Adult Medical-Surgical Nursing

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Adult Medical-Surgical Nursing

• Endocrine Module
• Diabetes Mellitus
• (Lecture 1) Introduction

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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)

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Diabetes Mellitus Definition

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

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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)

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Complications of Diabetes Mellitus

• Hyperglycaemia leads to both acute and longterm
  complications

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Acute Complications of Diabetes Mellitus

• Diabetic ketoacidosis (type 1 DM)
• Hyperglycaemic hyperosmolar non-ketotic syndrome
  (type 2 DM)
• Hypoglycaemia and coma

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Longterm Complications of Diabetes Mellitus

• Macrovascular ? coronary artery disease,
  cerebro-vascular disease, peripheral vascular
  disease
• Chronic microvascular ? nephropathy, retinopathy
• Neuropathy

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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

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Diabetes Mellitus Type 1

• Absence of insulin secretion due to auto-immune
  destruction of the ß cells of the Islets of
  Langerhans
• Usually onset at a younger age(lt30 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

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Type 1 Diabetes Mellitus Pathophysiology

• Auto-immune destruction of ß cells ? insulin and
  unchecked hyperglycaemia
• If gt 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

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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

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Diabetes Mellitus Type 2

• Reduced cell sensitivity to insulin (insulin
  resistance) therefore reduced uptake of glucose
  reduced action of insulin
• Age of onset usually gt30 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

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Type 2 Diabetes Mellitus Pathophysiology

• Insulin resistance reduces uptake of glucose by
  cells
• In an attempt to control (reduce) blood glucose
  level, ß cells ? insulin production
• Eventually inadequate insulin, relative to
  elevated glucose levels ? hyperglycaemia (type 2
  DM) (exhaustion of ß cells)
• As some insulin present, uncontrolled fat
  breakdown and ketoacidosis is prevented

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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

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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

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Positive Diagnosis of Diabetes Mellitus

• Random (RBS) gt11.1 m mol/l (200mg/dl)
• Fasting (FBS) gt7 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) gt6
• (When blood glucose elevated, molecules attach to
  haemoglobin for lifespan of RBCs average 2-3
  month glucose level)

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Diabetes Mellitus Treatment Plan

• Control blood glucose levels
• Prevent acute or longterm complications which
  occur with lack of control