Endotracheal tube biofilm in critically ill patients during the COVID-19 pandemic : description of an underestimated microbiological compartment.

Biofilm (BF) growth is believed to play a major role in the development of ventilator-associated pneumonia (VAP) in the intensive care unit. Despite concerted efforts to understand the potential implication of endotracheal tube (ETT)-BF dispersal, clinically relevant data are lacking to better characterize the impact of its mesostructure and microbiological singularity on the occurrence of VAP. We conducted a multicenter, retrospective observational study during the third wave of the COVID-19 pandemic, between March and May 2021. In total, 64 ETTs collected from 61 patients were included in the present BIOPAVIR study. Confocal microscopy acquisitions revealed two main morphological aspects of ETT-deposited BF: (1) a thin, continuous ribbon-shaped aspect, less likely monobacterial and predominantly associated with Enterobacter spp., Streptococcus pneumoniae or Viridans streptococci, and (2) a thicker, discontinuous, mushroom-shaped appearance, more likely characterized by the association of bacterial and fungal species in respiratory samples. The microbiological characterization of ETT-deposited BF found higher acquired resistance in more than 80% of analyzed BF phenotypes, compared to other colonization sites from the patient's environment. These findings reveal BF as a singular microbiological compartment, and are of added clinical value, with a view to future ETT-deposited BF-based antimicrobial stewardship in critically ill patients. Trial registration NCT04926493. Retrospectively registered 15 June 2021.

Effect of the addition of vasopressin or vasopressin plus nitroglycerin to epinephrine on arterial blood pressure during cardiopulmonary resuscitation in humans.

BACKGROUND: Infusion of a vasopressor during cardiopulmonary resuscitation (CPR) in humans increases end decompression (diastolic) arterial blood pressure, and consequently increases vital organ perfusion pressure and survival. Several vasoactive drugs have been tested alone or in combination, but their hemodynamic effects have not been investigated clinically in humans. STUDY OBJECTIVE: We tested the hypothesis that epinephrine (1 mg) co-administered with vasopressin (40 IU) ± nitroglycerin (300 µg) results in higher diastolic blood pressure than epinephrine alone. STUDY DESIGN: A prospective, randomized, double-blinded controlled trial in the prehospital setting. The study included 48 patients with witnessed cardiac arrest. Patients received either epinephrine alone (E alone) or epinephrine plus vasopressin (E+V) or epinephrine plus vasopressin plus nitroglycerin (E+V+N). A femoral arterial catheter was inserted for arterial pressure measurement. OUTCOME MEASURES: The primary end point was diastolic blood pressure during CPR, 15 min after the first drug administration (T = 15 min). RESULTS: After exclusions, a total of 44 patients were enrolled. Diastolic blood pressures (mm Hg) at T = 15 min were not statistically different between groups (median [interquartile range]: 20 [10], 15 [6], and 15 [13] for E alone, E+V, and E+V+N, respectively. The rate of return of spontaneous circulation was 63% (n = 10) in the epinephrine group, 43% (n = 6) in the epinephrine plus vasopressin group, and 36% (n = 5) in the triple therapy group (NS). CONCLUSIONS: Addition of vasopressin or vasopressin plus nitroglycerin to epinephrine did not increase perfusion blood pressure compared to epinephrine alone in humans in cardiac arrest, suggesting the absence of benefit in using these drug combination(s).

Cutaneous ear lobe Pco2 at 37°C to evaluate microperfusion in patients with septic shock.

BACKGROUND: Tissue hypercarbia is related to hypoperfusion and microcirculatory disturbances in patients with septic shock. Transcutaneous Pco2 devices using a heated sensor to arterialize the tissue have been used as an alternative method for estimation of Paco2. This study investigates whether a cutaneous sensor attached to an ear lobe and regulated to 37°C could be used to measure cutaneous Pco2 (Pcco2) and evaluate microperfusion in patients with septic shock. METHODS: Fifteen stable patients in an ICU were studied as a control group. Forty-six patients with septic shock who were ventilated were enrolled as the study group. The difference of the gradients between Pcco2 and Paco2 (Pc-aco2) and between Pcco2 and end-tidal Pco2(Pc-etco2) were evaluated for 36 h. Variations of the Pc-aco2 and Pc-etco2 during fluid challenge were compared with microcirculatory skin blood flow (mBFskin) assessed by laser Doppler flowmetry. RESULTS: The baseline levels for Pc-aco2 and Pc-etco2 were significantly higher in the patients with septic shock than in the control group (14.8 [12.6] vs 6 [2.7] mm Hg and 25 [16.3] vs 9 [3.8] mm Hg, P < .0001, respectively). During the following 36 h, the Pc-aco2 and Pc-etco2 for the surviving patients with septic shock decreased significantly compared with the nonsurvivors (P < .01). The evolution of macrohemodynamic parameters showed no differences between survivors and nonsurvivors. At hour 24, a Pc-aco2 > 16 mm Hg and a Pc-etco2 > 26 mm Hg were related to poor outcome. Pc-aco2 and Pc-etco2 variations during fluid challenge were inversely correlated with changes in mBFskin (r² = 0.7). CONCLUSIONS: Ear lobe cutaneous Pco2 at 37°C represents a noninvasive technique to assess tissue Pco2 measurement. Pc-aco2 and Pc-etco2 were related to outcome and provide continuous information on microperfusion in patients with septic shock.