4-Fluid and Electrolyte PDF

BASIC SURGERY LECTURER: DR. JEREMY TAN This is a sample computation of a male 70kg (average male) the total percentage of...

BASIC SURGERY LECTURER: DR. JEREMY TAN This is a sample computation of a male 70kg (average male) the total percentage of fluid water is 42 liters or 42,000ml because that’s 60% of 70 and it could be broken down as this: (70 x.60 = 42) TOTAL BODY WATER Ø Water → ~50% to 60% of total body weight Total Body Water is 60% ® 42 liters Relationship between total body weight and total Total extracellular volume is 20% ® 14 liters body water (TBW) is constant and is a reflection of o Plasma is 3.5 liters (5%) + interstitial fluid 10.5 liters (15%) body fat. Total intracellular volume is 40% ® 28 liters Lean tissues (muscle and solid organs) have higher water content than fat and bone. Look for gender, weight and if obese or malnourished, and anong component ang tanong, tas all goods ka na Ø Young, lean males → higher proportion of body weight as What is the TBW of an average young adult female with a total body water than elderly or obese individuals weight of 60kg? Ø Ave. young adult male → 60% of total body weight Female ® 50%; 60 x.50 = 30L Ø Ave. young adult female → 50% of total body weight Lower in females due to higher percentage of adipose tissue What is the TBW of an average young adult male with a total body and lower percentage of muscle mass. weight of 80kg ? Ø Obese → Estimates adjusted downward ~10-20% Male ® 60% = 80 x.60 = 48L Ø Malnourished → Estimates adjusted upward by 10% Ø Newborns → ~80% of their total body weight consisted of If a 70kg Male patient has a TBW of 42L, how much of this is found water. intracellularly? Decreases to ~65% by 1 year of age and remains Intracellular fluids ® 40% = 72 x.40 = around 28L constant. (>2 years old, same na sa constants sa ave A 32 year old male patient is significantly malnourished due to young adult sa taas) Obese Male patient = 40-50% (mas mataba, mas mababa) metastatic lung cancer. If the patient presently has a total body weight Malnourished Male Patient = 70% (mas payat, mas mataas) of 50kg what is his TBW? (MUSCLES MORE WATER THAN FAT). If nalilimutan, tandaan na mas Male patient (gender) ® 60% madaming tubig sa muscle kesa sa fat and bones. So mas mataba ka, mas Conditional: Malnourished = +++10% mataas taba mo kesa muscle, mas konti tubig mo. Mas payat naman, mas 60% + 10 % = 70% madami muscle mo kesa taba, mas madami tubig mo. 50 x.70 = 35L FLUID COMPARTMENTS COMPOSITION OF FLUID COMPARTMENTS Ø Three functional fluid compartments: Ø ECF compartment (Interstitial + Plasma) o Plasma Sodium (principal cation) o Extravascular interstitial fluid Chloride and Bicarbonate (principal anion) o Intracellular fluid (Skeletal muscle) Ø ICF compartment → composed primarily of: Ø Extracellular water → ~20% of total body weight (1/3 of Magnesium and Potassium (Principal cation) TBW) Phosphate and sulfate (Anions) o Plasma → 5% of body weight Proteins o Interstitial fluid → 15% of body weight. Ø Concentration gradient is maintained by Na/K-ATPase Ø Intracellular water → 40% of total body weight (2/3 of TBW) pump. PISO = Potassium inside, Sodium outside o Largest proportion in the skeletal muscle mass. FUNCTIONAL BODY FLUIDS What is the principal Cation in the Sodium % of Total Volume of Male Female & P120 - Extracellular fluid compartment Kakasabi lang ng PISO Body Weight TBW (70kg) (60kg) a. Calcium b. Magnesium Potassium inside, Extracellular c. Potassium d. I Sodium sodium outside Plasma (5%) 14,000 mL 10,000 mL Volume What is the most predominant cation Potassium Interstitial Plasma 3,500 mL 2,500 mL & found intracellularly PlSO- PISO nga Fluid (15%) Interstitial 10,500 mL 7,500 mL a. Calcium b. Magnesium Intracellular Intracellular 28,000 mL 20,000 mL I c. Potassium d. Sodium Volume (40%) volume TOTAL 42,000 mL 30,000 mL KUMUNOY’S IMPROPERTY 1  BASIC SURGERY LECTURER: DR. JEREMY TAN What is the total body water in liters of an What is the total body water of an adult 30 average young adult female with a total 40 malnourished female- 58 + 10 with total body 50kg x 60% = 30L - Young adult female = 60% kasi body weight of 80kg? 50% weight of 50kg in liters? 