Fluid and Electrolyte Management of the Surgical Patient Dr Abdollahi Afshar Hospital Fluid therapy is often poorly taught, poorly understood and poorly done ‘Fluid therapy should be directed not only to effective volume expansion of a leaky circulation but also to micro vascular protection’. Fluid and electrolyte management are paramount to the care of the surgical patient. Changes in both fluid volume and electrolyte composition occur preoperatively, intraoperatively, and post operatively, as well as in response to trauma and sepsis. Total Body Water Who is having higher proportion of body weight as water? And Why? Males or Females Lean or Obese Young or elderly Body Fluid Compartments: 2/3 X 50~70% lean body weight ICF: 55%~75% TBW 3/4 • • • • • Male (55%) > female (45%) Most concentrated in skeletal muscle TBW=0.6xBW ICF=0.4xBW ECF=0.2xBW 1/3 ECF 1/4 Extravascular Interstitial fluid Intravascular plasma Total body water (TBW) • TBW varies with age ,gender and body habitus • In adult males= 55% of body weight • In adult female=45% of body weight • In infant = 80% of body weight • Obese patients have less TBW per Kg than lean body adult. Body compartment fluid 1= Intracellular fluid (ICF)=55% TBW or 30%-40% BW 2= Extracellular fluid (ECF) =45%TBW or 20% BW Interstitial fluid =15% of body weight Intravascular fluid or plasma volume = 5% of body weight. Example: men with 70kg TBW= 55%70 =38.5 L ICF = 55% 38.5 =21.2L ECF = 45% 38.5=17.3L 1. ISF = 15% 70 = 10.5L 2. PV = 5% 70 =3.5L Fluid compartments ICF Fluid compartments ICF Interstitial ECF Fluid compartments ICF Interstitial ECF Fluid compartments Capillary Membrane ICF Interstitial ECF Fluid compartments Capillary Membrane ICF Interstitial ECF Fluid compartments Capillary Membrane Cell Membrane ICF Interstitial ECF Colloid osmotic pressure Capillary Membrane Interstitial ECF Capillary membrane freely permeable to water and electrolytes but not to large molecules such as proteins (albumin). Colloid osmotic pressure Capillary Membrane Interstitial ECF Capillary membrane freely permeable to water and electrolytes but not to large molecules such as proteins (albumin). Colloid osmotic pressure Capillary Membrane H2O Interstitial H2O ECF Capillary membrane freely permeable to water and electrolytes but not to large molecules such as proteins (albumin). The albumin on the plasma side gives rise to a colloid osmotic pressure gradient favouring movement of water into the plasma Colloid osmotic pressure Capillary Membrane H2O H2O Interstitial H2O 120/80 H2O Capillary membrane freely permeable to water and electrolytes but not to large molecules such as proteins (albumin). The albumin on the plasma side gives rise to a colloid osmotic pressure gradient favouring movement of water into the plasma This is balanced out by the hydrostatic pressure difference ECF Cell Membrane Cell Membrane H2O H2O ICF Interstitial Cell membrane is freely permeable to H20 but Cell Membrane Cell Membrane H2O H2O Interstitial ICF Na+ K+ Cell membrane is freely permeable to H20 but Na and K are pumped across this membrane to maintain a gradient! Cell Membrane Cell Membrane H2O H2O Interstitial ICF Na- K+ [K+] =4 Cell membrane is freely permeable to H20 but Na and K are pumped across this membrane to maintain a gradient! Cell Membrane Cell Membrane H2O H2O Interstitial ICF Na- K+ [K+] =4 [K+] =150 Cell membrane is freely permeable to H20 but Na and K are pumped