Abstract
Rev Bras Ter Intensiva. 2022;34(1):185-196
DOI 10.5935/0103-507X.20220013-en
Although the PaO 2/FiO 2 derived from arterial blood gas analysis remains the gold standard for the diagnosis of acute respiratory failure, the SpO2/FiO2 has been investigated as a potential substitute. The current narrative review presents the state of the preclinical and clinical literature on the SpO2/FiO2 as a possible substitute for PaO2/FiO2 and for use as a diagnostic and prognostic marker; provides an overview of pulse oximetry and its limitations, and assesses the utility of SpO2/ FiO2 as a surrogate for PaO2/FiO2 in COVID-19 patients. Overall, 49 studies comparing SpO2/FiO2 and PaO2/FiO2 were found according to a minimal search strategy. Most were conducted on neonates, some were conducted on adults with acute respiratory distress syndrome, and a few were conducted in other clinical scenarios (including a very few on COVID-19 patients). There is some evidence that the SpO2/ FiO2 criteria can be a surrogate for PaO2/FiO2 in different clinical scenarios. This is reinforced by the fact that unnecessary invasive procedures should be avoided in patients with acute respiratory failure. It is undeniable that pulse oximeters are becoming increasingly widespread and can provide costless monitoring. Hence, replacing PaO2/FiO2 with SpO2/FiO2may allow resourcelimited facilities to objectively diagnose acute respiratory failure.
Abstract
Rev Bras Ter Intensiva. 2021;33(4):537-543
DOI 10.5935/0103-507X.20210081
To compare gas exchange indices behavior by using liberal versus conservative oxygenation targets in patients with moderate to severe acute respiratory distress syndrome secondary to COVID-19 under invasive mechanical ventilation. We also assessed the influence of high FiO2 on respiratory system mechanics.
We prospectively included consecutive patients aged over 18 years old with a diagnosis of COVID-19 and moderate-severe acute respiratory distress syndrome. For each patient, we randomly applied two FiO2 protocols to achieve SpO2 88% - 92% or 96%. We assessed oxygenation indices and respiratory system mechanics.
We enrolled 15 patients. All the oxygenation indices were significantly affected by the FiO2 strategy (p < 0.05) selected. The PaO2/FiO2 deteriorated, PA-aO2 increased and Pa/AO2 decreased significantly when using FiO2 to achieve SpO2 96%. Conversely, the functional shunt fraction was reduced. Respiratory mechanics were not affected by the FiO2 strategy.
A strategy aimed at liberal oxygenation targets significantly deteriorated gas exchange indices, except for functional shunt, in COVID-19-related acute respiratory distress syndrome. The respiratory system mechanics were not altered by the FiO2 strategy.
Abstract
Rev Bras Ter Intensiva. 2021;33(3):346-352
DOI 10.5935/0103-507X.20210053
To assess pulmonary embolism incidence, its relationship with D-dimer levels and other possible associated factors in addition to anticoagulation and contrast medium adverse effects.
A retrospective observational cohort study at a Chilean public hospital was performed. Intensive care unit mechanically ventilated COVID-19 patients older than 18 years old between March and June 2020 were included. All patients received heparin thromboprophylaxis, which was increased to the anticoagulation dose with D-dimer greater than 3µg/mL.
A total of 127 patients were followed up, of whom 73 underwent pulmonary computed tomography angiography (mean age, 54 ± 12 years; 49 men). Sixty-two of the 73 patients (84.9%) received full anticoagulation before computed tomography angiography. In addition, 18 of the 73 patients had pulmonary embolism (24.7%). When comparing patients with and without pulmonary embolism, no significant differences were observed in age, sex, obesity, smoking, Wells and revised Geneva scores, D-dimer or mortality. Anticoagulant use was similar in both groups. Days from the start of anticoagulation until computed tomography angiography were significantly lower in the pulmonary embolism group (p = 0.002). Three patients presented post contrast-acute kidney injury (4.1%), and one patient had major bleeding.
Despite anticoagulation, one in four COVID-19 patients connected to mechanical ventilation and evaluated with pulmonary computed tomography angiography had pulmonary embolism. With a longer the delay in performing computed tomography angiography once empirical anticoagulation was started, significantly less pulmonary embolism was identified.
Abstract
Rev Bras Ter Intensiva. 2021;33(3):457-460
DOI 10.5935/0103-507X.20210067
A 63-year-old woman presented to the emergency department with an acute history of fever, prostration and dyspnea. She was diagnosed with severe COVID-19 acute respiratory distress syndrome and, despite optimized critical care support, met the indications for veno-venous extracorporeal membrane oxygenation. On day 34, after 7 days of wean sedation with a positive evolution of neurologic status, she presented a limited generalized tonic-clonic seizure not related to hydroelectrolytic or metabolic imbalance, which led to a diagnostic investigation; her brain imaging tests showed a posterior reversible encephalopathy syndrome. This case emphasizes the issue of neurological complications in patients with severe COVID-19 infection and the importance of early diagnosis and support.
