| 1. |
- Gogniat, Emiliano, et al.
(författare)
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Dead space analysis at different levels of positive end-expiratory pressure in acute respiratory distress syndrome patients
- 2018
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Ingår i: Journal of critical care. - : W B SAUNDERS CO-ELSEVIER INC. - 0883-9441 .- 1557-8615. ; 45, s. 231-238
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To analyze the effects of positive end-expiratory pressure (PEEP) on Bohr's dead space (VDBohr/VT) in patients with acute respiratory distress syndrome (ARDS).Material and methods: Fourteen ARDS patients under lung protective ventilation settingswere submitted to 4 different levels of PEEP (0, 6, 10, 16 cmH(2)O). Respiratory mechanics, hemodynamics and volumetric capnography were recorded at each protocol step.Results: Two groups of patients responded differently to PEEP when comparing baseline with 16-PEEP: those in which driving pressure increased > 15% (Delta P.(15%), n = 7, p = .016) and those in which the change was <= 15% (Delta P-<= 15%, n = 7, p = .700). VDBohr/VT was higher in Delta P-<= 15% than in Delta P-<= 15% patients at baseline ventilation [0.58 (0.49-0.60) vs 0.46 (0.43-0.46) p = .018], at 0-PEEP [0.50 (0.47-0.54) vs 0.41 (0.40-0.43) p = .012], at 6-PEEP [0.55 (0.49-0.57) vs 0.44 (0.42-0.45) p = .008], at 10-PEEP [0.59 (0.51-0.59) vs 0.45 (0.44-0.46) p = .006] and at 16-PEEP [0.61 (0.56-0.65) vs 0.47 (0.45-0.48) p =. 001]. We found a good correlation between Delta P and VDBohr/VT only in the Delta P.(15%) group (r = 0.74, p < .001).Conclusions: Increases in PEEP result in higher VDBohr/VT only when associated with an increase in driving pressure.
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| 2. |
- Tusman, Gerardo, et al.
(författare)
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Multimodal non-invasive monitoring to apply an open lung approach strategy in morbidly obese patients during bariatric surgery
- 2020
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Ingår i: Journal of clinical monitoring and computing. - : SPRINGER HEIDELBERG. - 1387-1307 .- 1573-2614. ; 34:5, s. 1015-1024
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate the use of non-invasive variables for monitoring an open-lung approach (OLA) strategy in bariatric surgery. Twelve morbidly obese patients undergoing bariatric surgery received a baseline protective ventilation with 8 cmH(2)O of positive-end expiratory pressure (PEEP). Then, the OLA strategy was applied consisting in lung recruitment followed by a decremental PEEP trial, from 20 to 8 cmH(2)O, in steps of 2 cmH(2)O to find the lung's closing pressure. Baseline ventilation was then resumed setting open lung PEEP (OL-PEEP) at 2 cmH(2)O above this pressure. The multimodal non-invasive variables used for monitoring OLA consisted in pulse oximetry (SpO(2)), respiratory compliance (Crs), end-expiratory lung volume measured by a capnodynamic method (EELVCO2), and esophageal manometry. OL-PEEP was detected at 15.9 +/- 1.7 cmH(2)O corresponding to a positive end-expiratory transpulmonary pressure (P-L,P-ee) of 0.9 +/- 1.1 cmH(2)O. ROC analysis showed that SpO(2) was more accurate (AUC 0.92, IC95% 0.87-0.97) than Crs (AUC 0.76, IC95% 0.87-0.97) and EELVCO2 (AUC 0.73, IC95% 0.64-0.82) to detect the lung's closing pressure according to the change of P-L,P-ee from positive to negative values. Compared to baseline ventilation with 8 cmH(2)O of PEEP, OLA increased EELVCO2 (1309 +/- 517 vs. 2177 +/- 679 mL) and decreased driving pressure (18.3 +/- 2.2 vs. 10.1 +/- 1.7 cmH(2)O), estimated shunt (17.7 +/- 3.4 vs. 4.2 +/- 1.4%), lung strain (0.39 +/- 0.07 vs. 0.22 +/- 0.06) and lung elastance (28.4 +/- 5.8 vs. 15.3 +/- 4.3 cmH(2)O/L), respectively; all p < 0.0001. The OLA strategy can be monitored using noninvasive variables during bariatric surgery. This strategy decreased lung strain, elastance and driving pressure compared with standard protective ventilatory settings. Clinical trial number NTC03694665.
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| 3. |
- Tusman, Gerardo, et al.
(författare)
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Reference values for volumetric capnography-derived non-invasive parameters in healthy individuals
- 2013
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Ingår i: Journal of clinical monitoring and computing. - : Springer Science and Business Media LLC. - 1387-1307 .- 1573-2614. ; 27:3, s. 281-288
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to determine typical values for non-invasive volumetric capnography (VCap) parameters for healthy volunteers and anesthetized individuals. VCap was obtained by a capnograph connected to the airway opening. We prospectively studied 33 healthy volunteers 32 +/- A 6 years of age weighing 70 +/- A 13 kg at a height of 171 +/- A 11 cm in the supine position. Data from these volunteers were compared with a cohort of similar healthy anesthetized patients ventilated with the following settings: tidal volume (VT) of 6-8 mL/kg, respiratory rate 10-15 bpm, PEEP of 5-6 cmH(2)O and FiO(2) of 0.5. Volunteers showed better clearance of CO2 compared to anesthetized patients as indicated by (median and interquartile range): (1) an increased elimination of CO2 per mL of VT of 0.028 (0.005) in volunteers versus 0.023 (0.003) in anesthetized patients, p < 0.05; (2) a lower normalized slope of phase III of 0.26 (0.17) in volunteers versus 0.39 (0.38) in anesthetized patients, p < 0.05; and (3) a lower Bohr dead space ratio of 0.23 (0.05) in volunteers versus 0.28 (0.05) in anesthetized patients, p < 0.05. This study presents reference values for non-invasive volumetric capnography-derived parameters in healthy individuals. Mechanical ventilation and anesthesia altered these values significantly.
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