Maintained inspiratory activity during proportional assist ventilation in surfactant-depleted cats early after surfactant instillation: phrenic nerve and pulmonary stretch receptor activity

Table 1 Comparison of arterial blood gases, inspired oxygen fraction (F_iO₂), tidal volume (V_T), esophageal deflection pressure (Δ P_eso), transpulmonary pressure (P_tp), and lung compliance (C_L) between CPAP and PAV before and after lung lavage and after instillation of surfactant.

		CPAP	PAV	*CPAP-PAV p (ANOVA)*
		*Mean* ± *S.D* .	*Mean±S.D*.
Before lung lavage	pH	7.31 ± 0.04	7.33 ± 0.03	NS
	PaCO ₂ , kPa	5.47 ± 0.80	5.20 ± 0.80	NS
	PaO ₂ , kPa	11.20 ± 0.80	12.40 ± 0.67	<0.001
	F _i O ₂	0.21 ± 0.00	0.21 ± 0.0	NS
	V _T , mL	36 ± 10	38 ± 6	NS
	ΔP _eso , kPa	0.32 ± 0.09	0.18 ± 0.08	<0.02
	P _tp , kPa	0.41 ± 0.12	0.44 ± 0.11	NS
	C _L , mL/cm H ₂ O	6.43 ± 1.96	6.43 ± 1.96	NS
After lung lavage	pH	7.24 ± 0.08 ^a	7.29 ± 0.10	<0.05
	PaCO ₂ , kPa	6.93 ± 1.73 ^a	5.87 ± 1.60 ^a	<0.03
	PaO ₂ , kPa	8.27 ± 2.67 ^a	9.47 ± 2.13 ^a	<0.01
	F _i O ₂	0.77 ± 0.18 ^a	0.75 ± 0.20 ^a	NS
	V _T , mL	25 ± 9 ^a	46 ± 28	<0.02
	ΔP _eso , kPa	0.86 ± 0.36 ^a	0.27 ± 0.21 ^a	<0.02
	P _tp , kPa	1.34 ± 0.53 ^a	1.83 ± 0.57 ^a	p <0.0001
	C _L , mL/cm H ₂ O	2.59 ± 0.76 ^a	2.59 ± 0.76 ^a	NS
After surfactant instillation	pH	7.22 ± 0.08	7.29 ± 0.11	<0.01
	PaCO ₂ , kPa	7.73 ± 1.60	6.13 ± 2.00	<0.01
	PaO ₂ , kPa	9.47 ± 2.40 ^b	11.47 ± 2.53 ^b	<0.05
	F _i O ₂	0.76 ± 0.29	0.76 ± 0.29	NS
	V _T , mL	25 ± 7	48 ± 16	<0.01
	ΔP _eso , kPa	0.56 ± 0.31 ^b	0.22 ± 0.09 ^b	<0.02
	P _tp , kPa	1.11 ± 0.49 ^b	1.62 ± 0.25 ^b	p <0.0001
	C _L , mL/cm H ₂ O	3.10 ± 0.61 ^b	3.10 ± 0.61 ^b	NS

^a significant difference between pre- and post-lavage values
^bsignificant difference between post-lavage value and value after surfactant instillation
^a,b p < 0.05; ANOVA; two-tailed paired Student's t-test.
NS, non-significant; S.D., standard deviation.

ISSN: 1465-993X