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CC May 2017 Lactic acidosis

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echoecho's version from 2017-05-15 13:49

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Question Answer
How does lactic acidosis occur?when oxygen is NOT readily available, pyruvate (which is converted to adenosine triphosphate in aerobic conditions), is instead converted by lactate dehydrogenase into LACTATE
What organ removes most circulating lactate through the process of gluconeogenesis? The remainder is removed by what by converting lactate into what?1) liver 2) mitochondrial-rich tissues (myocytes) 3)pyruvate
A small amount of lactate (<5%) is ____ excreted?really
What normal physiologic process may result in a rapid increase in circulating lactate, but it is also rapidly cleared once the process ceases?vigorous exercise
Differentiate the different causes of lactic acidosis?1) Type A = hyperlactatemia typically results when tissue hypoxia results in faster production of lactate than removal; 2) type B = hyperlactatemia results from other causes not due to tissue hypoxia; 3) Type B1 = hyperlactatemia due to underlying disease; 4) Type B2 = hyperlactatemia due to drugs or toxins; 5) Type B3 = hyperlactatemia due to inborn errors of metabolism
List the causes of Type A lactic acidosis?1) carbon monoxide poisoning 2) cardiogenic shock 3) decompensated heart failure 4) hypovolemic shock 5) sepsis 6) severe anemia 7) severe trauma 8)vigorous exercise
List the causes of Type B1 lactic acidosis?1) cancer 2) DM 3) fulminant liver disease 4) pheochromocytoma
List the causes of Type B2 lactic acidosis?1) alcohol 2) cocaine 3) cyanide 4) diethylene glycol 5) met for in 6) methanol 7) nucleoside reverse-transcriptase inhibitors 8) proposal 9) propylene glycol 10) salicylate
List the causes of Type B3 lactic acidosis?pyruvate carboxylase deficiency
What is a contributing factor to cellular toxicity, as is an ____ (alkaline vs. acidic) environment?1) tissue hypoxia 2) acidic
Locally, the above may lead to what?1) decreases in cardiac myocyte contractility 2) blood pressure 3) tissue perfusion 4) sensitization to arrhythmia 5) lower sensitivity to circulating catecholamines
Is it certain that higher levels of lactate itself contribute to tissue dysfunction?no
While elevated lactate levels associated with conditions such as sepsis, trauma and cardiac arrest are associated with worsening prognosis, can the same be said for uncomplicated diabetic ketoacidosis or an acute exacerbation of asthma?no
So what is needed to determine the treatment of elevated lactate levels?clinical context
List the disease states that lactic acidosis should be considered in?1) severe cardiopulmonary disease (cardiogenic shock, decompensated heart failure) 2) systemic inflammatory syndrome 3) sepsis 4) severe trauma 5) severe dehydration
Elevations in anion gap are consistent with lactic acidosis, but what other substances can result in an increase in anion gap?1) uremia 2) methanol ingestion
In one study a normal anion gap was seen in ___% of patients with lactic acidosis?50%
True or false?Elevated blood lactate levels are required for diagnosis, but even levels at the upper limit of normal have been associated with increased mortality among patients who are severely ill?true
An acidic pH may not be seen if a respiratory _____ is also present?alkalosis
*** What is the treatment of lactic acidosis?1) restoring tissue perfusion. 2) treating the underlying conditions that many be present
What is required in patients with hypovolemic states?aggressive fluid resuscitation
Is there an advantage to using crystal Lois over colloid solutions to improve tissue perfusion?no
Vasopressors may be needed, but as previously stated, lactic acidosis may blunt tissue responses to what?catecholamines
Anemia patients should be transfused with packed RBCs to a goal hgb of what?7
Adequate oxygenation may require what?1) non-invasive pressure support 2) intubation 3) mechanical ventilation
If sepsis is suspected, what must be started immediately?broad-spectrum antibiotics
Severe trauma may need what?corrective surgery
Toxins and drugs should be removed emergently with what?dialysis
Specific supportive and therapeutic measures for heart failure and MI should be administered, true or false?true
*** Is there evidence for improving mortality and hemodynamics with administration of IV sodium bicarbonate for patients with severe academia (pH < 7.2)?no
Is the use of lactate clearance to monitor and guide therapy certain?no
*** In one study, reduction of blood lactate by ___% every 2 hours for the first 8 hours of therapy was associated with a reduction in morbidity and mortality?20%
Higher levels oflactate are associated with a greater risk of what?death
What is the goal of therapy in patients with lactic acidosis regarding mean arterial pressure?65-70 mmHg
What is the goal of therapy in patients with lactic acidosis regarding heart rate?< 100 beats per minute
What is the goal of therapy in patients with lactic acidosis regarding central venous pressure?8-12 mmHg
What is the goal of therapy in patients with lactic acidosis regarding pulmonary wedge pressure?12-15 mmHg (mechanically ventilated patients)
What is the goal of therapy in patients with lactic acidosis regarding urine output?> 0.5 mL/kg/hour
What is the goal of therapy in patients with lactic acidosis regarding hemoglobin?> 7 g/dL
What is the goal of therapy in patients with lactic acidosis regarding arterial oxygen saturation?> 92%
What is the goal of therapy in patients with lactic acidosis regarding central venous oxygen saturation?> 70%
What is the goal of therapy in patients with lactic acidosis regarding arterial blood pH?> 7.2
What is the goal of therapy in patients with lactic acidosis regarding blood lactate?< 1-2 mmol/liter
*** SUMMARY = What is the most common type of metabolic acidosis among hospitalized patients?lactic acidosis
*** SUMMARY = List the underlying causes of lactic acidosis?1) shock 2) cardiac arrest 3) sepsis 4) severe trauma 5) drug ingestion
*** SUMMARY = List the treatment of lactic acidosis?1) improving oxygenation 2) improving tissue perfusion 3) improving the underlying causes of the conditions that may be present
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