50% 50% if average a. 50 I b. 40 80 x.50 = 40 I 30 b. 35. c. 20 d. 25 a. -60 % Pero malnourished sya so + 10% c. 20 d. 60 What is the total body water of an Which of the following is a cation in the average young adult male with total 54008 & - intracellular fluid compartment? Magnesium body weight of 90kg in milliliters? 90 kg x 60% = 54L Uy! Hinanap ang Potassium, a. Sodium k Mg PotaMag - INN a. 5400 c. 45000 Liters to mL = 54,000 b. Proteins Sodium – extra I 54000 d. 4500 b. c. Phosphate Phosphate – anion A 40 year old male patient is significantly 35 - 60 + 10 ↓d. Magnesium malnourished due to metastatic colon 50 kg x 70% = 30 L Which of the following electrolyte is cancer. The patient has a total body 70% kasi 60% if average sya essential in the homeostasis of other but since malnourished sya, weight of 50kg, what is his total body + 10% electrolytes, such as calcium and water (TBW) in liters ? Magnesium potassium? a. 20 #b. 35. c. 28 d. 24 a. Phosphorus b. Sodium What is the total body water (TBW) of a 3,200 -> 80% c. Bicarbonate I Magnesium d. newborn infant who was delivered with a newborn = 80% If a 70kg Male patient has a total body 14 total body weight of 4kg, in mL? 4kg x.80 = water of 42L, how much of this in liters is Weight = 70kg a. 2,400 b. 2,800 3.2 L or 3,200 mL Plasma = 5%; IF = 15% found in plasma and interstitial fluid? So hinahanap mo ay 20% ng / c. 3,200 d. 3,600 I 14 c. 28 d. 7 a. 21 b. ↳ ECF = 20% 70kg = 14 L What percentage of total body 40 What percentage of total body weight is weight is the total body water (TBW) 50% if average but the intracellular water volume of an adjust downward ng 10- 40 of an obese male? average young adult? ↳ 40% ↳ 60 10 - 501 20% kasi nga diba pag I a. 40 - = a. 25 b. 30 c. 35 d. I 40 28 40/ mas mataba ka, mas b. 80 - = What is the total body water of an madami fat than average young adult female with a total c. 20 muscle, lesser water J 30 Liters body weight of 60kg? ↳ 50 % d. 60 (FEMALE: 50%) I a. 24 L b. 30 L c. 36 L d. 42 L What is the total body water of an average young adult male with a total 48 Liters - 40% body weight of 80kg? (MALE: 60%) 1 a. 32 L b. 40 L c. 48 L d. 56 L What is the total body water of an 65% of total body & average 1 year old male? newborn = 80 % weight Ia. 65% of total body weight 72 = 60 % Newborn 85% b. 70% of total body weight 1yr old 65% c. 75% of total body weight >2 same na sa matanda d. 80% of total body weight If a 70kg Male patient has a TBW of 42L, 28L how much of this is found intracellularly (ICF for males is 40% of TBW) Tingin sa table under Fluid < 40 % / a. 4L. b. 12L. c. 20L. d. 28L Compartments!!!! A 32y/o male patient is significantly % malnourished%8 due to metastatic lung 35L cancer. If the patient presently has a total body weight of 50kg, what is his total - (MALE 60% & Ø Plasma and interstitial fluid composition differs only slightly body water (TBW) Malnourished +10%) in ionic composition. I 35L c. 40L d. 45L a. 30L b. - % 45 Slightly higher protein content (organic anions) in What is the total body water of a 1 year 8.45 - plasma → Higher plasma cation composition old male with total body weight of 13kg in 1 yo = 65% liters? - 13 x.65 relative to the IF (Gibbs-Donnan equilibrium equation). I a. 7.8 b. 8.45. c. 