Tracheobronchial injury during intratracheal pulmonary ventilation in rabbits.
Crit Care Med
; 31(3): 916-23, 2003 Mar.
Article
em En
| MEDLINE
| ID: mdl-12627005
ABSTRACT
OBJECTIVE:
We compared tracheobronchial injury following short-term intratracheal pulmonary ventilation (ITPV) and conventional mechanical ventilation (CMV) in a healthy rabbit model. ITPV, a form of tracheal gas insufflation, has been shown to decrease deadspace ventilation and increase CO2 removal and therefore may reduce ventilator-induced lung injury.SETTING:
Medical center laboratory.SUBJECTS:
Twenty-five rabbits.INTERVENTIONS:
Rabbits were randomly assigned to either ITPV or CMV (n = 15 and 10, respectively). Both groups were mechanically ventilated for 8 hrs at the same ventilator settings (FIO2, 0.4; rate, 30 breaths/min; flow, 4 L x min(-1); positive end-expiratory pressure, 4 cm H2O; tidal volume, 40 mL). Peak, mean, and end-expiratory carinal pressures, ITPV flow rate, and hemodynamic variables were continuously monitored. Tissue samples for histologic analysis were obtained postmortem from the trachea contiguous to the tip of the endotracheal tube, the distal trachea, the carina, and the main bronchus. The histologic sections were scored, in a single-blind fashion, for ciliary damage, ulceration, hemorrhage, overall inflammation, intraepithelial inflammatory infiltrate, and edema. MEASUREMENTS AND MAINRESULTS:
ITPV was associated with significantly lower Paco and deadspace ventilation ratio than CMV. The combined tracheobronchial injury scores for all samples were significantly higher in the ITPV group compared with the CMV group (p <.005; Mann-Whitney U test). The ITPV injury scores, compared with CMV injury scores, were significantly higher at the carina and main bronchus (p <.01; Kruskal-Wallis test followed by Dunn's multiple comparison test). The area adjacent to the endotracheal tube showed the same degree of damage in both groups. Analysis of the injury scores in individual damage categories demonstrated the greatest difference in the ulceration category (p <.001).CONCLUSIONS:
In our study, ITPV, compared with CMV at the same minute ventilation, was associated with a significantly greater difference in tracheobronchial damage at the carina and main bronchus. We postulate that this difference may have been caused by the turbulence of the gas flow generated by the small-caliber ITPV catheter used in our neonatal-size animal model.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oxigenoterapia
/
Respiração Artificial
/
Traqueia
/
Brônquios
/
Insuflação
/
Modelos Animais de Doenças
Tipo de estudo:
Etiology_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Animals
Idioma:
En
Revista:
Crit Care Med
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Estados Unidos