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The Role of Temperature in the Action of Mepivacaine

Nikolaos DabarakisDDS, PhD,

Anastasios TsirlisDDS, PhD,

Nikolaos ParisisDDS, PhD, and

Dimitrios TsoukalasDDS, PhD

Article Category: Research Article

Volume/Issue: Volume 53: Issue 3

Online Publication Date: Jan 01, 2006

DOI: 10.2344/0003-3006(2006)53[91:TROTIT]2.0.CO;2

Page Range: 91 – 94

It is well known since ancient times that the placement of something cold (eg, ice) produces anesthesia at the specific site of its placement. 1 Moreover, the effect of lidocaine in blocking nerve impulses both in vitro and in vivo is potentiated by cooling. 2–4 The nerve-blocking effect of lidocaine is also reported as being potentiated by increasing the temperature above 37°C. 2 In other studies, the potency of various tertiary amine local anesthetics in impairing the excitability of frog skeletal muscle was markedly enhanced by an

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; Perioperative temperature records. Record of the patient's temperature throughout the procedure. The rectal (blue) and forehead (green) temperatures did not decrease after induction. The axillary temperature (red) decreased briefly but promptly recovered 10 minutes before the start of surgery.

Ruri Teshima,

Akiko Nishimura,

Akira Hara,

Yuhei Ubukata,

Sayaka Chizuwa,

Mone Wakatsuki, and

Takehiko Iijima

Figure 2.; Change in body temperature during general anesthesia.

Figure 2.

Change in body temperature during general anesthesia.

Figure 1; Hypothalamic thermoregulation. Temperature inputs to the hypothalamus are integrated and compared with threshold temperatures that trigger appropriate thermoregulatory responses. Normally these responses are initiated at as little as 0.1°C above and below normal body temperature of 37°C (98.6°F). Therefore the difference between temperatures that initiate sweating versus those initiating vasoconstriction is only 0.2°C. This is defined as the interthreshold range and represents the narrow range at which the body does not initiate thermoregulatory efforts. Most general anesthetics depress hypothalamic responses, widening this interthreshold range to as much as 4°C. Therefore patients are less able to adjust to temperature changes that occur during treatment.

Marcos Díaz and

Daniel E. Becker

Figure 1

Hypothalamic thermoregulation. Temperature inputs to the hypothalamus are integrated and compared with threshold temperatures that trigger appropriate thermoregulatory responses. Normally these responses are initiated at as little as 0.1°C above and below normal body temperature of 37°C (98.6°F). Therefore the difference between temperatures that initiate sweating versus those initiating vasoconstriction is only 0.2°C. This is defined as the interthreshold range and represents the narrow range at which the body does not initiate thermoregulatory efforts. Most general anesthetics depress hypothalamic responses, widening this interthreshold range to as much as 4°C. Therefore patients are less able to adjust to temperature changes that occur during treatment.

Figure 2.; Changes in rectal temperature in each group according to the season in which the operation was performed. The figure shows the means and standard deviations. Climate had the greatest effect on rectal temperature at the 120 min time point after anesthesia induction. The mean temperature was approximately 37°C in all the groups at the 15 min time point after anesthesia induction. However, the difference in rectal temperature between groups gradually increased. The mean value of rectal temperature in the cold season markedly decreased to below 36.0°C 60 min after anesthesia induction.

Figure 2.

Changes in rectal temperature in each group according to the season in which the operation was performed.

The figure shows the means and standard deviations. Climate had the greatest effect on rectal temperature at the 120 min time point after anesthesia induction. The mean temperature was approximately 37°C in all the groups at the 15 min time point after anesthesia induction. However, the difference in rectal temperature between groups gradually increased. The mean value of rectal temperature in the cold season markedly decreased to below 36.0°C 60 min after anesthesia induction.

Figure 1. ; Using infrared thermography, the changes in the surface temperatures of the tracheal tube between the tip and 15 cm from the proximal end are measured following dipping into 60°C water for 3 minutes. Infrared thermographs show the changes in the surface temperature after 5 minutes of the Mallinckrodt Nasal RAE Tube (a) and the Portex North Polar Preformed Tube (b) after withdrawing the tube from 60°C water. Color bars represent the temperature scale ranging from 20 to 60°C.

