Skip Navigation LinksHome > December 1995 - Volume 83 - Issue 6 > Shivering Threshold during Spinal Anesthesia Is Reduced in E...
Anesthesiology:
Clinical Investigation

Shivering Threshold during Spinal Anesthesia Is Reduced in Elderly Patients

Vassilieff, Nicolas MD; Rosencher, Nadia MD; Sessler, Daniel I. MD; Conseiller, Christian MD

Free Access
Article Outline
Collapse Box

Author Information

Collapse Box

Abstract

Background: Both accidental and perioperative hypothermia are common in the elderly. The elderly are at risk because their responses to hypothermia may be delayed or less efficient than in those of younger subjects. For example, the vasoconstriction threshold during isoflurane anesthesia is [nearly equal] 1 degree Celsius less in elderly than younger patients. However, the extent to which other cold defenses are impaired in the elderly remains unclear, especially in those older than 80 yr. Operations suitable for spinal anesthesia provided an opportunity to quantify shivering thresholds in patients of varying ages. Accordingly, the hypothesis that the shivering threshold is reduced as a function of age during spinal anesthesia was tested.
Methods: Twenty‐eight ASA Physical Status 1–3 patients undergoing lower extremity orthopedic procedures were studied. Spinal anesthesia was induced without preanesthetic medication, using bupivacaine sufficient to produce a dermatomal level near T9. Electrocardiogram signals were recorded at 10‐min intervals. Subsequently, an observer masked to patient age and core temperature identified the onset of sustained electromyographic artifact consistent with shivering. The tympanic membrane temperature triggering shivering identified the threshold.
Results: Three patients did not shiver at minimum core temperatures exceeding 36.2 degrees Celsius. Fifteen patients aged < 80 yr (58 plus/minus 10 yr) shivered at 36.1 plus/minus 0.6 degree Celsius; in contrast, ten patients aged greater or equal to 80 yr (89 plus/minus 7 yr) shivered at a significantly lower mean temperature, 35.2 plus/minus 0.7 degree Celsius (P = 0.002). The shivering thresholds in seven of the ten patients older than 80 yr was less than 35.5 degrees Celsius, whereas the threshold equaled or exceeded this value in all younger patients (P = 0.0002).
Conclusions: Age‐dependent inhibition of autonomic thermoregulatory control in the elderly might be expected to result in hypothermia. That it usually does not suggests that behavioral regulation (e.g., increasing ambient temperature, dressing warmly) compensates for impaired autonomic control. Elderly patients undergoing spinal anesthesia, however, may be especially at risk of hypothermia because low core temperatures may not trigger protective autonomic responses. Furthermore, hypothermia in the elderly given regional anesthesia may not be perceived by the patient (who typically feels less cold after induction of the block), or by the anesthesiologist (who does not observe shivering). Consequently, temperature monitoring and management usually is indicated in these patients. (Key words: Anesthesia: spinal. Thermoregulation: shivering; temperature.)
ACCIDENTAL hypothermia (core temperature < 36 degrees Celsius) is relatively common in the elderly, [1,2] but rare in younger persons unless the condition is predisposed by intoxication [3,4] or extreme environmental exposure. [5] Similarly, intraoperative hypothermia is most common, and most severe, in elderly patients. [6–8] Hypothermia‐‐whatever the cause‐‐presumably increases the risk of temperature‐related complications including myocardial ischemia, [9] wound infection, [10] and prolonged drug action. [11].
The elderly are at risk for hypothermia because their responses to hypothermia may be delayed [12] or less efficient than in younger subjects. [13] However, the extent to which thermoregulatory control is impaired in the elderly remains unclear. Most studies of perioperative thermoregulation in the elderly did not evaluate enough patients older than 80 yr, [14,15] or failed to specifically determine response thresholds (i.e., triggering core temperature). [13].
Shivering thresholds usually were not determined in previous studies because investigators understandably were reluctant to cool elderly subjects to core temperatures < 35 degrees Celsius. Such hypothermia is, however, common during anesthesia and surgery. [16] We have previously demonstrated that the vasoconstriction threshold is [nearly equal] 1 degree Celsius less in elderly than younger patients during isoflurane anesthesia. [17] Interpretation of this result is, however, complicated by the large effect of general anesthesia per se on thermoregulatory control, [18] and the known age‐dependent effects of volatile anesthetics. [19,20].
Operations suitable for spinal anesthesia provided an opportunity to quantify shivering thresholds in patients of varying ages with less confounding effect than might occur during general anesthesia. Accordingly, we tested the hypothesis that the shivering threshold is reduced more in the elderly than in younger persons during spinal anesthesia.
Back to Top | Article Outline

