How to Estimate QT Interval in Patients With Left or Right Bundle Branch Block: A Systematic Review.

PURPOSE/BACKGROUND: Prolonged QT interval related to psychopharmacological treatment is a risk factor for potentially life-threatening arrhythmias. Electrocardiographic measurements are recommended in patients with cardiovascular risk factors before initiating treatment with potentially QT-prolonging medications, such as certain antidepressants or antipsychotics. In patients with left bundle branch block (LBBB) or right bundle branch block (RBBB), conventional QT-estimation methods will lead to overestimation of the QT interval, as the conduction defect, reflected by the QRS duration, will increase the QT interval without representing longer repolarization as in drug-induced QT prolongation. METHODS/PROCEDURES: We conducted a systematic review of methods to estimate QT interval in the presence of LBBB or RBBB. We searched electronic databases Embase and Medline (last search, August 12, 2020). FINDINGS/RESULTS: We found 8 different methods, including linear correction formulae with and without correction for heart rate, or simpler formula correcting QRS duration with empirically derived modifiers. Only 3 of 8 methods were applicable in the presence of RBBB, whereas all 8 methods could be applied in the presence of LBBB. IMPLICATIONS/CONCLUSIONS: The QT interval is overestimated in patients with LBBB or RBBB, when using conventional measurements. Several alternative correction formulae exist, which can be applied using standard measurements from ordinary electrocardiographic readings. However, it is currently unknown whether or not the QT prolongation observed in the presence of bundle branch block significantly increases the risk of arrhythmias, as these formulae have not been tested against patient-specific clinical outcomes.

Indications for fluid resuscitation in patients with septic shock: Post-hoc analyses of the CLASSIC trial.

BACKGROUND: Fluid resuscitation is recommended in septic shock, but the specific indications for fluids have not been established. Our aim was to investigate the indications currently used for fluid resuscitation and the effect of fluid on these indications in patients with septic shock admitted to the intensive care unit (ICU). METHODS: This was a post-hoc analysis of the CLASSIC trial, where patients with septic shock were randomized to fluid restriction or standard care. We recorded indications for and effect of each fluid bolus during the first 24 hours. RESULTS: In total, 256 fluid boluses were administered on 515 indications to the 76 patients in the standard care group. The most frequent indications were low blood pressure/increase in noradrenalin dose (199 boluses, 78%), high lactate (94, 37%), and low urinary output (68, 27%). While the analyses of all 418 fluid boluses given in all 151 patients failed to show any effect of fluid on these variables, the data did suggest that time from randomization altered the effect; fluid may have increased urinary output when given early and increased noradrenalin dose when given later. For 56% of the fluid boluses given on the most frequent indications, a second fluid bolus was given on the same indication. CONCLUSIONS: In ICU patients with septic shock, low blood pressure, high lactate, and low urinary output were the most frequent indications for fluid. The effects of fluids when given on these indications were less clear, but may dependent on the time course of sepsis resuscitation.

Early goal-directed nutrition versus standard of care in adult intensive care patients: the single-centre, randomised, outcome assessor-blinded EAT-ICU trial.

PURPOSE: We assessed the effects of early goal-directed nutrition (EGDN) vs. standard nutritional care in adult intensive care unit (ICU) patients. METHODS: We randomised acutely admitted, mechanically ventilated ICU patients expected to stay longer than 3 days in the ICU. In the EGDN group we estimated nutritional requirements by indirect calorimetry and 24-h urinary urea aiming at covering 100% of requirements from the first full trial day using enteral and parenteral nutrition. In the standard of care group we aimed at providing 25 kcal/kg/day by enteral nutrition. If this was not met by day 7, patients were supplemented with parenteral nutrition. The primary outcome was physical component summary (PCS) score of SF-36 at 6 months. We performed multiple imputation for data of the non-responders. RESULTS: We randomised 203 patients and included 199 in the intention-to-treat analyses; baseline variables were reasonably balanced between the two groups. The EGDN group had less negative energy (p < 0.001) and protein (p < 0.001) balances in the ICU as compared to the standard of care group. The PCS score at 6 months did not differ between the two groups (mean difference 0.0, 95% CI -5.9 to 5.8, p = 0.99); neither did mortality, rates of organ failures, serious adverse reactions or infections in the ICU, length of ICU or hospital stay, or days alive without life support at 90 days. CONCLUSIONS: EGDN did not appear to affect physical quality of life at 6 months or other important outcomes as compared to standard nutrition care in acutely admitted, mechanically ventilated, adult ICU patients. Clinicaltrials.gov identifier no. NCT01372176.