Inflammatory response phases and their hypothetical trophic meaning.

The length of the larynx was y4–5 mm. The cricoid cartilage formed a complete ring at the inferior aspect of the larynx and was fixed to the tracheal rings. The trachea was entered after passing through the cricoid cartilage and ended at the division into the right and left main stem bronchi at the carina. The bronchoscope was introduced through the larynx and directed to the trachea. The length and internal diameter of the trachea wasy25–27 mm and 3–4 mm, respectively. The angle between the longitudinal axis of the trachea and the bifurcation of the main bronchi was approximately 15–17u. The angle of the right main bronchus was only slightly less than that of the left main bronchus. Once the trachea was entered, the tip of the bronchoscope was gently slid along the right and left lateral wall of the trachea. This manoeuvre allowed both the right and left main bronchi to be entered easily. In addition, to enter the right and left main bronchi, the rat9s head was turned and flexed slightly to the ipsilateral side and the proximal portion of the bronchoscope moved toward the contralateral corner of the mouth. The main stem bronchi was y6–7 mm in length and its internal diameter was 2–3 mm. The tip of the bronchoscope was advanced 4–5 mm into the right and left main bronchi. At this point, the distal progression of the instrument was halted. Overall, these attempts provided convincing results on proceeding tracheo-bronchial endoscopy. Thus, we strongly believe that our "simulated bronchoscopy" had the main physical properties of a rigid bronchoscope. The rat airway was not visualised in these experiment, yet, we think that this would not have changed the pathophysiological sequence leading to bacterial translocation following bronchoscopy. There may some reports indicating that rigid bronchoscopy does not impair ventilation and oxygenation [2]. However, what about clinical studies that do show that rigid bronchoscopy induces alterations in arterial blood gases, including hypox-aemia, respiratory acidosis and hypercarbia [3–5]? GODDEN et al. [3] measured serial arterial blood gases in 10 patients during rigid bronchoscopy and showed carbon dioxide retention in nine patients even though ventilation was adequate in all. MATHISEN and GRILLO [4] observed 19 complications of 56 patients after rigid bronchoscope, in whom two of those complications were hypoxia and/or hypercarbia. It may intuitively appear that associated procedures during rigid bronchoscopy will increase resistance to ventilation and result in derangements …