9 - Altered Mental Status Flashcards
(180 cards)
What does altered mental status (AMS) encompass?
A broad range of disorders leading to a change in cognition or level of consciousness.
Clinical presentations include stupor, delirium, and coma.
What is dementia in relation to AMS?
A chronic form of AMS that develops over a prolonged period and is predominant in the elderly.
While not usually life-threatening, it can cause numerous complications.
Why is it important to identify the underlying etiology of AMS?
The differential diagnosis is vast and patients are often unable to provide an accurate history.
Family members or caregivers should be included when obtaining history.
What are common causes included in the differential diagnosis of acute AMS?
- Trauma
- Infection
- Psychiatric disorders
- Vascular issues
- Structural problems
- Hypoxic disorders
- Metabolic disorders
This chapter emphasizes metabolic derangements.
What symptoms did the 25-year-old man exhibit in the case study?
- Stuporous state
- Incoherent rambling
- Repetitive vomiting
- Weight loss
- Excessive fluid intake
- Dry mucus membranes
- Poor skin turgor
- Mild hypoxia
He also exhibited Kussmaul respirations and tachycardia.
What were the laboratory findings for the patient?
Urinalysis showed a pH of 5.5, 4+ ketone bodies, and a specific gravity of 1.035.
EKG revealed sinus tachycardia with peaked T waves.
What is a key term associated with metabolic acidosis in the context of diabetes?
Diabetic ketoacidosis (DKA).
Characterized by hyperglycemia, hyperkalemia, and metabolic acidosis.
What is the primary cause of the problems observed in diabetic ketoacidosis?
Insulin deficiency.
This leads to an acute stress response despite high blood glucose levels.
How is glucose homeostasis maintained in the fed state?
Insulin promotes glucose uptake and storage while counterregulatory hormones facilitate glucose release.
Key hormones include glucagon, epinephrine, cortisol, and growth hormone.
What happens to glucose after a meal?
- Beta cells secrete insulin
- Insulin promotes glucose uptake in adipose and skeletal muscle
- Excess glucose is stored as glycogen
- Some glucose is converted to fatty acids
GLUT4 transporter is insulin-dependent for glucose uptake.
What roles do insulin and glucagon play in glucose metabolism?
Insulin promotes glycogen synthesis and glycolysis, while glucagon promotes glycogenolysis and gluconeogenesis.
They have opposing activities in maintaining plasma glucose levels.
What happens to pyruvate in the fasting state?
Pyruvate is converted to oxaloacetate instead of acetyl CoA due to high NADH levels and glucagon signaling.
This pathway supports gluconeogenesis.
What is the structure of insulin?
A polypeptide hormone produced by the beta cells of the Islets of Langerhans, consisting of two chains (A and B) linked by disulfide bridges.
C-peptide is released alongside insulin and indicates insulin production.
What stimulates insulin secretion from the pancreas?
- Glucose
- Amino acids
- Gastrointestinal hormones
Incretins also promote insulin secretion in anticipation of glucose increases.
How does glucagon affect insulin secretion?
Glucagon stimulates insulin secretion to promote glucose utilization.
Insulin also inhibits glucagon release.
What enzymes are involved in gluconeogenesis?
- Pyruvate carboxylase
- Fructose 1,6-bisphosphatase
- Glucose 6-phosphatase
These enzymes facilitate the conversion of substrates to glucose.
What is the result of glucagon signaling in the liver?
Promotes gluconeogenesis and inhibits glycolysis by affecting key enzymes.
It prevents the conversion of newly made PEP back to pyruvate.
What is the role of pyruvate kinase in metabolism?
Pyruvate kinase is inhibited by glucagon and epinephrine signaling to prevent the conversion of PEP back to pyruvate.
What is the energy requirement for gluconeogenesis?
Gluconeogenesis requires 6 high-energy phosphate bonds to convert 2 pyruvate molecules to 1 glucose molecule.
What process provides energy for gluconeogenesis during fasting?
The energy for gluconeogenesis in the fasting state is obtained from the beta-oxidation of fatty acids.
What happens to acetyl CoA during fasting?
Acetyl CoA accumulates from beta-oxidation and is diverted toward ketogenesis when it exceeds the capacity for oxidation through the TCA cycle.
What is the pathophysiology of hyperglycemia with ketosis in diabetes?
Diabetes is characterized by insulin deficiency or resistance, leading to increased hepatic glucose output and decreased glucose uptake by tissues.
What are the main causes of hyperglycemia in type I diabetes?
The main causes include a severe deficiency of insulin and increased counterregulatory hormones.
What is the effect of cortisol in diabetes?
Cortisol promotes protein catabolism in muscles to supply substrates for gluconeogenesis.