Early association between respiratory mechanics and radiological changes in mechanically ventilated critically ill patients with COVID-19.

The chest X-ray (CXR) Brixia scoring system was developed exclusively for COVID-19 severity assessment. However, no association between the score and respiratory mechanics during mechanical ventilation has been examined. Our aim was to evaluate the association between the CXR Brixia score and respiratory mechanics on the first day of mechanical ventilation in critically ill COVID-19 patients. A total of 77 COVID-19 patients who underwent mechanical ventilation and CXR in the ICU setting were retrospectively included. The CXR Brixia scoring system was applied, and respiratory mechanics data were recorded on the first day of invasive mechanical ventilation. Median Simplified Acute Physiologic Score II (SAPSII) and Sequential Organ Failure Assessment (SOFA) scores were 40 (31-54) and 6 (4-8), respectively. The median Brixia score was 14 (11-16). The correlation between the Brixia score and static compliance or driving pressure was significant, at r = -0.38, p < 0.001 and r = 0.33, p = 0.003, respectively. Using multivariable linear regression, the model with the B zone was significantly better associated with static compliance (F = 11.5, R2 = 0.14, p = 0.001) and driving pressure (F = 11.3, R2 = 0.13, p = 0.001). In logistic regression analysis, the Brixia score (OR 1.24; 95% CI 1.07, 1.45; p = 0.005), B zone (OR 2.60; 95% CI 1.30, 5.20; p = 0.007), C zone (OR 2.50; 95% CI 1.23, 5.11; p = 0.012), A zone (OR 2.01; 95% CI 1.16, 3.44; p = 0.012), and D zone (OR 1.84; 95% CI 1.07, 3.17; p = 0.027) significantly predicted a driving pressure > 14 cmH2O. There is a relationship between changes in Brixia-scored chest X-ray images and compliance and driving pressure on the first day of invasive mechanical ventilation. We identified some CXR areas using the Brixia score, and evaluation of the Brixia score may provide additional information for predicting respiratory mechanics.

Can the inferior vena cava collapsibility index be useful in predicting hypotension during spinal anaesthesia in a spontaneously breathing patient? A mini fluid challenge.

The study was performed at the Department of Orthopaedics and Traumatology of the Kauno Klinikos Hospital of Lithuanian University of Health Sciences. BACKGROUND: Intravascular fluids are empirically administered to prevent hypotension induced by spinal anaesthesia. Ultrasound measurements of the inferior vena cava (IVC) and the IVC collapsibility index (IVC-CI) is a non-invasive method to evaluate the intravascular volume status. The aim of the study was to identify the prognostic value of the IVC collapsibility index in spontaneously breathing patients to predict severe intraoperative hypotension. MATERIALS AND METHODS: Sixty patients undergoing elective knee arthroplasty under spinal anaesthesia were included in the prospective study. The diameters of IVCex, IVCin, and IVC-CI were measured before and 15 min after spinal anaesthesia when administration of 500 ml of normal saline using infusion pump was finished. The haemodynamic parameters (heart rate, systolic, diastolic, and mean blood pressures, breathing rate) were collected. RESULTS: Severe arterial hypotension was noticed in 18.3% of the patients. No statistically significant differences were detected between changes in IVCex, IVCin, and IVC-CI comparing hypotensive and non-hypotensive patients at the baseline and after the interventions (p > 0.005). According to receiver operating characteristic (ROC) analysis, IVC-CI is not effective in the prediction of severe hypotension during spinal anaesthesia in spontaneously breathing patients: the area under the ROC curve for IVC-CI was <0.7, p > 0.05. CONCLUSIONS: IVC-CI is not an effective predictor of severe hypotension after induction of spinal anaesthesia followed by normal saline administration in spontaneously breathing patients undergoing elective knee arthroplasty. More trials, including different patient subgroups, will be needed.

The correlation of post-operative acute kidney injury and perioperative anaemia in patients undergoing cardiac surgery with cardiopulmonary bypass.

BACKGROUND AND OBJECTIVE: Acute kidney injury (AKI) following cardiac surgery with cardiopulmonary bypass (CPB) is polyethiological clinical syndrome. During CPB haemodilution develops, which is useful in reducing the risk of thrombosis; however, haemodilutional anaemia decreases oxygen transfer and provokes tissue hypoxia, which can lead to acute organ damage. The aim of the study was to find out the impact of perioperative anaemia on AKI after cardiac surgery with CPB. MATERIALS AND METHODS: This prospective study included 58 adult patients undergoing elective cardiac surgery with CPB, without any preoperative chronic renal disease or any systemic autoimmune disease. Serum concentrations of NGAL had been tested before the surgery, 2 hours, 6 hours, and one day after the surgery. Perioperative anaemia was assessed according to the Ht value before the surgery, the Ht value during CPB, and immediately after the surgery. RESULTS: The rate of haemodilutional anaemia is 77.59% in this study. The average of serum NGAL concentration before CPB was 63.95 ± 33.25 ng/mL and it was significantly lower than the average concentration 2 hours after the surgery, 6 hours after the surgery and one day after the surgery (respectively 148.51 ± 62.39, 119.44 ± 55, 128.70 ± 59.04 ng/mL, p < 0.05). AKI developed in 46.55% of the patients. A significant positive reasonable correlation between the development of perioperative anaemia and AKI was determined (r = 0.50, p < 0.05). CONCLUSIONS: Post-operative AKI after cardiac surgery with CPB has a moderate positive correlation with perioperative haemodilutional anaemia. A longer CPB time and aortic cross-clamping time were found to be the risk factors for the development of AKI.