Abstract P136: Tracheal Temperature for Monitoring Core Temperature during Mild Hypothermia in Pigs

Purpose of the stud y: Early out-of-hospital induction of mild hypothermia after cardiac arrest needs an easy to use and accurate core temperature monitoring, which might be achievable with tracheal temperature measurement. The aim of the study was to evaluate which tracheal temperature site (Ttra) reflects best pulmonary artery temperature (Tpa) during the induction of mild hypothermia. Methods: Eight pigs (29 –38 kg) were anesthetized and intubated with a specially designed endotracheal tube with three temperature probes: Ttra1 was attached to the wall of the tube, 1 cm proximal to the cuff-balloon, without contact to the mucosa; Ttra2 and Ttra3 were placed on the cuff-balloon with tight contact to the mucosa, whereas Ttra3 was covered by a plastic tube to protect the mucosa. Core temperature was measured with a pulmonary artery catheter (Tpa). Pigs were cooled with a new surface cooling device (Emcoolspad®, Vienna, Austria). Data are presented as mean (±SD), and mean differences (95% CI). Results: Emcoolspad® decreased Tpa from 38.5°C to 33°C in 31±10 min, which translates into a cooling rate of 11.9±3.8°C/h. Overall mean differences of tracheal temperatures to pulmonary artery temperature (Tpa) are shown in table 1 . Ttra 1 showed the least difference to Tpa, followed by Ttra 2 and Ttra 3. There was a significant difference in temperature differences (Ttra-Tpa) related to temperature measurement site on the tracheal tube (p<0.007). Conclusions: The temperature probe proximal of the cuff (Ttra 1) reflects best pulmonary artery temperature. It seems to be an accurate surrogate for core temperature during the induction of mild hypothermia. The industry is asked to provide a tracheal tube with a temperature sensor for simple temperature monitoring during fast cooling to facilitate the implementation of mild hypothermia after cardiac arrest in the out-of-hospital setting.

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A comparison of five methods of temperature measurement in febrile intensive care patients

American Journal of Critical Care ◽

10.4037/ajcc1995.4.4.286 ◽

1995 ◽

Vol 4 (4) ◽

pp. 286-292 ◽

Cited By ~ 76

Author(s):

T Schmitz ◽

N Bair ◽

M Falk ◽

C Levine

Keyword(s):

Intensive Care ◽

Pulmonary Artery ◽

Temperature Measurement ◽

Core Temperature ◽

Rectal Temperature ◽

False Negative ◽

Negative Likelihood Ratio ◽

Likelihood Ratios ◽

Axillary Temperature ◽

Intensive Care Patients

BACKGROUND: A clinically useful temperature measurement method should correlate well with the body's core temperature. Although previous investigators have studied temperature readings from different sites in hypothermic and normothermic patients, none have compared methods specifically in febrile patients. OBJECTIVE: To compare temperature measurement methods in febrile intensive care patients. METHODS: Temperature readings were obtained in rapid sequence from an electronic thermometer for oral and axillary temperature, rectal probe, infrared ear thermometer on "core" setting, and pulmonary artery catheter, approximately every hour during the day and every 4 hours at night. The sample consisted of 13 patients with pulmonary artery catheters and with temperatures of at least 37.8 degrees C. RESULTS: Rectal temperature correlated most closely with pulmonary artery temperature. Rectal temperature showed closest agreement with pulmonary artery temperature, followed by oral, ear-based, and axillary temperatures. Rectal and ear-based temperatures were most sensitive in detecting temperatures greater than 38.3 degrees C. Likelihood ratios for detecting hyperthermia were 5.32 for oral, 2.46 for rectal, and 1.97 for ear-based temperature. Rectal and ear-based temperatures had the lowest negative likelihood ratios, indicating the least chance of a false negative reading. Axillary temperature had a negative likelihood ratio of 0.86. CONCLUSIONS: Rectal temperature measurement correlates most closely with core temperature. If the rectal site is contraindicated, oral or ear-based temperatures are acceptable. Axillary temperature does not correlate well with pulmonary artery temperature. These results underscore the importance of consistency in method when establishing temperature trends, and of awareness of method when interpreting clinical data.

