Can dynamic indicators help the prediction of fluid responsiveness in spontaneously breathing critically ill patients?

OBJECTIVE: To investigate whether the respiratory changes in arterial pulse (DeltaPP) and in systolic pressure (DeltaSP) could predict fluid responsiveness in spontaneously breathing (SB) patients. Because changes in intrathoracic pressure during spontaneous breathing (SB) might be insufficient to modify loading conditions of the ventricles, performances of indicators were also assessed during a forced respiratory maneuver. DESIGN: Prospective interventional study. SETTING: A 34-bed university hospital medico-surgical ICU. PATIENTS AND PARTICIPANTS: Thirty-two SB patients with clinical signs of hemodynamic instability. INTERVENTION: A 500-ml volume expansion (VE). MEASUREMENTS AND RESULTS: Cardiac index, assessed using transthoracic echocardiography, increased by at least 15% after VE in 19 patients (responders). At baseline, only dynamic indicators were higher in responders than in nonresponders (13+/-5% vs. 7+/-3%, p=0.003 for DeltaPP and 10+/-4% vs. 6+/-2%, p=0.002 for DeltaSP). Moreover, they significantly decreased after VE (11+/-5% to 6+/-4%, p<0.001 for DeltaPP and 8+/-4% to 6+/-3%, p<0.001 for DeltaSP). DeltaPP and DeltaSP areas under the ROC curve were high (0.81+/-0.08 and 0.82+/-0.08; p=0.888, respectively). A DeltaPP>or=12% predicted fluid responsiveness with high specificity (92%) but poor sensitivity (63%). The forced respiratory maneuver reproducing a dyspneic state decreased the predictive power. CONCLUSIONS: Due to their lack of sensitivity and their dependence to respiratory status, DeltaPP and DeltaSP are clearly less reliable to predict fluid responsiveness during SB than in mechanically ventilated patients. However, when their baseline value is high without acute right ventricular dysfunction in a participating patient, a positive response to fluid is likely.

Effect of ventilator-associated tracheobronchitis on outcome in patients without chronic respiratory failure: a case-control study.

INTRODUCTION: Our objective was to determine the effect of ventilator-associated tracheobronchitis (VAT) on outcome in patients without chronic respiratory failure. METHODS: This was a retrospective observational matched study, conducted in a 30-bed intensive care unit (ICU). All immunocompetent, nontrauma, ventilated patients without chronic respiratory failure admitted over a 6.5-year period were included. Data were collected prospectively. Patients with nosocomial pneumonia, either before or after VAT, were excluded. Only first episodes of VAT occurring more than 48 hours after initiation of mechanical ventilation were studied. Six criteria were used to match cases with controls, including duration of mechanical ventilation before VAT. Cases were compared with controls using McNemar's test and Wilcoxon signed-rank test for qualitative and quantitative variables, respectively. Variables associated with a duration of mechanical ventilation longer than median were identified using univariate and multivariate analyses. RESULTS: Using the six criteria, it was possible to match 55 (87%) of the VAT patients (cases) with non-VAT patients (controls). Pseudomonas aeruginosa was the most frequently isolated bacteria (34%). Although mortality rates were similar between cases and controls (29% versus 36%; P = 0.29), the median duration of mechanical ventilation (17 days [range 3-95 days] versus 8 [3-61 days]; P < 0.001) and ICU stay (24 days [range 5-95 days] versus 12 [4-74] days; P < 0.001) were longer in cases than in controls. Renal failure (odds ratio [OR] = 4.9, 95% confidence interval [CI] = 1.6-14.6; P = 0.004), tracheostomy (OR = 4, 95% CI = 1.1-14.5; P = 0.032), and VAT (OR = 3.5, 95% CI = 1.5-8.3; P = 0.004) were independently associated with duration of mechanical ventilation longer than median. CONCLUSION: VAT is associated with longer durations of mechanical ventilation and ICU stay in patients not suffering from chronic respiratory failure.

First-generation fluoroquinolone use and subsequent emergence of multiple drug-resistant bacteria in the intensive care unit.

OBJECTIVE: The objective of this study was to determine the relationship between fluoroquinolone (FQ) use and subsequent emergence of multiple drug-resistant bacteria (MRB) in the intensive care unit (ICU). DESIGN: The authors conducted a prospective observational cohort study and a case control study. SETTING: The study was conducted in a 30-bed ICU. METHODS: All immunocompetent patients hospitalized for >48 hrs who did not receive antibiotics before ICU admission were eligible during a 15-month period. Routine MRB screening was performed at ICU admission and weekly thereafter. This screening included tracheal aspirate and nasal, anal, and axilla swabs. Univariate and multivariate analyses were used to determine risk factors for MRB emergence in the ICU. In addition, a case control study was performed to determine whether FQ use is associated with subsequent emergence of MRB. RESULTS: Two hundred thirty-nine patients were included; 108 ICU-acquired MRB were isolated in 77 patients. FQ use and longer duration of antibiotic treatment were identified as independent risk factors for MRB occurrence (odds ratio [95% confidence interval [CI] = 3.3 [1.7-6.5], 1.1 [1.0-1.2]; p < .001; respectively). One hundred thirty-five (56%) patients received FQ; matching was successful for 72 (53%) of them. Number of MRB (40 vs. 15 per 1,000 ICU days; p = .019) and percentage of patients with MRB (40% vs. 22%; OR [95% CI] = 1.5 [1.0-2.4]; p = .028) were significantly higher in cases than in controls. Although methicillin-resistant Staphylococcus aureus (26% vs. 12%; OR [95% CI] = 1.6 [.6-2.9]; p = .028) and extending-spectrum beta-lactamase-producing Gram-negative bacilli (11% vs. 1%; OR [95% CI] = 4.7 [0.7-30.2]; p = .017) rates were higher in cases than in controls, ceftazidime or imipenem-resistant Pseudomonas aeruginosa (15% vs. 8%), Acinetobacter baumannii (1% vs. 5%), and Stenotrophomonas maltophilia (2% vs. 1%) rates were similar (p > .05) in case and control patients. CONCLUSION: FQ use and longer duration of antibiotic treatment are independently associated with MRB emergence. Reducing antimicrobial treatment duration and restricting FQ use could be suggested to control MRB spread in the ICU.