9.1. d. 10.4 = 8.45 Ø Movements of ions and proteins between fluid compartments is restricted. KUMUNOY’S IMPROPERTY 2  BASIC SURGERY LECTURER: DR. JEREMY TAN Ø Sodium Ø Sensible water losses Confined to the ECF compartment. Sweating (hypotonic) → small sodium loss Where sodium goes, water follows. Pathologic loss of GI (isotonic to slightly hypotonic) Sodium-containing fluids are distributed throughout → net gain or loss of free water when measured the ECF and add to the volume the intravascular and appropriately replaced by isotonic salt and interstitial spaces. solutions. Ø Administration of sodium-containing fluids expands the Loss of electrolytes as well as water. intravascular volume and the interstitial space by ~3x as Ø Typical individual consumes 3-5 g of dietary salt per day, much as the plasma. with the balance maintained by the kidneys. Hyponatremia or hypovolemia → Na excretion can be reduced to as little as 1 mEq/d-5000 mEq/d to achieve balance except in people with salt- Ø Movement of water across a cell membrane depends on wasting kidneys. osmosis → movement is due to solute concentration on each side of the membrane. Ø Osmotic pressure → measured in units of osmoles (osm) or milliosmoles (mOsm) that refer to the actual number of osmotically active particles. Ø Principal determinants of osmolality: Na, Glucose, and urea (blood urea nitrogen, or BUN). 7#% :;4 !"#$%#"&'( *'+%, -.,/#"#0&1 = 245 + + 18 2.8 2Na (Tuna), Sugar 18, BUN 2.8 Ø Normal ICF and ECF Osmolality: 290 and 310 mOsm. Change in osmotic pressure is accompanied by a redistribution of water until the osmotic pressure between compartments is equal. Increased Na in ECF → net movement of water is We cannot do anything but to memorize these things. from intracellular to the extracellular compartment. This table should be common knowledge to all Doctors. Decreased Na in ECF → water moves into the cells. Ø Most significant gains and losses of body fluid are directly -800-1500 How much is the average water loss per day of a 60kg male through urine and stool? ~ 0 to 258 800 mL to 1750 mL Urine = 800-1500 from the extracellular compartment. What is the normal osmolality of the I a. 250 mL to 800mL. b. 800 mL to 1750 mL + c. 850 mL to 1550 mL d. 1250 mL to 2000 mL Stool = 0-250 2909418 extracellular fluid? S a. 280-310. c. 155-185 280-310 = How much is the daily insensible water loss, such as through the lungs and skin of an b. 245-275 d. 310-335 average healthy male a. 500 mL. Ib. 600 mL 600 mL c. 700 mL. d. 800 mL Which of the following condition will have an Fever increased insensible water loss? NORMAL EXCHANGE OF FLUID AND ELECTROLYTES Hyperventilation Ø Average water consumption of a healthy person: 2000 mL a. Hypothyroidism ↓ b. Fever Hypermetabolism c. Congestive Heart Failure d. Diabetes Mellitus of water per day. (75% from oral intake) How much is the maximum daily insensible Ø DAILY WATER LOSSES water loss in liters per day of an average - 1.5 800-1200 mL in urine → clear products of healthy male? 1500 mL = 1 5 L. Check table metabolism 500-800/day regardless of oral intake a. 1.8 b. 1.2 c. 1.5. d. 1 250 mL in stool How much is the maximal loss of water in liters - 4 600 mL in insensible losses per hour, can a 60kg male can lose through Check table, 4000 § Skin (75%), Lungs (25%) 8 sweat? 