The Science Journal of the American Association for Respiratory Care
Introduction: In the process of weaning from mechanical ventilator or trach tube, patients with cervical (C3-C5) spinal cord injuries (SCI) may undergo trach tube capping. Selected SCI patients may not tolerate trach tube capping due to an associated increased work of breathing. Four trach tube cap configurations were compared with a conventional trach tube cap to determine if any configuration enabled SCI patients with trach tube cap intolerance (TTCI) to experience significant improvements in RR, EtCO2, SpO2 and HR. Improvement in these measures was considered an important first step enabling patients to gradually tolerate increased work of breathing associated with placement of a conventional trach tube cap.
Methods and Materials: Cervical SCI patients (n=5) with 8-mm-ID (Portex) trach tube were deemed ready for trach tube cap placement by their ability to maintain HR < 120, RR < 30, SpO2 > 92% on 28% O2, and minimum VT 400 cc while on CPAP 5 and PSV 5 via mechanical ventilator (Purtian Bennett PB 7200a) for 24 hours. Prior to clinical trial, patients received tracheal suctioning, hyperinflation, bronchodilator via MDI, deflation of cuff and decannulation of inner cannula. Patients who exhibited TTCI (RR > 30 and / or VT < 350) during previous trach tube cap placement (control), received the following sequence of trach tube cap configurations:
|Configuration 1)||single one-way valve + 2 l/m O2 NC 10 minutes|
|Configuration 2)||dual one-way valve + 2 l/m O2 NC 10 minutes|
|Configuration 3)||single one-way valve + 2 l/m O2 TGI 10 minutes|
|Configuration 4)||dual one-way valve + 2 l/m O2 TGI 10 minutes|
RR, EtCO2, SpO2 and HR were measured for each configuration. After trial, patients were returned to previous vent settings. Data were analyzed by Repeated Measures ANOVA and Bonferroni t-test.
Results: When compared with conventional trach tube cap, all configurations resulted in lower (p < 0.05) RR. Configuration 4 resulted in lower (p < 0.05) EtCO2. Configurations 3 and 4 resulted in higher (p < 0.05) SpO2. HR, dyspnea ratings, resistance of devices, and trans tracheal tidal airway pressures were not significant.
Conclusion: In SCI patients with TTCI, only configuration 4, a dual one-way valve U/Adapit ?T? Adapter (Baxter) + 2 l/m O2 TGI, was associated with significant improvements in RR, EtCO2, and SpO2. Continued use of this configuration enabled patients to eventually tolerate workload associated with trach tube cap.