across this membrane to maintain a gradient! Cell Membrane Cell Membrane H2O Na+= 144 H2O Interstitial ICF Na- K+ [K+] =4 [K+] =150 Cell membrane is freely permeable to H20 but Na and K are pumped across this membrane to maintain a gradient! Cell Membrane Cell Membrane H2O Na+= Na+= 10 144 H2O Interstitial ICF Na- K+ [K+] =4 [K+] =150 Cell membrane is freely permeable to H20 but Na and K are pumped across this membrane to maintain a gradient! Composition of Fluid Compartments 200 mEq/L 154 mEq/L CATIONS Na+ 142 154 mEq/L ANIONS Cl HC03 - K+ Ca++ Mg++ Na+ ANIONS Cl - CATIONS K+ HC03- 3 114 504 4 organic Acid 5 PLASMA 150 — 30 HCO3- K+ 3 Protein 16 ANIONS 150 HPO4 --- 4 5 144 153 mEq/L 27 504— PO4 CATIONS 103 - 153 mEq/L 200 mEq/L 504— PO4--- 3 organic Acid 5 Ca++ 3 Mg++ 2 Protein INTERSTITAL FLID 10 1 Mg++ 40 Protein Na+ 10 INTRACELLULAR FLID 40 Composition of Body Fluids: Cations 150 Anions 100 50 0 ECF Na+ ClHCO3- 2+ Ca Mg 2+ Protein K+ Organic anion ICF 50 PO43- 100 150 Osmolarity = solute/(solute+solvent) Osmolality = solute/solvent (290~310mOsm/L) Tonicity = effective osmolality Plasma osmolility = 2 x (Na) + (Glucose/18) + (Urea/2.8) Plasma tonicity = 2 x (Na) + (Glucose/18) عوامل موثر روی تغییرات آب والکترولیت .1 .2 .3 .4 نوع عمل جراحی (میزان خونریزی -تبخیر آب – حجم فضای سوم ) وضعیت آب والکترولیت قبل از عمل بیماریهای همراه (اندوکرینوپاتی( اثر داروهای بیهوشی (نسدونال -پروپوفل)RA -MR - Reasons for fluid therapy Preserve oxygen delivery to tissues • Correct hypovolaemia Colloids + RBCs • Maintain cardiac output • Optimise gas exchange • Replace electrolytes & water Crystalloids • Maintain urine output Identify what is the goal Choose fluid which best achieves the goal ارزیابی حجم مایع داخل عروقی • • • • • • • • • شرح حال بیمار فشار خون (ایستاده – خوابیده ) ضربان قلب بیمار برون ده ادراری هماتوکریت نیتروژن خون الکترولیت ها ABG CVP محلولهای وریدی Fluids • Crystalloids • Colloids • blood Which of the following solutions is isotonic? A. D5W B. 0.45% saline C. 0.9% saline D. D5 in 0.9% saline Common parenteral fluid therapy Solutions Volumes Na+ K+ Ca2+ Mg2+ Cl- HCO3- Dextrose mOsm/L ECF 142 4 5 103 27 280-310 Lactated Ringer’s 130 4 3 109 28 273 0.9% NaCl 154 154 308 0.45% NaCl 77 77 154 D5/0.45% NaCl 77 77 3% NaCl 513 513 1026 500 154 154 310 250,500 130160 <2.5 130160 330 20,50,100 130160 <2.5 130160 330 D5W 6% Hetastarch 5% Albumin 25% Albumin 50 406 Crystalloids: Isotonic crystalloids - Lactated Ringer’s, 0.9% NaCl - only 25% remain intravascularly • Hypertonic saline solutions - 3% NaCl • Hypotonic solutions - D5W, 0.45% NaCl - less than 10% remain intravascularly, inadequate for fluid resuscitation • Colloid Solutions: • Contain high molecular weight substancesdo not readily migrate across capillary walls • Preparations - Albumin: 5%, 25% - Dextran - Gelifundol - Haes-steril 10% رینگر الکتات • مایع نمکی ایزوتونیک جهت جایگزینی از دست دادنهای GIو کاهش ECFبدون اشکاالت عمده در ترکیبات و اجزا رینگر الکتات است. • ایزوتونیک Na=130meq/l • CL=109meq/l lactat=28meq/l osm=273 0.9%Nacl • Na=154 • CL= 154 • این مایع جهت جبران کاهش ECFدر حضور هیپوناترمی وهیپوکلرمی و آلکالوز متابولیک ایده ال استPH=5.6. Postoperative (maintenance) 0.45%Nacl +5% dextrose +KCL Perioperative management of fluid balance include: 1. Preoperative evaluation 2. Intraoperative maintenance 3. Replacement of fluid losses Preexisting fluid deficits • NPO time and abnormal fluid losses (vomitingdirreha- asites- infected