Implementation of a decision aid for recognition and correction of volume alterations (Recova^®) in haemodialysis patients

Figures & data

Figure 1. The Recova^® scoring system for systemized clinical assessment of fluid status (from Reference [18]). The symptom score can total 0–16 points: 0–8 fluid overload points and 0–8 fluid depletion points.

Table 1. Fluid status groups, the suggested clinical response and the plausible post-dialysis target weight to aim for in each group – as defined by recova.

	A	B	C	D
Clinically assessed fluid status	Overload	Overload	Depletion or no symptoms	Depletion or no symptoms
OH post (BIS measured)	≤0 L	>0 L	>0 L	≤0 L
Suggested clinical response	Decrease TW 0.5–1 kg/week	Decrease TW 0.5–1 kg/week	First, treat malnutrition and inflammation	Increase TW 0.5–1 kg/week
Plausible OH post target	−2 to 0 L	±1 L	0 to +2 L	±1 L

BIS: bioimpedance spectroscopy; OH: overhydration; TW: target weight.

Table 2. Differences in baseline characteristics between groups of different types of fluid status, based on recova definitions.

Parameter	All participants (n = 49)		Group A (n = 4)		Group B (n = 10)		Group C (n = 15)		Group D (n = 20)		Level of significance
Age (years)	73	(67–80)	77	(69.5–81.5)	77	(74–84)	72	(59.5–75)	70.5	(61.5–78)	0.096
Clinical assessments
Fluid overload score	0	(0–2)	2.0	(1.5–2.5)	2.0	(1–3)	0	(0–1)	0	(0–0	0.000**
Fluid depletion score	0	(0–2)	0.5	(0–1.5)	0	(0–1)	1.0	(0–2)	1.0	(1–2)	0.517
BP systolic (mmHg)	143	(121–159)	150	(123–170)	152	(149–160)	132	(119–147)	139	(122–155)	0.210
BP diastolic (mmHg)	65	(57–74)	58	(48–68)	77	(49–83)	61	(54–66)	67	(59–73.5)	0.187
Bioimpedance spectroscopy readings
NH (kg)	73.3	(64–81.4)	78.8	(71.9–88.1)	70.8	(58.7–78)	73.1	(62.4–79.5)	73.3	(65.8–82.7)	0.704
OH pre (L)	1.7	(0.9–3.4)	0.9	(0.8–1.3)	3.8	(3.3–4.2)	2.7	(1.5–3.6)	1.0	(0.8–1.5)	0.000**
OH post (L)	0.10	(−0.8 to 1.3)	−1.55	(−2.6 to −0.35)	1.85	(1.4 to 2.1)	1.10	(0.2 to 1.4)	−0.85	(−1.6 to −0.4)	0.000**
UFV (L)	2.0	(1.3–2.7)	2.55	(1.15–3.9)	2.05	(1.1–2.4)	1.40	(1.1–2.1)	2.40	(1.7–2.7)	0.156
BMI (kg/m^2)	27	(22.7–28.5)	28.6	(27.85–29.7)	26.2	(22–27.7)	23.9	(22.4–31.4)	27.1	(25.6–28.3)	0.360
LTI (kg/m^2)	12	(10.6–13.6)	12.8	(9.85–14.95)	13.3	(11.5–13.9)	11.5	(10.6–12.6)	11.4	(9.7–13)	0.463
FTI (kg/m^2)	12	(9.7–17.2)	15.6	(13.35–17.75)	10.4	(7.2–12)	10.5	(9.1–18.8)	14.7	(10.85–17.4)	0.214
Dialysis prescriptions (dialysate)
Treatment time (hours)	4	(4–4.5)	4.3	(4–4.5)	4.0	(4–4)	4.5	(4–5)	4.0	(4–4.5)	0.356
Sessions/week	3	(3–3)	3.0	(2.5–3)	3.0	(3–3)	3.0	(3–3)	3.0	(3–3)	0.515
D-K (mmol/L)	2	(2–3)	2.5	(2–3)	2.0	(2–3)	2.0	(2–3)	2.5	(2–3)	0.922
D-Na (mmol/L)	138	(138–138)	138	(138–139)	138	(138–138)	138	(138–138)	138	(138–138)	0.437
D-temp (°C)	36.5	(36.5–36.5)	36.5	(36–36.5)	36.5	(36.5–36.5)	36.5	(36.5–36.5)	36.5	(36.5–36.5)	0.778
Target weight (kg)	73	(64.5–82)	77.5	(70–87)	71.8	(60.5–79)	75.5	(66.5–82.5)	72.8	(64.3–82.8)	0.829
Laboratory results (plasma)
P-NT-proBNP (ng/L)	9270	(2490–19,600)	27,150	(10,735–52,400)	33,250	(17,500–41,200)	4050	(2160–10,650)	6130	(1795–11,600)	0.000**
P-CRP (mg/L)	5.9	(3.1–18)	28.0	(10.4–49.5)	13.5	(4.9–20)	7.2	(3.25–16.5)	3.95	(2.65–7.45)	0.097
P-Haemoglobin (g/L)	111	(102–117)	107	(98.5–116.5)	105	(96–11)	112	(104–117.5)	115	(104–119)	0.380
P-Na (mmol/L)	140	(138–142)	139	(137–140)	142	(140–144)	140	(138–142)	140	(138–141)	0.075
P-K (mmol/L)	4.6	(4.3–5)	4.5	(4.4–4.6)	4.6	(4.1–5)	4.3	(3.95–5.05)	4.75	(4.55–5.1)	0.269
P-Albumin (g/L)	32	(28–33)	32	(28–35)	30	(28–35)	32	(27–33)	32	(28–32.5)	0.921
P-Calcium (mmol/L)	2.22	(2.09–2.32)	2.11	(2–2.3)	2.15	(2.01–2.36)	2.25	(2.13–2.32)	2.23	(2.18–2.33)	0.473
P-Phosphate (mmol/L)	1.52	(1.05–1.85)	1.3	(0.96–1.46)	1.3	(1.05–2.24)	1.6	(0.93–1.9)	1.52	(1.21–1.73)	0.703

