Background: The knowledge of new prognostic factors in out-of-hospital cardiac arrest (OHCA) that can be evaluated since the beginning of cardiopulmonary resuscitation (CPR) manoeuvres could be helpful in the decisionmaking process of prehospital care. We aim to identify metabolic variables at the start of advanced CPR at the scene that may be associated with two main outcomes of CPR (recovery of spontaneous circulation (ROSC) and neurological outcome). Methods: Prospective observational study of all non-traumatic OHCA in patients older than 17 years assisted by emergency medical services (EMS), with doctor and nurse on board, between January 2012 and December 2017. Venous blood gases were sampled upon initially obtaining venous access to determine the initial values of pH, pCO 2 , HCO 3 − , base excess (BE), Na + , K + , Ca 2+ and lactate. ROSC upon arrival at the hospital and neurological status 30 days later (Cerebral Performance Categories (CPC) scale) were recorded. Results: We included 1552 patients with OHCA with blood test data in a 6-year period. ROSC was achieved in 906 cases (58.4%), and good neurological recovery at 30 days (CPC I-II) occurred in 383 cases (24.68%). In multivariate analysis, we found a significant relationship between non-recovery of spontaneous circulation (no-ROSC) and low pH levels (adjusted odds ratio (OR) 0.03 (0.002-0.59), p = 0.020), high pCO 2 levels (adjusted OR 1.03 [1.01-1.05], p = 0.008) and high potassium levels (adjusted OR 2.28 [1.43-3.61], p = 0.008). Poor neurological outcomes were associated with low pH levels (adjusted OR 0.06 [0.02-0.18], p < 0.001), high pCO 2 (adjusted OR 1.05 [1.03-1.08], p < 0.001), low HCO 3 − (adjusted OR 0.97 [0.94-0.999], p = 0.044), low BE (adjusted OR 0.96 [0.93-0.98], p < 0.001) and high potassium levels (adjusted OR 1.37 [1.16-1.60], p < 0.001). Conclusion: There is a significant relationship between severe alterations of venous blood-gas variables and potassium at the start of CPR of non-traumatic OHCA and low-ROSC rate and neurological prognosis.

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We describe the use of off-label ceftolozane/tazobactam in the management of a multidrug-resistant Pseudomonas aeruginosa bacteremia that was already being treated with colistin and amikacin, the only active antibiotics according to the antibiogram.

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The current COVID-19 pandemic has rendered up to 15% of patients under mechanical ventilation. Because the subsequent tracheotomy is a frequent procedure, the three societies mostly involved (SEMICYUC, SEDAR and SEORL-CCC) have setup a consensus paper that offers an overview about indications and contraindications of tracheotomy, be it by puncture or open, clarifying its respective advantages and enumerating the ideal conditions under which they should be performed, as well as the necessary steps. Regular and emergency situations are displayed together with the postoperative measures.

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, con el consentimiento de los autores y de los editores. * Autor para correspondencia.

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