tissue-fever –sweatinghyperventilation) • Hypotonic fluid (0.5% saline ) or isotonic crystalloids Maintenance requirements • Up to 10 kg = 4cc/kg/hr • 11-20kg = add 2cc/kg/hr • 21kg and above = add 1cc/kg/hr • Insensible losses = 2cc/kg/hr Surgical fluid losses Blood loss (measurement) 1. Suction container 2. Surgical sponge 3. Hct and tachycardia not specific 4. ABG and UO if hypoperfusion occur 5. Blood loss=3/1 with crystalloid Other losses (third space loss) Third space loss 1. Minimal (herniorrapy) =2-4cc/kg/hr 2. Moderate (cholecystectomy)=4-6cc/kg/hr 3. Severe (bowel resection) = 6-8cc/kg/hr Crystalloid solution 1. 2. 3. 4. The main solutions is either glucose or saline Hypotonic or isotonic or hypertonic. Safe , nontoxic, reaction free ,inexpensive. Complication is edema if large volumes are needed. 5. During surgery isotonic solution favored (normal saline - lactate ringer and plasma lyte) Colloids 1. Albumin 2. Hydroxyethyl starch 3. Dextran Complications 1. 2. 3. • • Hypersensitivity reactions (anaphylaxis ) Pruritis (hetastarch) Couglopathy (dextran 70 and hetastarch) > 1 litter Dextran ( platelet aggregation , adhesive) Hetastarch (reduction in factor vlll and VOB factor ) These colloid is best avoided in patients with coagulopaty. The Influence of Colloid & Crystalloid on Blood Volume: Blood volume Infusion volume 200 1000cc 500cc 500cc 500cc 600 1000 Lactated Ringers 5% Albumin 6% Hetastarch Whole blood Colloid versus crystalloid solutions Transfusion consideration • HB <7 mg /dl increase CO • Ideal Hb is 7-8 mg/dl • In IHD patients or pulmonary disease > 10 mg/dl اختالل در حجم مایعات بدن 1. Fluid volume deficit 2. Fluid volume excess Fluid volume deficit )(FVD کاهش آب والکترولیتهای بدن( به نسبتی که در مایعات طبیعی بدن وجود دارد ) به صورتی که نسبت الکترولیتهای بدن به آب یکنواخت باقی بماند کاهش حجم مایع FVDبه وجود خواهد آمد (کاهش ایزوتونیک). میزان الکترولیتهای سرم در FVDنرمال باقی میماند مگر اختالل دیگری همراه با آن باشد DEHYDRATION • در دهیدریشن کاهش آب همراه با افزایش سدیم سرمی وجود دارد. علل کاهش حجم خارج سلولی .1از دست دادن غیر طبیعی آب بدن:استفراغ –اسهال- -تعریق- NGT .2کاهش میزان دریافت آب بدن:تهوع یا ناتوانی دسترسی به مایعات .3خروج مایعات از سیستم کاردیواسکوالر ( third space )lossمثل سوختگی –ترومای جراحی Signs of Hypovolemia: • Diminished skin turgor • Dry oral mucus membrane • Oliguria - <500ml/day - normal: 0.5~1ml/kg/h • Tachycardia • Hypotension • Hypoperfusioncyanosis • Altered mental status Clinical Diagnosis of Hypovolemia: • Thorough history taking: poor intake, GI bleeding…etc • BUN : Creatinine > 20 : 1 - BUN↑: hyperalimentation, glucocorticoid therapy, UGI bleeding • Increased specific gravity • Increased hematocrit • Electrolytes imbalance • Acid-base disorder Signs of Hypervolemia: • • • • • Hypertension Polyuria Peripheral edema Especially when hypoalbuminemia Wet lung Jugular vein engorgement Management of Hypervolemia: • Prevention is the best way • Guide fluid therapy with CVP level or pulmonary wedge pressure • Diuretics • Increase oncotic pressure: FFP or albumin infusion (may followed by diuretics) • Dialysis Fluid Management: • Goal: - to maintain urine output of 0.5~1.0mg/kg/h • Rule: • Electrolytes require: - Na+: 1-2mmol/kg/day - K+: 0.5~1.0mmol/kg/day • Avoid fluid overload, especially in malnutrition, heart failure and renal insufficiency patient Electrolyte physiology Sodium physiology Na is the most abundant positive