Dynamic Changes in Respiratory Frequency/Tidal Volume May Predict Failures of Ventilatory Liberation in Patients on Prolonged Mechanical Ventilation and Normal Preliberation Respiratory Frequency/Tidal Volume Values

Rapid shallow breathing index (RSBI, respiratory frequency [f] divided by tidal volume [Vt]) has been used to prognosticate liberation from mechanical ventilation (LMV). We hypothesize that dynamic changes in RSBI predict failed LMV better than isolated RSBI measurements. We conducted a retrospective study of patients who were mechanically ventilated (MV) for longer than 72 hours. Failed LMV was defined as need for reinstitution of MV within 48 hours post-LMV. Ventilatory frequency (f) and Vt (liters) were serially recorded. The instantaneous RSBI (i-RSBI) was defined as f/Vt. Dynamic f/Vt ratio (d-RSBI) was defined as the ratio between two consecutive i-RSBI (f/Vt) measurements ([f2/Vt2]/[f1/Vt1]). RSBI Product (RSB-P) was defined as (i-RSBI × d-RSBI). Data from 32 patients were analyzed (Acute Physiology and Chronic Health Evaluation II 13.4, male 69%, mean age 57 years). Mean length of stay was 19.5 days (11.5 ventilator; 14.1 intensive care unit days). For LMV failures, mean time to reinstitution of invasive MV was 20.8 hours. All patients had pre-LMV i-RSBI less than 100. Failed LMVs had higher i-RSBI values (68.9, n = 18) than successful LMVs (44.2, n = 23, P \u3c 0.01). Failures had higher d-RSBI (1.48) than successful LMVs (1.05, P \u3c 0.04). The RSB-P was higher for failed LMVs (118) than for successful LMVs (48.8, P \u3c 0.01) with failures having larger proportion of pre-LMV d-RSBI values greater than 1.5 (39.0 vs 10.7%, P \u3c 0.03). Pre-LMV RSB-P may offer early prediction of failed LMV in patients on MV for longer than 72 hours despite normal pre-LMV i-RSBI. Divergence between RSB-P for successful and failed LMVs occurred earlier than i-RSBI divergence with a greater proportion of pre-LMV d-RSBI greater than 1.5 among failures

Dynamic Changes in Respiratory Frequency/Tidal Volume May Predict Failures of Ventilatory Liberation in Patients on Prolonged Mechanical Ventilation and Normal Preliberation Respiratory Frequency/Tidal Volume Values

Rapid shallow breathing index (RSBI, respiratory frequency [f] divided by tidal volume [Vt]) has been used to prognosticate liberation from mechanical ventilation (LMV). We hypothesize that dynamic changes in RSBI predict failed LMV better than isolated RSBI measurements. We conducted a retrospective study of patients who were mechanically ventilated (MV) for longer than 72 hours. Failed LMV was defined as need for reinstitution of MV within 48 hours post-LMV. Ventilatory frequency (f) and Vt (liters) were serially recorded. The instantaneous RSBI (i-RSBI) was defined as f/Vt. Dynamic f/Vt ratio (d-RSBI) was defined as the ratio between two consecutive i-RSBI (f/Vt) measurements ([f2/Vt2]/[f1/Vt1]). RSBI Product (RSB-P) was defined as (i-RSBI × d-RSBI). Data from 32 patients were analyzed (Acute Physiology and Chronic Health Evaluation II 13.4, male 69%, mean age 57 years). Mean length of stay was 19.5 days (11.5 ventilator; 14.1 intensive care unit days). For LMV failures, mean time to reinstitution of invasive MV was 20.8 hours. All patients had pre-LMV i-RSBI less than 100. Failed LMVs had higher i-RSBI values (68.9, n = 18) than successful LMVs (44.2, n = 23, P \u3c 0.01). Failures had higher d-RSBI (1.48) than successful LMVs (1.05, P \u3c 0.04). The RSB-P was higher for failed LMVs (118) than for successful LMVs (48.8, P \u3c 0.01) with failures having larger proportion of pre-LMV d-RSBI values greater than 1.5 (39.0 vs 10.7%, P \u3c 0.03). Pre-LMV RSB-P may offer early prediction of failed LMV in patients on MV for longer than 72 hours despite normal pre-LMV i-RSBI. Divergence between RSB-P for successful and failed LMVs occurred earlier than i-RSBI divergence with a greater proportion of pre-LMV d-RSBI greater than 1.5 among failures

Upper Gastrointestinal Perforations: A Possible Danger of Antibiotic Overuse

BACKGROUND: The role of changes in gut microflora on upper gastrointestinal (UGI) perforations is not known. We conducted a retrospective case-control study to examine the relationship between antibiotic exposure-a proxy for microbiome modulation-and UGI perforations in a national sample. METHODS: We queried a 5% random sample of Medicare (2009-2013) to identify patients \u3e /= 65 years old hospitalized with UGI (stomach or small intestine) perforations using International Classification of Diseases diagnosis codes. Cases with UGI perforations were matched with 4 controls, each based on age and sex. Exposure to outpatient antibiotics (0-30, 31-60, 61-90 days) prior to case patients\u27 index hospitalization admission data was determined with Part D claims. Univariate and multivariable regression analyses were performed to evaluate the effect of antibiotic exposure on UGI perforation. RESULTS: Overall, 504 cases and 2016 matched controls were identified. Compared to controls, more cases had antibiotic exposure 0-30 days (19% vs. 3%, p \u3c 0.001) and 31-60 days (5% vs. 2%, p \u3c 0.001) prior to admission. In adjusted analyses, antibiotic exposure 0-30 days prior to admission was associated with 6.8 increased odds of an UGI perforation (95% CI 4.8, 9.8); 31-60 days was associated with 1.9 increased odds (95% CI 1.1, 3.3); and 61-90 days was associated with 3.7 increased odds (95% CI 2.0, 6.9). CONCLUSIONS: Recent outpatient antibiotic use, in particular in the preceding 30 days, is associated with UGI perforation among Medicare beneficiaries. Exposure to antibiotics, one of the most modifiable determinants of the microbiome, should be minimized in the outpatient setting