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Its been over 10 years since our August 17,
2010 Patient Safety Tip of the Week Preoperative
Consultation Time to Change in which we recommended screening for
obstructive sleep apnea (OSA) as one of the 3 most important preoperative
considerations (the other 2 being screening for delirium risk and frailty). OSA
is, of course, one of the biggest risk factors for opioid-induced respiratory
depression (OIRD), which may occur in both surgical and medical patients. This
month there were several key studies published in Anesthesia and Analgesia on
OSA in the perioperative period.
The Society of Anesthesia and Sleep Medicine partnered
with the Anesthesia Closed Claims Project to create an international registry
of unexpected critical events occurring in patients with OSA. Bolden et al.
published a comprehensive analysis of 66 cases submitted to the OSA Death and Near
Miss Registry who had procedures under general anesthesia or combined general
plus regional anesthesia (Bolden
2020). Most patients (83%) had a confirmed diagnosis
of OSA and the rest had been screened as high risk for
OSA. Sixty-five percent of patients died or had brain damage; the remaining 35%
experienced other critical events.
Fifty-six percent of
events occurred on the hospital ward and 21% occurred at home after
discharge. The majority
of events occurred
within the first 24 postoperative hours. Inadequate respiratory monitoring,
no supplemental oxygen, lack of personnel closely observing the patient, and
coadministration of sedatives and opioids were all associated with worse
outcomes.
Of the events that occurred at home, half occurred
within 24 hours of procedure end. Notably, these patients were ASA physical
status III or IV, and all had received opioids within 24 hours of the
event.
Lack of monitoring was an important
contributing factor. Whereas most patients in the PACU, stepdown unit, or ICU were
monitored, only 57% on the ward and none at home were monitored. Monitoring consisted
of intermittent or continuous pulse oximetry. There were no reports of chest
impedance or end-tidal carbon dioxide monitoring (capnography).
52% of the patients were receiving supplemental
oxygen at the time of the event. But only 7.5% had a positive airway pressure
(PAP) device at the time of the event. Nearly all PACU or ICU/step-down unit
events were witnessed, with most ward or at-home cases not witnessed.
As youd expect, death
or brain damage was less common when the event was witnessed. It was also less
common when patients were receiving supplemental oxygen or when patients had respiratory
monitoring.
There was no evidence for an association
between the outcome and sex, age, body mass index (BMI), ASA physical status,
OSA diagnosed versus suspected, presence of cardiovascular or pulmonary comorbidities,
or hours between anesthesia end and the event. There was also no evidence for
an association between severity of OSA and outcome. There was no evidence for
an association between MME and outcome.
There was, however, a strong association of death
or brain damage with use of sedatives in addition to opioids compared to
patients receiving opioids without sedatives (OR = 4.133).
Timing appears to be very
important. The majority of events occurred
within the first 24 postoperative hours. Note that a previous systematic review
of opioids and OSA (Cozowicz 2018) also found the initial
24 hours after opioid administration appear to be most critical with regard to life-threatening
OIRD.
Bolden and colleagues called for special
attention to the fact that 21% of these events occurred at home. They stress
that, with the trend toward ambulatory rather than inpatient surgery, OSA patients
will increasingly have ambulatory surgery and potentially be at risk for
catastrophic outcomes after discharge. They also note that, despite use of
CPAP, patients may still experience postoperative hypoxic events.
Though they found no statistically
significant association between severity of OSA and outcome, they note that lack
of an association might be attributed to the small sample size. They cite two
large studies which demonstrated that patients with severe OSA had higher risk for
postoperative adverse outcomes. They also note the lack of an association
between MME and outcome might be attributable to the small sample size.
The Postoperative Vascular Complications in
Unrecognized OSA (POSA) study (Chan
2019) was a large, multicenter,
prospective observational cohort study designed to evaluate the association
between the results of preoperative sleep testing for OSA and 30-day postoperative
cardiovascular outcomes among patients undergoing noncardiac surgery. Rates of
undiagnosed OSA were high. 37.1% of patients had mild OSA, 19.3% moderate OSA, and
11.2% severe OSA. Postoperative cardiovascular events occurred in 19.3% of patients.