ion of ECF compartment and is critical in determining the ECF and ICF osmolality. Normal amount 135-145 meq/l Osmotic Pressure Calculated serum osmolality = 2 sodium+ glucose/18 + BUN /2.8 Osmolality = 290 mosm Concentration 1.Serum sodium concentration 2.Serum osmolarity • Hypovolemic/hypernatremic (burn, fever) • Hypovolemic/hyponatremic (vomiting ,diarrhea or fistula drainage) • Normovolemic/hyponatremic (decrease kidney reserve ) • Hypervolemic/hyponatremic (excessive water intake,TURP, DW5%) Hypernatremia Serum Na>145mEq/L Hypernatremia: Loss of Free Water - Hypernatremia Gain of sodium in excess of water Hypo volemic -Hypernatremia Hyper volemic Normo volemic Hypernatremia Volume Status High Normal Low Iatrogenic sodium administration Nonrenal water loss Nonrenal water loss Skin Mineralocorticoid excess Aldosteronism Cushing’s disease Congenital adrenal hyperplasia Skin Gastrointestinal losses Gastrointestinal Renal water losses Renal water loss Renal (tubular) Diuretics Renal disease Diuretics Diabetes insipidus Osmotic diuretics Diabetes insipidus Adrenal failure Asymptomatic Hypernatremia Symptomatic (Na>160 meq/L) Clinical Manifestations of Abnormalities in Serum Sodium Body system Central nervous system Musculoskeletal Cardiovascular Tissue Renal Metabolic hypernatremia Restlessness, lethargy, ataxia, irritability, tonic spasms, delirium, seizures, coma weakness Tachycardia, hypotension, syncope Dry sticky mucous membranes, red swollen tongue, decreased saliva and tears Oliguria Fever Treatment Normal saline in hypovolemic patients Hypotonic fluid (D/w 5%, D/W 5% in ¼ or ½ normal saline, or entral water) The formula used to estimate the amount of water required to correct hypernatremia: Water deficit (L)= Serum sodium-140 × TBW 140 Estimate TBW as 55% of lean body mass in men and 45% in women The rate of fluid administration: 1. Acute hypernatremia: a decrease in serum sodium of no more than 1meq/h and 12meq/d 2. Chronic hypernatremia: a decrease in serum sodium of no more than 0.7meq/L/h Hyponatremia: Na<135mEq/L Causes : 1. Sodium depletion 2. Sodium dilution • Incidence = 4.5% • After surgery=1% • Mortality = 2 times normal Sodium depletion 1. Decrease intake Low Na diet Enteral feeds 2. Increase loss Gastrointestinal Losses Vomiting Prolonged NGT suctioning Diarrhea Renal Losses Diuretics Primary renal disease 3. Depletional hyponatreamia is often accompanied by extracellulr volume deficit Sodium dilution 1. Due to excess extracellular water Intentional: excessive oral intake Iatrogenic: Intravenous 2. Drugs Antipsychotics Tricyclic antidepressants Angiotensin-converting enzyme inhibitors 3. Hyperosmolar Mannitol Hyperglycemia 4.Pseudohyponatremia Plasma lipids Plasma proteins Sign and symptoms • CNS symptom when Na<123 meq/l • Cardiac symptom when Na<100 meq/l For every 100 mg/dL increment in plasma glucose above normal, the plasma sodium should decrease by 1.6 mEq/L. Clinical Manifestations of Abnormalities in Serum Sodium Body System Hyponatremia central nervous system Headache, confusion, hyper-or hypoactive deep tendon reflexes, seizures, coma, increased intracranial pressure Weakness, fatigue, muscle cramps/twitching Anorexia, nausea, vomiting, watery diarrhea Hypertension and bradycardia if significant increases in intracranial pressure Lacrimation, salivation Oliguria Musculoskeletal Gastrointestinal Cardiovascular Tissue Renal Treatment 1=Depend on ECF 