Revista Brasileira de Terapia Intensiva最新文献

Objective: To investigate the association between noninvasive ventilation delivery devices and the incidence of nasal septum injury in preterm infants.

Methods: This retrospective singlecenter cohort study included preterm infants supported by noninvasive ventilation. The incidence of nasal injury was compared among three groups according to the noninvasive ventilation delivery device (G1 - nasal mask; G2 - binasal prongs; and G3, rotation of nasal mask with prongs). Nasal injury was classified according to the National Pressure Ulcer Advisory Panel as stages 1 - 4. Multivariate regression analyses were performed to estimate relative risks to identify possible predictors associated with medical device-related injuries.

Results: Among the 300 infants included in the study, the incidence of medical device-related injuries in the rotating group was significantly lower than that in the continuous mask or prong groups (n = 68; 40.48%; p value < 0.01).The basal prong group presented more stage 2 injuries (n = 15; 55.56%; p < 0.01). Staying ≥ 7 days in noninvasive ventilation was associated with a higher frequency of medical device-related injuries, regardless of device (63.81%; p < 0.01). Daily increments in noninvasive ventilation increased the risk for nasal injury by 4% (95%CI 1.02 - 1.06; p < 0.01). Higher birth weight indicated protection against medical device-related injuries. Each gained gram represented a decrease of 1% in the risk of developing nasal septum injury (RR: 0.99; 95%CI 0.99 - 0.99; p < 0.04).

Conclusion: Rotating nasal masks with nasal prongs reduces the incidence of moderate to severe nasal injury in comparison with single devices. The addition of days using noninvasive ventilation seems to contribute to medical device-related injuries, and higher birth weight is a protective factor.

Objective: To test whether tissue oxygen saturation (StO2) after a venous occlusion test estimates central venous oxygen saturation (ScvO2).

Methods: Observational study in intensive care unit patients. Tissue oxygen saturation was monitored (InSpectra Tissue Spectrometer Model 650, Hutchinson Technology Inc., MN, USA) with a multiprobe (15/25mm) in the thenar position. A venous occlusion test in volunteers was applied in the upper arm to test the tolerability and pattern of StO2 changes during the venous occlusion test. A sphygmomanometer cuff was inflated to a pressure 30mmHg above diastolic pressure until StO2 reached a plateau and deflated to 0mmHg. Tissue oxygen saturation parameters were divided into resting StO2 (r-StO2) and minimal StO2 (m-StO2) at the end of the venous occlusion test. In patients, the cuff was inflated to a pressure 30mmHg above diastolic pressure for 5 min (volunteers' time derived) or until a StO2 plateau was reached. Tissue oxygen saturation parameters were divided into r-StO2, m-StO2, and the mean time that StO2 reached ScvO2. The StO2 value at the mean time was compared to ScvO2.

Results: All 9 volunteers tolerated the venous occlusion test. The time for tolerability or the StO2 plateau was 7 ± 1 minutes. We studied 22 patients. The mean time for StO2 equalized ScvO2 was 100 sec and 95 sec (15/25mm probes). The StO2 value at 100 sec ([100-StO2] 15mm: 74 ± 7%; 25mm: 74 ± 6%) was then compared with ScvO2 (75 ± 6%). The StO2 value at 100 sec correlated with ScvO2 (15 mm: R2 = 0.63, 25mm: R2 = 0.67, p < 0.01) without discrepancy (Bland Altman).

Conclusion: Central venous oxygen saturation can be estimated from StO2 during a venous occlusion test.

Objective: To compare the predictive performance of residents, senior intensive care unit physicians and surrogates early during intensive care unit stays and to evaluate whether different presentations of prognostic data (probability of survival versus probability of death) influenced their performance.

Methods: We questioned surrogates and physicians in charge of critically ill patients during the first 48 hours of intensive care unit admission on the patient's probability of hospital outcome. The question framing (i.e., probability of survival versus probability of death during hospitalization) was randomized. To evaluate the predictive performance, we compared the areas under the ROC curves (AUCs) for hospital outcome between surrogates and physicians' categories. We also stratified the results according to randomized question framing.