Severe OSA was significantly associated with a higher rate of postoperative cardiovascular
events (adjusted hazard ratio 2.23) but the associations for mild or moderate
OSA did not reach statistical significance.
They found a higher risk for postoperative
cardiovascular events with longer duration of postoperative oxygen desaturation
less than 80%. No significant association was observed between the type of
anesthesia or supplemental oxygen therapy and perioperative outcomes. Somewhat
surprisingly, they found no significant association with postoperative opioids.
In an editorial accompanying the Chan study, Auckley and Memtsoudis (Auckley 2019) state Although the
effectiveness of these interventions is poorly studied, some suggested
strategies may include enhanced monitoring (oximetry, CO2 monitoring), conservative
measures (elevating the head of the bed, avoiding supine sleep position,
minimizing opioids), and specific OSA therapies such as the perioperative use
of positive airway pressure.
Since the vast majority of
patients with OSA are undiagnosed at the time of surgery, we rely heavily on screening
tools to identify patients at high risk for OSA. Multiple screening tools
are available, including the ASA Check List, the Berlin Questionnaire, the STOP
and STOP-Bang Questionnaires, the BOSTN tool, and the P-SAP Score.
The most frequently used tool is the STOP-Bang
questionnaire. Sequin et al. (Seguin
2020) note that STOP-Bang has
a high sensitivity at scores ≥3, but its specificity is moderate,
particularly for scores of 3-4. So, they prospectively studied 115 surgical
patients with preoperative STOP-Bang scores of 38. Patients were categorized
into 2 subgroups: patients with an intermediate (STOP-Bang 34) or a high risk
of OSA (STOP-Bang 58). Patients had a portable polygraph study at their homes (recording
blood oxygen saturation (Spo2), electrocardiogram, movements of the chest and
abdomen, and breathing events via a nasal cannula overnight).
They concluded that the STOP-Bang
questionnaire detected moderate-to-severe OSA patients when scores reached 58.
However, STOP-Bang scores of 34 and alternative scoring models with specific
combinations of factors failed to improve the screening of these patients.
They suggest that using the lower STOP-Bang cutoff
may result in unnecessary referrals for sleep studies. As an example, they note
that a 55-year old man with a history of hypertension scores a 3 on STOP-Bang,
even though he has no OSA symptoms or obesity.
One alternative
screening tool we have previously highlighted is the BOSTN tool (see our April 2019 What's New in the Patient Safety World
column New Simple OSA Screening Tool: BOSTN). Raub et al. (Raub 2020) recently assessed use of the BOSTN score
and a perioperative pathway for management of patients with suspected obstructive
sleep apnea (OSA) in patients undergoing noncardiac surgery. Their results were
somewhat surprising. Patients at high risk of OSA required postoperative mechanical
ventilation less frequently and were hospitalized for shorter periods of time, despite
higher odds of early post-extubation oxygen desaturation.
Those authors note that some previous studies
have shown lower perioperative mortality rates for patients at high risk for OSA but others have shown higher rates. In attempt to
explain the seeming paradox that lower mortality rates might be seen, they note
that, in OSA, intermittent hypoxia and ischemic preconditioning have been
postulated as potential mechanisms underlying the protective effects of obesity
on mortality.
Our January
2020 What's New in the Patient Safety World column Opioids and Apnea: Not Just
Surgical Patients
noted that opioid-induced respiratory depression is not just a problem in
surgical patients. The OpiatesHF Study (Niroula 2019) showed that a large percentage
of inpatients with acute heart failure
and sleep disordered breathing received opioids. Among those with an AHI
greater than or equal to 10/h, escalation of care occurred in 26% of those who
received opiates versus 4% of those who did not.
