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University of Medicine and Pharmacy, Iasi School of Medicine ANESTHESIA and INTENSIVE CARE Conf. Dr. Ioana Grigoras. MEDICINE 4 th year English Program Suport de curs. WATER AND ELECTROLYTES DISTURBANCES. PHYSIOLOGY. Body water = 55-60% of body weight Water distribution :
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University of Medicine and Pharmacy, Iasi School of Medicine ANESTHESIA and INTENSIVE CARE Conf. Dr. Ioana Grigoras MEDICINE 4th year English Program Suport de curs WATER AND ELECTROLYTES DISTURBANCES
PHYSIOLOGY Body water= 55-60% of body weight Water distribution: • Intracellular water – 66% of total (2/3) • Extracellular water – 33% of total (1/3) • Intracellular water – 40%of body weight • Extracellular water – 20%of body weight • Intravascular water (volemia) - 5%of body weight • Interstitial water - 15%of body weight
IntravascC InterstC Na 142 142 K 5 5 Ca 2,5 2,5 Extracell C. Intracell C Mg 1 1 Na 142 15 Cl 103 110 K 5 150 HCO 27 27 Ca 2,5 - Phosphat 1 1 Mg 1 13 Proteins 14 2 Cl 103 0-5 6 6 HCO 27 10 ~ 300 ~ 300 Phosphat 1 55 Proteins 14 80 Org. acids 6 - ~ 300 ~ 300 PHYSIOLOGYElectrolytic composition of water compartments Org. acids
WATER AND ELECTROLYTES BALANCE Evaluation CLINICAL EVALUATION : • History • Water and salt ingestion • Losses • Thurst • Skin and mucous membranes examination • Oral mucosae humidity • Skin humidity • Skin colour and temperature • Cutaneous turgor • Body weight • Respiratory system clinical exam • Polypneea • Crackles at lung bases • Clinical examination of peripheral veins • Haemodynamic parameters • Arterial blood pressure • Pulse wave amplitude • Orthostatic challenge • CVP,... • Urinary outflow • Evaluation of the counscience level
WATER AND ELECTROLYTES BALANCE Evaluation Clinical evaluation of the intravascular compartment: • thurst • BP, heart rate, orthostatic challenge • central venous pressure • pulmonary capillary wedge pressure, cardiac output • organ function: • conscience • urinary flow • tissue perfusion
WATER AND ELECTROLYTES BALANCE Evaluation Clinical evaluation of interstitial space: unreliable • skin and mucous membrane examination • colour • humidity • turgour • edema
WATER AND ELECTROLYTES BALANCE Evaluation Clinical examination of intracellular compartment: unreliable • thurst • mental status disturbances • neurological signs
WATER AND ELECTROLYTES BALANCE Evaluation LABORATORY EVALUATION • Hematocrit and total proteins • Blood and urinary electrolytes measurement • Blood and urinary osmolarity • ECG
OSMOLARITY • Plasma osmolarity=the sum contributions of all osmotic active substances • The main plasma osmotic active substances: Na, glucose, ureea • Plasma osmolarity • measured osmolarity • estimated (calculated) osmolarity • Calculated osmolarity= Na-mia x 2 + blood glucose/18 +ureea/2,8 Intracellular volume disturbances are the consequences of effective osmotic pressure variation
WATER AND ELECTROLYTES DISTURBANCESClassification (Shires şi Baxter) • Volume disturbances • Volume contraction • Volume expansion • Concentration disturbances • Hyponatremia • Hypernatremia • Other hyperosmolar states • Composition disturbances • Hypo/hyperpotasemia • Hypo/hypercalcemia • Hypo/hypermagnesemia • Hypo/hyperphosphatemia • Hydrogen ion disturbances (acid-base disturbances)
WATER AND ELECTROLYTES DISTURBANCESClassification (Shires şi Baxter) • Volume disturbances • Volume contraction • Volume expansion • Concentration disturbances • Hyponatremia • Hypernatremia • Other hyperosmolar states • Composition disturbances • Hypo/hyperpotasemia • Hypo/hypercalcemia • Hypo/hypermagnesemia • Hypo/hyperphosphatemia • Hydrogen ion disturbances (acid-base disturbances)
