. 2012 Apr;76(2):99–108.

Table II.

Mean ± standard deviation respiratory and metabolic variables and change in plasma and blood volume in 6 anesthetized dogs with 3% end-tidal isoflurane (ETI) to decrease arterial blood pressure (ABP) and cardiac index (CI) and treated for 1 h with 1 mL/kg bodyweight per min of an isotonic solution while at 3% ETI for the first 45 min and then lowered towards 1.6% ETI for the last 15 min of treatment

Variables	Baseline (1.0 MAC)	Deep anesthesia (2.3 MAC)	Fluid therapy

			30 min (2.3 MAC)	60 min (1.2 MAC)
End-tidal CO₂ (mmHg)	38 ± 2^a	36 ± 3^a	37 ± 3^a	43 ± 4^b
Arterial pH	7.395 ± 0.033^a	7.403 ± 0.034^a	7.379 ± 0.035^a	7.345 ± 0.043^b
PacO₂ (mmHg)	38 ± 3^a	36 ± 2^a	39 ± 4^a	44 ± 5^b
PaO₂ (mmHg)	583 ± 41^a	584 ± 29^a	620 ± 16^b	627 ± 17^b
Arterial HCO⁻₃ (mEq/L)	24 ± 1.5^a,c	23 ± 1.8^b	23 ± 1.9^a,b	24 ± 1.9^c
Arterial base deficit (mEq/L)	−1.8 ± 1.8^a	−2.4 ± 2.1^a	−2.5 ± 1.9^a	−1.7 ± 2.1^a
Arterial lactate (mmol/L)	1.3 ± 0.6^a	1.5 ± 0.7^a	1.5 ± 0.7^a	1.5 ± 0.7^a
SaO₂ (%)	99.1 ± 0.1^a	99.1 ± 0.1^a	99.2 ± 0.1^a	99.1 ± 0.1^a
Central venous pH	7.355 ± 0.027^a,b	7.352 ± 0.034^a,b	7.332 ± 0.031^a	7.318 ± 0.036^b
Central venous CO₂ (mmHg)	45 ± 4^a	45 ± 3^a	47 ± 5^a	49 ± 4^b
Central venous O₂ (mmHg)	78 ± 16^a,b	53 ± 8^a	64 ± 31^a	109 ± 68^b
Central venous HCO⁻₃ (mEq/L)	25 ± 2.1^a,b	25 ± 1.1^a,b	25 ± 1.7^a	26 ± 1.2^b
Central venous base deficit (mEq/L)	−0.9 ± 2.1^a	−0.8 ± 1.6^a	−1.2 ± 1.5^a	−1.0 ± 1.5^a
Central venous lactate (mmol/L)	1.5 ± 0.7^a	1.4 ± 0.7^a	1.5 ± 0.7^a	1.5 ± 0.7^a
ScvO₂ (%)	93.8 ± 5.1^a	81.6 ± 9.3^b	80.3 ± 18.0^b	94.7 ± 5.5^a
VO₂ (mL O₂/kg per minute)	4.1 ± 1.5^a	4.6 ± 1.2^a	4.8 ± 2.1^a	5.0 ± 1.3^a
DO₂ (mL O₂/kg per minute)	33.1 ± 7.6^a	19.0 ± 6.3^b	20.0 ± 7.9^b	37.5 ± 11.9^a
ERO₂ (%)	12 ± 4.7^a	25 ± 7.4^b	27 ± 15.9^b	14 ± 5.1^a
CaO₂ (mL/L)	20.8 ± 1.4^a	19.8 ± 1.4^b	16.3 ± 1.2^c	15.7 ± 1.5^d
CcvO₂ (mL/L)	18.2 ± 2.0^a	14.9 ± 1.7^b	11.7 ± 2.5^c	13.5 ± 1.2^c
Hb (g/dL)	14.3 ± 1.1^a	13.6 ± 1.0^b	10.8 ± 0.9^c	10.4 ± 1.2^d
PCV (%)	40 ± 4^a	37 ± 2^b	31 ± 3^c	28 ± 3^d
Change in plasma volume (%)	ND	13^*,^a	41^§,^b	49^§,^c
Change in blood volume (%)	ND	8^*,^a	19^§,^b	32^§,^c
TP (g/dL)	5.3 ± 0.4^a	5.0 ± 0.3^b	3.8 ± 0.3^c	3.3 ± 0.4^d
COP (mmHg)	19.5 ± 2.2^a	16.4 ± 1.7^b	10.7 ± 0.7^c	9.8 ± 0.9^d
Na⁺ (mEq/L)	144 ± 1.0^a	143 ± 1.0^b	141 ± 0.5^c	141 ± 1.0^c
K⁺ (mEq/L)	3.8 ± 0.1^a	4.2 ± 0.1^b,c	4.2 ± 0.3^b	4.4 ± 0.4^c
Cl⁻ (mEq/L)	116 ± 2^a	116 ± 2^a	115 ± 1^a	113 ± 2^b
Ca²⁺ (mEq/L)	1.29 ± 0.03^a	1.25 ± 0.03^b	1.12 ± 0.02^c	1.10 ± 0.03^d

Compared to baseline at 1.0 MAC.

^§

Compared to 2.3 MAC without fluids.

^a,b,c,d

Different superscript letters within a row indicate significant (P < 0.05) differences between values in that row.

MAC — Minimum alveolar concentration; CO₂ — Carbon dioxide; mm/Hg — Millimeters of mercury; PaCO₂ — Arterial partial pressure of carbon dioxide; PaO₂ — Arterial partial pressure of oxygen; SaO₂ — Saturation of hemoglobin in arterial blood; O₂ — oxygen; HCO⁻₃ — Bicarbonate ion; ScvO₂ — Saturation of hemoglobin in central-venous blood; VO₂ — oxygen consumption; DO₂ — oxygen delivery; ERO₂ — oxygen extraction ratio; CaO₂ — Arterial oxygen content; CcvO₂ — Central-venous oxygen content; Hb — Hemoglobin; PCV — Packed cell volume; TP — Total protein; COP — Colloid osmotic pressure; Na⁺ — Sodium ion; K⁺ — Potassium ion; CI⁻ — Cardiac index; Ca²⁺ — Calcium ion.