Prospective randomized comparison of oral sodium phosphate and polyethylene glycol lavage for colonoscopy preparation

Table 1 Grades of bowel cleansing

Score	Stool amount	Stool consistency	Percent wall visualized	Overall assessment
0	None	None	≥90%
1	Small	Clear lavage	75-89%	Excellent (small volume of clear liquid)
2	Moderate	Liquid stool	50-74%	Good (large volume of clear liquid)
3	Large	Particulate stool	≤49%	Fair (some semi-solid stool that could be suctioned or washed away)
4		Semi-solid stool		Poor (semi-solid stool that could not be suctioned or washed away)
5		Solid stool

Table 2 Demographic characteristics and prior bowel preparation experience

Variables	NaP (n = 40)			PEG (n = 40)
		N	%	N	%	P1
Gender						0.178
Male		18	45.0	25	62.5
Female		22	55.0	15	37.5
Age						0.948
Mean±SD2		52.2±13.6		52.4±12.6
Median (range)		51.9 (25.6-75.6)		54.2 (23.1-77.3)
Frame size						0.571
Small (BMI<21)		6	15.0	6	15.0
Medium (BMI:21–24)		30	75.0	26	65.0
Large (BMI>24)		4	10.0	8	20.0
Concomitant edication		4	10.0	5	12.5	1.000
Anti-hypertensive		1	2.5	4	10.0
Others		3	7.5	4	10.0
Previous bowel preparation						1.000
		13	32.5	14	35.0

¹Fisher’s exact test or 2-sample Student’s t-test, when appropriate.

²SD: standard deviation.

Table 3 Consumption rate of oral solution

Variables	NaP (n = 38)		PEG (n = 40)
	N	%	N	%	P1
Consumption rate (%)
100%	32	84.2	11	27.5	<0.001
75-99%	6	15.8	15	37.5
<75%	0	0	14	35.0
Mean±SD2	97.2±6.9		73.4±21.1		<0.001
Median (range)	100 (75–100)		75 (25–100)

¹Mantel–Haenszel χ² test and t-test when appropriate.

²SD: standard deviation.

Table 4 Overall assessment of preparation by the colonoscopist and stratified by completion of solution

Group	Excellent (%)	Good (%)	Fair (%)	Poor (%)	χ2M–HP	Good/excellent (%)	P
Overall
NaP (n = 38)	22 (57.9)	8 (21.1)	8 (21.1)	0 (0.0)	0.648	30 (78.9)	0.7781
PEG (n = 40)	22 (55.0)	11 (27.5)	3 (7.5)	4 (10.0)		33 (82.5)
Complete	100				0.5842		0.3212
NaP (n = 32)	19 (59.4)	7 (21.9)	6 (18.8)	0 (0.0)		26 (81.3)
PEG (n = 11)	8 (72.7)	2 (18.2)	1 (9.1)	0 (0.0)		10 (90.9)
Incomplete	0-99
NaP (n = 6)	3 (50.0)	1 (16.7)	2 (33.3)	0 (0.0)		4 (66.7)
PEG (n = 29)	14 (48.3)	9 (31.0)	2 (6.9)	4 (13.8)		23 (79.3)

¹Fisher’s exact test.

²Cochran-Mantel-Haenszel χ² test controlling for completion of oral solution.

Table 5 Colonic segmental assessment of preparation

	Stool amount (none/small) N (%)			Stool consistency (none/clear lavage) N (%)			% Colonic wall visualized (≥75%) N (%)
	NaP (N = 38)	PEG (N = 40)	P	NaP (N = 38)	PEG (N = 40)	P	NaP (N = 38)	PEG (N = 40)	P
Rectum	37 (97.4)	33 (82.5)	0.057	31 (81.6)	32 (80.0)	1.000	37 (97.4)	37 (92.5)	0.616
Descending	36 (94.7)	28 (70.0)	0.007	32 (84.2)	33 (82.5)	1.000	38 (100)	35 (87.5)	0.055
Transverse1	35 (94.6)	29 (74.4)	0.025	31 (83.8)	34 (87.2)	0.752	37 (100)	37 (94.9)	0.494
Ascending2	35 (100)	35 (89.7)	0.117	24 (68.6)	31 (79.5)	0.302	35 (100)	38 (97.4)	1.000
Cecum2	35 (100)	35 (89.7)	0.117	23 (65.7)	31 (79.5)	0.202	35 (100)	37 (94.9)	0.495

¹One patient in NaP group and 1 in PEG group did not have this data.

