BACKGROUND: One-lung ventilation-related hypoxaemia (OLV-RH) can occur in patients with healthy lungs. In this case, PEEP frequently improves oxygenation. The aim of this study was to determine, in a healthy lung model of OLV, whether the increase in PEEP improved oxygenation and whether the mechanisms involved include both inspiratory lung recruitment and an end-expiratory lung volume increase. Since inhaled nitric oxide (iNO) may have a synergistic effect on oxygenation in the case of PEEP-induced recruitment, their association was also tested. METHODS: Twenty pigs were studied during open-chest, left OLV. Arterial blood gases and haemodynamic variables were measured at different levels of PEEP (0, 5, 10 and 15 cm H(2)O) applied in random order with or without iNO 4 p.p.m. Pressure-volume curves were measured at each level of PEEP. RESULTS: PEEP(5) and PEEP(10) improved Pa(O(2))/FI(O(2)) ratio (P<0.005) and shunt (P<0.005) regardless of the presence of iNO. PEEP(15) improved oxygenation and shunt only when it was associated with iNO (P<0.001). Whereas PEEP(5), PEEP(10) and PEEP(15) were associated with a significant increase in end-expiratory volume (P<0.001), only PEEP(5) and PEEP(10) were associated with continuous lung volume recruitment (P<0.01). Moreover, PEEP(15) induced a significant decrease in linear compliance (P<0.001). CONCLUSIONS: In a healthy porcine lung model of OLV-RH, moderate PEEP can improve oxygenation. This effect implies both expiratory and inspiratory pulmonary recruitment. Co-administration of 4 p.p.m. iNO was ineffective.
BACKGROUND: One-lung ventilation-related hypoxaemia (OLV-RH) can occur in patients with healthy lungs. In this case, PEEP frequently improves oxygenation. The aim of this study was to determine, in a healthy lung model of OLV, whether the increase in PEEP improved oxygenation and whether the mechanisms involved include both inspiratory lung recruitment and an end-expiratory lung volume increase. Since inhaled nitric oxide (iNO) may have a synergistic effect on oxygenation in the case of PEEP-induced recruitment, their association was also tested. METHODS: Twenty pigs were studied during open-chest, left OLV. Arterial blood gases and haemodynamic variables were measured at different levels of PEEP (0, 5, 10 and 15 cm H(2)O) applied in random order with or without iNO 4 p.p.m. Pressure-volume curves were measured at each level of PEEP. RESULTS: PEEP(5) and PEEP(10) improved Pa(O(2))/FI(O(2)) ratio (P<0.005) and shunt (P<0.005) regardless of the presence of iNO. PEEP(15) improved oxygenation and shunt only when it was associated with iNO (P<0.001). Whereas PEEP(5), PEEP(10) and PEEP(15) were associated with a significant increase in end-expiratory volume (P<0.001), only PEEP(5) and PEEP(10) were associated with continuous lung volume recruitment (P<0.01). Moreover, PEEP(15) induced a significant decrease in linear compliance (P<0.001). CONCLUSIONS: In a healthy porcine lung model of OLV-RH, moderate PEEP can improve oxygenation. This effect implies both expiratory and inspiratory pulmonary recruitment. Co-administration of 4 p.p.m. iNO was ineffective.
Authors: Marina E Boules; Nabila Ibrahim Laz; Ahmed A Elberry; Raghda R S Hussein; Mohamed E A Abdelrahim Journal: Beni Suef Univ J Basic Appl Sci Date: 2022-04-15
Authors: Ana Fernandez-Bustamante; Soshi Hashimoto; Ary Serpa Neto; Pierre Moine; Marcos F Vidal Melo; John E Repine Journal: BMC Anesthesiol Date: 2015-05-06 Impact factor: 2.217
Authors: Dharshi Karalapillai; Laurence Weinberg; Jonathan Galtieri; Neil Glassford; Glenn Eastwood; Jai Darvall; Jake Geertsema; Ravi Bangia; Jane Fitzgerald; Tuong Phan; Luke OHallaran; Adriano Cocciante; Stuart Watson; David Story; Rinaldo Bellomo Journal: BMC Anesthesiol Date: 2014-10-01 Impact factor: 2.217