgesia. See Table 1.

2.10 The need for postoperative monitoring should be determined based on the perioperative risk score. See Table 2.

2.11 The perioperative risk score is a guideline for the anticipated postoperative monitoring requirement for patients.

2.12 The attending anesthesiologist may use discretion, based on their clinical assessment of the patient, to determine if a different level of monitoring is appropriate.

2.13 An order must be written in the chart for monitoring in the remote oximetry unit or enhanced care unit.

2.14 The remote oximetry monitoring protocol will be followed for all patients monitored on the remote oximetry unit.

2.15 Continuous pulse oximetry monitoring should be maintained until room air oxygen saturation remains above 90% during sleep.

3. Discharge Criteria: Outpatient Surgery for Adult Patients with OSA

3.1. Patients must meet the standard discharge criteria for home-readiness.

3.2. Patients must have a low perioperative risk of complications (Score 1-2).

3.3. Patients must be monitored for at least 4 hours after a general anesthetic.

3.4. Room air oxygen saturation must return to baseline.

3.5. Patient must not have episodes of hypoxemia or airway obstruction if left undisturbed in the recovery area.

3.6. Patients should be monitored for 8 hours after an episode of airway obstruction or hypoxemia while breathing room air in an un-stimulating environment.

Table 1: Obstructive Sleep Apnea Scoring System ASA Task Force on Perioperative Management of Patients with OSA, 2005
A) Severity and Treatment of OSA AHI	Points
Mild 5-15	1
Moderate 16-30	2
Severe > 30	3
Clinical S&S consistent with OSA: assume moderate^1	2
Results from sleep study not available: assume moderate^1	2
CPAP / oral appliance will be used pre and postoperatively	-1
Resting PaCO2 > 50 mmHg	+1
Score A
B) Type of surgery / Anesthesia	Points
Superficial / no sedation	0
Superficial / mod sedation or general anesthesia	1
Peripheral / regional anesthesia with moderate sedation	1
Peripheral / general anesthesia	2
Airway surgery / moderate sedation	2
Major surgery / general anesthesia	3
Airway surgery / general anesthesia	3
Score B
C) Need for postoperative opioids	Points
None	0
Low dose oral opioids	1
High dose oral opioids	3
Parenteral / neuraxial opioids	3
Score C
Total Score: Score for A + greater of either Score of B OR C
Total = A + (B or C)

1. If patients have signs and symptoms consistent with severe OSA (markedly increased BMI, respiratory pauses which frighten the observer, falls asleep within minutes of sitting, reading etc) they should be treated as though they were severe (score 3).

Table 2: Postoperative Management of Adult Patients with OSA^1
Score	Perioperative Risk from OSA	Postoperative Management
1 - 2	Probably low perioperative risk	· Consider ward bed or discharge home if they meet OSA discharge criteria (see page 2)
3 - 4	May be at increased perioperative risk	· Continuous pulse oximetry monitoring by telemetry
5 - 6	May be at significantly increased perioperative risk	· Enhanced Care Unit for continuous pulse oximetry and cardiac monitoring

1. The perioperative risk score is a guideline for the anticipated postoperative monitoring requirements for patients. The attending anesthesiologist may use discretion, based on their clinical assessment of the patient, to determine if a different level of monitoring is appropriate for an individual patient (e.g., risk score of 3 with frequent desaturation and obstruction may require ECU or, risk score of 5 with no desaturation after a prolonged period of observation may be suitable for remote oximetry).