The Evolution of Central Venous-to-arterial Carbon Dioxide Difference (PCO2 Gap) during Resuscitation Affects ICU Outcomes: A Prospective Observational Study.

Introduction: The usual methods of perfusion assessment in patients with shock, such as capillary refill time, skin mottling, and serial serum lactate measurements have many limitations. Veno-arterial difference in the partial pressure of carbon dioxide (PCO2 gap) is advocated being more reliable. We evaluated serial change in PCO2 gap during resuscitation in circulatory shock and its effect on ICU outcomes. Materials and methods: This prospective observational study included 110 adults with circulatory shock. Patients were resuscitated as per current standards of care. We recorded invasive arterial pressure, urine output, cardiac index (CI), PCO2 gap at ICU admission at 6, 12, and 24 hours, and various patient outcomes. Results: Significant decrease in PCO2 gap was observed at 6 h and was accompanied by improvement in serum lactate, mean arterial pressure, CI and urine output in (n = 61). We compared these patients with those in whom this decrease did not occur (n = 49). Mortality and ICU LOS was significantly lower in patients with low PCO2 gap, while more patients with high PCO2 gap required RRT. Conclusion: We found that a persistently high PCO2 gap at 6 and 12 h following resuscitation in patients with shock of various etiologies, was associated with increased mortality, need for RRT and increased ICU LOS. High PCO2 gap had a moderate discriminative ability to predict mortality. How to cite this article: Zirpe KG, Tiwari AM, Kulkarni AP, Vaidya HS, Gurav SK, Deshmukh AM, et al. The Evolution of Central Venous-to-arterial Carbon Dioxide Difference (PCO2 Gap) during Resuscitation Affects ICU Outcomes: A Prospective Observational Study. Indian J Crit Care Med 2024;28(4):349-354.

Timing of Invasive Mechanical Ventilation and Mortality among Patients with Severe COVID-19-associated Acute Respiratory Distress Syndrome.

BACKGROUND: Severe acute respiratory distress syndrome associated with coronavirus disease-2019 (COVID-19) (CARDS) pneumonitis presents a clinical challenge as regards to the timing of intubation and ambiguity of outcome. There is a lack of clear consensus on when to switch patients from trials of noninvasive therapies to invasive mechanical ventilation. We investigated the effect of the timing of intubation from the time of admission on the clinical outcome of CARDS. AIM AND OBJECTIVE: The aim and objective was to analyze the effect of timing of intubation early (within 48 hours of admission to critical care unit) versus delayed (after 48 hours of admission to critical care unit) on mortality in severe CARDS patients. MATERIALS AND METHODS: A retrospective observational study performed in a 28-bedded COVID-19 intensive care unit of a tertiary care hospital in Pune, India. All patients admitted between April 1, 2020, and October 15, 2020, with confirmed COVID-19 (RT-PCR positive) requiring mechanical ventilation were included in the study. RESULTS: The primary outcome was in-hospital mortality. Among 2,230 patients that were admitted to the hospital, 525 required critical care (23.5%), invasive mechanical ventilation was needed in 162 patients and 147 (28%) of critical care admission were included in the study cohort after exclusion. Seventy-five patients (51%) were intubated within 48 hours of critical care admission (early group) and 72 (48.9%) were intubated after 48 hours of critical care admission (delayed group). With regards to the total of 147 included patients; male patients were 74.1% with a median age of 59 years (interquartile range, 51-68 years). Diabetes (44.9%) and hypertension (43.5%) were the most common comorbidities. Higher admission acute physiology and chronic health evaluation II scores and lower absolute lymphocyte count were observed in patients intubated within 48 hours. The early intubated group had a mortality of 60% whereas the same was observed as 77.7% in delayed intubation group, and this difference was statistically significant (p = 0.02). CONCLUSION: Current study concludes that early intubation is associated with improved survival rates in severe CARDS patients. HOW TO CITE THIS ARTICLE: Zirpe KG, Tiwari AM, Gurav SK, Deshmukh AM, Suryawanshi PB, Wankhede PP, et al. Timing of Invasive Mechanical Ventilation and Mortality among Patients with Severe COVID-19-associated Acute Respiratory Distress Syndrome. Indian J Crit Care Med 2021;25(5):493-498.