Pain-related psychological correlates of pediatric acute post-surgical pain

Figures & data

Table 1 Recruitment process

Total number of eligible participants	534
Reason not recruited
No research staff available	95
Developmental/cognitive delays	78
Discharged	71
Parent absent	40
Noncommunicative	31
Sleeping	22
Pediatric intensive care unit	21
Parents not fluent in English	19
Undergoing other medical procedures	6
Other	3
Total number of potential participants approached	148
Reason for refusal to participate
Not interested	18
Too tired	16
Too nauseous	12
Parents too busy	5
Already in other studies	4
Too much pain	3
Too sleepy	3
Other	4
Total number of participants	83
Lost to follow-up	14
Total number of completed follow-up 2 weeks after discharge	69

Table 2 Peri-operative Information

SURGERY	Mean (SD)
Surgery Time (minutes)	317.5 (141.3)
Intraoperative Opioids	n (%)
Fentanyl + Remifentanil + Morphine	20 (24.0)
Fentanyl + Morphine	23 (27.7)
Remifentanil + Morphine	12 (14.5)
Fentanyl	11 (13.2)
Fentanyl + Other	7 (8.4)
Fentanyl + Remifentanil	3 (3.6)
Morphine	2 (2.5)
Other	2 (2.5)
Remifentanil	1 (1.2)
Intraoperative opioid data not available	2 (2.5)
PACU	Mean (SD)
Time in PACU	181.2 (143.3)
PACU analgesics	n (%)
Morphine	28 (33.8)
Acetaminophen + Morphine	26 (31.4)
Acetaminophen + Fentanyl	5 (6.0)
Acetaminophen + Other	5 (6.0)
Acetaminophen + Hydromorphone	5 (6.0)
Other	4 (4.8)
Hydromorphone	2 (2.4)
Fentanyl	2 (2.4)
Acetaminophen + NSAID + Morphine	1 (1.2)
Acetaminophen + NSAID	1 (1.2)
Acetaminophen	1 (1.2)
PACU analgesic data not available	3 (3.6)
DAY 1
Acetaminophen and NSAIDs	n (%)
Acetaminophen PO	50 (60.2)
Acetaminophen PR	13 (15.7)
Acetaminophen PO +NSAID IV	9 (10.8)
Acetaminophen PO +NSAID PO	2 (2.5)
Acetaminophen PR+NSAID IV	1 (1.2)
Acetaminophen PR+NSAID PO	1 (1.2)
NSAID PO	1 (1.2)
Day 1 analgesic consumption not available	6 (7.2)
Opioids	n (%)
Morphine IV	50 (60.2)
Hydromorphone IV	12 (14.5)
Fentanyl IV	6 (7.2)
Morphine IV + Hydromorphone IV	1 (1.2)
Morphine IV + Other	1 (1.2)
Morphine PO + Fentanyl IV	1 (1.2)
Other	3 (3.6)
Day 1 analgesic consumption not available	9 (10.9)
	Mean (SD)
Least Pain Score (NRS)	1.50 (1.6)
Highest Pain Score (NRS)	4.81 (2.5)

Abbreviation: NRS, Numerical Rating Scale; NSAID, nonsteroidal anti-inflammatory drug; PACU, post anesthesia care unit; PO, orally; PR, per rectum; IV, intravenously; SD, standard deviation.

Table 3 Mean (standard deviation) of pain and related psychological variables for boys, girls, and the total sample when measured 48–72 hours after surgery and 2 weeks after discharge

	48–72 hours after surgery (0)			Two weeks after discharge (2)
	Boys	Girls	Total	Boys	Girls	Total
Pain anxiety (CPASS)	46.11 (18.9)	48.09 (19.5)	47.45 (19.2)	35.23 (16.4)	38.77 (19.4)	37.64 (18.4)
Pain catastrophizing (PCSC)	21.69 (12.7)	21.91 (12.1)	21.84 (12.2)
Anxiety sensitivity (CASI)	30.00 (6.0)†	34.32 (7.6)	32.92 (7.4)
Depression (CES-DC)	22.70 (10.4)	23.55 (12.4)	23.27 (11.7)
Anxiety (MASC-10)	9.54 (4.9)†	12.84 (5.2)	11.74 (5.3)
Pain	Yes = 23	Yes = 53	Yes = 76	Yes = 14	Yes = 38	Yes = 52
	No = 4	No = 3	No = 7	No = 8	No = 9	No = 17
Pain intensity (NRSI)*	3.44 (2.4)	4.06 (2.3)	3.86 (2.3)	2.20 (2.1)	2.32 (2.2)	2.28 (2.2)
Pain unpleasantness (NRSU)*	3.70 (2.6)†	4.98 (2.8)	4.57 (2.8)	2.23 (2.3)	2.73 (2.7)	2.57 (2.6)
Functional disability (FDI)*				16.32 (9.4)†	21.15 (8.0)	19.61 (8.8)

Notes:

* Pain intensity, pain unpleasantness, and functional disability scores are computed only for children who reported experiencing pain and do not take into account children who did not endorse pain at each time point.

† Signficant difference between boys and girls (P < 0.05).

Abbreviations: CPASS, Child Pain Anxiety Symptoms Scale; PCSC, Pain Catastrophizing Scale-Children; CASI, Childhood Anxiety Sensitivity Index; CES-DC, Center for Epidemiological Studies-Depression Scale for Children; MASC-10, Multidimensional Anxiety Scale for Children-10; NRSI, Numerical Rating Scale for Pain Intensity; NRSU, Numerical Rating Scale for Pain Unpleasantness; FDI, Functional Disability Inventory.

