5 research outputs found
Unintended consequences; fluid resuscitation worsens shock in an ovine model of endotoxemia
No full textFluid resuscitation is widely considered a life saving intervention in septic shock however recent evidence has questioned both its safety and efficacy in sepsis. This study sought to compare fluid resuscitation with vasopressors with vasopressors alone in a hyperdynamic model of ovine endotoxemia.Endotoxemic shock was induced in sixteen sheep after which they received fluid resuscitation with 40mls/kg of 0.9% saline or commenced haemodynamic support with protocolized noradrenaline and vasopressin. Microdialysis catheters were inserted into the arterial circulation, heart, brain, kidney and liver to monitor local metabolism. Blood samples were recovered to measure serum inflammatory cytokines, creatinine, troponin, ANP, BNP and hyaluronan. All animals were monitored and supported for 12 hours after fluid resuscitation.After resuscitation animals receiving fluid resuscitation required significantly more noradrenaline to maintain the same mean arterial pressure in the subsequent 12 hours (68.9mg vs. 39.6mg p=0.04). Serum cytokines were similar between groups. Atrial natriuretic peptide increased significantly after fluid resuscitation compared to animals managed without fluid resuscitation (335ng/mL (256-382) vs. 233ng/mL (144 - 292) p 0.04). Cross-sectional time series analysis showed the rate of increase of the glycocalcyx glycosaminoglycan hyaluronan was greater in the fluid resuscitated group over the course of the study (p=0.02) Conclusion: Fluid resuscitation resulted in a paradoxical increase in vasopressor requirement. Additionally, It did not result in improvements in any of the measured microcirculatory or organ specific markers measured. The increase in vasopressor requirement seen may have been due to endothelial/glycocalyx damage secondary to ANP mediated glycocalyx shedding
Packed red cell age associated with adverse cardiovascular changes in an ovine model of septic shock resuscitation
No full textAn innovative ovine model of severe cardiopulmonary failure supported by veno-arterial extracorporeal membrane oxygenation
No full textRefractory cardiogenic shock (CS) often requires veno-arterial extracorporeal membrane oxygenation (VA-ECMO) to sustain end-organ perfusion. Current animal models result in heterogenous cardiac injury and frequent episodes of refractory ventricular fibrillation. Thus, we aimed to develop an innovative, clinically relevant, and titratable model of severe cardiopulmonary failure. Six sheep (60 +/- 6 kg) were anaesthetized and mechanically ventilated. VA-ECMO was commenced and CS was induced through intramyocardial injections of ethanol. Then, hypoxemic/hypercapnic pulmonary failure was achieved, through substantial decrease in ventilatory support. Echocardiography was used to compute left ventricular fractional area change (LVFAC) and cardiac Troponin I (cTnI) was quantified. After 5 h, the animals were euthanised and the heart was retrieved for histological evaluations. Ethanol (58 +/- 23 mL) successfully induced CS in all animals. cTnI levels increased near 5000-fold. CS was confirmed by a drop in systolic blood pressure to 67 +/- 14 mmHg, while lactate increased to 4.7 +/- 0.9 mmol/L and LVFAC decreased to 16 +/- 7%. Myocardial samples corroborated extensive cellular necrosis and inflammatory infiltrates. In conclusion, we present an innovative ovine model of severe cardiopulmonary failure in animals on VA-ECMO. This model could be essential to further characterize CS and develop future treatments
An appraisal of respiratory system compliance in mechanically ventilated covid-19 patients