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Core temperature measurement: A comparison of rectal, axillary and pulmonary artery blood temperature

Intensive and Critical Care Nursing ◽

10.1016/s0964-3397(05)80002-3 ◽

1993 ◽

Vol 9 (4) ◽

pp. 217-225 ◽

Cited By ~ 25

Author(s):

Paul Fulbrook

Keyword(s):

Pulmonary Artery ◽

Temperature Measurement ◽

Core Temperature ◽

Blood Temperature

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Femoro-iliacal artery versus pulmonary artery core temperature measurement during therapeutic hypothermia: An observational study

Resuscitation ◽

10.1016/j.resuscitation.2012.11.022 ◽

2013 ◽

Vol 84 (6) ◽

pp. 805-809 ◽

Cited By ~ 21

Author(s):

Danica Krizanac ◽

Peter Stratil ◽

David Hoerburger ◽

Christoph Testori ◽

Christian Wallmueller ◽

...

Keyword(s):

Observational Study ◽

Pulmonary Artery ◽

Temperature Measurement ◽

Therapeutic Hypothermia ◽

Core Temperature

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Non-Invasive Core Temperature Monitoring System: Providing Consistent, Reliable Temperature Measurement in the Perianesthesia Patient

Journal of PeriAnesthesia Nursing ◽

10.1016/j.jopan.2021.06.023 ◽

2021 ◽

Vol 36 (4) ◽

pp. e6

Author(s):

Team Leader: Cristina Brooks ◽

Team Member: Sarah Bosserman Matulewicz

Keyword(s):

Temperature Measurement ◽

Monitoring System ◽

Core Temperature ◽

Temperature Monitoring ◽

Non Invasive ◽

Reliable Temperature

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Surface Cooling for Rapid Induction of Mild Hypothermia After Cardiac Arrest: Design Determines Efficacy

Academic Emergency Medicine ◽

10.1111/j.1553-2712.2010.00700.x ◽

2010 ◽

Vol 17 (4) ◽

pp. 360-367 ◽

Cited By ~ 16

Author(s):

Thomas Uray ◽

Moritz Haugk ◽

Fritz Sterz ◽

Jasmin Arrich ◽

Nina Richling ◽

...

Keyword(s):

Cardiac Arrest ◽

Mild Hypothermia ◽

Surface Cooling ◽

Rapid Induction

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Therapeutic hypothermia and neurological outcome after cardiac arrest

Vojnosanitetski pregled ◽

10.2298/vsp1106495p ◽

2011 ◽

Vol 68 (6) ◽

pp. 495-499 ◽

Cited By ~ 6

Author(s):

Milovan Petrovic ◽

Gordana Panic ◽

Aleksandra Jovelic ◽

Tibor Canji ◽

Ilija Srdanovic ◽

...

Keyword(s):

