Impact of deep oropharyngeal suctioning on microaspiration, ventilator events, and clinical outcomes: A randomized clinical trial

Abstract

Aims To evaluate a deep oropharyngeal suction intervention (NO‐ASPIRATE) in intubated patients on microaspiration, ventilator‐associated events and clinical outcomes. Design Prospective, two‐group, single‐blind, randomized clinical trial. Methods The study was conducted between 2014 ‐ 2017 in 513 participants enroled within 24 hr of intubation and randomized into NO‐ASPIRATE or usual care groups. Standard oral care was provided to all participants every 4 hr and deep oropharyngeal suctioning was added to the NO‐ASPIRATE group. Oral and tracheal specimens were obtained to quantify α‐amylase as an aspiration biomarker. Results Data were analysed for 410 study completers enrolled at least 36 hr: NO‐ASPIRATE (N = 206) and usual care (N = 204). Percent of tracheal specimens positive for α‐amylase, mean tracheal α‐amylase levels over time and ventilator‐associated events were not different between groups. The NO‐ASPIRATE group had a shorter hospital length of stay and a subgroup with moderate aspiration at baseline had significantly lower α‐amylase levels across time. Conclusion Hospital length of stay was shorter in the NO‐ASPIRATE group and a subgroup of intervention participants had lower α‐amylase across time. Delivery of standardized oral care to all participants may have been an intervention itself and possibly associated with the lack of significant findings for most outcomes. Impact This trial compared usual care to oral care with a deep suctioning intervention on microaspiration and ventilator‐associated events, as this has not been systematically studied. Further research on the usefulness of α‐amylase as an aspiration biomarker and the role of oral suctioning, especially for certain populations, is indicated. Trial registration number: ClinicalTrials.gov: NCT02284178.

Is α-Amylase an Important Biomarker to Detect Aspiration of Oral Secretions in Ventilated Patients?

“…In contrast, other researchers used α-amylase to evaluate outcomes of interventions and reported data related to VAE. In these studies, no relationships were observed between α-amylase levels and development of VAE ( 12 , 16 ).…”

“…Once oral secretions are aspirated, it is unknown how long α-amylase is detectable in pulmonary secretions. Studies with multiple measures detected α-amylase up to 14 days after intubation ( 11 , 12 , 16 ), and no changes in either the α-amylase values or T/O ratio over time ( 16 ). Reported values may reflect ongoing aspiration around the ETT cuff and/or stability of α-amylase in the pulmonary system once aspiration occurs.…”

“…As expected, values of α-amylase decreased depending on the proximity of specimen collection from the mouth. Approximately 5–7% of oral α-amylase is detectable in tracheal samples calculating a T/O ratio ( 9 , 16 ). The majority of subjects across studies had aspiration as indicated by positive levels of α-amylase in pulmonary specimens.…”

“…Alpha-amylase values that indicate microaspiration or macroaspiration are unknown. Some researchers classified patients as having aspirated if α-amylase was detected at a minimal level detectable by laboratory methods ( 10 , 16 – 18 ). Other studies used a higher value based on sensitivity and specificity analysis, requiring values of 1,685 U/L or higher to indicate aspiration ( 11 , 13 ).…”

“…It has been suggested that the ratio of tracheal values to oral α-amylase values (T/O ratio) is an indicator of the degree of aspiration ( 9 ). T/O ratios in recent studies have ranged from 0.055 (5.5%) in a sample of 26 patients to 0.07 (7.0%) in a sample of 410 patients ( 9 , 16 ). Although one study showed a higher rate of pulmonary infection in patients with a higher T/O ratio ( 14 ), another found no differences in clinical outcomes ( 16 ).…”