PowerPoint Presentation (PDF) - Perfusion.com

Craig S. Warren CCP
Eastern Maine Medical Center
Bangor, Maine.

We have no material, financial or other
relationship with any Healthcare related
business whose products or services that were
used in this project.

Avoid Hyperthermia
S
(Class IIa, Level B)
S
JTCVS 2006
Oxygenator Temperature ports – Check for accuracy/ Calibrate
(Shann, JTCVS 2006)

Guideline
Limiting Arterial line Temperature to
37 Degrees Celsius may be useful for
avoiding cerebral hyperthermia. (Class
II A, Level B)

The temperature from the oxygenator arterial outlet
temperature port can underestimate the actual temperature
of the perfusate.
In Vitro Validation of the Affinity
NT Oxygenator Arterial Outlet
Temperatures
JECT, 2005
Kieron C. Potger, BSc, CCP; Darryl McMillan,
CCP
Department of Anaesthesia and Pain
Management, Perfusion and Autotransfusion
Unit, Royal North Shore Hospital,
Sydney, Australia
Presented at the 20th Annual Scientific Meeting
of the Australasian Society of Cardio-Vascular
Perfusionists,
“ Coupled temp probes should be checked for accuracy and
calibrated”

Perfusionists
NNE PERFUSION GROUP

Perfusion Registry
Form

Diodato, JECT 2008
Ject 2008
Gaps exist between practice and published recommendations
WIDE VARIATION IN PRACTICE EXISTS

1
Regional Quality
Improvement
Project
3
2
4
CABG Surgery Patients Jan 2006- Dec 2008
Four NNE Centers

•Validation and calibration of coupled temp ports
•Lowering target temperature for separation from CPB
•Resetting Heater Cooler thermostats
•Employment of audible temperature alarms
•Reducing the rate of re-warming
•Purchase of new heater-coolers

Fluke-Precision
biomedical grade
temperature analyzer

Thermistor Probe

1. A prime solution was circulated at 4 LPM in a
closed-loop circuit.
3. Steady state measurements were made at 30, 38 and
40 degrees centigrade on the heater-cooler.
4. All centers utilized a Sorin S3 pump (Heart-lung
machine), which was used to monitor and display
temperature.

Temperature port vs. Thermistor probe
Center 1: 0.05 degrees higher
Center 2: 0.5 degrees lower
Center 3: 1 degree lower
Center 4: 0.5 degrees lower

Four centers within NNE
Submitted data concerning highest arterial blood
temperatures for CABG procedures between 2006-
2008 and analyzed data to thresholds of 37.0 and
37.5 degrees C.

Results
Data for 3,318 procedures
1,180 before interventions, 1,438 after.
Pre-Interventions VS Post-Interventions
88 % temps ≥ 37⁰ 74% temps ≥ 37⁰
48 % temps ≥ 37.5⁰ 23 % temps ≥ 37.5⁰

Percent of Inflow Temperature>=37: Pre and Post Intervention
100
90
80
70
60
50
40
30
20
p

Degrees Centigrade
H i g h e s t b l o o d t e m p e r a t u r e o n C P B
( l a s t 200 b y p a s s p r o c e d u r e s f o r e a c h c e n t e r )
3 8
3 7 . 5
3 7
3 6 . 5
3 6
1 2 3 4
e x c l u d e s o u t s i d e v a l u e s
C e n t e r

Degrees Centigrade
H i g h e s t b l o o d t e m p e r a t u r e o n C P B
3 9
3 8
3 7
3 6
2009
2008
2007
2006
2005
2009
2008
2007
2006
2005
2009
2008
2007
2006
2005
2009
2008
2007
2006
2005
1 2 3 4
C e n t e r
e x c l u d e s o u t s i d e v a l u e s

Table II. Univariate Associations Between Patient Characteristic and Disease Variables, and Risk of Hypethermia
Variable % of Subjects % Hyperthermia p-value Variable % of Subjects % Hyperthermia p-value
Patients (number) 3,318 82.0 Patients (number) 3,318 82.0
Age(years)
Number of Diseased Vessels
75 19.5 78.1 3 43.8 84.1
0.45 ptrend