Methods

With approval from the Ethics Committee at the Cochin Port‐Royal University Hospital and after obtaining patients' informed consent, we studied 28 ASA Physical Status 1–3 patients undergoing lower extremity orthopedic procedures. None was obese, febrile, receiving vasodilators or medications likely to alter thermoregulation, or had a history of thyroid disease or dysautonomia. Ambient operating room temperature was maintained near 19 degrees Celsius.
Spinal anesthesia was induced in each patient without preanesthetic medication, using [nearly equal] 14 mg isobaric 0.5% bupivacaine. Typically, this produced a dermatomal level (as determined by lack of cutaneous cold sensation) near T9. One liter of lactated Ringer's solution warmed to 37 degrees Celsius was administered in the [nearly equal] 15 min before induction of anesthesia. Subsequently, warmed crystalloid was given at a rate of 4 ml per estimated ml of surgical blood loss. No patients required blood transfusion. Postoperatively, patients were rapidly rewarmed using an electric blanket; this blanket could not be used during surgery because it is not approved for intraoperative use.
Core temperature was recorded from the tympanic membrane using Mon‐a‐Therm thermocouples (Mallinckrodt Anesthesiology Products, Inc., St. Louis, MO). The aural probe was inserted until patients detected the thermocouple touching the tympanic membrane; appropriate placement was confirmed when patients easily detected a gentle rubbing of the attached wire. The aural canal was occluded with cotton, the probe securely taped in place, and a gauze bandage positioned over the external ear. There is an excellent correlation between tympanic membrane and distal esophageal temperatures in the perianesthetic period. [18].
Sentient skin temperature was estimated from four sites using the following regional percentages: chest, 33%, upper arm, 31%; forearm, 21%; and finger, 15%. [21]. Ambient temperature was measured using a thermocouple positioned at the level of the patient, well away from any heat‐producing equipment. All thermocouple probes were connected to Mon‐a‐Therm Model 6510 thermometers (Mallinckrodt). Temperatures were recorded at 10‐min intervals.
Blood pressure was determined oscillometrically at 5‐min intervals. We used oscillometric rather than direct arterial blood pressure measurements to minimize the artifact induced by thermoregulatory vasoconstriction. [22] Heart rate was monitored continuously using lead‐two electrocardiography. Silver‐silver chloride electrodes were applied after skin degreasing and mild abrasion. Electrocardiographic signals were recorded on a strip chart at 10‐min intervals; recordings were made during periods in which electrosurgery units were inactive. Subsequently, an observer masked to patient age and core temperature identified the onset of sustained electromyographic artifact consistent with shivering. The signals were considered to be shivering when they demonstrated the typical 4–6 cycle/min waxing‐and‐waning pattern. The core temperature triggering shivering identified the threshold.
From the patients' heights (Ht) in centimeters and weights (Wt) in kilograms, lean body mass in kg was calculated using formulas adapted to gender [23]: females: lean body mass = (1.07 *symbol* Wt) ‐ [148 *symbol* (Wt/Ht)2]; males: lean body mass = (1.10 *symbol* Wt) ‐ [128 *symbol* (Wt/Ht)2]. The percentage body fat was then calculated from the lean body mass and weight of each participant. The body surface area in m2 of each patient was estimated using the equation: Area = (Wt sup 0.425) *symbol* (Ht0.725) *symbol* (0.0072). [24] As in previous studies, [25] we estimated the ratio of heat production to heat loss by dividing patients' weights by their calculated surface areas.
Shivering thresholds, sentient skin temperatures, ambient temperatures, morphometric data, and hemodynamic data in patients aged older and younger than 80 yr were compared using two‐tailed unpaired t or Fisher Exact tests, as appropriate. An age of 80 yr was used to divide the patients because results differed substantially in patients younger and older than this age. Data are reported as means plus/minus SD; P < 0.01 was considered statistically significant.
Back to Top | Article Outline

