Diabetes mellitus
- is a chronic metabolic syndrome characterized by hyperglycemia.The most common 2 types:
1. type 1: deficiency of insulin secretion due to T-cell mediated autoimmune destruction of pancreatic islet β-cells.
2. type 2: insulin resistance occurring at the level of skeletal muscle, liver, & adipose t. w` various degrees of β-cell impairment. MODY: is a subclass of type 2 DM. It may require insulin Rx. There is no auto immune destruction of β-cells.
less common types of D.M are:
3. mixed D.M
4. gestational
5. neonatal: 1) transient
2) permanent pancreatic agenesis (rare)
6. secondary (to ex. Cystic fibrosis or those using glucocorticoid Rx)
Rx of Diabetes Mellitus:
1. insulin:
type of insulin, type of syringe, no spirit, storage in refregerators, rotation of injection sites, not stop insulin even du illness, aspirate soluble insulin before lenti in the same syringe.
- pt who not need for life long Rx for D.M are: Transient DM of neoborn, Gestational DM, Secondary DM
- types of insulin:
insulin given 30 min before meal. After S.C injection:
Duration
Peak
Onset
Type
6-8 hr
2-4
10 min
Short acting (soluble, nutral)
24
4-12
1-2
Intermediate (isophane, semi lente, lente)
24-36
14-20
4-8
Long (ultra lente, protamin zinc)
Biphasic (mixtard) (30% short + 70% intermed)
Intramuscular insulin have higher peak & shorter duration than s.c.
insulin absorption vary w` site, faster in abdominal wall, followed by upper limbs & then lower limbs.insulin should not injected into area which is going to be exercised, so if playing tennis, inject insulin into abdominal wall.
Insulin formulations are stable if kept out of light, freezing or extremes of heat. Loss of potency of 5–10% occurs in vials kept at high ambient room temperatures for 2–3 months. Insulin should therefore be stored in a domestic refrigerator except for the vials, cartridges or pens in current use which, depending on the individual preparation, may be stable for 4–6 weeks. When pen injector devices are in use, they should never be stored in a refrigerator as there have been reports of devices ‘seizing up’ when stored in the cold
- increase insulin requirement during: Growth, Puberty, Antibody to insulin, Infec, Stress, Surgery, Hyperthyr, Down phenomina.
- decrease insulin requirement during: Renal failure, Hypothyr, Hypoadrenalism (Addison), Excersize, Change diet (food manipulation), Honeymoon period, Somogyi phenomina, Vomiting, Hospitalization.
- factors affecting insulin absorption (Note: faster abs less duration of action):
Dose: smaller dose more rapid abs
Age: younger child (less s.c fat) more rapid absorption
Site: abdomen > buttock > leg & arm
Type: low insulin concentration in the vial rapid
Temp.: increase temp of pt rapid
Oral hypoglycemic agents potentiate action of insulin:
Biguanide (ex. metformin) &sulphonylureas (ex. glibenclamid)
2. diet: give usual diet (except high refined sugar ex. Chocolate, honey, sugar, pepsi, & juice bec it cause sudden & rapid inc bl.sugar)
s.b no much restriction of diet because the child is in a period of growth.
4. social advice
5. regular checking visits
6. long term Rx: prevention of infec, BCG vaccine, decrease stress.
- hypoglycemia in DM is due to:
1. Wrong dose (high) 2. Excersize
3 . Inadequate diet 4. Honeymoon period
5. Defective counter regulatory hormon ex. Addison
Compl of D.M:
Early compl: . DKA
. Hypogly
. Non ketotic hyperosmolar acidosis
. Increase incidence of infec because of defective WBC function.
. S.E of insulin: lipodystrophy at insulin injection sites, insulin allergy, insulin shock (hypogly), insulin antibody.
Long term compl:
1) microvascular compl: retinopathy (is the leading cause of blindness), lense opacity, nephropathy (is the leading cause of end stage renal dis).
2) macrovascular compl: accelerated coronary artery dis, cerebrovascular dis, periph vascular dis
3) neuropathies: peripheral & autonomic (diarrhea, postural hypotension).
4) o`: atheroma & thrombosis, skin ulcer, delay healing of scars
- drugs that may cause hypoglycemia are:
any drug used in Rx of hypergly, ACEI, disopiramid (for Rx of cardiac dis), MAOI (for Rx of depression), pentoxifilin, proboxifin, salicylates (ex aspirin), sulfonamide antibiotics.
- some drugs that may cause hypergly (Diabetogenic drugs) a`:
Steroids, danazole, diazoxide (for HrT), diuretics, glucagon, INH (for T.B), estrogen & progesterone (ex. Contraceptive pills), Phenothiazine, GH, epinephrine, salbutamol, terbutalin, thyroid hormone, protease inhibitor (in Rx of AIDS).
- drugs that may cause hypogly OR hypergly a`:
1. β-blockers 2. Clonidin 3. lithium salts
Diabetic ketoacidosis DKA
- is a state of severe metaolic derangement resulted from both insulin def & inc counter-regulatory hor (catecholamine, glucagon, cortisol, & GH).
Its main features a`: Hyperglycemia: glucose > 300 mg/dl
Ketonemia: s.ketones > 3 mmol/l w` ketonuria
Acidosis: venous pH < 7.3 & s.HCO3 < 15 mEq/l
Treatment of DKA:
1. Fluid: rehydration lowers glucose level by improving renal perfusion & enhancing renal exc.
2. Insulin.
3. K+ : There is always substantial decrease of total body K whatever the initial plasma level, which will fall once insulin is commenced.
because the pt will receive excess Chloride (which may aggravate acidosis) it is prudent to use K phosphate rather than K chloride.
Notes about sodium bicar:
Indications for sod bicar: 1.severe acidosis (pH < 7)
2.impending circulatory collapse requiring inotropic support ex HoT, cardiac instability
3. resp depression
It may inc risk of: 1. cereral oedema: due to large Na load
2. hypokalemia: due to rapid shift of K+ into cells.
الدكتور
صلاح مهدي فرحاناختصاصي طب الاطفال والخدج
مستشفى الحسين (ع) التخصصي للاطفال