2=CNS sign Treatment 1. Asymptomatic : increase the sodium level by no more than 0.5-1 meq/L/h to a maximum increase of 12 meq/L per day 2. Symptomatic: (Na<120 meq/L) Increase the sodium level by no more than 1meq/L per hour until the serum Na level reaches 130 meq/L or neurologic symptoms are improved Rapid correction of hyponatremia Pontine myelinolysis Seizures, weakness/paresis, akinetic movements, unresponsiveness Permanent brain damage Death Dose Na deficit meq =(140- Na meq/l) TBW اصالح باید 0.5-1 meq/l /hباشد تا سدیم به 125meq/lبرسد و سپس آهسته اصالح شود . Potassium abnormalities • The average dietary intake of potassium: 50-100meq/d • The average renal excretion of potassium: 10-700 meq/d - 2% of the total body potassium in ECF (4.5meq/L) - Factors that influence serum potassium: 1. Surgical stress 2. Injury 3. Acidosis 4. Tissue catabolism Hyperkalemia The normal range of serum potassium: 3.5-5 meq/L Etiology of Hyperkalemia Increased intake Potassium supplementation Blood transfusions Endogenous load/destruction: hemolysis, rhabdomyolysis, cruch injury, gastrointestinal hemorrhage Increased release Acidosis Rapid rise of extracellure osmolality (hyperglycemia or mannitol) Impaired excretion of potassium Renal insufficiency/failure Clinical manifestation of hyperkalemia System hyperkalemia Gastrointestinal Neuromuscular Cardiovascular Nausea/vomiting ,colic, diarrhea weakness, paralysis, respiratory failure Arrhythmia, arrest ECG changes Peaked T waves (early change) Flattened P wave Prolonged PR interval (first-degree block) Widened QRS complex Sine wave formation Ventricular fibrillation Treatment Treatment of symptomatic hyperkalemia Potassium removal Kayexalate Oral administration is 15-30 g in 50-100 mLof 20% sorbitol Rectal administration is 50 g in 200 mL 20% sorbitol Dialysis Shift potassium Glucose 1 vial of D50% and regular insulin 5-10 units intravenous Bicarbonate 1 vial intravenous Counteract cardiac effects Calcium gluconate 5-10 mL of 10% solution Hypokalemia Etiology : inadequate intake Dietary, potassium-free intravenous fluids, potassium-deficient total parenteral nutrition Excessive potassium excretion Hyperaldosteronism Medications Gastrointestinal losses Direct loss of potassium from gastrointestinal fluid (diarrhea) Renal loss of potassium (gastric fluid, either as vomiting or high nasogastric output) Intracellular-shift (metabolic alkalosis or insulin therapy) Potassium changes associated with alkalosis: Potassium decrease by 0.3 meq/L for every 0.1 increase in PH above normal Magnesium Depletion (drug induced: amphotericin, amioglycosides, cisplatin) Renal potassium wastage Hypokalemia Clinical Manifestation of Abnormalities in potassium System Gastrointestinal Neuromuscular Cardiovascular ECG changes hypokalemia Ileus, constipation Decreased reflexes, fatigue, weakness, paralysis Arrest U-waves T-wave flattening ST-segment changes Arrhythmias Treatment Electrolyte Replacement Therapy Protocol Potassium Serum potassium level <4.0 mEq/L Asymptomatic, tolerating enteral nutrition: KC1 40 mEq per entral access × 1 doses Asymptomatic, not tolerating entral nutrition: KC1 20 mEq IV q2h × 2 doses Symptomatic: KC1 20 mEq IV q1h × 4 doses Recheck potassium level 2 hours after end of infusion; if <3.5 mEq/L and asymptomatic, replace as per above protocol • • Oral repletion for mild and asymptomatic hypokalemia IV repletion for severe and symptomatic