Question: 73-year-old man, ex-smoker, history of hypertension, grade II obesity, type 2 diabetes and severe COPD with chronic home oxygen therapy. He went to the Emergency Department due to a progressive increase in his habitual dyspnea, purulent expectoration and a temperature of 37.9ºC in 4 days of evolution. His family doctor had prescribed moxifloxacin, paracetamol, deflazacort, aerosol therapy and increased oxygen flow 2 days before. On physical examination the patient is in regular general condition, conscious, sleep tendency, tachypneic at 28 rpm and utilization of accessory muscles, temperature 38.2ºC, oxygen saturation of 87%, TA 115/62 mmHg, heart rate 110 lpm; vesicular murmur diminished globally, wheezing and scattered rhonchi and moist crepitations in bases. The analyte highlights 16,500 / uL leukocytes with 14,900 neutrophils, hemoglobin 14 g / dL, glucose 240 mg / dL, urea 56 mg / dL, creatinine 1.3 mg / dL, Na 133 mEq / L, K 3.7 mEq / L. In the ECG, sinus tachycardia was observed. The arterial blood gases show: pH 7.29, pCO2 64 mmHg, pO2 59 mmHg, HCO3 28 mg / dL. The chest radiograph shows no condensation or pleural effusion. Which of the following clinical management options would you establish in the first place? 
 Options:  <1> Start treatment with intravenous diuretics, oxygen with a high-flow 50% mask and continue with the rest of the prescribed treatment. <2> Start treatment with salbutamol and steroid sprays, add a cephalosporin to the antibiotic treatment, intensify oxygen therapy in nasal glasses at 4 liters per minute and maintain deflazacort. <3> Start treatment of acidosis with 1M bicarbonate, correct hyperglycemia, maintain antibiotic treatment and prescribe steroids plus intravenous diuretics. <4> Given the patient's serious situation, orotracheal intubation would be carried out prior to preparation (pre-oxygenation and premedication) and to notify Intensive Care Medicine. <5> Start treatment with non-invasive mechanical ventilation (two-level positive pressure mode), prescribe salbutamol aerosols and intravenous steroids and maintain intravenous antibiotic treatment.
5