Coronavirus disease (COVID-2019) is a devastating viral illness that originated in Wuhan China in late 2019 and there are nearly 2 million confirmed cases. The mortality rate is approximately 5% of reported cases and over half of patients that require mechanical ventilation for respiratory failure. As the disease continues to spread, strategies for reducing duration of ventilator support in patients with COVID-19 could significantly reduce morbidity and mortality of these individuals and future patients requiring this severely limited life-saving resource. Methods to improve gas exchange and to reduce the inflammatory response in COVID-19 are desperately needed to save lives. The ketogenic diet is a high fat, low carbohydrate, adequate-protein diet that promotes metabolic ketosis (ketone body production) through hepatic metabolism of fatty acids. High fat, low carbohydrate diets have been shown to reduce duration of ventilator support and partial pressure carbon dioxide in patients with acute respiratory failure. In addition, metabolic ketosis reduces systemic inflammation. This mechanism could be leveraged to halt the cytokine storm characteristic of COVID-19 infection. The hypothesis of this study is that the administration of a ketogenic diet will improve gas exchange, reduce inflammation, and duration of mechanical ventilation. The plan is to enroll 15 intubated patients with COVID 19 infection and administer a 4:1 ketogenic formula during their intubation.
Coronavirus disease (COVID-2019) is a devastating viral illness that originated in Wuhan China in late 2019. The number of confirmed cases worldwide has nearly reached 2 million and more than 125,000 people have died. Early studies from Wuhan reported a mortality rate of 2-3% with lower rates in surrounding provinces as the disease spread (closer to 0.7% of confirmed cases). One hypothesized cause for the higher mortality rate in Wuhan compared to surrounding regions was the rapid "surge" of COVID-19 infections before the disease was identified and social distancing implemented. Critically ill patients developed acute respiratory distress syndrome with inflammatory pulmonary edema and life-threatening hypoxemia requiring mechanical ventilation. This resulted in a significant strain on health-care resources such as availability of mechanical ventilators to treat patients with acute respiratory failure. As the disease spreads worldwide, strategies for reducing duration of ventilator support in patients with COVID-19 could significantly reduce morbidity and mortality of these individuals and future patients requiring this severely limited life-saving resource. Alterations in macronutrient composition may be leveraged to improve ventilation and inflammation in COVID-19 patients. The ketogenic diet is a high fat, low carbohydrate, adequate protein diet that promotes ketone body production through hepatic metabolism of fatty acids. High fat, low carbohydrate diets have been shown to reduce duration of ventilator support and partial pressure carbon dioxide in patients with acute respiratory failure. Switching from glucose to fat oxidation lowers the respiratory quotient, thereby reducing the amount of carbon dioxide produced. This reduces ventilator demands and may improve oxygenation by lowering alveolar carbon dioxide levels, ultimately reducing time on mechanical ventilation. A study published in 1989 compared 10 participants intubated for acute respiratory failure and randomized to a high-fat, low carbohydrate diet and 10 participants receiving a standard isocaloric, isonitrogenous diet and showed a decrease in the partial pressure of carbon dioxide of 16% in the ketogenic diet group compared to a 4% increase in the standard diet group (p=0.003). The patients in the high-fat diet group had a mean of 62 fewer hours on a ventilator (p = 0.006) compared to the control group. The high-fat diet used in the study had a ratio of 1.2:1 fat to protein and carbohydrate combined in grams. The ketogenic diet, which has been used safely and effectively in patients with chronic epilepsy for nearly one century and more recently in critically ill, intubated patients for the management of refractory and super-refractory status epilepticus has a 4:1 ratio (90% fat kilocalories). While a 1:1 ratio diet can produce a state of mild metabolic ketosis (typically \~ 1 mmol/L of the ketone body betahydroxybutyrate, measured in serum), a higher 4:1 ratio ketogenic diet can produce higher ketone body betahydroxybutyrate levels and more rapidly (up to 2 mmol/L within 24 hours of initiation). One study of obese patients treated with ketogenic diet reported that increases in ketone body production correlated with a lower partial pressure of carbon dioxide levels. A more recent study showed that patients with refractory epilepsy had a reduction in the respiratory quotient and increased fatty acid oxidation without a change in the respiratory energy expenditure with chronic use of the ketogenic diet. These findings were replicated in healthy subjects on ketogenic diet compared to a control group and patients on a ketogenic diet also had a significant reduction in carbon dioxide output and partial pressure of carbon dioxide. The authors concluded that a ketogenic diet may decrease carbon dioxide body stores and that use of a ketogenic diet may be beneficial for patients with respiratory failure. Even in patients without hypercapnia (primarily hypoxic respiratory failure), lowering carbon dioxide production permits lowering tidal volumes - a cornerstone of acute respiratory distress syndrome management. In addition to reducing the partial pressure of carbon dioxide, metabolic ketosis reduces systemic inflammation. This mechanism could be leveraged to halt the cytokine storm characteristic of COVID-19 infection. Several studies provide evidence that pro-inflammatory cytokine production is significantly reduced in animals fed a ketogenic diet in a variety of disease models. In a rodent model of Parkinson's disease, mice were found to have significantly decreased levels of pro-inflammatory, macrophage secreted cytokines interleukin-1β, interleukin-6, and Tumor necrosis factor-alpha after 1 week of treatment with a ketogenic diet. Likewise, rats pretreated with a ketogenic diet prior to injection with lipopolysaccharide to induce fever did not experience an increase in body temperature or interleukin-1β, while significant increases were seen in control animals not pretreated with a ketogenic diet. In a mouse model of NLRP3-mediated diseases as well as human monocytes, the ketone body beta-hydroxybutyrate inhibited the NLRP3 inflammasome-mediated production of interleukin-1β and interleukin-18. These findings have been replicated in several recent animal studies and preliminary studies in humans. The hypothesis of this study is that through induction of metabolic ketosis combined with carbohydrate restriction, a ketogenic diet is protective against the cytokine storm in COVID-19. With its carbon dioxide-lowering and anti-inflammatory properties, a ketogenic diet may become an important component of the acute respiratory distress syndrome arsenal with immediate relevance to the current COVID-19 pandemic.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