Abstract
Rev Bras Ter Intensiva. 2021;33(2):196-205
DOI 10.5935/0103-507X.20210027
To identify more severe COVID-19 presentations.
Consecutive intensive care unit-admitted patients were subjected to a stepwise clustering method.
Data from 147 patients who were on average 56 ± 16 years old with a Simplified Acute Physiological Score 3 of 72 ± 18, of which 103 (70%) needed mechanical ventilation and 46 (31%) died in the intensive care unit, were analyzed. From the clustering algorithm, two well-defined groups were found based on maximal heart rate [Cluster A: 104 (95%CI 99 - 109) beats per minute versus Cluster B: 159 (95%CI 155 - 163) beats per minute], maximal respiratory rate [Cluster A: 33 (95%CI 31 - 35) breaths per minute versus Cluster B: 50 (95%CI 47 - 53) breaths per minute], and maximal body temperature [Cluster A: 37.4 (95%CI 37.1 - 37.7)°C versus Cluster B: 39.3 (95%CI 39.1 - 39.5)°C] during the intensive care unit stay, as well as the oxygen partial pressure in the blood over the oxygen inspiratory fraction at intensive care unit admission [Cluster A: 116 (95%CI 99 - 133) mmHg versus Cluster B: 78 (95%CI 63 - 93) mmHg]. Subphenotypes were distinct in inflammation profiles, organ dysfunction, organ support, intensive care unit length of stay, and intensive care unit mortality (with a ratio of 4.2 between the groups).
Our findings, based on common clinical data, revealed two distinct subphenotypes with different disease courses. These results could help health professionals allocate resources and select patients for testing novel therapies.
Abstract
Rev Bras Ter Intensiva. 2021;33(2):320-324
DOI 10.5935/0103-507X.20210041
We report a case of Influenza B infection and Kawasaki disease in an adolescent, diagnosed during the COVID-19 pandemic. An asthmatic female adolescent presented with fever and flu-like symptoms for 7 days and was admitted with acute respiratory failure requiring mechanical ventilation. She progressed with hemodynamic instability responsive to vasoactive drugs. Antibiotic therapy and support measures were introduced, showing progressive hemodynamics and respiratory improvement, however with persistent fever and increased inflammatory markers. During the hospitalization, she developed bilateral non-purulent conjunctivitis, hand and feet desquamation, strawberry tongue, and cervical adenopathy, and was diagnosed with Kawasaki disease. She was prescribed intravenous immunoglobulin and, due to the refractory clinical conditions, corticosteroid therapy was added; 24 hours later, the patient was afebrile. No coronary changes were found. A full viral panel including COVID-19 C-reactive protein and serology could only isolate the Influenza B virus. During the hospitalization, she was diagnosed with pulmonary thromboembolism; coagulopathies were investigated, and she was diagnosed with heterozygous factor V Leiden mutation. There is a potential association between Kawasaki disease and infection with Influenza B or with other viruses such as coronavirus. Therefore, this association should be considered in pediatric patients, adolescents included, with prolonged febrile conditions.
Abstract
Rev Bras Ter Intensiva. 2021;33(2):325-325
DOI 10.5935/0103-507X.20210042
COVID-19 was declared a pandemic by the World Health Organization on March 11, 2020. The clinical presentation is predominantly respiratory symptoms; however, in the current literature, several neurological manifestations associated with SARS-CoV-2 infection have been described. The authors present the clinical case of a 45-year-old man hospitalized for pneumonia with a positive test result for SARS-CoV-2, without a neurological history, who, on the sixteenth day of hospitalization, presented a sudden change in his state of consciousness accompanied by conjugated right gaze deviation and myoclonus of the face and thoracic region to the left, followed by generalized tonic-clonic seizures associated with persistent left hemiparesis. The present study highlights a positive RT-PCR test for SARS-CoV-2 in cerebrospinal fluid. The patient progressed with gradual improvement, and the outcome was favorable.
Abstract
Rev Bras Ter Intensiva. 2021;33(1):48-67
DOI 10.5935/0103-507X.20210005
To propose agile strategies for a comprehensive approach to analgesia, sedation, delirium, early mobility and family engagement for patients with COVID-19-associated acute respiratory distress syndrome, considering the high risk of infection among health workers, the humanitarian treatment that we must provide to patients and the inclusion of patients’ families, in a context lacking specific therapeutic strategies against the virus globally available to date and a potential lack of health resources.
A nonsystematic review of the scientific evidence in the main bibliographic databases was carried out, together with national and international clinical experience and judgment. Finally, a consensus of recommendations was made among the members of the Committee for Analgesia, Sedation and Delirium of the Sociedad Argentina de Terapia Intensiva.
Recommendations were agreed upon, and tools were developed to ensure a comprehensive approach to analgesia, sedation, delirium, early mobility and family engagement for adult patients with acute respiratory distress syndrome due to COVID-19.
Given the new order generated in intensive therapies due to the advancing COVID-19 pandemic, we propose to not leave aside the usual good practices but to adapt them to the particular context generated. Our consensus is supported by scientific evidence and national and international experience and will be an attractive consultation tool in intensive therapies.