²Three patients in NaP group and 1 in PEG group did not have this data.

Table 6 Occurrence and severity of anticipated adverse events

	NaP (n = 40)				PEG (n = 40)
	Mild	Moderate	Severe	Occurrence (%)1	Mild	Moderate	Severe	Occurrence (%)1	P2
Nausea	17	0	1	18 (45)	14	4	0	18 (45)	1.000
Vomiting	9	1	0	10 (25)	5	4	0	9 (22.5)	1.000
Abdominal bloating	16	2	0	18 (45)	12	0	0	12 (30)	0.248
Abdominal pain	14	1	1	16 (40)	11	0	0	11 (27.5)	0.344
Anal irritation	13	3	0	16 (40)	10	1	1	12 (30)	0.482
Dizziness	13	2	1	16 (40)	10	1	0	11 (27.5)	0.344
Chills	3	0	1	4 (10)	3	0	0	3 (7.5)	1.000
Hunger pains	7	0	0	7 (17.5)	7	0	0	7 (17.5)	1.000
Headache	6	1	0	7 (17.5)	6	0	0	6 (15)	1.000
Insomnia3	4	1	0	5 (12.8)	2	0	0	2 (5)	0.263
Total	11	4	117	11	80	10	1	91

¹Occurrence rate was calculated by “frequency of occurrence/total number of subject”. ²Fisher’s exact test for occurrence frequency of adverse events.

³One patient in NaP group was taking Lorazepan (Ativan, Wyeth, USA) for insomnia during the bowel preparation, therefore this event was not assessable for this patient.

Table 7 Electrolytes

	NaP (n = 40)			PEG (n = 40)			Overall			2-Sample
	Baseline	Follow-up	Change1	Baseline	Follow-up	Change1	Baseline	Follow-up	Change1	t-test
	Mean±SD2	Mean±SD2	Mean±SD2	Mean±SD2	Mean±SD2	Mean±SD2	Mean±SD2	Mean±SD2	Mean±SD2	P3
Na (meq/L)	138.83±2.15	140.40±2.42	1.58±2.57b	138.85±2.15	140.88±2.37	2.03±1.83b	138.84±2.14	140.64±2.39	1.80±2.23b	0.370
K (meq/L)	3.99±0.34	3.86±0.39	-0.13±0.43	4.02±0.40	4.10±0.50	0.09±0.40	4.00±0.37	3.98±0.46	-0.02±0.43	0.022a
Cl (meq/L)	104.93±2.75	101.48±2.77	-3.45±2.84b	105.20±2.85	101.43±2.38	-3.78±2.71b	105.06±2.78	101.45±2.57	-3.61±2.76b	0.602
Ca (mg/dL)	9.17±0.35	9.17±0.39	-0.01±0.49	9.14±0.36	9.29±0.34	0.15±0.40a	9.16±0.35	9.23±0.37	0.07±0.46	0.129
P (mg/dL)	3.42±0.83	2.71±0.50	-0.71±0.76b	3.25±0.57	3.10±0.51	-0.16±0.57	3.34±0.71	2.90±0.54	-0.43±0.73b	<0.001b

^aP<0.05;

^bP<0.01.

¹Change: value obtained at follow-up visit – value obtained at baseline visit.

²SD: standard deviation. ³The change from baseline (change) was compared between the two groups by independent 2-sample t-test.

Table 8 Hemodynamic profile

	Baseline		Day of colonoscopy change1 from baseline		Follow-up visit change1 from baseline
	NaP	PEG	NaP	PEG	NaP	PEG
Pulse (beats/min) mean±SD2	76.4±11.2	72.9±12.4	5.4±13.6	6.7±12.6	1.7±10.9	0.6±13.0
Elevation in pulse rate ±10 beats/min (n %)			13 (32.5%)	13 (32.5%)	8 (20%)	9 (22.5%)
Elevation in pulse rate ±20 beats/min (n %)			5 (12.5%)	4 (10%)	3 (7.5%)	3 (7.5%)
SBP3 (mmHg) mean±SD2	128.0±16.4	130.4±16.0	-6.8±12.5	-1.7±10.8	-4.3±10.7	-1.4±13.6
Drop in SBP ≥10 mmHg (n %)			13 (32.5%)	11 (27.5%)	14 (35%)	7 (17.5%)
Drop in SBP ≥20 mmHg (n %)			3 (7.5%)	0 (0.0%)	2 (5%)	4 (10%)

¹Change: value obtained at the visit – value obtained at baseline visit.

²SD: standard deviation.

³SBP: systolic blood pressure.