Cardiac Arrest ◽

Therapeutic Hypothermia ◽

Neurological Outcome ◽

Mild Hypothermia ◽

Spontaneous Circulation ◽

Neurologic Outcome ◽

Return Of Spontaneous Circulation ◽

Significant Difference ◽

Normothermic Group ◽

The Impact

Introduction/Aim. The most important clinically relevant cause of global cerebral ischemia is cardiac arrest. Clinical studies showed a marked neuroprotective effect of mild hypothermia in resuscitation. The aim of this study was to evaluate the impact of mild hypothermia on neurological outcome and survival of the patients in coma, after cardiac arrest and return of spontaneous circulation. Methods. The prospective study was conducted on consecutive comatose patients admitted to our clinic after cardiac arrest and return of spontaneous circulation, between February 2005 and May 2009. The patients were divided into two groups: the patients treated with mild hypothermia and the patients treated conservatively. The intravascular in combination with external method of cooling or only external cooling was used during the first 24 hours, after which spontaneous rewarming started. The endpoints were survival rate and neurological outcome. The neurological outcome was observed with Cerebral Performance Category Scale (CPC). Follow-up was 30 days. Results. The study was conducted on 82 patients: 45 patients (age 57.93 ? 14.08 years, 77.8% male) were treated with hypothermia, and 37 patients (age 62.00 ? 9.60 years, 67.6% male) were treated conservatively. In the group treated with therapeutic hypothermia protocol, 21 (46.7%) patients had full neurological restitution (CPC 1), 3 (6.7%) patients had good neurologic outcome (CPC 2), 1 (2.2%) patient remained in coma and 20 (44.4%) patients finally died (CPC 5). In the normothermic group 7 (18.9%) patients had full neurological restitution (CPC 1), and 30 (81.1%) patients remained in coma and finally died (CPC 5). Between the two therapeutic groups there was statistically significant difference in frequencies of different neurologic outcome (p = 0.006), specially between the patients with CPC 1 and CPC 5 outcome (p = 0.003). In the group treated with mild hypothermia 23 (51.1%) patients survived, and in the normothermic group 30 (81.1%) patients died, while in the group of survived patients 23 (76.7%) were treated with mild hypothermia (p = 0.003). Conclusion. Mild therapeutic hypothermia applied after cardiac arrest improved neurological outcome and reduced mortality in the studied group of comatose survivors.

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Decompressive craniectomy combined with mild hypothermia in patients with large hemispheric infarction: a randomized controlled trial

BMC Neurology ◽

10.1186/s12883-021-02142-7 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Linlin Fan ◽

Yingying Su ◽

Yan Zhang ◽

Hong Ye ◽

Weibi Chen ◽

...

Keyword(s):

Decompressive Craniectomy ◽

Neurological Outcome ◽

Mild Hypothermia ◽

Controlled Trial ◽

Good Neurological Outcome ◽

Surface Cooling ◽

Local Cooling ◽

Head Surface ◽

Significant Difference ◽

Hemispheric Infarction

Abstract Background The effect of hypothermia on large hemispheric infarction (LHI) remains controversial. Our study aimed to explore the therapeutic outcomes of decompressive craniectomy (DC) combined with hypothermia on LHI. Methods Patients were randomly divided into three groups: the DC group, the DC plus head surface cooling (DCSC) group and the DC plus endovascular hypothermia (DCEH) group. The DC group was maintained normothermia. The DCSC group received 24-h ice cap on the head for 7 days. While the DCEH group were given endovascular hypothermia (34 °C). Mortality and modified Rankin Scale (mRS) score at 6 months were evaluated. Results Thirty-four patients were included in the study. Mortality of the DC, DCSC and DCEH groups at discharge were 22.2% (2/9), 0% (0/14) and 9.1% (1/11), respectively. However, it increased to 44.4% (4/9), 21.4% (3/14) and 45.5% (5/11) at 6 months, respectively (p = 0.367). Pneumonia (8 cases) was the leading cause of death after discharge. Twelve cases (35.3%) achieved good neurological outcome (mRS 0–3) at 6 months. The proportions of good neurological outcome in the DC, DCSC and DCEH groups were 22.2% (2/9 cases), 42.9% (6/14 cases) and 36.4% (4/11), respectively. The DCSC group seemed to have higher proportion of good outcomes, but there was no significant difference between groups (p = 0.598). Among survivors, endovascular hypothermia had a higher proportion of good outcome (DC group, 2/5 cases, 40.0%; DCSC group, 6/11 cases, 54.5%; DCEH group, 4/6 cases, 66.7%; p = 0.696). The incidence of complications in the DCEH group was higher than those of the DC and DCSC groups (18.9%, 12.0%, and 12.1%, respectively; p = 0.025). Conclusions There is still no evidence to confirm that hypothermia further reduces long-term mortality and improves neurological outcomes in LHI patients with DC. However, there is a trend to benefit survivors from hypothermia. A local cooling method may be a better option for DC patients, which has little impact on systematic complications. Trial registration Decompressive Hemicraniectomy Combined Hypothermia in Malignant Middle Cerebral Artery Infarct, ChiCTR-TRC-12002698. Registered 11 Oct 2012- Retrospectively registered, URL: http://www.chictr.org.cn/showproj.aspx?proj=6854.

