AN INTRAOPERATIVE SMALL DOSE OF KETAMINE PREVENTS REMIFENTANIL-INDUCED POSTANESTHETIC SHIVERING...
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AN INTRAOPERATIVE SMALL DOSE OF KETAMINE PREVENTS REMIFENTANIL-INDUCED POSTANESTHETIC SHIVERING Hilary Wagner RN, BSN, SRNA Oakland University- Beaumont/MSN-Anesthesia Class of 2013
AN INTRAOPERATIVE SMALL DOSE OF KETAMINE PREVENTS REMIFENTANIL-INDUCED POSTANESTHETIC SHIVERING Hilary Wagner RN, BSN, SRNA Oakland University-Beaumont/MSN-
AN INTRAOPERATIVE SMALL DOSE OF KETAMINE PREVENTS
REMIFENTANIL-INDUCED POSTANESTHETIC SHIVERING Hilary Wagner RN,
BSN, SRNA Oakland University-Beaumont/MSN- Anesthesia Class of
2013
Slide 2
Nakusuji, M., Nakamura, M., Imanaka, N., Tanaka, M., Nomura,
M., & Suh, S. H. (2011). An intraoperative small dose of
ketamine prevents remifentanil- induced postanesthetic shivering.
Anesthesia & Analgesia, 113 (3).
Slide 3
INTRODUCTION Published in the September 2011 edition of
Anesthesia & Analgesia The study was approved by the Human
Ethics Review Committee of Kansai Denryoku Hospital in Japan
Slide 4
STUDY OBJECTIVES/PURPOSE Postanesthetic shivering (PAS) is
frequently encountered in patients after discontinuation of
remifentanil infusion Remifentanil is more likely to cause PAS than
other opioids However, the exact cause of remifentanil- induced PAS
remains undetermined at this time
Slide 5
STUDY OBJECTIVES/PURPOSE To investigate whether or not a
ketamine infusion while using remifentanil during gynecological
laparotomy cases reduces the incidence of PAS
Slide 6
STUDY Patients were enrolled in this study from August 2009 to
October 2010 Randomized controlled trial Prospective study
Dependent variable = Postanesthetic shivering Independent variable
= Ketamine infusion
Slide 7
INCLUSION CRITERIA ASA status of I or II Under age 60 Surgical
time less than 3.5 hours (surgical times longer than 3.5 hours are
correlated with PAS) Patients were automatically excluded if they
were: undergoing emergency surgery scheduled for radical
hysterectomy
Slide 8
METHODS Signed written consent form was obtained from each
subject 64 patients meeting inclusion criteria were randomly
assigned to receive either 0.5 mg/kg ketamine at induction followed
by an infusion of 0.3 mg/kg/hr for the duration of surgery (n=32)
or a similar volume of saline (n=32). The patients were randomly
assigned via envelope randomization
Slide 9
METHODS (CONT.) In both groups, all patients received:
Midazolam IM (2.5-5 mg) 15 minutes before OR arrival An epidural
catheter at the T12-L1 interspace Epidural ropivacaine titrated
intraoperatively to maintain systolic arterial blood pressure
within 20% or less of preoperative blood pressure General
anesthesia induced with propofol at 1.5-2 mg/kg IV and a
remifentanil infusion at 0.25-0.5 mcg/kg/min (for analgesia)
Vecuronium bromide for tracheal intubation at 0.1 mg/kg IV
Slide 10
METHODS (CONT.) Total IV anesthesia with propofol titrated to
maintain a target Bispectral Index (BIS) value between 30-50 FiO 2
at 0.40 (a mix of oxygen and air, no nitrous oxide was used) 100
mcg of fentanyl via the epidural catheter after closure of the
peritoneum 1.25 mg of droperidol at the end of the case to prevent
postoperative nausea and vomiting Forced air blanket to lower
extremities at 32C which was discontinued when rectal temperature
reached 37C Lactated ringers solution infused at ambient
temperature of 25-27C
Slide 11
METHODS (CONT.) The OR staff were unaware as to which patients
were part of the experimental and control groups The staff
monitored the patients for PAS while in the OR and for 30 minutes
post-emergence
Slide 12
OUTCOME MEASURES(CONT.) Measured shivering with a 5-point
rating scale 0: no shivering 1: peripheral vasoconstriction with no
visible muscular activity 2: visible muscular activity confined to
only 1 muscle group 3: visible muscular activity in more than 1
muscle group 4: gross muscular activity involving the whole body A
score between 3 and 4 indicated PAS
Slide 13
METHODS (CONT.) The anesthesia provider remained absent during
the PAS evaluation so as not to allow bias related to anesthetic
regimen knowledge Postoperative pain was also evaluated using the
visual analog scale from 0 (no pain) to 10 (worst pain) PAS was
then treated using a warm blanket If PAS persisted longer than 15
minutes, 50 mg of flurbiprofen axetil was administered (COX
inhibitor)
Slide 14
Slide 15
Slide 16
A flow diagram of inclusion and exclusion criteria applied in
this study, based on the CONSORT (Consolidated Standards of
Reporting Trials) statement. Nakasuji M et al. Anesth Analg
2011;113:484-487
Slide 17
STATISTICAL ANALYSIS Student t test and the Mann-Whitney U test
were used for statistical comparisons Differences between the
groups were considered statistically significant when the P value
was