Diagnostic value of digital continuous bowel sounds in critically ill patients with acute gastrointestinal injury: A prospective observational study

Table 8 Acute gastrointestinal injury grade and clinical variables

Variables	Non-AGI (n = 30)	AGI I (n = 32)	AGI II (n = 10)	AGI III-IV (n = 3)	PF/χ2	Pr	rs
Mean bowel sound rate (counts per minute)	4.343 ± 2.756	1.308 ± 1.610	0.942 ± 0.994	0.717 ± 0.690	< 0.001b	< 0.001b	-0.621
Duration of bowel sounds (seconds)	1.579 ± 1.049	0.513 ± 0.795	0.719 ± 1.385	0.178 ± 0.180	< 0.001b	< 0.001b	-0.572
Amplitude (dB)	0.121 ± 0.097	0.032 ± 0.043	0.065 ± 0.144	0.011 ± 0.009	< 0.001b	< 0.001b	-0.568
Average frequency (Hz)	708.559 ± 219.649	366.215 ± 238.280	344.720 ± 256.841	287.276 ± 260.841	< 0.001b	< 0.001b	-0.592
Interval time (seconds)	3.977 ± 1.410	2.180 ± 1.554	1.851 ± 1.285	2.045 ± 2.171	< 0.001b	< 0.001b	-0.514
Citrulline (μmol/L)	19.29 ± 1.46	18.47 ± 1.68	18.53 ± 1.94	18.22 ± 0.88	0.212	0.044a	-0.237
Intestinal fatty acid-binding protein (ng/L)	467 ± 59	489 ± 58	516 ± 61	467 ± 68	0.145	0.106	0.191
Gastrin (ng/L)	79.45 ± 12.16	72.49 ± 12.11	77.07 ± 11.22	93.33 ± 13.01	0.016a	0.651	-0.054
Motilin (ng/L)	215.20 ± 37.58	212.23 ± 38.97	218.42 ± 33.79	186.32 ± 46.98	0.625	0.692	-0.047
Sequential Organ Failure Assessment score, points	6 ± 3	9 ± 4	9 ± 6	12 ± 3	0.033a	0.008b	0.308
Acute Physiology and Chronic Health Evaluation II score, points	17 ± 6	21 ± 8	27 ± 12	20 ± 5	0.025a	0.017a	0.276
Hemoglobin (g/L)	98 ± 26	95 ± 21	96 ± 23	110 ± 8	0.733	0.890	0.017
Platelets (109/L)	161 ± 104	138 ± 95	78 ± 52	67 ± 38	0.087	0.025a	-0.266
white blood cell (109/L)	8.45 ± 3.36	10.58 ± 4.78	9.07 ± 2.41	7.01 ± 2.34	0.202	0.339	0.115
Neutrophil count (109/L)	7.32 ± 3.09	9.56 ± 4.61	6.84 ± 3.03	6.16 ± 1.68	0.110	0.544	0.073
Percentage of central granulocyte count	84.9 ± 7.9	89.5 ± 6.0	84.9 ± 8.3	89.3 ± 7.0	0.069	0.201	0.154
C-reactive protein (mg/L)	99.3 ± 72.7	98.2 ± 77.6	107.3 ± 96.1	159.3 ± 50.3	0.544	0.625	0.059
Procalcitonin (ng/mL)	3.768 ± 7.037	7.504 ± 14.053	4.888 ± 4.323	10.927 ± 7.004	0.150	0.073	0.215
Interleukin 6 (ng/mL)	103.68 ± 256.797	164.07 ± 358.46	169.29 ± 232.63	187.21 ± 170.99	0.066	0.007b	0.322
Total protein (g/L)	52.0 ± 6.7	50.8 ± 6.3	47.1 ± 6.0	46.1 ± 4.808	0.124	0.024a	-0.267
Albumin (g/L)	28.6 ± 3.6	28.0 ± 4.4	27.2 ± 3.8	25.7 ± 3.0	0.604	0.186	-0.159
Creatinine (µmol/L)	115 ± 108	111 ± 88	94 ± 66	131 ± 79	0.827	0.767	0.036
Blood urea nitrogen (mmol/L)	11.25 ± 6.00	11.03 ± 6.90	10.64 ± 7.24	25.19 ± 13.52	0.219	0.746	0.039
Serum sodium (mmol/L)	140.28 ± 5.17	138.51 ± 3.96	139.12 ± 7.87	142.91 ± 3.64	0.216	0.584	-0.066
Serum potassium (mmol/L)	4.09 ± 0.52	4.02 ± 0.44	4.08 ± 0.37	4.03 ± 0.46	0.933	0.944	-0.008
Serum calcium (mmol/L)	2.07 ± 0.17	2.04 ± 0.15	2.00 ± 0.16	1.92 ± 0.09	0.310	0.126	-0.183
Serum phosphorus (mmol/L)	0.94 ± 0.32	0.93 ± 0.40	1.02 ± 0.58	1.10 ± 0.12	0.623	0.725	0.042
Potential of hydrogen	7.457 ± 0.060	7.427 ± 0.075	7.397 ± 0.075	7.441 ± 0.074	0.114	0.021a	-0.273
Partial pressure of oxygen (mmHg)	106.4 ± 37.8	106.5 ± 39.7	103.3 ± 15.7	101.7 ± 31.7	0.980	0.910	0.014
Partial pressure of carbon dioxide (mmHg)	36.8 ± 8.9	39.0 ± 8.3	35.8 ± 7.4	34.6 ± 8.7	0.590	0.907	0.014
Bicarbonate (mmol/L)	26.4 ± 5.6	25.6 ± 4.3	21.8 ± 3.4	23.1 ± 2.3	0.073	0.036a	-0.249
Lactic acid (mmol/L)	1.2 ± 0.8	1.4 ± 1.0	1.6 ± 1.1	1.7 ± 1.3	0.529	0.140	0.177
Serum magnesium (mmol/L)	0.95 ± 0.13	0.96 ± 0.14	0.91 ± 0.11	0.84 ± 0.19	0.518	0.388	-0.109
Body mass index (kg/m2)	22.52 ± 4.25	23.47 ± 4.96	22.07 ± 4.98	23.44 ± 7.21	0.855	0.784	0.036
Age (years)	59 ± 16	62 ± 18	58 ± 23	73 ± 13	0.406	0.232	0.140

^aP < 0.05.

^bP < 0.01.

P_F/χ² is obtained by one-way analysis of variance or non-parametric tests to analyze the differences of observed indexes among different acute gastrointestinal injury (AGI) grades; r_s refers to the correlation coefficient, which was obtained using Spearman’s rank correlation analysis between each observation index and AGI grade. AGI: Acute gastrointestinal injury.