PRINCIPLES of TREATMENT • Treatment of causative disease • STOP THE LOSSES • Volume replacement
Volume replacement • Routes of volume administration • Solutions for volume replacement • Rhythm of administration • Monitorization of volume replacement efficiency
WATER AND ELECTROLYTES DISTURBANCESClassification (Shires şi Baxter) • Volume disturbances • Volume contraction • Volume expansion • Concentration disturbances • Hyponatremia • Hypernatremia • Other hyperosmolar states • Composition disturbances • Hypo/hyperpotasemia • Hypo/hypercalcemia • Hypo/hypermagnesemia • Hypo/hyperphosphatemia • Hydrogen ion disturbances (acid-base disturbances)
VOLUME EXPANTION PRINCIPLES of TREATMENT • Treatment of causative disease • Limitation of water intake • Diuretics
WATER AND ELECTROLYTES DISTURBANCESClassification (Shires şi Baxter) • Volume disturbances • Volume contraction • Volume expansion • Concentration disturbances • Hyponatremia • Hypernatremia • Other hyperosmolar states • Composition disturbances • Hypo/hyperpotasemia • Hypo/hypercalcemia • Hypo/hypermagnesemia • Hypo/hyperphosphatemia • Hydrogen ion disturbances (acid-base disturbances)
SODIUM DISTURBANCES • Plasma sodium concentration= extracellular water – sodium ratio • Na-mia is not a predictor of intravascular volume
WATER AND ELECTROLYTES DISTURBANCESClassification (Shires şi Baxter) • Volume disturbances • Volume contraction • Volume expansion • Concentration disturbances • Hyponatremia • Hypernatremia • Other hyperosmolar states • Composition disturbances • Hypo/hyperpotasemia • Hypo/hypercalcemia • Hypo/hypermagnesemia • Hypo/hyperphosphatemia • Hydrogen ion disturbances (acid-base disturbances)
HYPERNATREMIANa-mia > 145mEq/l • Physiological effects • Extracellular hyperosmolarity • Water movement out of the cell • Preservation of extracellular volume despite losses • Intracellular volume contraction
HYPERNATREMIANa-mia > 145mEq/l • Clinical picture • Clinical signs of intracellular volume contraction – neurological signs • Restlessness, iritability, letargia, hyporeflexia, coma, convultions • High mortality, neurological sequelae
HYPERNATREMIANa-mia > 145mEq/l • Treatment • Water administration in order to correct hyperosmolarity • When clinical signs of extracellular volume contraction (hypovolemia) are present, isotonic solution should be given untill correction of intravascular volume • Calculation of water deficit 0,6 x kg x (Na actual / 140 – 1) • Speed of correctionNO > 2mEq/hour
HYPERNATREMIANa-mia > 145mEq/l CLASSIFICATION • HYPOVOLEMIC • Water and Na deficit • Deficit of water > Na • Body total amount of Na False hypernatremia • ISOVOLEMIC • Water deficit • Body total amount of Na - normal • HYPERVOLEMIC • Water and Na excess • Excess of Na >water • Body total amount of Na ↑ True hypernatremia
HYPOVOLEMIC HYPERNATREMIA Totalbody Na MECHANISM - Water and Na deficit; deficit of water > Na; body total amount of Na CAUSES • Extrarenal losses • Skin losses (profuse sweating) • Digestive losses (cholera, infant diarrheea) • Renal losses • osmotic diuresis • excess of diuretics • polyuria DIAGNOSTIC • Clinical signs of extracellular volume contraction • Na urinary< 10mEq/l – extrarenal losses • Na urinary> 20mEq/l – renal losses TREATMENT • Water and sodium administrationin isotonic proportions until correction of hypovolemia; hypotonic solution (NaCl 0,45%)