4:1 ratio enteral ketogenic formula within 48 hours of intubation
standard of care/supportive therapy
Change in the partial pressure of carbon dioxide (PaCO2)
PaCO2 is the partial pressure of carbon dioxide Units: millimeters of mercury
Time frame: Daily until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in minute ventilation
Minute ventilation is the product of respiratory rate and tidal volume. Units: Liter per minute
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in respiratory system compliance
Respiratory system compliance measures the extent to which the lungs will expand. In a ventilated patient, compliance can be measured by dividing the delivered tidal volume by the \[plateau pressure minus the total peep\]. Units: liter/centimeter of water
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in driving pressure
Driving pressure is a measure of the strain applied to the respiratory system and the risk of ventilator-induced lung injuries Driving pressure = Plateau pressure - Total Positive end-expiratory pressure (PEEP) Units: centimeter of water
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in ventilator synchrony
Ventilator synchrony is the match between the patient's neural inspiratory time and the ventilator insufflation time
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in mean arterial pressure
Mean arterial pressure is the average pressure in a patient's arteries during one cardiac cycle. Mean arterial pressure = diastolic blood pressure +\[1/3(systolic blood pressure - diastolic blood pressure)\] Units: millimeter of mercury
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in the fraction of inspired oxygen percentage of oxygen (FiO2)
FiO2: Fraction of Inspired Oxygen Percentage of oxygen in the air mixture that is delivered to the patient. Units: %
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in the partial pressure of carbon dioxide (PaO2) to the fraction of inspired oxygen percentage of oxygen (FiO2) ratio
PaO2/FiO2 ratio is the ratio of arterial oxygen partial pressure (PaO2) to fractional inspired oxygen. Units: millimeter of mercury
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in hydrogen ion activity (pH)
pH measures hydrogen ion activity. It is a conventional part of every arterial blood gas determination pH: no units.
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in Bicarbonate (HCO3)
Bicarbonate is a conventional part of every arterial blood gas determination Units: milliequivalents/Liter
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in red blood cell count
Red blood cell count measure anemia or hypoglycemia. Units: cells per liter
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in white blood cell count
White blood cell count evaluates leukopenia or leukocytosis. Units: cells/liter
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in white cell differential
White cell differential shows the amount of neutrophils, lymphocytes, basophils, eosinophils and may give some clue of the type of infection. Units: %
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in hemoglobin levels
Hemoglobin is an indirect way to measure red blood cells. Units: gram/deciliter
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in hematocrit
Hematocrit measures the volume percentage of red blood cells in blood. Units: %
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in mean cell volume
Mean cell volume is a measure of the average volume of a red blood corpuscle. Units: femtoliters
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in mean cell hemoglobin
Mean cell hemoglobin is the average mass of hemoglobin per red blood cell in a sample of blood. Units: picograms
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in mean cell hemoglobin concentration
Mean cell hemoglobin concentration is the average concentration of hemoglobin in a given volume of blood. Units: %
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in platelet count
Platelet count measures the number of platelets in the blood and determines thrombocytopenia or thrombocytosis. Units: platelets/liter
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in red cell distribution width
Red cell distribution width is a measure of the range of variation of red blood cell volume. Units: no units
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in blood albumin level
Liver function test Units: gram/deciliter
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in serum alkaline phosphatase level
Liver function test Units: international units/liter
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in serum aspartate transaminase level
Liver function test Units: international units/liter
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in serum alanine aminotransferase level
Liver function test Units: international units/liters
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in blood urea nitrogen levels
Kidney function test Units: milligram/deciliter
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in serum calcium level
Kidney function test Units: milligram/deciliter
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in serum chloride level
Kidney function test Units: millimole/liter
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in serum potassium level
Kidney function test Units: millimole/liter
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in serum creatinine level
Kidney function test Units: gram/deciliter
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Date patient is re-intubated or need mechanical ventilation for a second time
If the patient needs mechanical ventilation for a second time, this information will be collected.
Time frame: Up to 10 days
Length of intensive care unit stay
Time from intensive care unit admission until death or transfer to hospital bed.
Time frame: Up to 10 days
The total hospital stay
Time from hospital admission to discharge from the hospital. This information will be collected.
Time frame: Up to 10 days
Disposition at discharge
Once the patient feels better and can leave the hospital, he/she will be discharged. The place of discharge (e.g. home, rehab facility, nursing home, etc), time and date will be collected.
Time frame: Up to 10 days
Change in heart rate
Heart rate: is the number of times a person's heart beats per minute
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
Change in the dosage of vasopressor medication
Units: milligram
Time frame: every 6 hours until the patient is wean off the ventilator or die, whichever came first, assessed up to 10 days
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