Adult Medical-Surgical Nursing

Presentation on theme: "Adult Medical-Surgical Nursing"— Presentation transcript:

1 Adult Medical-Surgical Nursing
Endocrine Module: Diabetes Mellitus (Lecture 1): Introduction

2 The Role of Insulin Anabolic role: regulates the uptake and storage of glucose by the cells: insulin binds to cell surface receptors allowing uptake of glucose (storage as glycogen) Controls the level of glucose in the blood (together with glucagon)

3 Diabetes Mellitus: Definition
Diabetes is a metabolic problem of hyperglycaemia resulting from defects in either or both of the following: Insulin production: pancreatic β cells may stop secreting insulin (type 1) Insulin action: the body cells may stop responding to insulin (insulin resistance) (type 2)

4 Diabetes Mellitus: Classification
Type 1: (5-10% of cases) Type 2: (90-95% of cases) Gestational DM (in pregnancy, similar to type 2 but resolves at end of pregnancy: may lead to type 2 at later date)

5 Complications of Diabetes Mellitus
Hyperglycaemia leads to both acute and longterm complications

6 Acute Complications of Diabetes Mellitus
Diabetic ketoacidosis (type 1 DM) Hyperglycaemic hyperosmolar non-ketotic syndrome (type 2 DM) Hypoglycaemia and coma

7 Longterm Complications of Diabetes Mellitus
Macrovascular → coronary artery disease, cerebro-vascular disease, peripheral vascular disease Chronic microvascular → nephropathy, retinopathy Neuropathy

8 Diabetes Mellitus: USA Factsheet
Leading cause of blindness in working-age adults, non-trauma amputation and end-stage renal disease Leading cause of hospitalisation Third leading cause of death from disease: mainly coronary artery disease and cerebro-vascular disease Source: Centre for Disease Control, 2008; American Diabetic Association, 2008 in Brunner & Suddarth, 12th edition, 2010

9 Diabetes Mellitus: Type 1
Absence of insulin secretion due to auto-immune destruction of the β cells of the Islets of Langerhans Usually onset at a younger age(<30 years) Acute onset requiring urgent treatment Genetic predisposition: HLA tissue-typing DR3/DR4 has ↑ risk up to 20 times, but stressors may trigger or enhance disorder Insulin required as treatment

10 Type 1 Diabetes Mellitus: Pathophysiology
Auto-immune destruction of β cells: ↓ insulin and unchecked hyperglycaemia If > renal threshold (9.9 m mol/l) kidneys may not reabsorb glucose → glycosuria Osmotic diuresis: polyuria, dehydration No insulin to control catabolic action of glucagon (glycogen, fat, protein) Breakdown of fat → ketone bodies (Diabetic ketoacidosis)may→ coma/ death

11 Type 1 DM: Clinical Manifestations (Acute Onset)
Polyuria (↑ urine output) Polydipsia (thirst) Polyphagia (↑ appetite) Weight loss Fatigue, weakness Dehydration, dry skin Recurrent infections, poor wound healing Maybe ↓ vision, numb, cool extremities

12 Diabetes Mellitus: Type 2
Reduced cell sensitivity to insulin (“insulin resistance”) therefore reduced uptake of glucose: reduced action of insulin Age of onset usually >30 years Insidious, gradual onset (75% detected incidentally and may have complications) Family history common Associated with obesity: Diet to ↓ weight, and exercise are first line of treatment

13 Type 2 Diabetes Mellitus: Pathophysiology
Insulin resistance reduces uptake of glucose by cells In an attempt to control (reduce) blood glucose level, β cells ↑ insulin production Eventually inadequate insulin, relative to elevated glucose levels → hyperglycaemia (type 2 DM) (exhaustion of β cells) As some insulin present, uncontrolled fat breakdown and ketoacidosis is prevented

14 Type 2 DM: Clinical Manifestations (Gradual Onset)
Polyuria Polydipsia Maybe associated with obesity (central) Fatigue, weakness Dehydration, dry skin Recurrent infections, poor wound healing Maybe ↓ vision, numb, cool extremities *May be unaware until complications arise

15 Diabetes Mellitus: Diagnosis
Patient history and clinical picture Random blood glucose Fasting blood glucose Oral glucose tolerance test (GTT) Glycosylated Haemoglobin (Hb A1C) Screen for complications: BP, ECG, arterial pulses, lipid profile, kidney function test, urine protein (24 hour), eye examination, neurological assessment

16 Positive Diagnosis of Diabetes Mellitus
Random (RBS): >11.1 m mol/l (200mg/dl) Fasting (FBS): >7 m mol/l (126mg/dl) (With symptoms or more than once) GTT (fasting, 50-75g glucose orally): if 2 hours postprandial, 11.1 m mol/l or above Glycosylated Haemoglobin (Hb A1C): >6% (When blood glucose elevated, molecules attach to haemoglobin for lifespan of RBCs: average 2-3 month glucose level)

17 Diabetes Mellitus: Treatment Plan
Control blood glucose levels Prevent acute or longterm complications which occur with lack of control