hypokalemia Calcium • • .1 .2 .3 .4 بیش از %99از كلسیم بدن در سیستم اسكلتي است (استخوان –دندانها). نقش كلسیم: انتقال ایمپالسهاي عصبي)(NMJ انقباض عضالت صاف مسبب آزادسازي آنزیمهاي الزم برای واكنش هاي شیمیائي انعقاد Ca<4.5 meq/lهیپوكلسمي یونیزه • .1 .2 .3 .4 .5 .6 .7 علل: كم كاري پاراتیروئید پانكراتیت نارسائي كلیه (احتباس فسفر و مختل شدن تبدیل ویتامین Dبه فرم فعالش در کلیه) هیپرونتیالسیون (آلكالوز تنفسي) باعث افزایش باند شدن کلسیم با آلبومین میشود. ترانسفیوزن ماسیو تخلیه منیزیوم (مهار ترشح پاراتورمون) انفوزیون بیکربنات (کلسیم به طور مستقبم با بیکربنات تزریق شده پیوند می شود). عالئم هیپوکلسمی • • • • • • • • هیپر رفلکسی تشنج تتانی 25%( Chevostekافراد نرمال وجود دارد) (Trousseauدر 30%موارد هیپوکلسمی وجود ندارد) هیپوتانسیون کاهش برون ده قلبی آریتمی سایرعالئم • • • • • كاهش قدرت انقباضي قلب افزایش فشار ورید هاي مركزي كاهش فشار خون اسپاسم حنجره اسپاسم عضالت اسكلتي درمان • بر طرف کردن علت زمینه ای • کلسیم وریدی Ca>5.5meq/lهیپركلسمي • • • • هیپرپاراتیروئیدیسم كانسرها با متاستاز استخواني بی حرکتی طوالنی مدت داروها (لیتیوم – دیورتیک ) عالئم GI Cardiovascular Renal (polyuria) CNS • • • • عالئم قلبی • اختالالت هدایت قلبي (افزایش فاصله P-Rپهن شدن QRSوكوتاه شدن )Q-T Ca>7 meq/l درمان .1 .2 .3 .4 .5 انفوزیون محلول نمکی ایزوتونیک الزیکس کلسی تونین کورتون دیالیز Magnesium Abnormalities Normal dietary intake: 20meq (240mg) Excretion in both the feces and urine Normal serum level: 1.9-2.5 mg/dL منیزیوم • دومین کاتیون فراوان داخل سلولی است. • نقش آن به عنوان فاکتور کمکی در واکنش های آنزیمی و در حفظ قدرت انقباضی قلب و تون عروق محیطی دارد. • 55%به شکل یونیزه (فعال) و 45%باند پروتئین است. Hypermagnesemia Etiology: 1. Impaired renal function 2. Excess intake (in the from of TPN or magnesiumcontaining laxatives and antacids) Clinical manifestation hypermanesemia System Gastrointestinal Neuromuscular hypermanesemia Nausea/vomiting Cardiovascular weakness, lethargy, Decreased reflexes Hypotension, arrest ECG changes Increased PR interval Widened QRS complex Elevated T waves Treatment 1. 2. 3. 4. Withhold exogenous sources of magnesium Correct volume deficit Correct acidosis if present Calcium chloride (5-10 ml) to manage acute symptoms (cardiovascular effects) 5. Dialysis (if elevated levels or symptoms persist) عالئم • Patellar reflexes lost: • Respiratory depression: • Respiratory paralysis: • Cardiac arrest: 8-10 meq/L 10-15 meq/L 12-15 meq/L 25-30 meq/L Hypomagnesemia Calcium/ magnesium receptors on renal tubular cells is primarily responsible for mg homeostasis. Etiology: 1. Poor intake (starvation, alcoholism prolonged use of IV fluids, and TPN with inadequate supplementation of magnesium) 2. Increased renal excretion (alcohol, most diuretics, and amphotericin B) 3. GI losses (diarrhea) 4. Malabsorption 5. Acute pancreatitis 6. Diabetic ketoacidosis 7. Primary aldosteronism Clinical manifestation of hypomagnesemia: (similar to hypocalcemia) 1. Hyper active reflexes, muscle tremors, tetany with chevostek’s sign 2. Delirium and seizures in severe deficiency 3. ECG changes: Prolonged QT and PR interval ST-segment depression Flattening or inversion of P waves Torsades de pointes Arrhythmia Treatment 1. For asymptomatic and mild hypomagnesemia administer oral mg. 2. For severe deficit (<1meq/L) or symptomatic patient administer 1 to 2 g of mg-sulfate IV over 2 minute (simultaneous with ca-gluconate). Message for Today • Do not reccussitate sick patients with any Dextrose solution. 5% Dex ICF Interstitial