ABSTRACT
BACKGROUND: Septic shock is a highly lethal condition. Early recognition of tissue hypoperfusion and its reversion are key factors for limiting progression to multiple organ dysfunction and death. Lactate-targeted resuscitation is the gold-standard under current guidelines, although it has several pitfalls including that non-hypoxic sources of lactate might predominate in an unknown proportion of patients. Peripheral perfusion-targeted resuscitation might provide a real-time response to increases in flow that could lead to a more timely decision to stop resuscitation, thus avoiding fluid overload and the risks of over-resuscitation. This article reports the rationale, study design and analysis plan of the ANDROMEDA-SHOCK Study. METHODS: ANDROMEDA-SHOCK is a randomized controlled trial which aims to determine if a peripheral perfusion-targeted resuscitation is associated with lower 28-day mortality compared to a lactate-targeted resuscitation in patients with septic shock with less than 4 h of diagnosis. Both groups will be treated with the same sequential approach during the 8-hour study period pursuing normalization of capillary refill time versus normalization or a decrease of more than 20% of lactate every 2 h. The common protocol starts with fluid responsiveness assessment and fluid loading in responders, followed by a vasopressor and an inodilator test if necessary. The primary outcome is 28-day mortality, and the secondary outcomes are: free days of mechanical ventilation, renal replacement therapy and vasopressor support during the first 28 days after randomization; multiple organ dysfunction during the first 72 h after randomization; intensive care unit and hospital lengths of stay; and all-cause mortality at 90-day. A sample size of 422 patients was calculated to detect a 15% absolute reduction in mortality in the peripheral perfusion group with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. CONCLUSIONS: If peripheral perfusion-targeted resuscitation improves 28-day mortality, this could lead to simplified algorithms, assessing almost in real-time the reperfusion process, and pursuing more physiologically sound objectives. At the end, it might prevent the risk of over-resuscitation and lead to a better utilization of intensive care unit resources. Trial registration ClinicalTrials.gov Identifier: NCT03078712 (registered retrospectively March 13th, 2017).
ABSTRACT
INTRODUCTION: Chronic airflow obstruction in conditions such as chronic obstructive pulmonary disease is associated with respiratory muscle dysfunction. Our aim was to study the effects of salbutamol-a beta-adrenergic agonist known to improve muscle strength in physiologic and pathologic conditions-on diaphragm contractility in an animal model of chronic airway obstruction achieved by tracheal banding. MATERIALS AND METHODS: Twenty-four Sprague-Dawley rats were randomized into a control group and 3 tracheal banding groups, 1 that received acute salbutamol treatment, 1 that received chronic salbutamol treatment, and 1 that received nothing. Arterial blood gases, acid-base balance, and in vitro diaphragmatic contractility were evaluated by measuring peak twitch tension, contraction time, contraction velocity, half-relaxation time, relaxation velocity, and force-frequency curves. RESULTS: The 3 study groups had significantly reduced arterial pH and increased PaCO2 and bicarbonate levels compared to the control group (P<.05). The untreated tracheal banding group had significantly reduced peak twitch tension and contraction velocity, and a significantly lower force-frequency curve in comparison with the other groups (P<.05). The chronic treatment group had a higher relaxation velocity than the untreated study group (P<.05). The mean (SE) peak twitch tension values were 6.46 (0.90)N/cm(2) for the control group, 3.28 (0.55)N/cm(2) for the untreated tracheal banding group, 6.18 (0.71)N/cm(2) for the acute treatment group, and 7.09 (0.59)N/cm(2) for the chronic treatment group. CONCLUSIONS: Diaphragmatic dysfunction associated with chronic airflow obstruction improves with both the acute and chronic administration of salbutamol. The mechanisms involved in respiratory muscle dysfunction warrant further study.