Yoshihiro Takasugi,

Koichi Futagawa,

Takashi Umeda,

Kouhei Kazuhara, and

Satoshi Morishita

Figure 1.

Using infrared thermography, the changes in the surface temperatures of the tracheal tube between the tip and 15 cm from the proximal end are measured following dipping into 60°C water for 3 minutes. Infrared thermographs show the changes in the surface temperature after 5 minutes of the Mallinckrodt Nasal RAE Tube (a) and the Portex North Polar Preformed Tube (b) after withdrawing the tube from 60°C water. Color bars represent the temperature scale ranging from 20 to 60°C.

Figure 1.; Changes in rectal temperature in each group according to the preoperative behavior grade. The figure shows the means and standard deviations. Preoperative behavior grade had the greatest effect on rectal temperature at the 15 min time point after anesthesia induction. The mean rectal temperature of the patients in group 3 or 4, who showed definite refusal behavior, increased to about 37.4°C. Although the difference among the groups was maintained, the mean value of rectal temperature in each group decreased and settled to normal levels for as long as the anesthesia was maintained.

Figure 1.

Changes in rectal temperature in each group according to the preoperative behavior grade.

The figure shows the means and standard deviations. Preoperative behavior grade had the greatest effect on rectal temperature at the 15 min time point after anesthesia induction. The mean rectal temperature of the patients in group 3 or 4, who showed definite refusal behavior, increased to about 37.4°C. Although the difference among the groups was maintained, the mean value of rectal temperature in each group decreased and settled to normal levels for as long as the anesthesia was maintained.

Figure 2. ; Dots indicate the mean surface temperature between the tip and 15 cm from the distal end measured by infrared thermography (n = 5). Each polygonal line shows the sequential values of the surface temperatures of the tubes at 30-second intervals for 5 minutes after withdrawing the tube from 45 or 60°C water. (a) Mallinckrodt Nasal RAE Endotracheal Tube; (b) Ivory PVC Portex North Polar Preformed Endotracheal Tube.

Yoshihiro Takasugi,

Koichi Futagawa,

Takashi Umeda,

Kouhei Kazuhara, and

Satoshi Morishita

Figure 2.

Dots indicate the mean surface temperature between the tip and 15 cm from the distal end measured by infrared thermography (n = 5). Each polygonal line shows the sequential values of the surface temperatures of the tubes at 30-second intervals for 5 minutes after withdrawing the tube from 45 or 60°C water. (a) Mallinckrodt Nasal RAE Endotracheal Tube; (b) Ivory PVC Portex North Polar Preformed Endotracheal Tube.

Figure 3. ; Photo in the magnetic resonance imaging (MRI) room during MRI scanning under general anesthesia. During MRI scanning, the pulse and body temperature were checked by palpation. Propofol was dripping by gravity from the bottle using a 60 drips/mL infusion tube.

Mami Sasao-Takano,

Kan Misumi,

Masayuki Suzuki,

Yoko Kamiya,

Izumi Noguchi, and

Hiroshi Kawahara

Figure 3.

Photo in the magnetic resonance imaging (MRI) room during MRI scanning under general anesthesia. During MRI scanning, the pulse and body temperature were checked by palpation. Propofol was dripping by gravity from the bottle using a 60 drips/mL infusion tube.

Figure 3.; Epinephrine Concentration Between 0 and 90 Days The relatively uniform concentrations of epinephrine observed in samples across all day, light, and temperature treatments indicate that little or no degradation of epinephrine occurred in samples, regardless of the storage conditions. Bars represent average ± SD.

Caroline M. Sawicki,

Daniel B. McKim,

Hongrui Wang,

Morgan Vasas,

Joshua J. Blakeslee,

Courtney A. Jatana,

Patrick Dib,

Bryant W. Cornelius, and

Spencer D. Wade

Figure 3.

Epinephrine Concentration Between 0 and 90 Days

The relatively uniform concentrations of epinephrine observed in samples across all day, light, and temperature treatments indicate that little or no degradation of epinephrine occurred in samples, regardless of the storage conditions. Bars represent average ± SD.