Baylor University Medical Center Proceedings January 2014, Volume 27, Number 1 | Page 15

other signs of a difficult airway, and those at an increased risk of
reflux. No other sedatives or pain medications were administered.
All patients received supplemental oxygen via nasal cannulae.
The safety record of the NAPS technique has been reported to
be good, with less than 1 in 500 cases having a need for brief
periods of mask ventilation. In that review of more than 17,000
patients, no other adverse events were recorded (5).
In addition to standard-of-care monitoring of vital signs,
sedation levels were monitored with the Ramsay Sedation Scale
(RSS) (Table 1), and brain function was monitored using the
Patient State Index (PSI) obtained from a brain function monitor (Hospira, Inc., Lake Forest, IL). Transcutaneous carbon
dioxide (tcpCO2) was monitored with the TCM TOSCA®
monitor (Radiometer Copenhagen, Basel, Switzerland), and
end-tidal carbon dioxide (EtCO2) was monitored via nasal
cannulae. Blood pressure was recorded every 5 minutes, and
heart rate, respiratory rate, PSI, RSS, and oxygenation by SpO2,
EtCO2, and tcpCO2 were displayed continually and recorded at
the top of every minute during the course of the procedure.
The anesthesiologist was privy to the PSI data for the first
40 subjects enrolled so that a baseline level of sedation could be
ascertained as complemented by the PSI. The next 60 patients
were numbered sequentially as they were enrolled and randomized to a blinded or unblinded group. All even-numbered
patients were randomized to a blinded group where the anesthesiologist was blinded to the PSI data. The anesthesiologist
was able to view the PSI data for odd-numbered subjects. The
goal of this second part of the study was to see if information
from a brain function monitor would affect the management
of the sedation technique.
Each patient was monitored according to the standards of
the ASA by the a