23. Does the maximum allowable contrast dose (MACD) predict the risk of contrast induced nephropathy (CIN) in patients with chronic kidney disease (CKD)

BackgroundCIN is associated with high in-hospital mortality. Some studies recommend the utilization of the MACD formula to guide safe contrast dosing, however the evidence supporting use of this measure is limited.ObjectiveThe purpose of this study was to determine if MACD is helpful in predicting the risk of CIN in patients with CKD.Methods8670 patients who underwent coronary angiography in our center with or without Percutaneous Coronary Intervention (PCI) (2008–2013) were included. Patients with CKD (n=144) were selected. Patients in shock, on intra aortic balloon pump, on prophylactic hemofiltration or on dialysis were excluded.Creatinine was measured 48–72h post procedure. T-test, Chi-Square and multiple regression were used to compare those patients who developed CIN and those who did not develop CIN. CIN was defined as an increase in serum creatinine by ⩾25% or 0.5mg/dL from baseline within 48–72h after contrast exposure.ResultsCIN occurred in 28 patients (19.4%). Only 8 (5.6%) of the 144 patients exceeded MACD and 2 of these patients developed CIN. The use of biplane angiography explains the lower contrast dose. For this reason the impact of exceeding MACD could not be evaluated. Primary PCI was associated with CIN (p=0.012; OR 5.1)).ConclusionOverall it is best to limit contrast dose to the extent possible as this is a known risk factor, however MACD is not a useful variable in a risk model for predicting CIN in our population. Primary PCI was the only predictor of CIN in our population

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population