In Summary
Our Quality Improvement Project
•Improved performance around the published
guideline.
•Identified opportunities to improve temperature
management.
•Most patients were not exposed to elevated arterial
line temperatures. (37⁰C or 37.5⁰C)

Quality Improvement Project
and
Evidence Based Medicine
Why worry about Hyperthermia

Cerebral Injury after CPBypass
Predominant comorbidity
1% to 5% CABG stroke incidence
30-60% CABG neurocognitive deficit

Hypothermia
• Reduces cellular metabolism , improving tolerance
to ischemia.
• Decreases energy consumption (approx 7%/ deg C).
• Increases tolerance to reduced flow and oxygen
delivery.
• Minimizes acidosis that accompanies ischemia.

Hypothermia--Disadvantage
Potential for cerebral HYPERthermia during
rewarming
High arterial in-flow temperatures
Carotid artery proximity to
cannulation site

Actual brain
temp during
rewarming may
exceed core temp
by up to 3⁰C
39-40⁰

Physiologic effects of Hyperthermia
• Accentuates release of neurotransmitters
(glutamate)
• Increases oxygen free radical production
• Increases blood-brain barrier permeability
• Increases intracellular acidosis
• Delays neuronal metabolic recovery

Temperature Measurement Sites
Nasopharyngeal
Esophageal
Bladder
Rectal
Blood (PA catheter)
Arterial blood in-flow
(Jugular bulb venous temperature)

Nussmeier et al., from Texas Heart institute.
Nasopharyngeal, Esophageal, Bladder and Rectal
sites underestimated Jugular bulb temperature.
Cerebral HYPERthermia may result during rewarming.
Nasopharyngeal and Esophageal temperatures can underestimate
jugular bulb temperature by as much as 2⁰ C.
ONLY the temperature of the BLOOD EXITING THE
OXYGENATOR provides an accurate measure of jugular
temperature during rewarming.
Nussmeier, S. Li, A. G. Strickler, E. Dragan, R.K. Korkki, J.R. Cooper, Jr. Temperature measurement during Cardiopulmonary
Bypass. Anesth Analg. 2002;93,SCA1-SCA112

Grocott et al, Duke University
Patients rewarmed at an average of .49
⁰C/min. fared better than those rewarmed
at .56⁰ C/min (typical rate).
Grocott HP, Mackensen GB, Grigore AM, Mathew J, Reves
JG, Philips-ButeB, et at. Postoperative hyperthermia is
associated with cognitive dysfunction after coronary artery
bypass graft surgery. Stroke, 2002;33:537-41.

Grigore et al, from Duke University
Patients were warmed at a slower rate, maintaining no
more than 2⁰ difference between NP and Arterial blood
temperatures.
Greater neuropsychologic dysfunction in patients
randomized to a faster, rather than slower, rewarming
rate .
Grigore AM, Grocott HP, Mathew JP, Phillips-Bute B, Stanley TO,
Butler A, et al. The rewarming rate and increased peak temperature
alter neurocognitive outcome after cardiac surgery. Anesth Analg.
2002;94:4-10.

Slower Rates of Rewarming:
•Improves the ratio of O2 supply vs demand in the
Brain.
•Less chance of cerebral emboli (gaseous)
•Less Hyperthermia/Less tissue injury

Neurocognitive Function in Patients
Undergoing Coronary Artery Bypass Graft
Surgery With Cardiopulmonary Bypass: The
Effect of Two Different Rewarming Strategies.
Bikash Sahu, Sandeep Chauhan, et al. Cardiothoracic and Vascular
Anesthesia vol 23,# 1, 2009
Randomized trial of 80 adult patients
Group A-40 patients, Group B-40 patients
Primary isolated CABG’S cooled to 30⁰C
Group A warmed to 37⁰ NP vs Group B warmed to 33⁰ NP.

Results:
Significant deterioration in neurocognitive function in
patients warmed to 37⁰ C.
Increased levels of S100B in patients warmed to 37⁰
compared to patients warmed to 33⁰.
Time to extubation was longer in patients warmed to 33⁰.
There were no significant differences in:
Post-op blood loss
Blood product, inotrope, vasodilator, or pacing
requirements in patients warmed to 33⁰