Results

Figure 1
Figure 1
Image Tools
Three patients did not shiver at minimum core temperatures exceeding 36.2 degrees Celsius, two were aged > 80 yr and one was younger. Fifteen patients aged < 80 yr (58 plus/minus 10 yr) shivered at 36.1 plus/minus 0.6 degree Celsius; in contrast, ten patients aged > 80 yr (89 plus/minus 7 yr) shivered at a significantly lower mean temperature, 35.2 plus/minus 0.7 degree Celsius (P = 0.002). The shivering threshold in seven of the ten patients aged > 80 yr was less than 35.5 degrees Celsius, whereas the threshold equaled or exceeded this value in all younger patients (P = 0.0002, Figure 1). Two of the elderly patients with normal shivering thresholds were women.
Table 1
Table 1
Image Tools
Ambient temperatures and blood pressures at the time of shivering did not differ significantly in the two age groups. The weight and weight‐to‐surface area ratios were significantly less in patients aged 80 yr or older than in the younger patients (Table 1). However, there was no relationship between the shivering threshold and body weight, lean body mass, or percentage body fat.
Table 2
Table 2
Image Tools
(Table 2) shows the bupivacaine dose and resulting sensory block levels, shivering thresholds, and the corresponding sentient skin temperatures in patients younger than 80 yr and in those older than 80 yr. Elderly patients were given less bupivacaine, but had similar sensory block levels.
Back to Top | Article Outline

Discussion

Shivering thresholds in three of the elderly patients were similar to those in the younger patients. Shivering was delayed in seven others, however, until core temperatures were reduced to [nearly equal] 34.8 degrees Celsius. This [nearly equal] 1 degree Celsius age‐dependent decrease in the shivering threshold was similar to the reduction in the vasoconstriction threshold we reported previously in elderly patients during general anesthesia. [17] Combined with previous studies indicating that thermoregulation is impaired in aged subjects, [13,26,27] available data suggest that the elderly are especially at risk of hypothermia because low core temperatures often do not trigger protective responses.
That thermoregulatory responses were normal in some elderly patients, but markedly reduced in others is consistent with previous studies. [12,28] It is likely that thermoregulatory control does not simply gradually lose precision with increasing age. Instead, the elderly may consist of two populations‐‐one with normal thermoregulation, and a second in which control is diminished. Impaired thermoregulatory control is most likely in persons whose general health is poorer, but those in poor health would not usually be permitted to volunteer for physiologic investigations. In this scenario, subjects with abnormal thermoregulation might be systematically eliminated from volunteer studies, potentially producing a bias obscuring age‐dependent changes. [15,29].
Despite current and previous [8,12,14,17,26] evidence that thermoregulatory response thresholds are impaired in the elderly, core temperatures are generally similar in old and young patients. At usual ambient temperatures, tonic thermoregulatory vasoconstriction typically is required to maintain core normothermia. [30] (It is inhibition of this tonic vasoconstriction that causes redistribution hypothermia on induction of anesthesia. [31]) Thus, inhibition of autonomic thermoregulatory control in the elderly might be expected to result in hypothermia. That it usually does not suggests that behavioral regulation (e.g., increasing ambient temperature, dressing warmly) compensates for impaired autonomic control. Increased dependence on behavioral thermoregulation may partially explain the observation that the elderly frequently feel cold and tend to prefer warm environments.
Core hypothermia during regional anesthesia is usually associated with decreased cold sensation because it is associated with a slight actual increase in leg skin temperature [32] and a large apparent increase in skin temperature. [33] Sedative medications, which often supplement regional anesthesia, will further impair perception of core cooling and autonomic protective responses. [34] Hypothermia in the elderly given regional anesthesia thus may not be perceived by the patient (who typically feels less cold after induction of the block), or by the anesthesiologist (who does not observe shivering). Consequently, temperature monitoring and management usually are appropriate in these patients.
Regional anesthesia per se significantly impairs thermoregulatory control, [35] probably by increasing apparent leg temperature. [33] The shivering thresholds in most of our patients were thus probably less than might be observed in unanesthetized subjects. However, differences in the thresholds in elderly and younger patients most likely reflect age‐related loss of thermoregulatory precision.
Exaggerated hypothermia in our elderly patients may also have resulted simply from morphometric differences, including decreased subcutaneous fat. Consistent with this possibility, the percentage body fat and weight‐to‐surface area ratios were slightly less in the younger patients. However, these relatively small morphometric differences would have little effect on the core cooling rate. [25] The efficacy of thermoregulatory responses, once initiated, is characterized by their gain, defined as the incremental increase in response intensity produced by a further deviation in core temperature. Previous work indicates that the gain of vasoconstriction is reduced in 80‐yr‐old subjects. [26] Although it is likely that efficacy of shivering also is reduced in the elderly, [27] gain was not evaluated in this study.
Sentient skin temperature at the shivering threshold was [nearly equal] 1 degree Celsius less in the elderly patients than in those younger than 80 yr. This decrease presumably resulted mostly because core temperature also was [nearly equal] 1 degree Celsius less in these patients. Skin temperature contributes [nearly equal] 20% to control of shivering. [36] Consequently, the reduced skin temperature in the elderly patients would have been expected to increase the shivering threshold [nearly equal] 0.2 degree Celsius. Because the observed effect of age was an [nearly equal] 1 degree Celsius reduction in the core temperature triggering shivering, skin temperature is unlikely to have confounded our results.
In summary, the shivering thresholds in seven of the ten patients older than 80 yr was less than 35.5 degrees Celsius, whereas the threshold equaled or exceeded this value in all younger patients. This [nearly equal] 1 degree Celsius age‐dependent decrease in the shivering threshold was similar to the reduction in the vasoconstriction threshold reported previously in elderly patients during general anesthesia. Elderly patients undergoing spinal anesthesia are especially at risk of hypothermia because low core temperatures may not initiate autonomic protective responses. Consequently, temperature monitoring and management usually are appropriate in these patients.
The authors thank Andre Lienhart, M.D., for advice and encouragement.
Back to Top | Article Outline

