fluid-electro in surgery

fluid-electro in surgery - PRINCIPLES OF FLUID &...

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Unformatted text preview: PRINCIPLES OF FLUID & PRINCIPLES ELECTROLYTE BALANCE IN SURGICAL PATIENTS SURGICAL NORMAL DAILY LOSSES AND REQUIREMENTS FOR FLUIDS AND ELECROLYTES ELECROLYTES Volume Na+ K+ ML mmol mmol Urine 2000 80 60 Insensible losses 700 ­ ­ Faeces 300 ­ 10 Minus endogenous 300 ­ ­ Water Total 2700 80 70 ASSESSING LOSSES IN THE SURGICAL PATIENT SURGICAL INSENSIBLE FLUID LOSSES EFFECT OF SURGERY The stress response ‘Third­Space’ losses Loss from the gastrointestinal tract INTRAVENOUS FLUID INTRAVENOUS 5% DEXTROSE 0.9% NaCl RINGER’S LACTATE (HARTMANN’S SOLUTION) HAEMACCEL (SUCCINYLATED GELATIN) GELOFUSINE (POLYGELINE GELATIN) HETATARCH HUMAN ALBUMIN SOLUTION 4.5% (HAS;PPF) PROVISION OF NORMAL 24-HR FLUID & ELECTROLYTE REQUIREMENTS BY INTRAVENOUS INFUSION INTRAVENOUS Intravenous fluid Additive Duration 500 ml 0.9% NaCl 20mmol KCl 500 ml 5% Dextrose ­ 500 ml 5% Dextrose 500 ml 0.9%Dextrose 500 ml 5% Dextrose 20 mmol KCl 500 ml 5% Dextrose ­ 4hr 4hr 4hr 20 mmol KCl ­ 4hr 4hr 4hr AETIOLOGY OF HYPER AND HYPONATRAEMIA AETIOLOGY Hypernatraemia ­­­­­­­­­­­­­­­­­­­ Reduced intake fasting • nausea and vomiting • ileus • reduced conscious level • Increased loss *Sweating (pyrexia,hot environment) *respiratory tract loss(increased ventilation, administration of dry gases) *administration of dry gases *burns Inappropriate urinary water loss Diabetes inspidus(pituitary • or nephrogenic) Diabetes mellitus • Excessive Sodium load (hypertonic fluid, parenteral nutrition) Hyponatraemia ­­­­­­­­­­­­­­­­­­­ ­ Low extracellular fluid volume * Volume depletion (vomiting,diahrrhoea,burns,decreas ed fluid intake) * salt losing renal disease * Hypoadrenalism *diuretic use ­ Normal extracelluler fluid volume hypothyroidism SIADH Increased extracellular fluid volume excessive water • administration excessive mannitol use • cardiac failure • cirrhosis • nephritic syndrome • renal failure • CONSEQUENCES OF HYPER AND HYPOKALEMIA AND HYPERKALEMIA Arrythmias(broad­complex rhythms,bradycardia,heart block,ventricular fibrillation) Muscle heart block Ileus Hypokalemia ECG changes Ectopic beats Muscle weakness MANAGEMENT OF SEVERE ACUTE HYPERKALAEMIA (K+ > 7mmol/L) HYPERKALAEMIA Identify and treat cause 10 – 20 mL intravenous 10% calcium chloride over 10 min in patients with ECG abnormalities (reduced risk of ventricular fibrillation) 50 mL 50%dextrose plus 10 units short acting insulin over 2­3min Monitor plasma glucose and K+ over next30­60 min) Regular Salbutomol nebulizers Consider oral or rectal calcium Resonium (ion exchange resin),although this is more effective for non­acute hyperkalaemia. Haemodialysis for persistent hyperkalemia ACID BASE BALANCE ACID METABOLIC ACIDOSIS METABOLIC ALKALOSIS RESPIRATORY ACIDOSIS RESPIRATORY ALKALOSIS MIXED PATTERN OF ACID­BASE IMBALANCE COMMON CAUSES OF METABOLIC ACIDOSIS IN THE SURGICAL PATIENT PATIENT LACTIC ACIDOSIS Shock (any causes) Severe hypoxaemia Severe haemorrhage/anaemia ACCUMULATION OF OTHER ACIDS Diabetic Ketocaidosis Acute Renal Failure INCREASED BICARBONATE LOSS Diahrroea Intestinal Fistulae Ureterosigmoidostomy COMMON CAUSES OF METABOLIC ALKALOSIS ALKALOSIS LOSS OF SODIUM AND WATER Vomiting Aspiration of gastric secretions Diuretic administration HYPOKALEMIA CAUSES OF RESPIRATORY ACIDOSIS ACIDOSIS Excessive opiate administration Pulmonary complications e.g Pneumonia CAUSES OF RESPIRATORY ALKALOSIS ENCOUNTERED IN SURGICAL PRACTICE SURGICAL Hyperventilation during mechanical ventilation Pain Apprehension/hysterical hyperventilation Pneumonia Central nervous system disorders(meningitis,encephalopathy) Septicaemia Principles of fluid and Principles electrolyte balance in surgical patients surgical Discussions 1. What are the normal values or serum sodium, potassium, creatinine and urea? 2. What are the normal basal requirements for water, sodium and potassium? 3. How can this be provided in a patient who is fasting? 4. How is fluid retained in the intravascular compartment? 5. What might cause it to leak out? 6. In clinical practice, it is often desirable to "expand" the intravascular compartment. Why might this be desirable and how could it be done? 7. What are the clinical symptoms and signs of fluid depletion? How can the severity of fluid depletion be assessed? 8. How can clinicians assess the patient’s response to resuscitation in severe fluid depletion? 9. What biochemical disturbance might you expect in a patient with gastric outlet obstruction who has been vomiting for several days before admission? 10. What biochemical abnormalities might you expect in a patient who has had excessive diarrhoea and who has been drinking large amounts of water because of thirst? (If a house officer inadvertently prescribed too much 5% dextrose and not enough N Saline, you would find the same effect) In patients with massive burns, fluid losses are impossible to measure. How might you assess fluid requirements? ...
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This note was uploaded on 01/12/2012 for the course STEP 1 taught by Professor Dr.aslam during the Fall '11 term at Montgomery College.

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