Table 6 Factors associated with post-spinal shivering in those patients who took prophylactic dose of ketamine or tramadol and underwent orthopedic surgery at the comprehensive specialized hospital of Wolaita Sodo University from February 28/2020–August 28, 2020

Age

 18–35(young aged adult)

141(46.4)

163(53.6)

0.11(0.04, 0.32)

0.08(0.02, 0.27) ***

 36–55 (middle aged adult)

42(25.1)

125(74.9)

0.29(0.10, 0.86)

0.24(0.07, 0.81) *

  > 55 years (Older adults)

4(8.9)

41(91.1)

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Religion

 Orthodox

63(32.8)

129(67.2)

1.80(0.53, 1.21)

1.95(0.70, 4.92)

 Protestant

83(39.3)

128(60.7)

1.42(0.60, 1.74)

1.38(0.48, 3.34)

 Muslim

30(33.3)

60(66.7)

0.55(0.23, 1.33)

1.96(0.60, 5.54)

 Catholic

11(47.8)

12(52.2)

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Ethnicity

 Wolaita

70(39.1)

109(60.9)

0,83(0.39, 1.76)

0.69(0.29, 1.64)

 Amhara

14(42.4)

19(57.6)

1.08(0.63, 1.85)

0.59(0.20, 1.75)

 Oromo

29(34.9)

54(65.1)

1.02(0.55, 1.89)

0.60(0.23, 1.58)

 Gurage

21(37.5)

35(62.5)

1.73(0.84, 3.58)

0.70(0.25, 1.92)

 Hadia

12(26.1)

34(73.9)

1.13(0.60, 2.11)

1.21(0.41, 3.48)

 Gamo

19(33.3)

38(66.7)

0.71(0.31, 1.63)

0.75(0.28, 2.01)

 Sidama

12(46.2)

14(53.8)

1.39(0.64, 3.00)

0.50(0.15, 1.62)

 Others

10(27.8)

26(72.2)

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ASA classification

 ASA I

185(37.2)

312(62.8)

0.197(0.45,0.861)

0.47(0.09, 2.51)

 ASA II

2(10.5)

17(89.5)

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Body temperature

  < 36.0

65(37.6)

108(62.4)

0.98(0.67, 1.44)

0.24(0.07, 0.80)

 36.1–36.9

118(37.1)

200(62.9)

0.32(0.10, 0.96)

0.40(0.12, 1.29)

  > 37.0

4(16.0)

21(84.0)

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Prophylactive agent

 Ketamine

74(28.7)

184(71.3)

0.50(0.35–0.73)

0.427(0.28, 0.63) ***

 Tramadol

113(45.8)

145(56.2)

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Duration of surgery

  ≤ 1 h

177(68.9)

80(31.1)

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  > 1 h

11(4.2)

248(95.8)

17.66(7.2–43.34)

1.47(1.37, 1.58) ***

Blood loss during surgery

  < 100 ml

91(39.7)

138(60.3)

1.63(1.09, 2.42)

1.47(0.80, 2.68)

 100–199 ml

62(28.7)

154(71.3)

0.77(0.45, 1.32)

2.36(1.28, 4.34)

  ≥ 200 ml

34(47.9)

37(52.1)

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Sedation

 Yes

31(28.2)

1.597(1.01–2.532)

0.81(0.47, 1.37)

 No

155(38.3)

79(71.8)

250(61.7)

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