REFERENCES

1. Lonning PE, Skulberg A, Abyholm F: Accidental hypothermia: Review of the literature. Acta Anaesthesiol Scand 30:601-613, 1986.

2. Paton BC: Accidental hypothermia. Pharmacol Ther 22:331-377, 1983.

3. Fischbeck KH, Simon RP: Neurological manifestations of accidental hypothermia. Ann Neurol 10:384-387, 1981.

4. Kalant H, Le AD: Effects of ethanol on thermoregulation. Pharmacol Ther 23:313-364, 1984.

5. Reuler JB: Hypothermia: Pathophysiology, clinical settings, and management. Ann Intern Med 89:519-527, 1978.

6. Vaughan MS, Vaughan RW, Cork RC: Postoperative hypothermia in adults: Relationship of age, anesthesia, and shivering to rewarming. Anesth Analg 60:746-751, 1981.

7. Roe CF, Goldberg MJ, Blair CS, Kinney JM: The influence of body temperature on early postoperative oxygen consumption. Surgery 60:85-92, 1966.

8. Frank SM, Beattie C, Christopherson R, Norris EJ, Rock P, Parker S, Kimball AW: Epidural versus general anesthesia, ambient operating room temperature, and patient age as predictors of inadvertent hypothermia. ANESTHESIOLOGY 77:252-257, 1992.

9. Frank SM, Beattie C, Christopherson R, Norris EJ, Perler BA, Williams GM, Gottlieb SO: Unintentional hypothermia is associated with postoperative myocardial ischemia. ANESTHESIOLOGY 78:468-476, 1993.

10. Sheffield CW, Sessler DI, Hunt TK: Mild hypothermia during isoflurane anesthesia decreases resistance to E. Coli dermal infection in guinea pigs. Acta Anaesthesiol Scand 38:201-205, 1994.

11. Leslie K, Sessler DI, Bjorksten AR, Moayeri A: Mild hypothermia alters propofol pharmacokinetics and increases the duration of action of atracurium. Anesth Analg 80:1007-1014, 1995.

12. MacMillan AL, Corbett JL, Johnson RH, Smith AC, Spalding JMK, Wollner L: Temperature regulation in survivors of accidental hypothermia of the elderly. Lancet 2:165-169, 1967.

13. Wagner JA, Robinson S, Marino RP: Age and temperature regulation of humans in neutral and cold environments. J Appl Physiol 37:562-565, 1974.

14. Inoue Y, Nakao M, Araki T, Murakami H: Regional differences in the sweating responses of older and younger men. J Appl Physiol 71:2453-2459, 1991.

15. Yousef MK, Dill DB, Vitez TS, Hillyard SD, Goldman AS: Thermoregulatory responses to desert heat: Age, race and sex. J Gerontol 39:406-414, 1984.