Table 4 Pain-related psychological variables (48–72 hours after surgery) associated with APSP (48–72 hours after surgery) intensity and unpleasantness using linear regression analysis

	β	t	P	F	df	Adj R^2	R^2 change
Pain intensity
Step 1			0.270	1.35	3;52	0.02	0.07
Age	0.25	1.85	0.069
Gender	−0.03	−0.24	0.809
Morphine equivalent	−0.11	−0.82	0.413
Step 2			0.006	3.73	5;50	0.20	0.20
Age	0.34	2.71	0.009
Gender	−0.06	−0.45	0.654
Morphine equivalent	−0.10	−0.82	0.419
CES-DC	0.56	3.42	0.001
MASC-10	−0.19	−1.11	0.273
Step 3			0.001	5.97	6;49	0.35	0.15
Age	0.26	2.24	0.030
Gender	−0.09	−0.72	0.473
Morphine equivalent	−0.11	−0.95	0.349
CES-DC	0.36	2.31	0.025
MASC-10	−0.38	−2.28	0.027
CPASS	0.51	3.58	0.001
Pain unpleasantness
Step 1			0.109	2.11	3;55	0.05	0.10
Age	0.10	0.75	0.457
Gender	−0.22	−1.72	0.092
Morphine equivalent	−0.26	−1.96	0.056
Step 2			0.034	2.62	5;53	0.12	0.10
Age	0.16	1.26	0.275
Gender	−0.24	−1.78	0.081
Morphine equivalent	−0.25	−1.86	0.068
CES-DC	0.38	2.29	0.026
MASC-10	−0.12	−0.67	0.508
Step 3			0.012	3.05	6;52	0.18	0.06
Age	0.16	1.22	0.226
Gender	−0.25	−1.97	0.054
Morphine equivalent	−0.27	−2.08	0.042
CES-DC	0.26	1.55	0.127
MASC-10	−0.22	−1.25	0.216
PCSC	0.32	2.09	0.042

Abbreviations: Adj, adjusted; APSP, acute post-surgical pain; CPASS, Child Pain Anxiety Symptoms Scale; PCSC, Pain Catastrophizing Scale-Children; CESD-C, Center for Epidemiological Studies-Depression Scale for Children; MASC-10, Multidimensional Anxiety Scale for Children-10.

Figure 1 Summary of results showing that children who were surgery-naïve had higher levels of anxiety sensitivity and general anxiety compared with children who had undergone surgery in the past.

Notes: Girls reported higher levels of anxiety sensitivity, general anxiety, and pain unpleasantness 48–72 hours after surgery, as well as functional disability 2 weeks after discharge compared with boys. Age, depression, general anxiety, and pain anxiety scores were significantly associated with pain intensity, while analgesic consumption and pain catastrophizing were significantly associated with pain unpleasantness 48–72 hours after surgery. Levels of pain anxiety 48–72 hours after surgery predicted levels of functional disability 2 weeks after discharge from hospital. Plain one-sided arrows represent predictors of pain outcomes. Long-dashed, double-sided arrows represent correlates of pain outcomes. Short-dashed arrows represent predictors of changes in pain and functional disability over time. Black boxes represent pain and functional disability outcomes. Gray boxes represent predictors and correlates.

Table 5 Pain-related psychological variables (48–72 hours after surgery) associated with APSP (2 weeks after discharge) intensity and unpleasantness and functional disability using linear regression analysis

	β	t	P	F	df	Adj R^2	R^2 change
Pain intensity
Step 1			0.261	1.38	3;45	0.02	0.08
Age	0.18	1.25	0.219
Gender	0.23	1.55	0.127
Morphine equivalent	−0.13	−0.91	0.367
Step 2			0.105	1.95	5;43	0.09	0.10
Age	0.24	1.62	0.112
Gender	0.20	1.38	0.174
Morphine equivalent	−0.12	−0.79	0.433
CES-DC	0.42	2.15	0.037
MASC-10	−0.17	−0.85	0.400
Step 3
Age	No variables entered using stepwise method
Gender
CES-DC
MASC-10
Pain unpleasantness
Step 1			0.436	0.93	3;45	−0.01	0.06
Age	0.10	0.70	0.491
Gender	0.75	0.51	0.611
Morphine equivalent	−0.23	−1.52	0.135
Step 2			0.142	1.76	5;43	0.07	0.11
Age	0.17	1.18	0.245
Gender	0.09	0.60	0.550
Morphine equivalent	−0.18	−1.21	0.233
CES-DC	0.35	1.76	0.085
MASC-10	−0.01	−0.01	0.994
Step 3
Age	No variables entered using stepwise method
Gender
CES-DC
MASC-10
Functional disability
Step 1			0.302	1.25	3;45	0.08	0.08
Age	−0.01	−0.04	0.965
Gender	−0.16	−1.08	0.285
Morphine equivalent	−0.24	−1.66	0.104
Step 2			0.002*	4.53	5;43	0.35	0.27
Age	0.10	0.76	0.453
Gender	−0.14	−1.10	0.277
Morphine equivalent	−0.18	−1.34	0.188
CES-DC	0.56	3.21	0.002
MASC-10	−0.04	−0.23	0.823
Step 3			0.001*	5.32	6;42	0.43	0.09
Age	0.04	0.31	0.758
Gender	−0.15	−1.18	0.246
Morphine equivalent	−0.19	−1.53	0.133
CES-DC	0.42	2.42	0.020
MASC-10	−0.18	−1.01	0.319
CPASS	0.39	2.54	0.015

Note: P < 0.05

Abbreviations: Adj, adjusted; APSP, acute post-surgical pain; CPASS, Child Pain Anxiety Symptoms Scale; PCSC, Pain Catastrophizing Scale-Children; CESD-C, Center for Epidemiological Studies-Depression Scale for Children; MASC-10, Multidimensional Anxiety Scale for Children-10.