metabolic complications of diabetes mellitus
DESCRIPTION
Metabolic complications of Diabetes Mellitus. Dr. Essam H. Jiffri. Introduction. - Metabolic complications, particularly diabetic ketoacidosis and hypoglycaemia, are life-threatening and can cause permanent neurological damages. - PowerPoint PPT PresentationTRANSCRIPT
1
Metabolic complications of Diabetes Mellitus
Dr. Essam H. Jiffri
2
Introduction
- Metabolic complications, particularly diabetic ketoacidosis and hypoglycaemia,
are life-threatening and can cause permanent neurological damages.
-Diabetic patients present with impaired consciousness may be caused by other conditions
3
4
Diabetic Ketoacidosis
-Diabetic ketoacidosis (DKA) was responsible for 70% of diabetic deaths before the advent of insulin therapy and mortality rates are still up to 7%.
-It is mainly a recognized complication of IDDM, DKA can also occur in NIDDM.
5
Diabetic Ketoacidosis
-The clinical features of DKA result from:
– insulin deficiency – increases in counter-regulatory
hormones, produce major changes in:
• fuel, water and electrolyte metabolism
• glycogenolysis and gluconeogenesis occur.
6
Diabetic Ketoacidosis
Increased secretion
of counter-regulatory hormones leading to increased hepatic
glucose output
7
Diabetic Ketoacidosis
-Tissue uptake of glucose is reduced, contributing to the hyperglycaemia.
-As glucose does not enter cells, the extracellular osmotic pressure tends to rise, causing water to transfer from the intracellular to extracellular compartment.
- The renal threshold for glucose is exceeded and glycosuria occurs.
8
Diabetic Ketoacidosis
- The presence of excess non-absorbed solute in the glomerular filtrate causes an osmotic diuresis which interferes with tubular reabsorptive function, leading to:
• water
• sodium and
• potassium depletion
9
Diabetic Ketoacidosis
- Lipolysis results from insulin deficiency
- NEFAs are released and transported to liver(reduced insulin and increased glucagon) leading to:• greater amount of fatty acids being
metabolized by beta-oxidation• Acetyl CoA is exceeded and increased
amount of ketone bodies
10
Diabetic Ketoacidosis
- Acetoacetate and β-hydroxybutyrate are week acids and increase H+ conc in the blood, exceeding the buffering capacity and causing acidosis
- The H+ ions exchange with potassium across cell membranes, causing hyperkalaemia in some patients.
11
Diabetic Ketoacidosis
The effect of acidosis
is direct stimulation
of respiratory centre
by H+, causing deep hyperventilation (Kussmaul breathing)
12
Diabetic Ketoacidosis
- A history of polyuria, polydipsia, fatigue and vomiting.
- Physical signs include:• dehydration• tachycardia,• warm skin• Kussmaul respiration• Odour of acetone on the breath
13
14
Diabetic KetoacidosisManagement
- Diabetic ketoacidosis is a medical emergency.
- The aim of treatment is to replace fluids and electrolytes, and restore metabolic control.
- Patients require several liters of isotonic solution of saline to be infused, because of
loss of sodium.
15
Diabetic KetoacidosisManagement
-Intravenous insulin infusion is required, initially 6 units h-1.
- Intravenous potassium may be required, the rate depending on the plasma potassium
level.
- Bicarbonate is sometimes infused to correct the metabolic acidosis in severely affected patients (pH 7.0).
16
Diabetic KetoacidosisMonitoring
- Blood glucose should be monitoring hourly using test strip.
- Laboratory analysis of glucose and electrolytes should be done after 2h, and four hourly until the patient is stable.
- Blood gases should be monitored periodaclly.
17
Hyperosmolar Non-ketotic Coma
- Occurs mainly in elderly patient with NIDDM
- Some degree of ketosis
- Hyperglycaemia is more severe than in DKA
- The condition has a high mortality rate over 50%
18
Lactic Acidosis
Lactic acidosis is usually associated with renal failure
19
Principal features of three forms of metabolic decompensation in diabetes
Features Diabetic ketoacidosis
Hyperosmolar nonketotic coma (HONK)
lactic acidosois
Plasma glucoseHighVery highVariable
KetosispresentNoneVariable
AcidosisModerate/
Severe
NoneSevere
DehydrationProminentProminentVariable
HyperventilationPresentNonePresent
20
Long-term complication
long-term complications may result from :
•Microvascular changes
•Macrovascular disease
21
KEY POINTS
Diabetic Ketoacidosis (DKA) is a medical emergency
Patients with DKA are dehydrated, sodium depleted and acidotic
Plasma potassium levels should be monitored during treatment