16. Joris H, Ozaki M, Sessler DI, Hardy AF, Lamay M, McGuire J, Blanchard D, Schroeder M, Moayeri A: Epidural anesthesia impairs both central and peripheral thermoregulatory control during general anesthesia. ANESTHESIOLOGY 80:268-277, 1994.

17. Kurz A, Plattner O, Sessler DI, Huemer G, Redl G, Lackner F: The threshold for thermoregulatory vasoconstriction during nitrous oxide/isoflurane anesthesia is lower in elderly than young patients. ANESTHESIOLOGY 79:465-469, 1993.

18. Stoen R, Sessler DI: The thermoregulatory threshold is inversely proportional to isoflurane concentration. ANESTHESIOLOGY 72:822827, 1990.

19. Stevens WC, Dolan WM, Gibbons RT. White A, Eger II EI, Miller RD, DeJong RH, Elashoff RM: Minimum alveolar concentrations (MAC) of isoflurane with and without nitrous oxide in patients of various ages. ANESTHESIOLOGY 42:197-200, 1975.

20. Kurz A, Kurz M, Poeschl G, Faryniak B, Redl G, Hackl W: Forced-air warming maintains intraoperative normothermia better than circulating-water mattresses. Anesth Analg 77:89-95, 1993.

21. Lund CC, Browder NC: The estimation of areas of burns. Surg Gynecol Obstet 79:352-358, 1994.

22. Hynson JM, Sessler DI, Moayeri A, Katz JA: Thermoregulatory and anesthetic-induced alterations in the differences between femoral, radial, and oscillometric blood pressure measurements. ANESTHESIOLOGY 81:1411-1421, 1994.

23. James WPT: Research in obesity. London, Her Majesty's Stationary Office, 1976.

24. DuBois D, DuBois EF: A formula to estimate the approximate surface area if height and weight be known. Arch Intern Med 17:863-871, 1916.

25. Kurz A, Sessler DI, Narzt E, Lenhart R: Morphometric influences on intraoperative core temperature changes. Anesth Analg 80:562-567, 1995.

26. Jennings RJ, Reynolds CF, Houck PR, Buysse DJ, Hoch CC, Hall F, Monk TH: Age and sleep modify finger temperature responses to facial cooling. J Gerontol 48:M108-M116, 1993.

27. Smolander J, Bar-Or O, Korhonen O, Ilmarinen J: Thermoregulation during rest and exercise in the cold in pre- and early pubescent boys and in young men. J Appl Physiol 72:1589-1594, 1992.

28. Tankersley CG, Smolander J, Kenney WL, Fortney SM: Sweating and skin blood flow during exercise: Effects of age and maximal oxygen uptake. J Appl Physiol 71:236-242, 1991.

29. Khan F, Spence VA, Wilson SB, Abbot NC: Quantification of sympathetic vascular responses in skin by laser Doppler flowmetry. Int J Microcirc 10:145-153, 1991.

30. Rowell LB: Cardiovascular aspects of human thermoregulation. Circ Res 52:367-379, 1983.

31. Matsukawa T, Sessler DI, Sessler AM, Schroeder M, Ozaki M, Kurz A, Cheng C: Heat flow and distribution during induction of general anesthesia. ANESTHESIOLOGY 82:662-673, 1995.

32. Sessler DI, Ponte J: Shivering during epidural anesthesia. ANESTHESIOLOGY 72:816-821, 1990.

33. Emerick TH, Ozaki M, Sessler DI, Walters K, Schroeder M: Epidural anesthesia increases apparent leg temperature and decreases the shivering threshold. ANESTHESIOLOGY 81:289-298, 1994.

34. Leslie K, Sessler DI, Bjorksten A, Ozaki M, Matsukawa T, Schroeder M, Lin S: Propofol causes a dose-dependent decrease in the thermoregulatory threshold for vasoconstriction, but has little effect on sweating. ANESTHESIOLOGY 81:363-360, 1994.

35. Kurz A, Sessler DI, Schroeder M, Kurz M: Thermoregulatory response thresholds during spinal anesthesia. Anesth Analg 77:721-726, 1993.

36. Cheng C, Matsukawa T, Sessler DI, Kurz A, Merrifield B, Lin H, Olofsson P: Increasing mean skin temperature linearly reduces the core-temperature thresholds for vasoconstriction and shvivering thresholds in humans. ANESTHESIOLOGY 82:1160-1168, 1995.