Differences tested for significance with kruskal–wallis H for non-parametric test between multiple groups.

*p < 0.05; **p < 0.01.

BP: blood pressure; BMI: body mass index; CRP: C-reactive protein; FTI: fat tissue mass index; K: potassium; LTI: lean tissue mass index; Na: sodium; NH: normal hydration weight; NT-proBNP: N-terminal pro-brain natriuretic peptide; OH: overhydration; UFV: ultrafiltration volume.

Table 3. Baseline characteristics of all enrolled patients.

Parameter	All participants		Group A		Group B		Group C		Group D		Level of sign.
Total number	49		4		10		15		20
Men	32	(65)	3	(75)	5	(50)	12	(80)	12	(60)	0.411
IHD	18	(37)	2	(50)	6	(60)	6	(40)	4	(20)	0.164
CHF	23	(47)	2	(50)	2	(50)	6	(40)	10	(50)	0.937
Stroke/TIA	10	(20)	3	(75)	2	(20)	2	(13)	3	(15)	0.043*
PVD	10	(20)	2	(50)	1	(10)	3	(20)	4	(20)	0.419
Hypertension	46	(94)	4	(100)	8	(80)	15	(100)	19	(95)	0.201
DM type 1	4	(8)	0		0		2	(13)	2	(10)	0.600
DM type 2	16	(33)	2	(50)	10	(40)	6	(40)	4	(20)	0.455
Total symptom score, thresholds and trigger											0.167
Level 0 points	16	(33)	0		0		7	(46)	9	(45)
Level 1–4 points	24	(49)	3	(75)	7	(70)	6	(40)	8	(40)
Level 5–6 points	8	(16)	1	(25)	3	(30)	1	(7)	3	(15)
Level ≥7 points	1	(2)	0		0		1	(7)	0

Differences tested for significance with the chi-square test.

Data presented as numbers of participants (%).

*p < 0.05; **p < 0.01.

IHD: ischaemic heart disease; CHF: congestive heart failure; DM: diabetes mellitus; PVD: peripheral vascular disease; TIA: transient ischaemic attack.

Table 4. Measure of process.

Parameter	Baseline		Follow-up			Level of significance
Haemodialysis unit 1 (n = 27)
BIS/month	0.50	(0.50–0.67)	0.75	(0.75–1.0)		0.035*
TW adjustments/month	0.50	(0.33–0.83)	0.75	(0.50–1.25)		0.021*
Haemodialysis unit 2 (n = 22)
BIS/month	0.50	(0.50–0.67)	1.00	(0.67–1.0)		0.002**
TW adjustments/month	0.67	(0.33–0.83)	1.00	(0.33–1.33)		0.005**

Significance of differences between baseline and follow-up tested with wilcoxon’s non-parametric test between dependent groups.

*p < 0.05; **p < 0.01.

BIS: bioimpedance spectroscopy; TW: target weight.

Table 5. Correlations in entire sample.

	FD score	OH pre	OH post	NT-proBNP	BIS/month	TW changes/month
FO score	0.24	0.17	0.29*	0.36*	0.24	0.22
FD score		−0.15	−0.08	−0.19	0.15	0.20
OH pre (L)			0.76**	0.36*	−0.01	−0.03
OH post (L)				0.21	−0.05	−0.05
NT-proBNP (ng/L)					0.20	0.09
BIS/month						0.63**

*p < 0.05; **p < 0.01.

BIS: bioimpedance; FD: fluid depletion; FO: fluid overload; NT-proBNP: N-terminal pro-brain natriuretic peptide; OH: overhydration; TW: target weight.

Figure 2. Bioimpedance-measured median overhydration (OH) post in the four groups at baseline and at end-of-study.

Figure 3. Comparison of distribution of pre-dialysis fluid symptom status in each group (frequencies), at baseline (BL) and at end-of-study (End).

Table 6. Differences between baseline and follow-up observations in subgroups, significance tested with Wilcoxon’s non-parametric test between dependent groups.