Results: We interviewed surrogates and physicians on the hospital outcomes of 118 patients. The predictive performance of surrogate decisionmakers was significantly lower than that of physicians (AUC of 0.63 for surrogates, 0.82 for residents, 0.80 for intensive care unit fellows and 0.81 for intensive care unit senior physicians). There was no increase in predictive performance related to physicians' experience (i.e., senior physicians did not predict outcomes better than junior physicians). Surrogate decisionmakers worsened their prediction performance when they were asked about probability of death instead of probability of survival, but there was no difference for physicians.

Conclusion: Different predictive performance was observed when comparing surrogate decision-makers and physicians, with no effect of experience on health care professionals' prediction. Question framing affected the predictive performance of surrogates but not of physicians.

Objective: The central venousarterial carbon dioxide pressure to arterial-central venous oxygen content ratio (Pcv-aCO2/Ca-cvO2) is frequently used as a surrogate for tissue oxygenation. We aimed to identify and synthesize literature and quality of evidence supporting Pcv-aCO2/Ca-cvO2 as a predictor of mortality in critically ill patients compared with lactate.

Methods: We searched several databases for studies measuring Pcv-aCO2/Ca-cvO2 in critically ill patients. Independent investigators performed the article screening and data extraction. A random-effects metaanalysis was performed. Pooled standardized mean differences (SMD) were used to compare the prognostic ability of Pcv-aCO2/Ca-cvO2 and lactate.

Results: We initially retrieved 172 studies; 17 were included for qualitative description, and 10 were included for quantitative synthesis. The mean Pcv-aCO2/Ca-cvO2 was higher in nonsurvivors than in survivors (pooled SMD = 0.75; 95%CI 0.34 - 1.17; I2 = 83%), as was the case with lactate levels (pooled SMD = 0.94; 95%CI 0.34 - 1.54; I2 = 92%). Both tests were statistically significant predictors of mortality, albeit with overlapping 95%CIs between them.

Conclusion: Moderate-quality evidence showed little or no difference in the ability of Pcv-aCO2/Ca-cvO2, compared with lactate, to predict mortality. Nevertheless, our conclusions are limited by the considerable heterogeneity among the studies.PROSPERO registration: CRD42019130387.

Objective: To analyze the influence of mechanical power and its components on mechanical ventilation for patients infected with SARS-CoV-2; identify the values of the mechanical ventilation components and verify their correlations with each other and with the mechanical power and effects on the result of the Gattinoni-S and Giosa formulas.

Methods: This was an observational, longitudinal, analytical and quantitative study of respirator and mechanical power parameters in patients with SARS-CoV-2.

Results: The mean mechanical power was 26.9J/minute (Gattinoni-S) and 30.3 J/minute (Giosa). The driving pressure was 14.4cmH2O, the plateau pressure was 26.5cmH2O, the positive end-expiratory pressure was 12.1cmH2O, the elastance was 40.6cmH2O/L, the tidal volume was 0.36L, and the respiratory rate was 32 breaths/minute. The correlation between the Gattinoni and Giosa formulas was 0.98, with a bias of -3.4J/minute and a difference in the correlation of the resistance pressure of 0.39 (Gattinoni) and 0.24 (Giosa). Among the components, the correlations between elastance and driving pressure (0.88), positive end-expiratory pressure (-0.54) and tidal volume (-0.44) stood out.

Conclusion: In the analysis of mechanical ventilation for patients with SARS-CoV-2, it was found that the correlations of its components with mechanical power influenced its high momentary values and and that the correlations of its components with each other influenced their behavior throughout the study period. Because they have specific effects on the Gatinnoni-S and Giosa formulas, the mechanical ventilation components influenced their calculations and caused divergence in the mechanical power values.