Cited By:

This article has been cited 30 time(s).

Anesthesiology
Perioperative heat balance
Sessler, DI
Anesthesiology, 92(2): 578-596.

Anesthesia and Analgesia
Buspirone and meperidine synergistically reduce the shivering threshold
Mokhtarani, M; Mahgoub, AN; Morioka, N; Doufas, AG; Dae, M; Shaughnessy, TE; Bjorksten, AR; Sessler, DL
Anesthesia and Analgesia, 93(5): 1233-1239.

Anesthesiology
Postoperative pain facilitates nonthermoregulatory tremor
Horn, EP; Schroeder, F; Wilhelm, S; Sessler, DI; Standl, T; von dem Busche, K; Esch, JSA
Anesthesiology, 91(4): 979-984.

Stroke
Neither arm nor face warming reduces the shivering threshold in unanesthetized humans
Doufas, AG; Wadhwa, A; Lin, CM; Shah, YM; Hanni, K; Sessler, DI
Stroke, 34(7): 1736-1740.
10.1161/01.STR.0000077014.47422.DB
CrossRef
Journal of Anesthesia
The effects of remifentanil or acetaminophen with epidural ropivacaine on body temperature during labor
Evron, S; Ezri, T; Protianov, M; Muzikant, G; Sadan, O; Herman, A; Szmuk, P
Journal of Anesthesia, 22(2): 105-111.
10.1007/s00540-007-0589-8
CrossRef
Thermoregulation
The threshold for thermoregulatory vasoconstriction during nitrous oxide/sevoflurane anesthesia is lower in elderly than in young patients
Ozaki, M; Sessler, DI; Suzuki, H; Ozaki, K; Atarashi, K; Negishi, C
Thermoregulation, 813(): 789-791.

International Journal of Stroke
Therapeutic hypothermia for acute stroke
Lyden, PD; Krieger, D; Yenari, M; Dietrich, WD
International Journal of Stroke, 1(1): 9-19.

Anesthesia and Analgesia
Independent risk factors for postoperative shivering
Eberhart, LHJ; Doderlein, F; Eisenhardt, G; Kranke, P; Sessler, DI; Torossian, A; Wulf, H; Morin, AM
Anesthesia and Analgesia, 101(6): 1849-1857.
10.1213/O1.ANE.0000184128.41795.FE
CrossRef
New England Journal of Medicine
Mild perioperative hypothermia
Sessler, DI
New England Journal of Medicine, 336(): 1730-1737.

Journal of the Neurological Sciences
Progress in shivering control
Mahmood, MA; Zweifler, RM
Journal of the Neurological Sciences, 261(): 47-54.
10.1016/j.jns.2007.04.038
CrossRef
Regional Anesthesia and Pain Medicine
Shivering and neuraxial anesthesia
Crowley, LJ; Buggy, DJ
Regional Anesthesia and Pain Medicine, 33(3): 241-252.
10.1016/i.rapm.2007.11.006
CrossRef
Arthroscopy-the Journal of Arthroscopic and Related Surgery
Comparative Study of the Influence of Room-Temperature and Warmed Fluid Irrigation on Body Temperature in Arthroscopic Shoulder Surgery
Kim, YS; Lee, JY; Yang, SC; Song, JH; Koh, HS; Park, WK
Arthroscopy-the Journal of Arthroscopic and Related Surgery, 25(1): 24-29.
10.1016/j.arthro.2008.08.005
CrossRef
Journal of International Medical Research
Intra-operative Warming with a Forced-air Warmer in Preventing Hypothermia after Tourniquet Deflation in Elderly Patients
Kim, YS; Jeon, YS; Lee, JA; Park, WK; Koh, HS; Joo, JD; In, JH; Seo, KW
Journal of International Medical Research, 37(5): 1457-1464.

Anaesthesist
Intraoperative heat conservation: A bunch of hot air?
Scherer, R
Anaesthesist, 46(2): 81-90.

Anesthesia and Analgesia
The threshold for thermoregulatory vasoconstriction during nitrous oxide sevoflurane anesthesia is reduced in the elderly
Ozaki, M; Sessler, DI; Matsukawa, T; Ozaki, K; Atarashi, K; Negishi, C; Suzuki, H
Anesthesia and Analgesia, 84(5): 1029-1033.

