Research Article: Standard Tracheal Secretion Assessment versus an acoustic Secretion Detector

Endotracheal intubation and mechanical ventilation are life-saving procedures in patients with respiratory insufficiency. But this can profoundly impair the defensive mechanisms which keep the lower respiratory tract sterile, increasing the risk of bacterial colonization and ventilator-associated pneumonia. Although endotracheal suctioning is a standard of care in all mechanically ventilated patients, clear guidelines regarding the technique and timing of suctioning are lacking. The applicable American Association for Respiratory Care (AARC) guideline suggests that endotracheal suctioning should be performed at some minimum frequency or when clinically indicated. Since endotracheal suctioning can cause hypoxemia, mechanical trauma, bronchospasm, and hemodynamic instability, an accurate assessment of the need for suctioning might decrease the frequency of suctioning complications. TBA Care is a novel device designed to generate a signal when secretions are present in the respiratory tract of an intubated patient, indicating the need for endotracheal suctioning. This is the first prospective randomized trial to compare different indications for endotracheal suctioning. This study compares the efficacy of TBA Care in detecting the presence of secretions in the airways to standard indications, and tested the hypothesis that different suctioning indications could impact the incidence of ventilator-associated pneumonia and extubation rate (Lucchini et al., 2011).

This is a quantitative research study with prospective randomized trial with 72 general intensive care unit patients randomized at intubation into 2 groups, differing only in suctioning indications. The study was conducted over a 9 month period and 72 adult patients who are over 18 years and are intubated or ventilated for more than 48 hours are selected. Equal number of patients were selected and randomly assigned to the control group or to the secretion-detector group. Although patients were assigned randomly, each group had the equal number of patients with suspected and confirmed pneumonia. This study was performed in the Department of Perioperative Medicine and Intensive Care, San Gerardo Hospital, Monza, Italy (Lucchini et al., 2011). .

To do an effective comparison of the endotracheal suctioning both groups were given the same clinical management and identical measures for ventilator associated pneumonia prevention which includes semi-recumbent position, continuous enteric nutrition, stress ulcer prophylaxis, and mechanical ventilation weaning protocol. For all the selected patients a heated humidifier was used for the entire study period. The two groups differed in the method of suctioning only. Patients in the control group were suctioned on the basis of the applicable American Association for Respiratory Care guidelines. In control group scheduled suctioning and clinically necessitated suctioning were performed. In the study group, secretions were monitored with the TBA Care system, and the decision to suction was based on the signal from the TBA Care system and/or the indications recommended in the AARC clinical practice guideline. A detailed written record was maintained after each suctioning which includes the day and time of suctioning, the indication for the suctioning, the number of suction catheter passes, and the quantity of secretions collected. To reduce any errors in defining the secretion quantity score, the nurses were trained prior to the study in the semi-quantitative system with in vitro simulations of the suctioning procedure. The number of suctioning passes in each suctioning session was also recorded (Lucchini et al., 2011).

Over a study period of 415 days for control group and 388 days for secretion-detector group, 1705 and 1354 suctioning were analyzed respectively. The collected secretion volume per suctioning session significantly differed between the two groups. In the secretion-detector group, 97% of the suctioning was performed following the TBA Care device’s signal. In the control group the main reason for suctioning was dyspnea (53%). Suctionings prompted by clinical deterioration were more frequent in the control group than in the secretion detector group. Patients in the secretion-detector group were suctioned less frequently and had fewer suctioning passes (Lucchini et al., 2011).

More than 76% of those unnecessary suctionings were scheduled suctionings. This result highlights the potentially harmful effects of scheduled suctioning in the absence of signs of secretion retention. Survival analysis for extubation showed no significant differences between the 2 groups. The mortality rate was 25% (9 patients) in both groups. Clinical suspicion of pneumonia at randomization was microbiologically confirmed in 7 patients per group. Ventilator associated pneumonia was diagnosed in 6 patients in the control group and 3 in the secretion-detector group. The study did not find any major complications related to the use of TBA Care device. The number of survival patients to extubation was slightly higher in the secretion-detector group (Lucchini et al., 2011).

TBA Care seems to provide reliable indication of the need for suctioning and will be a great help for critical care nurses. Its continuous airway monitoring allows suctioning before any clinical deterioration caused by secretion retention, reduces unnecessary suctionings, and reduces the number of suctioning passes. It has been stated from the patients that the suctioning procedures are very painful. The use of TBA care will reduce such discomforts (Lucchini et al., 2011).

It is very clear that all the three basic ethical principles such as autonomy, justice and beneficence were incorporated into this research study. Prior to the research consent was obtained from all the selected candidates for conducting the research on them. The researchers were able to show justice to all the participants by providing the same clinical management and equal measures to prevent ventilator associated pneumonia. The study did not cause any harm to the participants and there was no major risks associated with the study.

In intensive care units endotracheal intubation is a routine procedure performed several times a day and there is no clear indication about when to perform it. TBA Care seems to provide reliable indication of the need for suctioning. So it would be useful in critical care units. Even though the study did not find a significant difference in the occurrences of ventilator-associated pneumonia, further studies with a larger sample may be helpful. Although the nurses who did the suctioning were given training for categorizing the amount of secretion collected, further studies should get a more accurate method of measuring the quantity of secretion amount.

References
Lucchini, A., Zanella, A., Bellani, G., Gariboldi, R., Foti, G., & Pesanti, A. et al. (2011). Tracheal Secretion Management in the Mechanically Ventilated Patient: Comparison of
Standard Assessment and an Acoustic Secretion Detector. Respiratory Care, 56(5), 596-603. doi:10.4187/respcare.00909.