The Hemodynamic Changes And Their Clinical Significance Research In The Early Stage Of Large Area Severe Burn

BackgroundWith the development of minimally invasive and noninvasive monitoring technology, hemodynamic monitoring has been more and more used in clinical care management.In addition to the traditional perioperative patients and the management of critically ill patients in ICU, minimally invasive and noninvasive monitoring has been more used in trauma, burn care management field. Even in the gynecology and obstetrics, noninvasive hemodynamic monitoring has been used in perinatal management.In other words, the clinical application of hemodynamic monitoring is not only limited in the Fluid management. A growing number of studies has confirmed that the hemodynamic monitoring also has an important value on prediction and treatment of complications, diagnosis and identification of disease and the treatment outcome, and so on.Part one:Clinical evaluation for the change of hemodynamic parameters in severe burn injury and the impact on the outcomeObjective:to observe the changes of hemodynamic parameters in the early days of large area severe burn, and according to the patient outcome, and to invesgate whether there are differences in the changes of hemodynamic parameters in first week postburn between the survival and death.Methods:we applied for prospective, observational study in A quaternary-level university-affiliated ICU.Forty-five patients with burns of greater than or equal to 30% total body surface area, intubated with no previous cardiovascular comorbidities were enrolled.At admission,a PICCO system was attached and daily blood samples were taken from the arterial catheter. Treatment was carried out and adjusted daily according to Changhai Burns Consensus criteria. According to the outcome,patients were differed into two groups, the " Survival " and "non-Survival ".The differences of Hemodynamic were compared in two groups.Results:In the first week of large area severe burns, The heart rate and blood pressure were continuous higher than the normal level but the fluctuation was not obvious. Cardiac function parameters (CO,CI,SV,dPmx,GEF) and Cardiac preload indicators (CVP, ITBI, GEDI) were lower than the normal level after burn, then showed a gradual upward trend with fluid resuscitation.Compared with the point at 24 hours, CVP was significantly higher after 36 hours postburn (P< 0.05), other preload parameters (ITBI, GEDI) were significantly higher at 72 hours postburn (P< 0.05), Cardiac function parameters (CO,CI,SV,SVI) significantiy elevated between 72-84 hours postburn (P< 0.05). Systemic vascular tension index (SVRI) as one of Cardiac afterload parameters, was significantly higher than the nomal level in early burns, and then gradually decreased during the treatment. At the time of 72 hours postburn, it decreased significantly compared with 24 hours (P<0.05). Lung related parameters:EVLWI also showed a gradual upward trend with fluid resuscitation,and increased significantly in 60 hours postburn vs 24 hours (P< 0.05). PVPI postburn in acute phase rose,but not significantly.The preload parameters (CVP, GEDVI), cardic function parameters (CI, CFI, dPmx) and pulmonary vascular permeability index (PVPI) were not significantly difference between the two groups(P>0.05). But the cardiac afterload parameters SVRI and vascular lung water index (EVLWI) shows significant difference between the two groups (P<0.05).Conclusion:The clinic use of PICCO system in hemodynamic monitoring after burn injury can effectively evaluate the change of the cardiac load, myocardial contraction force and lung related parameters. At the same time, certain hemodynamic changes can be used as an early indicator of complications and outcome in patients with burn injury. The clinical significance of hemodynamic parameters postburn is a biomarkers in a "burning" issue but still a long way to go.Part two:The clinical usefulness of extravascular lung water and pulmonary vascular permeability index based on PiCCO system to diagnose and characterize burn-induced pulmonary edemaObjective:This study aimed to test whether the parameters assessed by PiCCO system enable to differentiate increased permeability pulmonary edema (ALI/ARDS) from hydrostatic pulmonary edema (hydrostatic/cardiogenic pulmonary edema) which were induced by burn.Methods:In this retrospective observational study, the extravascular lung water index (EVLWI), the pulmonary vascular permeability index (PVPI) and intrathoracic blood volume index(ITBVI)were measured by the PiCCO system in 70 severe burn patients complicated with pulmonary edema patients. According to the Berlin definition of ARDS, the burn induced Pulmonary edema was clarified the clinical pathophysiological features and definitive diagnosised by three experts. Patients were divided into the following two categories on the basis of the pathophysiological diagnostic differentiation of respiratory insufficiency:burn induced increased permeability pulmonary edema (ALI/ARDS Group), and burn induced hydrostatic pulmonary edema (non-ALI/ARDS Group).Results:38 Patients were included in the study at last. ALI/ARDS Group were noted in 17 patients, and 21 patients included in non-ALI/ARDS Group. EVLWI in ALI/ARDS Group was not significantly greater than that in non-ALI/ARDS Group (12.91±3.058,12.05±2.079; P>0.05). PVPI in ALI/ARDS Group was significantly higher than that in non-ALI/ARDS Group ((2.56±0.53,1.41±0.27;P<0.01). In ALI/ARDS Group, EVLWI was significantly positively correlated with PVPI and ITBVI (P<0.05); PaO2/FiO2 ratio was significantly negatively correlated with EVLWI and PVPI(P<0.05). In ALI/ARDS Group, EVLWI was significantly positive correlated with ITBVI (P< 0.01), and the correlate between EVLWI and PVPI was not significantly (P>0.05) PaO2/FiO2 ratio was not significantly correlated with EVLWI and PVPI (P>0.05). A PVPI≥1.9 as the cut-off value provided a definitive diagnosis of burn-induced ALI/ARDS with a sensitivity of 0.941 and specificity of 0.952.Conclusion:These results suggest that extravascular lung water index (EVLWI) and pulmonary vascular permeability index (PVPI) provided by PICCO system may be useful for determining the mechanism of pulmonary edema in the burn patients, and be beneficial for differential diagnosis of burn induced ALI/ARDS from non-ALI/ARDS pulmonary edema.