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Survival after Drowning with Cardiac Arrest and Mild Hypothermia

ISRN Cardiology ◽

10.5402/2011/895625 ◽

2011 ◽

Vol 2011 ◽

pp. 1-2 ◽

Cited By ~ 5

Author(s):

S. S. Rudolph ◽

S. Barnung

Keyword(s):

Cardiac Arrest ◽

Core Temperature ◽

Treatment Guidelines ◽

Mild Hypothermia ◽

Spontaneous Circulation ◽

Chest Compressions ◽

Pragmatic Approach ◽

Successful Resuscitation ◽

Randomized Controlled ◽

Current Guidelines

The current guidelines for resucitation following hypothermia and submersion with cardiac arrest state that rewarming should be continued until a core temperature of 32–34°C is achieved, after which death can be declared if no return of spontaneous circulation has occurred. As no randomized, controlled trials exist, these treatment guidelines are mostly based on a pragmatic approach. Wheater to start or stop resuscitation is notoriusly difficult. Submersion time, water temperature, and prompt resuscitation seem to be crucial factors for outcome. We report a case of successful resuscitation after the use of mechanical chest compressions and extracorporeal circulation in a patient with cardiac arrest due to submersion and accompanying mild hypothermia with a core temperature of 32,2°C caused by submersion.

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Accurate Non-Invasive Temperature Monitoring Device

2017 Design of Medical Devices Conference ◽

10.1115/dmd2017-3476 ◽

2017 ◽

Author(s):

Garrett Augustine ◽

Scott Augustine

Keyword(s):

General Anesthesia ◽

Temperature Measurement ◽

Core Temperature ◽

Real Option ◽

Temperature Monitoring ◽

Adverse Outcomes ◽

Peripheral Compartment ◽

Non Invasive ◽

Anesthetic Drugs ◽

Increased Risk

Core temperature is one of the most tightly auto-regulated physiological processes. Anesthetic drugs compromise the body’s ability to thermoregulate. When core temperature is outside of the normothermia range, patients are at increased risk of myriad complications. Hypothermic patients are at higher risk of, among other things, increased wound infections2, increased blood loss3, increased ICU times and hospital stays2, higher mortality rates4, increased transfusion requirements3. “Even mildly hypothermic patients could suffer an increase in adverse outcomes that can add costs of as much as $2,500–$7,000 per patient.”5 These risks are great such that clinicians actively warm hypothermic patients to achieve normothermia. Given the importance of the core temperature on outcomes, there is a clear necessity for accurate core temperature measurement. Core temperature measurement is often misunderstood. Perhaps due to the pervasive home use of oral mercury thermometers to “take your temperature,” many wrongly assume that non-invasive core temperature is measured easily and accurately. Oral, axilla, nasal are all unreliable. Temporal/forehead and ear are particularly inaccurate. “Global authorities in anesthesiology and medicine have cited inadequacies with virtually all thermometry”6 False assurance or false alarm are both dangerous. There is currently no non-invasive way to reliably and accurately measure core temperature. Why is this? The peripheral compartment is not in equilibrium with core. Fat and other layers further complicate the matter. Fat has the thermal conductivity of oak, and thus non-invasive methods to measure core are as Abreu puts it “taking measurements on the outside surface of an oak cask to determine the temperature of its contents.”6 Laws of Thermodynamics notwithstanding, many still try. Invasive esophageal or rectal and to a lesser extent bladder, are the only way to accurately measure core. The fact is, in order to measure their patients’ core temperature vital sign accurately, clinicians have only available to them the medical equivalent of a meat thermometer. Intubated patients under general anesthesia are perfectly suited for invasive core temperature monitoring. They are not going to gag the esophageal stethoscope, nor would they find rectal or bladder probing uncomfortable in their unconsciousness. Clinicians may find probing mildly unpleasant and a minor time consumption, but once again, given the lack of alternatives, the only real option is to grin and bear it. General anesthesia is not without risks, especially with increasingly increasing patients, and as sedation or blocks become more popular, invasive core temperature monitoring is unpractical. This highlights the stark question: Is it possible to accurately and reliably ascertain core temperature non-invasively?

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