“The influence of female body mass index, menstrual cycle phase and age on propofol injection pain”

Figures & data

Figure 1. Flow chart of the studied cases

Table 1. Characteristics of the study population

Variable	Mean ± SE/Number (%)
Age (years)	40.9 ± 1.6
Weight (kg)	83.7 ± 1.7
BMI (kg/m^2)	30.4 ± 0.7
BMI class
Non-Obese	40 (47.6%)
Obese	44 (52.4%)
Menstrual cycle phase
Menopausal	29 (34.5%)
Luteal	26 (31.0%)
Follicular	29 (34.5%)
ASA-PS
ASA-PS I	44 (52.4%)
ASA-PS II	40 (47.6%)
Site of IV cannulation
Dorsum of hand	72 (85.7%)
Cephalic vein at wrist	2 (2.4%)
Forearm	2 (2.4%)
Antecubital vein	8 (9.5%)
Propofol dose
Initial dose (mg)	43.6 ± 0.6
Total dose (mg)	190.0 ± 5.3
Duration of surgery (h)	1.83 ± 0.10

ASA-PS = American Society of Anesthesiologists – physical status, BMI = Body mass index, IV = Intravenous, SE = standard error.

Table 2. Percentage and characteristics of propofol-injection pain (PIP)

Variable	Mean ± SE/Number (%)
Propofol-injection pain
No PIP experienced	24 (28.6%)
PIP experienced	60 (71.4%)
VAS for PIP	3.05 ± 0.29
Pain severity
No PIP	24 (28.6%)
Mild	26 (31.0%)
Moderate	23 (27.4%)
Severe	11 (13.1%)
Type of PIP
Burning	48/60 (80.0%)
Paresthesia	10/60 (16.7%)
Both	2/60 (3.3%)
Onset of pain
Early	44/60 (73.3%)
Delayed	16/60 (26.7%)

SE = standard error, PIP = Propofol injection pain, VAS = visual analogue scale.

Table 3. Interaction between obesity and menstrual cycle phase

Source	Sum of Squares	DF	Mean Square	F	P-value
Obesity	3.421	1	3.421	0.494	0.484
Menstrual cycle phase	60.147	2	30.074	4.345	0.016
Obesity * Menstrual cycle phase	1.272	2	0.636	0.092	0.912
Residual	539.848	78	6.921

DF = degree of freedom, F = F-statistic.

Table 4. Bivariate analysis for risk factors of moderate/severe PIP

Variable	No/Mild PIP (n = 50)	Moderate/Severe PIP (n = 34)	p-value¶
Age (years)	45.0 ± 2.1	34.9 ± 12.4	0.002†
Age <35 years	11 (22.0%)	21 (61.8%)	<0.001
Menstrual cycle phase			0.068
Menopausal	22 (44.0%)	7 (20.6%)
Luteal	12 (24.0%)	14 (41.2%)
Follicular	16 (32.0%)	13 (38.2%)
Menopausal			0.027
Pre-Menopausal	28 (56.0%)	27 (79.4%)
Menopausal	22 (44.0%)	7 (20.6%)
BMI class			0.211
Non-Obese	21 (42.0%)	19 (55.9%)
Obese	29 (58.0%)	15 (44.1%)
ASA-PS			0.156
ASA-PS I	23 (46.0%)	21 (61.8%)
ASA-PS II	27 (54.0%)	13 (38.2%)
Site of IV cannulation			0.637§
Dorsum of hand	41 (82.0%)	31 (91.2%)
Cephalic vein at wrist	1 (2.0%)	1 (2.9%)
Forearm	2 (4.0%)	0 (0.0%)
Antecubital vein	6 (12.0%)	2 (5.9%)
Vein cannulated			0.345§
More proximal vein	9 (18.0%)	3 (8.8%)
Dorsum of hand	41 (82.0%)	31 (91.2%)
Initial dose of propofol(mg)	42.8 ± 0.7	44.9 ± 0.8	0.077

Data are mean ± SE or number (%). ¶. Pearson chi-squared test unless otherwise indicated. †. Independent-samples t-test. ‡. Chi-squared test for trend. §. Fisher’s exact test.

ASA-PS = American Society of Anesthesiologists – physical status, BMI = Body mass index, IV = Intravenous, PIP = Propofol injection pain.

Table 5. Multivariable binary logistic regression analysis for determinants of PIP

Variable	B	SE	Wald	P-value	Odds ratio	95% CI
Obesity†	−0.321	0.501	0.411	0.522	0.725	0.272to 1.937
Luteal phase of menstrual cycle‡	0.459	0.691	0.441	0.507	1.582	0.409 to 6.125
Follicular phase of menstrual cycle‡	−0.302	0.774	0.152	0.697	0.740	0.162 to 3.375
Age <35 years§	1.783	0.654	7.424	0.006	5.947	1.649 to 21.441
Constant	−0.986	0.496	3.950	0.047

B = Regression coefficient, SE = Standard error, Wald = Wald chi-squared statistic, 95% CI = 95% confidence interval.

†. Reference category is “Non-Obese”.

‡. Reference category is “Menopausal”.

§. Reference category is “Age ≥35 years”.

PIP = Propofol injection pain.

Availability of data and material

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.