QI: TEMP-03
Ketan Chopra MD
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Disclosures
• None
Agenda
• Defining the metric
• Past and current
performance
• Suggestions and solutions
• Questions
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TEMP-03: Perioperative Hypothermia
• Description: percentage of patients requiring general or
neuraxial anesthesia for whom a body temperature of >
36
degrees Celsius was not recorded within 30 minutes
before or 15 minutes after anesthesia end time
• Key points are
–The type of anesthetic
–The “window” of recording
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Why Monitor Temperature During Anesthesia?
• General anesthesia impairs thermoregulation, widening the
interthreshold range to 2–4°C.
–Refers to the narrow temperature band between the body's
cold and warm response thresholds
• This makes patients poikilothermic: they can’t defend
themselves against temperature shifts and become passive
to thermal changes.
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Why 36°C is the Threshold
• Below 36°C = ↑ wound infections, bleeding, cardiac risk
(Rauch et al., 2021)
• Sessler NEJM (1997): Keep temp >36°C unless
hypothermia is intentional
• Reflects loss of thermoregulation (Torossian, 2008)
• Endorsed by national clinical guidelines (Torossian et al.,
2015)
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How Do We Measure Temperature?
• Core temperature
–Tympanic membrane
–Pulmonary artery
–Distal esophagus
–Nasopharynx
–Zero-flux monitor
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Zero-Heat-Flux Cutaneous Thermometer
• A technology developed in the early 1970’s
• Consist of a thermal insulator adjacent to the skin, covered
by an electric heater
• Can effectively measure temperature approximately 1-2 cm
below skin surface
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Core Temp Surrogate
Evidence:
• Liang et al. (2024): Excellent agreement with esophageal/tympanic
temp
https://link.springer.com/article/10.1007/s10877-023-01078-2
• Jack et al. (2019): Comparable to ingestible probes
https://link.springer.com/article/10.1007/s10877-019-00252-9
• Conway et al. (2021): Systematic review supports ZHF accuracy
https://link.springer.com/article/10.1007/s10877-020-00543-6
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Clinical Benefits:
• Safe for awake or neuraxial
patients
• Avoids complications of
invasive probes
• Supports MPOG TEMP-03
compliance
Benefits of Zero-Flux
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Root Cause Analysis
• Myself and my team looked into
–Why are we missing?
• No temp versus temp too low
–Where are we missing?
–How can I present this data in a way that makes sense to my
department?
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• 30 minutes before
anesthesia end time
• 15 minutes after anesthesia
end time
“The Window”
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Cases with no Temp Recorded
>50% had a temperature >36
throughout a majority of the
case but none recorded
within “the window”
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Location/Case Type
• We noticed longer cases and neuro/vascular had the
highest incidence of either failed temp or no temp recorded
• Patients with ICU transfer also had a high incidence of no
temperature recorded
–After the transfer and the provider comes back, they forget to
document or the “window” has lapsed
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Other Thoughts
• Naming metric champions
–Minimum 35 cases
–I name a CRNA, resident, and attending
• Transparency: We share all audits, results with everyone
• Multiple flyers/newsletters posted in
physician/resident/CRNA lounge
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Zero-Flux
• Zero-Flux: Inaccurate or super accurate?
• Variability amongst monitoring modalities
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Thoughts
• What are we doing to ensure we have a reliable identification
process for hypothermia?
• Are we actually identifying hypothermia?
• Is hypothermia just that much more common and are we at the
forefront of identifying it with the Zero-Flux?
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Thoughts for the Future
• Are we really looking at the right thing?
–Is a temperature reading of 36 degrees C in the final 45
minutes of anesthesia time truly representative of an 8 hour
case where the temperature was 36+ the entire time and only
at the end was the bair hugger removed and the patient took
25 minutes to emerge?
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End of the Day
• I encourage all staff before they leave the room to make
sure a temperature is logged or manually entered
• If their temperature was compliant for the majority of the
case and only dips at the very end, I do encourage them to
manually enter an average of the reading during the case
• The spirit of this measure should be maintaining
temperature throughout the maintenance phase, not just
the very end
