【正文】 Meta alka N ? 66 Acidosis and Alkalosis Defect Cause Resp acid Retention of CO2 Depression of respiratory Resp alka Excessive loss of CO2 Hyperventilation Meta acid Retention of fixed acids Diabetes, diarrhea Loss of base bicarbonate Lactic acid accumulation Meta alka Loss of fixed acids Vomiting or gastric suction Gain of base bicarbonate Excessive intake of Potassium depletion bicarbonate 67 Respiratory Acidosis: Hypoventilation PCO2 is elevated and plasma bicarbonate concentration is normal. In the chronic form, Pco2 remains elevated and bicarbonate concentration rises as renal pensation occurs. Cause: 1. Airway obstruction: Foreign body, pneumonia, emphysema. 2. CNS: Depression, injury, tumor. 3. Thoracic injury: Pneumothorax, flail chest, tracheal. 4. Mechanical ventilation: Inadequate rate and/or tidal volume. 68 Mecanism of ventilation dysfunction Inhibition of Resp. muscle paralysis Lung disease Obstruc stenose of airway ?Inhibit ?Resp. ?Thorac lung disea. ?Airway obstruction ?Malventilation 69 co2 o2 co2 co2 O2+Hb HbO2 o2 o2 o2 co2 co2 Hb + HbcO External respiration Internal respiration Airway Pulm。 7 Three functional partments of the body water intracellular water 40% extracellular water 20% body weight 60% plasma 5% interstitial fluid 15% 8 Total blood volume of human body Generally 8％ of body weight， About 5000 ml for an adult。 increase23％～ 25％ in pregnancy women。 alveolus blood vessel Cell Respiration course 70 Respiratory Acidosis Signs： 1. chest stuffy， dyspnea， restless， cyanosis and headache caused by hypoxia， Delirium even a 2. Examination laboratory revealed a decreased pH, increased PaCO2, HCO3175。 79 Influence : ? Simple Cardiovascular system: ? Arrhythmia . Hypokalemia Arrhythmia ?Cardiac contract.↓ pH H+ Effect Block Ad contract.↓ coupling 80 pensation H+ ? Simple ? Blood HCO3 － CO2 H2O + ① ? Lung ② ? Cell K+ ③ ? Kidney H+ ④ 81 Metabolic acidosis Treatment: 1. Treatment primary disorder. 2. Replenishing any preexisting ECF volume deficit 3. Infusion with 5% NaHCO3 100~250ml 4. Intravenous administration of calcium gluconate or calcium chloride 82 Metabolic Alkalosis 1. Causes are loss of fixed acids or gain of bicarbonate and is aggravated by any existing potassium deficit. 2. Both the pH and the plasma bicarbonate concentration are elevated. 3. Compensation occurs primarily through renal mechanisms. 83 Influence of Met. Alkolosis 1 CNS： Excitation Mechanism： （ 1） GABA ↓ （ 2） →brain tissue hypoxia : Excitability? Ca+ ↓ 3. K + ↓ : Hypokalemia 4. Tissue hypoxia 84 Stomach duodenum Blood vessel H2CO3 HCO3 H+ HCO3 H+ H+ H2CO3 H+ HCO3 Cl Na+ Na+ Cl Cl gastric fluid loss and . Pancreas HCO3 Na+ esophagus 85 (1) H+Loss Stomach Vomit CO2 H2O H2CO3 HCO3 － H+ H+ H+ H+ H+ H－ + H+ H2CO3 HCO3 － H+ ? Simple Enteric cavity H+ pancreatic secretion HCO3 － Metab. Alkol 86 (1) H+ ↓ Stomach Vomit CO2 H2O H2CO3 HCO3 － H+ H+ H+ H+ H+ H+ H+ H2CO3 HCO3 － H+ ? Simple Enteric cavity H+ Pancreatic secretion HCO3－ Metablic alkolosis 87 Metabolic Alkalosis Treatment: 1. Treatment primary disorder. 2. Replenishing any preexisting ECF volume deficit 3. Intravenous administration of KCl 4. Intravenous administration of (1 mol/L chloride acid 150 ml+saline 1000ml，25~50ml/h） 88 Salt Gain and Losses ?In a normal individual the daily salt intake varies between 50 and 90 mmol. (3 to 5 gm.) as sodium chloride. ?Balance is maintained primarily by the kidneys, which excrete the excess salt. 89 Salt Gain and Losses Sodium Exchange Average Sodium Gain Diet 5090 mmol/day Sodium loss Skin (sweat) 1060 mmol/day Urine 1080 mmol/day Intestine 020 mmol/day 90 FLUID AND ELECTROLYTE THERAPY lactated Ringer39。 tissue signs of excessive intracellular water. 21 Hyponatremia: (Water intoxication ) serum sodium level less than 120 mmol/L CNS: Moderate severe Muscle twitching Convulsions Hyperactive tendon reflexes Loss of reflexes increased intracranial pressure CardioVascular: Bp change Tissue: increased salivation Watery diarrhea Renal: Oliguria progressing to anuria Metabolic: None 22 Mechanism of Hypernatremia Water intake deficient Diseases of digestive tract Excess loss water excess perspiration Vomite, diarrhea, suction 23 Hypernatremia: (Water deficit ) serum sodium level greater than 150 mmol/L CNS: Moderate severe Restlessness Delirium Weakness Maniacal behavior CardioVascular: Tachycardia, Hypotension Tissue: Decreased saliva and tears