Our first research question examined the precautions and clinical indications for suctioning. Only one new study was identified. Predictors of retained secretions were examined in a prospective observational study (15) on 66 patients requiring mechanical ventilation (MV). A sawtooth pattern on a flow-volume loop (seen on the ventilator screen) and respiratory sounds over the trachea had likelihood ratios of a positive test (presence of secretions greater than 0.5 mL) of 2.70 and 2.50, respectively, and likelihood ratios of a negative test of 0.25 and 0.45, respectively. When these two parameters were both present, the likelihood ratio for a positive test was increased to 14.7, while the negative test did not have an appreciable change (0.42) (15).
Summary:
For patients on MV, the best available evidence suggests the presence of retained secretions if a sawtooth pattern and/or respiratory sounds over the trachea are present.