Parameter	Baseline		End-of-study		Significance
Group A: Fluid overload symptoms but negative OH (n = 4)
Fluid overload score	2	(1.5–2.5)	0	(0–0.5)	0.102
Fluid depletion score	0.5	(0–1.5)	0	(0–0)	0.317
OH pre (L)	0.9	(0.8–1.3)	1.45	(0.85–2.1)	0.144
OH post (L)	−1.55	(−2.6 to −0.35)	−0.70	(−1.9 to −0.15)	0.715
NT-proBNP (ng/L)	27,150	(10,735–52,400)	30,950	(9851–54,650)	0.715
BP systolic (mmHg)	150	(123–170)	166	(131–194)	0.068
BP diastolic (mmHg)	58	(48–68)	60	(55–76)	0.144
Target weight (kg)	77.5	(70–87)	77.5	(72.8–87.5)	0.197
UFV (L)	2.55	(1.2–3.9)	2.70	(1.6–3.5)	1.000
BIS/month	0.42	(0.33–0.67)	0.75	(0.75–0.88)	0.141
DW adjustments/month	0.67	(0.25–0.92)	0.88	(0.50–1.38)	0.197
Group B: Fluid overload symptoms and positive OH (n = 10)
Fluid overload score	2	(1–3)	0	(0–1)	0.033*
Fluid depletion score	0	(0–1)	0	(0–1)	0.129
OH pre (L)	3.8	(3.2–4.2)	2.9	(2.6–3.4)	0.047*
OH post (L)	1.85	(1.4–2.1)	1.25	(0.3–1.5)	0.074
NT-proBNP (ng/L)	33,250	(17,500–41,200)	30,150	(22,700–57,700)	0.953
BP systolic (mmHg)	152	(149–160)	156	(126–172)	0.959
BP diastolic (mmHg)	77	(49–83)	71	(48–75)	0.314
Target weight (kg)	71.8	(60.5–79)	70.3	(56.5–79)	0.067
UFV (L)	2.05	(1.1–2.4)	1.85	(1.3–3.1)	0.919
BIS/month	0.67	(0.42–0.75)	1.0	(0.75–1.0)	0.176
DW adjustments/month	0.67	(0.50–0.75)	1.0	(0.63–1.33)	0.400
Group C: Fluid depletion or no symptoms but positive OH (n = 15)
Fluid overload score	0	(0–1.0)	0	(0–1.0)	0.931
Fluid depletion score	1	(0–2.0)	1	(0–2.0)	0.526
OH pre (L)	2.7	(1.5–3.6)	2.7	(1.6–4.5)	0.826
OH post (L)	1.10	(0.2 to 1.4)	1.20	(−0.9 to 2.7)	0.410
NT-proBNP (ng/L)	4050	(2160–10,650)	3320	(2430–9820)	0.256
BP systolic (mmHg)	132	(119–147)	130	(122–152)	0.513
BP diastolic (mmHg)	61	(54–66)	60	(56–69)	0.132
Target weight (kg)	75.5	(66.8–82.5)	75.5	(66.5–82.3)	0.503
UFV (L)	1.4	(1.1–2.1)	2.1	(1.3–2.4)	0.140
BIS/month	0.5	(0.33–0.50)	0.67	(0.50–1.0)	0.005**
DW adjustments/month	0.5	(0.17–0.67)	0.5	(0.25–1.17)	0.049*
Group D: Fluid depletion or no symptoms and negative OH (n = 20)
Fluid overload score	0	(0–0)	0	(0–1.5)	0.135
Fluid depletion score	1	(0–3)	1	(0–2)	0.340
OH pre (L)	1.0	(0.8–1.5)	1.3	(0.7–2.1)	0.248
OH post (L)	−0.85	(−1.6 to −0.4)	−0.5	(−1.0 to 0.1)	0.057
NT-proBNP (ng/L)	6130	(1795–11,600)	9625	(2070–21,700)	0.033*
BP systolic (mmHg)	139	(122–155)	151	(123–165)	0.057
BP diastolic (mmHg)	67	(59–74)	68	(58–74)	0.852
Target weight (kg)	72.8	64.3–82.8)	73.4	(66–84.5)	0.024*
UFV (L)	2.4	(1.7–2.7)	1.9	(1.45–2.9)	0.313
BIS/month	0.67	(0.5–0.75)	0.75	(0.71–1.0)	0.064
DW adjustments/month	0.5	(0.33–0.83)	0.75	(0.59–1.33)	0.005**

*p < 0.05; **p < 0.01.

BIS: bioimpedance spectroscopy; BP: blood pressure; FO: fluid overload; NT-proBNP: N-terminal pro-brain natriuretic peptide; OH: overhydration; UFV: ultrafiltration volume.

Siriopol I, Siriopol D, Voroneanu L, Covic A. Predictive abilities of baseline measurements of fluid overload, assessed by bioimpedance spectroscopy and serum N-terminal pro-B-type natriuretic peptide, for mortality in hemodialysis patients. Arch Med Sci. 2017;13:1121–9. doi:10.5114/aoms.2017.68993

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