Khanna et al. (Khanna
2020) recently reported the
results of the PRODIGY trial, a prospective, observational trial of blinded
continuous capnography and oximetry conducted at 16 sites in the United States,
Europe, and Asia aimed at prediction of opioid-induced respiratory depression
on inpatient wards. Over 1300 patients on general care floors were receiving
parenteral opioids (note: patients enrolled in the US were non-surgical
patients and those enrolled elsewhere were postsurgical).
46% had one or more episodes of respiratory
depression. Patients with ≥1 episode of respiratory depression were 2.5
times more likely to require some rescue intervention, including activation of
a rapid response team. They also experienced 3 days longer mean hospital length
of stay, which adds to costs.
The authors suggest that implementation of
the PRODIGY score could determine the need for continuous monitoring and may be
a first step to reduce the incidence and consequences of respiratory compromise
in patients receiving opioids on the general care floor. This could certainly
be welcome in those facilities that are resource-poor and cannot afford to do
universal continuous monitoring with these modalities.
In the editorial
accompanying the Khanna study, Prielipp et
al. (Prielipp 2020) note that, although OIRD can occur at any
time, the highest incidence has been reported in the first 624 postoperative
hours and that a majority of fatalities due to OIRD occur at night (midnight to
6 am), underscoring the likely contribution of decreased vigilance and
availability of night shift staff. They also note other risk factors for
development of OIRD: age >65 years, ASA PS ≥III, presence of OSA,
cardiac or neurologic disease, diabetes mellitus, hypertension, use of PCA,
concomitant use of sedative drugs, different routes of opioid administration,
and multiple prescribers of opioids. They also note that, although OIRD can occur
following any surgical procedure, the highest incidence appears to be in orthopedic
patients, likely reflecting their older age.
Prielipp et al. acknowledge the potential utility of
stratifying such patients by risk. However, they also point out the sobering
statistic that 26%
of patients who experience respiratory depression were not
identified.
The Society of Anesthesia and Sleep Medicine has
published guidelines on preoperative screening and assessment of adult patients
with obstructive sleep apnea (Chung
2016) and the intraoperative management
of adult patients with obstructive sleep apnea (Memtsoudis 2018). A
recent overview of OSA diagnosis and management (Gottlieb
2020) has limited discussion
on OSA patients undergoing surgery. But it does state that patients with known
OSA should inform all clinicians involved in their perioperative care,
including their surgeon and anesthesiologist, of their OSA diagnosis. It
recommends patients using PAP should continue this therapy in the perioperative
period and those with known or suspected OSA should be monitored closely during
the perioperative period, and the use of opiate analgesics should be minimized
or avoided if possible.
Our
prior columns on obstructive sleep apnea in the perioperative period and other
acute settings:
June 10, 2008 Monitoring
the Postoperative COPD Patient
August 18, 2009 Obstructive
Sleep Apnea in the Perioperative Period
August 17, 2010 Preoperative
Consultation Time to Change
July 2010 Obstructive
Sleep Apnea in the General Inpatient Population
July
13, 2010 Postoperative Opioid-Induced Respiratory
Depression
November 2010 More on Preoperative Screening for
Obstructive Sleep Apnea
February
22, 2011 Rethinking Alarms
November
22, 2011 Perioperative Management of Sleep Apnea
Disappointing
March 2012
Postoperative
Complications with Obstructive Sleep Apnea
May
22, 2012 Update on Preoperative Screening for Sleep
Apnea
February
