2003 OPEN FORUM Abstracts
OPEN VERSUS CLOSED ENDOTRACHEAL SUCTIONING DURING ARDSnet PROTOCOL.
G.Schettino MD.PhD, M.P.Caramez,MD.PhD, K.Suchodolski MD, T.Nishida MD , D.Hess, RRT.PhD and RM Kacmarek, RRT.PhD
Department of Anesthesia and Critical Care, and Respiratory Care, Massachusetts General Hospital and Harvard Medical School.
Previous studies have demonstrated
that disconnecting patients from the ventilator during open suctioning (OS) can
cause alveolar derecruitment, transient hypoxemia, especially with acute lung
injury (ALI) and acute respiratory distress syndrome (ARDS) [1, 2]. The use of
closed suction systems (CS), which allow non-interrupted ventilatory support
during suctioning, have the advantage of supplying oxygen-enriched gas and ventilation
with positive end expiratory pressure (PEEP) throughout suctioning. This theoretically
should limit or prevent hypoventilation, alveolar collapse and hypoxemia. There
are two recent reports regarding endotracheal suctioning during ALI/ARDS [3,
4] but ventilator management has not provided by the ARDSnet protocol. In this
study we evaluated the physiologic effects of OS and CS during pressure and volume
control ventilation, using the ARDSnet protocol in lung lavage injured sheep.
Mechanical ventilation was provided according to ARDSnet protocol with volume
(VC) and pressure control (PC) ventilation. (VT= 6ml/kg; RR< 35/min; PEEP
set by FiO2/PEEP). CS was performed using a 14 French, TrachCare catheter
with a suctioning time of 10 s and pressure of - 100 mmHg. OS was performed with
the same time and pressure but with the ventilator disconnected from the animal.
Flow and airway pressure were continuously recorded. Cardiac output and pressures
were monitored with a pulmonary artery catheter. Arterial blood-gases were monitored
with a continuous intravascular system. The mean PEEP and FiO2 were
18.2 cmH2O and 0.9 respectively during the experiment. PaO2/FiO2 was
recorded before, 1, 5 and 10 min after suctioning and changes are illustrated
in the enclosed figure. OS caused a greater PaO2/FiO2 decrease
than CS during both VC and PC (P < 0.05). No difference in oxygenation was
observed between VC and PC during CS. Pulmonary shunt and PaCO2 recorded
10 min after suctioning were greater than pre -suctioning for both OS and CS.
No significant changes in hemodynamics were detectable pre vs post suctioning
with OS or CS. In conclusion, PaO2/FiO2 was better during
CS with both VC and PC modes than OS during ARDSnet ventilation, however the
use of CS did not prevent increased hypercapnia 10 min post suctioning. Hemodynamics
were not affected by either suctioning procedure.
REFERENCES:
1. Brochard L, Mion G, Isabey D, et al. Am Rev Respir Dis 1991;
144(2): 395-400.
2. Cereda M, Villa F, Colombo E, Greco G, Nacoti M, Pesenti A:Intensive Care Med 2001; 27(4): 648-54.
3. Dyhr T, Bonde J, Larsson A: Crit Care 2003; 7(1): 55-62.
4. Maggiore SM, Lellouche F, Pigeot J, et al.: Am J Respir Crit Care Med 2003; 167(9): 1215-24.