ISOVOLEMIC HYPERNATREMIA total body Na normal MECHANISM • water deficit; total body Na normal CAUSES • Extrarenal losses • Skin losses (profuse sweating) • Respiratory losses (tachypnea, mechanical ventilation) • Renal losses • Central diabetes insipidus • Nephrogenic diabetes insipidus • Hypodipsia (decreased water intake) DIAGNOSTIC • Signs: fever, oliguria, azotemia, drowsiness, coma, convultions • hypotension (late finding) • variable urinary Na TREATMENT • Increased water intake (NaCl 0,45%,)
HYPERVOLEMIC HYPERNATREMIA total body Na↑ MECHANISM • water excess; total body Na ↑ CAUSES • excess administration of hypertonic saline (NaCl 7,5%) • Na bicarbonate administration • Salt water drowning DIAGNOSTIC • Signs of extracellular volume expansion • Signs of intracellular volume contraction TREATMENT • Diuretics • Increased water intake
WATER AND ELECTROLYTES DISTURBANCESClassification (Shires şi Baxter) • Volume disturbances • Volume contraction • Volume expansion • Concentration disturbances • Hyponatremia • Hypernatremia • Other hyperosmolar states • Composition disturbances • Hypo/hyperpotasemia • Hypo/hypercalcemia • Hypo/hypermagnesemia • Hypo/hyperphosphatemia • Hydrogen ion disturbances (acid-base disturbances)
HYPONATREMIANa-mia < 135mEq/l • Physiological effects • Extracellular hypoosmolarity • Water movement towards the cell • Signs of intracellular volume expansion
HYPONATREMIANa-mia < 135mEq/l • Clinical picture • Dominated by neurological signs (cerebral edema) • Letargy, apatia, drowsiness, anorexia, nausea, agitation, hyporeflexia, hypothermia, convulsions • Signs severity depends upon: • severity of hypoNa-miei (Na < 120mEq/l) • speed of hypoNa-mia occurrence (acute/chronic)
HYPONATREMIA • Treatment • Correction of extracellular osmolarity and water excess removal • Speed of correction depens upon: • severity of hypoNa-mia • prezence/absence of symptoms • speed of occurrence (acute/chronic) • Rapid correction of chronic hypoNa-mia – pontine mielinolysis (irreversible sequelae) • In the prezence of symptoms, rapid correction until Na-mie 120mEq/l, than slow correction
HYPONATREMIANa-mia < 135mEq/l CLASSIFICATION • Hypovolemic • Water and Na deficit • Deficit of Na >water • Total body Na True hyponatremia • Isovolemic • Water excess of extracellular compartment • Total body Na - normal Dilutional hyponatremia / Pseudohyponatremia • Hypervolemic • Water and Na excess • Excess of water> Na • Total body Na↑ Dilutional hyponatremia
HYPOVOLEMIC HYPONATREMIA total body Na MECHANISM • water and Na deficit; deficit of Na >water; total body Na CAUSES • Extrarenal losses • Digestive losses (vomiting, diarrheea) • Skin losses (profuse sweating) • Third space formation (pancreatitis, burns, crush syndrome, intestinal oclusions, etc.) • Renal losses • osmotic diuresis, excess of diuretics, polyuria DIAGNOSTIC • Signs of extracellular volume contraction (hypovolemia) • Na urinary< 10mEq/l – extrarenal losses • Na urinary> 20mEq/l – renal losses TREATMENT • Correction of extracellular volume • Isotonic solutions
ISOVOLEMIC HYPONATREMIA total body Na normal MECHANISM • water excess of the extracellular space; total body Na normal CAUSES • Syndrome of inappropiate antidiuretic hormone secretion (SIADH) • Fear, excitement, pain, drugs, surgical procedures • Hyperosmolar states (hyperglycemia, intoxications) DIAGNOSTIC • Extracellular water excess; no clinical signs • Na urinary> 20mEq/l TREATMENT • Water restriction
HYPERVOLEMIC HYPONATREMIA total body Na ↑ MECHANISM • Excess of water and Na; excess of water> Na; total body Na ↑ CAUSES • Edematous syndromes (cardiac failure, liver cirhosis, nephrotic syndrome) • Acute and chronic renal failure DIAGNOSTIC • Signs of extracellular volume expansion (edema) • Na urinary< 10mEq/l in edematous syndromes • Na urinar > 20mEq/l in renal failure TREATMENT • Water (and salt) restriction