12, 2013 CDPH: Lessons Learned from PCA Incident
February
19, 2013 Practical Postoperative Pain Management
March
26, 2013 Failure to Recognize Sleep Apnea Before Surgery
June
2013 Anesthesia Choice for TJR in Sleep Apnea
Patients
September
24, 2013 Perioperative Use of CPAP in OSA
May
13, 2014 Perioperative Sleep Apnea: Human and
Financial Impact
March
3, 2015 Factors Related to Postoperative Respiratory
Depression
August
18, 2015 Missing Obstructive Sleep Apnea
June
7, 2016 CPAP
for Hospitalized Patients at High Risk for OSA
October
11, 2016 New Guideline
on Preop Screening and Assessment for OSA
November
21, 2017 OSA,
Oxygen, and Alarm Fatigue
July
17, 2018 OSA
Screening in Stroke Patients
April
2019 New
Simple OSA Screening Tool: BOSTN
January
2020 Opioids and Apnea: Not Just
Surgical Patients
October
6, 2020 Successfully Reducing
Opioid-Related Adverse Events
Other
Patient Safety Tips of the Week pertaining to opioid-induced respiratory
depression and PCA safety:
References:
Bolden N, Posner K, Domino KB, et al. Postoperative
Critical Events Associated With Obstructive Sleep
Apnea: Results From the Society of Anesthesia and Sleep Medicine Obstructive
Sleep Apnea Registry. Anesthesia & Analgesia 2020; 131(4): 1032-1041
Cozowicz C, Chung
F, Doufas AG, et al. Opioids for Acute Pain Management
in Patients With Obstructive Sleep Apnea: A Systematic
Review. Anesthesia & Analgesia 2018; 127(4): 988-1001
Chan MTV, Wang CY, Seet
E, et al. Association of Unrecognized Obstructive Sleep Apnea With Postoperative Cardiovascular Events in Patients
Undergoing Major Noncardiac Surgery. JAMA 2019; 321(18): 1788-1798
https://jamanetwork.com/journals/jama/fullarticle/2733209
Auckley D, Memtsoudis S. Unrecognized Obstructive Sleep Apnea and
Postoperative Cardiovascular Complications: A Wake-up Call. JAMA 2019; 321(18):
1774-1776
https://jamanetwork.com/journals/jama/article-abstract/2733190
Seguin L, Tamisier
R, Deletombe B, et al. Preoperative Screening for
Obstructive Sleep Apnea Using Alternative Scoring Models of the Sleep Tiredness
Observed Pressure-Body Mass Index Age Neck Circumference Gender Questionnaire:
An External Validation. Anesthesia & Analgesia 2020; 131(4): 1025-1031
Raub D, Santer P, Nabel S, et al. BOSTN
Bundle Intervention for Perioperative Screening and Management of Patients With Suspected Obstructive Sleep Apnea: A Hospital Registry
Study, Anesthesia & Analgesia 2020; 130(5): 1415-1424
Niroula A, Garvia V, Rives-Sanchez M, et al. Opiate Use and Escalation
of Care in Hospitalized Adults with Acute Heart Failure and Sleep-disordered
Breathing (OpiatesHF Study). Ann Am Thorac Soc 2019; 16(9): 1165-1170
https://www.atsjournals.org/doi/abs/10.1513/AnnalsATS.201902-100OC
Khanna AK, Bergese
SD, Jungquist CR, et al. on behalf of the PRODIGY Group
Collaborators. Prediction of Opioid-Induced Respiratory Depression on
Inpatient Wards Using Continuous Capnography and Oximetry: An International
Prospective, Observational Trial, Anesthesia & Analgesia 2020; 131(4): 1012-1024
Prielipp, Richard
C. MD, MBA, FCCM*; Fulesdi, Bela MD, PhD; Brull, Sorin J. MD, FCARCSI (Hon) Postoperative
Opioid-Induced Respiratory Depression: 3 Steps Forward, Anesthesia &
Analgesia: October 2020 - Volume 131 - Issue 4 - p 1007-1011
Chung F, Memtsoudis
SG, Ramachandran SK, et al. Society of Anesthesia and Sleep Medicine guidelines
on preoperative screening and assessment of adult patients with
obstructive sleep apnea. Anesth
Analg 2016; 123: 452-473
Memtsoudis SG, Cozowicz C, Nagappa M, et al.
Society of Anesthesia and Sleep Medicine guideline on intraoperative management
of adult patients with obstructive sleep apnea. Anesth
Analg 2018; 127: 967-987
Gottlieb DJ, Punjabi NM. Diagnosis and
Management of Obstructive Sleep Apnea: A Review. JAMA 2020;3 23(14):1389-1400
https://jamanetwork.com/journals/jama/fullarticle/2764461
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