Patient Safety Tip of the Week
June 7, 2016
CPAP for Hospitalized Patients at High Risk for OSA
Most of our focus on
obstructive sleep apnea (OSA) in the hospitalized patient has focused on the
perioperative period (see list of prior columns below). But OSA prevalence is
also high in patients admitted to medical (non-surgical) units. In our
July 2010 Patient Safety Tip of the Week Obstructive
Sleep Apnea in the General Inpatient Population we noted that screening
with the STOP and Berlin questionnaires found a potential 60% prevalence of obstructive sleep apnea in patients
admitted to general medicine units in an urban academic hospital, most of whom
had never been diagnosed with OSA. Many of the patients were obese and most had
comorbidities. A high percentage of these patients received intravenous
narcotics or were prescribed benzodiazepines or both and none of these received
any supplemental respiratory monitoring. The study highlights the risk of using
such medications in potentially high risk patients and also highlights the
potential benefits of using simple tools like STOP in identifying potential OSA
candidates.
In our prior columns
weve also discussed the relative paucity of evidence for use of CPAP in hospitalized
patients deemed at high risk for OSA by screening.
Now a new study
addresses both issues. Sharma and colleagues (Sharma
2016) used the STOP tool to screen
obese patients (BMI ≥ 30 kg/m2) admitted to select medical (non-surgical)
services and sorted them into high- and low-risk for OSA groups. They found
that rapid response system (RRS) activations were significantly more frequent
in those patients in the high-risk group. Moreover, high-risk patients who were
put on PAP (CPAP, BiPAP, or APAP) and were compliant
with PAP were significantly less likely to have RRS activations than those
high-risk patients not compliant with PAP or not receiving PAP.
They screened over
2500 inpatients over a 15-month period and found that 76% were at high risk for
OSA (Yes answer to 2 or more of the 4 questions in STOP). Admitting teams
were notified when a high risk designation was made and whether to get a
Pulmonary/Sleep Medicine consultation was left up to the admitting team.
Slightly less than half the high-risk group received such consultations. Note
that patients with known OSA were excluded from the analysis. Of those who
received consultations, PAP (usually CPAP but BiPAP
or APAP for some) was recommended for almost three quarters. Almost 70% of the
latter were deemed compliant with PAP (based on at least 4 hours PAP use during
sleep noted by respiratory therapists).
The RRS activation
rate per 1000 admissions was 43.6 for patients at high risk for OSA vs. 25.9 in
low-risk patients. For PAP-compliant patients the RRS activation rate per 1000
admissions was 16.99 vs. 53.4 in PAP non-compliant patients. In addition, mean
hospital LOS (length of stay) was significantly higher in the high risk group
(7.52 vs. 6.98 days). The study implies (but does not actually include the
data) that those patients compliant with PAP had lower mean LOS.
The study was an
observational study and because it was not randomized there may have been
biases or confounding factors that affected the decision to use PAP. As the
authors appropriately note, it is also not surprising that patients at high
risk for OSA would have longer LOS since they also likely have more
comorbidities.
But this study
certainly lays the foundation for larger randomized controlled studies. While
it would have been useful to have data on other outcomes, the beneficial effect
of PAP on reducing RRS activations and LOS would seem to justify further study
not only for patient safety concerns but also potentially for the bottom line
of hospitals.
Weve always
strongly advocated screening pre-op patients for OSA risk with the STOP-Bang
tool. This study would suggest we might extend such screening to all inpatients
who have at least a high BMI. We already recommend any hospital inpatient who
will be receiving opioids be screened with the STOP-Bang questionnaire. Though
we recommend universal use of capnography for inpatients on opioids, those
hospitals with limited resources should at least be using capnography or
otherwise monitoring for apnea in patients at high risk for OSA who are
receiving opioids. The current study is also another one on the pro- side for
using PAP in hospitalized patients deemed at high risk for OSA, though further definitive
research is needed.
Our prior columns on
obstructive sleep apnea in the perioperative period:
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
References:
Sharma S, Chowdhury A, Tang L, et al. Hospitalized Patients
at High Risk for Obstructive Sleep Apnea Have More Rapid Response System Events
and Intervention Is Associated with Reduced Events. PLOS One 2016; Published:
May 11, 2016
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0153790
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