Stroke
Dexmedetomidine and meperidine additively reduce the shivering threshold in humans
Doufas, AG; Lin, CM; Suleman, MI; Liem, EB; Lenhardt, R; Morioka, N; Akca, O; Shah, YM; Bjorksten, AR; Sessler, DI
Stroke, 34(5): 1218-1223.
10.1161/01.STR.0000068787.76670.A4
CrossRef
Anaesthesia
Effect of intra-operative end-tidal carbon dioxide partial pressure on tissue oxygenation
Akca, O; Liem, E; Suleman, MI; Doufas, AG; Galandiuk, S; Sessler, DI
Anaesthesia, 58(6): 536-542.

Scottish Medical Journal
Hypothermia in elderly patients presenting to Accident & Emergency during the onset of winter
Pedley, DK; Paterson, B; Morrison, W
Scottish Medical Journal, 47(1): 10-11.

Anaesthesist
Postoperative shivering
Schafer, M; Kunitz, O
Anaesthesist, 51(9): 768-783.
10.1007/s00101-002-0381-y
CrossRef
Anesthesia and Analgesia
Age-related thermoregulatory differences in a warm operating room environment (approximately 26 degrees C)
El-Gamal, N; El-Kassabany, N; Frank, SM; Amar, R; Abu Khabar, H; El-Rahmany, HK; Okasha, AS
Anesthesia and Analgesia, 90(3): 694-698.

Current Therapeutic Research-Clinical and Experimental
Effect of dexmedetomidine IV on the duration of spinal anesthesia with prilocaine: A double-blind, prospective study in adult surgical patients
Tekin, M; Kati, I; Tomak, Y; Kisli, E
Current Therapeutic Research-Clinical and Experimental, 68(5): 313-324.

Anasthesiologie Intensivmedizin Notfallmedizin Schmerztherapie
Hypothermia - Pathophysiology, prophylaxis and therapy
Horn, EP
Anasthesiologie Intensivmedizin Notfallmedizin Schmerztherapie, 37(7): 409-428.

Journal of Anesthesia
The effects of anesthetic technique and ambient temperature on thermoregulation in lower extremity surgery
Ozer, AB; Tosun, F; Demirel, I; Unlu, S; Bayar, MK; Erhan, OL
Journal of Anesthesia, 27(4): 528-534.
10.1007/s00540-013-1555-2
CrossRef
Critical Care Medicine
Thermoregulatory defense mechanisms
Sessler, DI
Critical Care Medicine, 37(7): S203-S210.
10.1097/CCM.0b013e3181aa5568
PDF (423) | CrossRef
Anesthesiology
Temperature Monitoring and Perioperative Thermoregulation
Sessler, DI
Anesthesiology, 109(2): 318-338.
10.1097/ALN.0b013e31817f6d76
PDF (737) | CrossRef
Anesthesiology
Predictors of Hypothermia during Spinal Anesthesia
Frank, SM; El-Rahmany, HK; Cattaneo, CG; Barnes, RA
Anesthesiology, 92(5): 1330-1334.

PDF (153)
Anesthesiology
Non‐thermoregulatory Shivering in Patients Recovering from Isoflurane or Desflurane Anesthesia
Horn, E; Sessler, DI; Standl, T; Schroeder, F; Bartz, H; Beyer, JC; Schulte Esch, J
Anesthesiology, 89(4): 878-886.

PDF (6541)
Anesthesiology
Perioperative Shivering: Physiology and Pharmacology
De Witte, J; Sessler, DI
Anesthesiology, 96(2): 467-484.

PDF (280)
Anesthesiology
Nefopam and Alfentanil Additively Reduce the Shivering Threshold in Humans whereas Nefopam and Clonidine Do Not
Alfonsi, P; Passard, A; Gaude–Joindreau, V; Guignard, B; Sessler, DI; Chauvin, M
Anesthesiology, 111(1): 102-109.
10.1097/ALN.0b013e3181a979c1
PDF (416) | CrossRef
Anesthesiology
Complications and Treatment of Mild Hypothermia
Sessler, DI
Anesthesiology, 95(2): 531-543.

PDF (210)
Back to Top | Article Outline

© 1995 American Society of Anesthesiologists, Inc.

Publication of an advertisement in Anesthesiology Online does not constitute endorsement by the American Society of Anesthesiologists, Inc. or Lippincott Williams & Wilkins, Inc. of the product or service being advertised.
Login

Article Tools

Images

Share