Table 1 Patient Demographic, Clinical, Operative, and Anesthetic Details for Startle Sign and Non-Startle Sign Cases

Demographic Characteristics

Age, years

50 [35, 59]

-

46 [34, 56]

-

0.42

Female Sex

24

47%

5

39%

0.81

Race

-

-

-

-

0.51

 White

38

74%

10

77%

 Black

3

6%

1

8%

 Asian

2

4%

2

15%

 Other

6

12%

0

0%

 Declined

1

2%

0

0%

 Unavailable

1

2%

0

0%

BMI, kg/m²

27 [23, 33]

-

27 [23, 33]

-

0.83

Clinical History

Neuroma Location

-

-

-

-

0.77

 Lower extremity

38

74%

9

69%

 Upper extremity

12

24%

4

31%

 Trunk

1

2%

0

0%

Neuroma Pain Duration, years

2 [1, 3]

-

2 [2, 3]

-

0.12

Inciting Event

-

-

-

-

0.78

 Infection

1

2%

0

0%

 Surgery

32

63%

9

69%

 Trauma

15

29%

4

31%

 Unknown

3

6%

0

0%

Pre-operative Medications

-

-

-

-

 Anti-hypertensives

6

12%

2

15%

1.00

 Beta-blockers

6

12%

0

0%

0.44

 Narcotics

12

23%

3

23%

1.00

 Gabapentinoids

16

31%

0

0%

0.05

 NSAIDs

10

19%

4

31%

0.62

Pre-operative Success of Diagnostic Nerve Block

-

-

-

-

0.40

 Yes

25

49%

4

31%

 No

1

2%

0

0%

 Not performed

25

49%

9

69%

ASA Physical Status

-

-

-

-

0.31

 1

8

16%

4

31%

 2

32

63%

8

61%

 3

11

21%

1

8%

Operative Characteristics

Operation

-

-

-

-

0.83

 Excision +/- burying

10

20%

3

23%

 Excision & allograft recon

29

57%

8

62%

 Excision & targeted muscle reinnervation

9

17%

2

15%

 Excision & regenerative peripheral nerve interface

3

6%

0

0%

Operative Duration, minutes

76 [60, 95]

-

88 [70, 119]

-

0.35

Tourniquet

40

78%

10

77%

1.00

 Tourniquet Time, minutes^a

54 [34, 66]

-

67 [15, 85]

-

Anesthesia Variables

Airway Management

 Laryngeal Mask Airway

22

43%

6

54%

0.36

 Endotracheal Tube

22

43%

7

46%

 Natural Airway

7

14%

0

 0%

Induction Medications

 Propofol

48

94%

13

100%

0.87

  mg^a

200 [150, 220]

-

200 [200, 250]

-

 Ketamine

15

29%

3

23%

0.91

  mg^a

50 [40, 50]

-

30 [25, 40]

-

 Fentanyl

45

88%

11

85%

1.00

  mcg^a

100 [50, 100]

-

100 [50, 100]

-

 Lidocaine

40

78%

9

69%

0.74

  mg^a

100 [80, 100]

-

80 [60, 100]

-

 Long-acting Paralytic

8

16%

3

23%

0.83

 Use of Any Inhaled Anesthetics

38

75%

12

92%

0.31

 Total Age-Adjusted Mean Alveolar Concentration^a

1.2 [0.9, 1.6]

-

1.0 [0.7,1.2]

-

Primary Anesthesia Mode

0.001

 Inhaled Anesthesia

33

64%

5

38%

 TIVA

8

16%

1

8%

 CIVIA

4

8%

7

54%

 Monitored Anesthetic Care

6

12%

0

0%

Maintenance Anesthesia

-

-

 Sevoflurane

38

75%

10

77%

1.00

  Expired, percent^a

1.8 [1.4, 1.9]

-

1.4 [1.2, 1.8]

-

 Nitrous Oxide

20

39%

5

39%

1.00

  Expired, percent^a

43.4 [39.3, 56.2]

-

49.8 [41.8, 52.0]

-

 Isoflurane

0

0%

1

8%

0.46

 Dexmedetomidine

0

0%

1

8%

0.46

 Propofol

20

39%

8

62%

0.26

  mcg/kg/min^a

96.6 [84.5, 114.4]

-

104.8 [62.4, 137.4]

-

 Ketamine

7

14%

2

15%

1.00

  mcg/kg/min^a

10.6 [10.4, 12.1]

-

18.2 [15.1, 21.4]

-

 Remifentanil

6

12%

1

8%

1.00

  mcg/kg/min^a

0.10 [0.08, 0.10]

-

0.10 [0.10, 0.10]

-

Use of Opioids

 Hydromorphone

16

31%

4

31%

1.00

 Fentanyl

13

26%

6

46%

0.27

Local Anesthesia

0.84

 Local (administered by surgeon at surgical site)

40

78%

11

84%

 Regional Block

4

8%

1

8%

 None

7

14%

1

8%

Intravenous Morphine Equivalents

29

57%

9

70%

0.62

 mg/kg (all patients)

0.04 [0.00, 0.11]

-

0.08 [0.00, 0.10]

-

0.36

 mg/kg^a

0.09 [0.05, 0.16]

-

0.10 [0.08, 0.14]

-

 mg (all patients)

3.35 [0.00, 7.50]

-

5.00 [0.00, 9.96]

-

0.37

 mg^a

6.67 [3.37, 13.29]

-

8.31 [5.00, 15.00]

-