No full textInternational audienceAbstract Background Heterogeneous respiratory system static compliance ( C RS ) values and levels of hypoxemia in patients with novel coronavirus disease (COVID-19) requiring mechanical ventilation have been reported in previous small-case series or studies conducted at a national level. Methods We designed a retrospective observational cohort study with rapid data gathering from the international COVID-19 Critical Care Consortium study to comprehensively describe C RS —calculated as: tidal volume/[airway plateau pressure-positive end-expiratory pressure (PEEP)]—and its association with ventilatory management and outcomes of COVID-19 patients on mechanical ventilation (MV), admitted to intensive care units (ICU) worldwide. Results We studied 745 patients from 22 countries, who required admission to the ICU and MV from January 14 to December 31, 2020, and presented at least one value of C RS within the first seven days of MV. Median (IQR) age was 62 (52–71), patients were predominantly males (68%) and from Europe/North and South America (88%). C RS , within 48 h from endotracheal intubation, was available in 649 patients and was neither associated with the duration from onset of symptoms to commencement of MV ( p = 0.417) nor with PaO 2 /FiO 2 ( p = 0.100). Females presented lower C RS than males (95% CI of C RS difference between females-males: − 11.8 to − 7.4 mL/cmH 2 O p < 0.001), and although females presented higher body mass index (BMI), association of BMI with C RS was marginal ( p = 0.139). Ventilatory management varied across C RS range, resulting in a significant association between C RS and driving pressure (estimated decrease − 0.31 cmH 2 O/L per mL/cmH 2 0 of C RS , 95% CI − 0.48 to − 0.14, p < 0.001). Overall, 28-day ICU mortality, accounting for the competing risk of being discharged within the period, was 35.6% (SE 1.7). Cox proportional hazard analysis demonstrated that C RS (+ 10 mL/cm H 2 O) was only associated with being discharge from the ICU within 28 days (HR 1.14, 95% CI 1.02–1.28, p = 0.018). Conclusions This multicentre report provides a comprehensive account of C RS in COVID-19 patients on MV. C RS measured within 48 h from commencement of MV has marginal predictive value for 28-day mortality, but was associated with being discharged from ICU within the same period. Trial documentation: Available at https://www.covid-critical.com/study . Trial registration : ACTRN12620000421932
Impact of Hemoglobin Levels on Composite Cardiac Arrest or Stroke Outcome in Patients With Respiratory Failure Due to COVID-19
No full textOBJECTIVES:. Anemia has been associated with an increased risk of both cardiac arrest and stroke, frequent complications of COVID-19. The effect of hemoglobin level at ICU admission on a composite outcome of cardiac arrest or stroke in an international cohort of COVID-19 patients was investigated.
DESIGN:. Retrospective analysis of prospectively collected database.
SETTING:. A registry of COVID-19 patients admitted to ICUs at over 370 international sites was reviewed for patients diagnosed with cardiac arrest or stroke up to 30 days after ICU admission. Anemia was defined as: normal (hemoglobin ≥ 12.0 g/dL for women, ≥ 13.5 g/dL for men), mild (hemoglobin 10.0–11.9 g/dL for women, 10.0–13.4 g/dL for men), moderate (hemoglobin ≥ 8.0 and < 10.0 g/dL for women and men), and severe (hemoglobin < 8.0 g/dL for women and men).
PATIENTS:. Patients older than 18 years with acute COVID-19 infection in the ICU.
INTERVENTIONS:. None.
MEASUREMENTS AND MAIN RESULTS:. Of 6926 patients (median age = 59 yr, male = 65%), 760 patients (11.0%) experienced stroke (2.0%) and/or cardiac arrest (9.4%). Cardiac arrest or stroke was more common in patients with low hemoglobin, occurring in 12.8% of patients with normal hemoglobin, 13.3% of patients with mild anemia, and 16.7% of patients with moderate/severe anemia. Time to stroke or cardiac arrest by anemia status was analyzed using Cox proportional hazards regression with death as a competing risk. Covariates selected through clinical knowledge were age, sex, comorbidities (diabetes, hypertension, obesity, and cardiac or neurologic conditions), pandemic era, country income, mechanical ventilation, and extracorporeal membrane oxygenation. Moderate/severe anemia was associated with a higher risk of cardiac arrest or stroke (hazard ratio, 1.32; 95% CI, 1.05–1.67).
CONCLUSIONS:. In an international registry of ICU patients with COVID-19, moderate/severe anemia was associated with increased hazard of cardiac arrest or stroke
