With a limited supply of mechanical ventilators, it is important to recognize patients with risk factors associated with the need for mechanical ventilation, and how people with diabetes respond to intubation.
Information on the SARS-CoV-2 virus is rapidly evolving, creating a challenge in keeping up to date on the latest data. It has been well established that patients with comorbidities are at an increased risk for complications from infection with COVID-19. However, a recent study estimates that only 5.8% of reported cases specify details on these comorbidities. This study aims to identify individual risk factors associated with intubation among hospitalized patients with laboratory-confirmed COVID-19. Additionally, as mechanical ventilators are limited, there is concern that there will not be enough ventilators for those who need one, making it increasingly necessary to identify upon their initial presentation which patients are likely to need one.
This study is a retrospective observational study that includes patients across ten hospitals in the Northwestern Memorial HealthCare system throughout the Chicago metropolitan area. Patients were included if they were 18 or older and admitted to the hospital with a confirmed case of COVID-19, defined by a positive result on a reverse transcription-polymerase chain reaction (RT-PCR) assay collected via nasopharyngeal swab. The primary outcome was intubation with an oral endotracheal tube and attachment to a mechanical ventilator during hospitalization. The secondary outcome was time to extubation, defined as the number of days from intubation to extubation.
There were 486 hospitalized patients included in the analysis. Of these patients, a total of 138 required mechanical ventilation. Among patients who required mechanical ventilation, there was a higher median age (65 vs. 57 years, P<.001), a higher percentage of males (63.8% vs. 52.6%, P=.033), and a higher prevalence of diabetes (40.6% vs. 29.9%, P=.031). A multivariable logistic regression model was completed, which stratified variables by hospital location. In this model, a history of diabetes remained a statistically significant risk factor for the need for intubation (OR, 1.64; 95% CI, 1.02-2.66; p=.046). For the secondary outcome of time to extubation, a Kaplan-Meier survival analysis was performed. This analysis found that age >65 years was associated with a decreased chance of extubation compared to age <50 years. Additionally, a BMI of 30-39.9 or ≥40 was associated with a reduced chance of extubation versus a BMI of <30. There were not any significant differences found in the primary or secondary outcome among the other comorbidities analyzed in the study, including hypertension and cardiovascular disease.
In addition to clinical signs of respiratory distress, patients with COVID-19 who are older, male, or have a history of diabetes are at higher risk of requiring intubation. Among intubated patients, those who are older and those with obesity are at higher risk for prolonged intubation. This study has several limitations. The first is that some outcomes, including mortality, were unknown as some patients were still hospitalized at the time of the last follow-up. Furthermore, the decision to intubate patients with COVID-19 may be different among providers. Lastly, as this is a retrospective study, the completion of a randomized control trial would be needed to draw causal conclusions in clinical practice. Additionally, a study published out of the Bronx, NY, looked at worse in-hospital outcomes and did not find a significant difference in the need for intubation in patients with diabetes, further stressing the importance of additional research in this area.
In summary, with a limited supply of mechanical ventilators, it is important to recognize patients at an increased risk of requiring intubation, including patients with diabetes and those with other risk factors, such as being >60 years and being male. However, with conflicting data, additional research is needed to draw a causal conclusion definitively.
- History of diabetes, age >60, and being male are associated with an increased risk of needing mechanical ventilation.
- Diabetes was not found to be a predictive factor for time to extubation.
- Future studies are needed to determine the clinical significance of specific comorbidities and risk of intubation.
Hur, Kevin et al. “Factors Associated with Intubation and Prolonged Intubation in Hospitalized Patients With COVID-19.“ Otolaryngology–head and neck surgery: official journal of American Academy of Otolaryngology-Head and Neck Surgery, 194599820929640. May 19. 2020, doi:10.1177/0194599820929640.
Palaiodimos, Leonidas et al. “Severe obesity, increasing age, and male sex are independently associated with worse in-hospital outcomes, and higher in-hospital mortality, in a cohort of patients with COVID-19 in the Bronx, New York.“ Metabolism: clinical and experimental, vol. 108 154262. May 16. 2020, doi:10.1016/j.metabol.2020.154262.
Jessica Rogers, PharmD candidate, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences