Acid–base balance, serum electrolytes and need for non-invasive ventilation in patients with hypercapnic acute exacerbation of chronic obstructive pulmonary disease admitted to an internal medicine ward

Table 3 Linear association among pCO₂ and serum electrolytes in groups of patients according to ABG analysis values and in the entire cohort

Variables		Mixed respiratory acidosis – metabolic alkalosis (N = 36)	Compensated respiratory acidosis (N = 51)	Mixed respiratory - metabolic acidosis (N = 23)	Hypercapnic COPD, entire group (N = 110)
Na⁺	R²	0.10	0.01	0.16	0.002
	Slope	0.67	1.06	−1.33	−0.02
	p	0.06	0.03	0.06	0,62
K⁺	R²	0.001	−0.02	−0.001	0.003
	Slope	−1.53	−0.66	−8.08	1.45
	p	0.58	0,84	0.33	0.58
HCO₃ ⁻	R²	0.84	0.90	0.49	0.24
	Slope	1.26	2.18	2.20	1.14
	p	0.001	0.001	0.001	0.001
Cl⁻	R²	0.30	0.32	0.21	0.20
	Slope	−1.28	−1.45	−1.24	−1.37
	p	0.001	0.001	0.04	0.001
Anion Gap	R²	0.20	0.11	0.08	0.04
	Slope	−0.71	−1.39	−0.82	−0.67
	p	0.006	0.01	0.23	0.03
Lactate	R²	0.10	0.02	0.01	0.01
	Slope	−5.54	−3.42	−0.95	1.58
	p	0.06	0.30	0.65	0.25

ISSN: 2049-6958