Can ventilator settings reduce the negative effects of endotracheal suctioning? Investigations in a mechanical lung model

Table 1 Effects of device insertion and suctioning

(1) Closed catheter insertion (no suction)^¤
	P_{PEAK MA}	P_{EEP MA}	Vt_i	Vt_e	Vt_i - vt_e
ETT 9 before	22	6	679	659	20
after	21	6	583	569	14
ETT 8 before	22	6	652	635	17
after	20	6	470	461	9
ETT 7 before	21	6	593	566	27
after	18	7	393	376	17
(2) Closed catheter suctioning (moderate vs. maximum suction pressure)^¤
	P_{PEAK MA}	P_{EEP MA}	Vt_i	Vt_e	Vt_i - Vt_e
ETT 9 mod	20	6	765	331	434
max	17	3	873	226	647
ETT 8 mod	18	5	623	216	407
max	14	3	660	83	577
ETT 7 mod	15	4	492	136	356
max	13	5	555	21	534
(3) Bronchoscopic suctioning (moderate vs. maximum suction pressure)^¤
	P_{PEAK MA}	P_{EEP MA}	Vt_i	Vt_e	Vt_i - Vt_e
ETT 9 mod	17	4	647	294	353
max	16	4	724	166	558
ETT 8 mod	15	4	513	177	336
max	13	3	540	52	488
ETT 7 mod	10	4	286	8	278
max	3	−5	389	0	389
(4) Effect of volume controlled ventilation (closed catheter system, mod. vs. max. suction pressure)
	P_{PEAK MA}	P_{EEP MA}	Vt_i	Vt_e	Vt_i - Vt_e
ETT 9 mod	16	5	503	150	353
max	13	4	506	2	504
ETT 8 mod	16	5	506	139	367
max	11	3	514	0	514
ETT 7 mod	16	5	507	144	363
max	12	5	517	9	508
(5) Effect of volume controlled ventilation (bronchoscopic suction, mod. vs. max. suction pressure)
	P_{PEAK MA}	P_{EEP MA}	Vt_i	Vt_e	Vti - Vt_e
ETT 9 mod	15	4	507	185	322
max	12	3	507	43	464
ETT 8 mod	15	5	498	164	334
max	13	5	510	13	497
ETT 7 mod	17	4	499	185	314
max	11	3	498	17	481

¤ = PCV, l:E 1:2, flowtrigger (F/5). Mod.suction = -382 cm H₂0 (-37.5 kPa). Max.suction = -765 cm H₂0 (-75 kPa)
The table exemplifies an experiment were a conventional ventilator setting is used; I:E ratio 1:2 and flowtrigger F/5. Model airway pressures and tidal volumes are presented with variations in ETT size, suction device, suction pressure level and ventilation mode (PCV in sections 1–3, VCV in section 4–5)

ISSN: 1471-2253