ABSTRACT Introduction: Risk factors and postoperative complications can worsen the condition of patients undergoing coronary artery bypass grafting; some of these factors and complications are closely related to mortality rate. Objective: To describe clinical factors and outcomes related to mortality of patients undergoing coronary artery bypass grafting and on invasive mechanical ventilation. Methods: This is a single-center retrospective data analysis of patients who underwent coronary artery bypass grafting on invasive mechanical ventilation between 2013 and 2019. Data regarding clinical characteristics, postoperative complications, intensive care unit and mechanical ventilation time, and their relationship with mortality were analyzed. Results: Four hundred seventy-two patients who underwent coronary artery bypass grafting entered the study. Their mean age was 62.3 years, and mean body mass index was 27.3. The mortality rate was 4%. Fifty percent of the patients who had ventilator-associated pneumonia died. Considering the patients who underwent hemotherapy and hemodialysis, 20% and 33% died, respectively. Days of intensive care unit stay and high Acute Physiology and Chronic Health Evaluation score and Simplified Acute Physiology Score were significantly related to death. Conclusion: Factors and clinical conditions such as the patients’ age, associated comorbidities, the occurrence of ventilator-associated pneumonia, length of stay in the intensive care unit, and mechanical ventilation time are related to higher mortality in patients undergoing coronary artery bypass grafting.

INTRODUÇÃO: A concentração de 2,3-difosfoglicerato nos eritrócitos (2,3-DPG/Hct) aumenta como ocorrência fisiológica ao aumento do pH e à hiperventilação. Esta resposta foi testada em pacientes com traumatismo craniencefálico (TCE) grave. MÉTODO: A concentração de 2,3-DPG/Hct foi medida diariamente, durante seis dias, em 11 pacientes com TCE grave necessitando de hiperventilação otimizada por causa da hipertensão intracraniana. RESULTADOS: Houve correlação entre o pH e a concentração de 2,3-DPG/Hct. A concentração de 2,3-DPG/Hct permaneceu predominantemente dentro da normalidade, com ligeira tendência à elevação no sexto dia de estudo. Houve correlação entre a concentração de 2,3-DPG/Hct e a pressão parcial de oxigênio que satura 50% da hemoglobina (P50st), confirmando a consistência dos dados. CONCLUSÃO: A esperada resposta fisiológica de aumento progressivo da concentração de 2,3-DPG/Hct não foi observada. Este fato pode ser explicado pela aplicação intermitente e não sustentada de hiperventilação, como ditado pelo protocolo clínico de ventilação otimizada.

INTRODUCTION: The concentration of 2,3-diphosphoglycerate (2,3-DPG/Hct) increases as a physiological occurrence to pH increase and hyperventilation. This response was tested in patients with severe traumatic brain injury (TBI). METHOD: The concentration of 2,3-DPG/Hct was measured daily for six days in eleven patients with severe TBI in need of optimized hyperventilation because of intracranial hypertension. RESULTS:There was correlation between pH and the concentration of DPG/Hct. The concentration of 2,3-DPG/Hct remained predominantly within normal levels with slight increase in the sixth day of the study. The concentration of 2,3-DPG/Hct correlated significantly with measured partial pressure of oxygen that saturates 50% the hemoglobin of the blood (P50st), confirming the consistency of our data. CONCLUSION: The expected physiological response of a progressive increase in concentration of 2,3-DPG/Hct to hyperventilation was not observed. This fact may be explained by the intermittent and not sustained hyperventilation as dictated by the protocol of optimized ventilation.