4000m) 4L = ml/hour § Increased by fever, hypermetabolism, a. 2 b. 3 c. 5 ↓ d. 4 hyperventilation. KUMUNOY’S IMPROPERTY 3  BASIC SURGERY LECTURER: DR. JEREMY TAN How much is the average water loss in ml per O day of a 60kg male thru urine? a. 1,000 to 1,800 800 to 1,500 Ib. 800 to 1,500 Check the values ulit c. 1,500 to 2,000 d. 600 to 80 CLASSIFICATION OF BODY FLUID CHANGES MOST COMMON ANG GI FLUID LOSS, 2ND LANG SI BLOOD LOSS, kasi ang katawan natin maganda ang control when it comes to bleeding, Ø Disorders in fluid balance: disturbances in volume, naalala mga nangyayari sa wound healing? Ako di ko na maalala, so concentration, and composition. big boss PASOK! Joke baka lumalim pa to. so nakita example GI fluid May occur simultaneously. loss by suction (surgical), vomiting, diarrhea at kung ano ano pa, pag Isotonic gain or loss of salt solution → ECV changes, nawala lahat ng fluid dyan sa GI mo, may deficit ka ng 1000-2000ml with little impact on ICF volume. deficit agad. Ø Unlike with Na, concentration of other ions in the ECF can be altered without significant change in the total number Example naman sa small intestine yung enterocutaneous fistula, may opening ng small intestine sa skin, tapos di na siya nakakabit sa colon, of osmotically active particles. meron kang 2000-3000ml fluid loss per day e.g. Doubling serum K levels alters myocardial function without altering volume of the fluid spaces. Ganyan ganyan lang yung sa table sinasabi lang na if may nangyari sa organ mo tapos may fluid loss, ganyan yung deficit ng numbers, and ECV DEFICIT dapat ireplace ng doctor. Ø Most common fluid disorder in surgical patients Ø Acute volume deficit Sequestration is loss of water kasi nagt-travel to to injury sites. Massive blood loss accident and stab wounds Sa soft tissue pag nagpunta dun = EDEMA Sa burns à no more keratin in skin (protective covering) à more CV signs: tachycardia, low BP evaporation ngayon or more insensible loss sa skin CNS signs: irritability, loss of consciousness Ø Chronic volume deficits Peritonitis, obstruction and prolonged surgery naman all causes Tissue signs (e.g. decrease in skin turgor and sunken edema. So same lang, may fluid loss kasi umalis tubig sa kung saan eyes), CV and CNS signs talaga papunta sa mga sites na yan. Skin turgor: pinch test Ø Laboratory Examination ECV EXCESS Elevated BUN level → reduced glomerular filtration. Ø Iatrogenic (drinking a lot of fluids) Hemoconcentration (Increased Hct) Ø Secondary to: Urine osmolality > serum osmolality Renal dysfunction (1,500/day) Low urine sodium (20 mEq/L excess Ø Urine osmolarity → 300 mOsm/L ↓ d. Mineralocorticoid excess Which of the following is a clinical manifestation of hypernatremia? So dito naman high water volume (hypervolemic) and high sodium a. Muscle cramping Lethargy (hypernatremia) and ang cause. b. Abnormal deep tendon reflex Iatrogenic = nilagyan ng sodium containing fluids. I Lethargy c. Example: excessive IVF d. Watery diarrhea Tandaan yung mga sakit na pwedeng mag cause nito tulad ng Cushing’s or kung ano ano pa kasi tinatanong yan sa exam. SYMPTOMATIC HYPERNATREMIA Which of the following is a cause of high Ø In patients with impaired thirst or restricted access to fluid. volume hypernatremia? Ø Thirst will result in increased water intake. a. Increased Water Intake X hypo Gluc exerts Cushing’s Syndrome b. Diabetes Insipidus hypo osmotic pressure SIGNS AND SYMPTOMS Ic. Cushing’s Syndrome ~ d. Postoperative Antidiuretic Hormone Ø Symptoms are rare until the serum Na is >160 mEq/L Secretion Ø Symptoms are related to hyperosmolarity → CNS effects hypo predominate. NORMOVOLEMIC HYPERNATREMIA Ø Hyperosmolar extracellular space → water moves out of Ø Renal causes → DI, diuretic use, and renal disease the cell → cellular dehydration → traction on the cerebral Ø Non-renal causes → GI tract or skin vessels → subarachnoid hemorrhage. Dito mataas sodium mo pero normal ang water, for example sa o CNS symptoms: restlessness and irritability to diuretic use, yung ibang diuretic na gamot sodium sparing at seizures, coma, and death nirerelease lang tubig. Ø Hypovolemic Hypernatremia → tachycardia, orthostasis, HYPOVOLEMIC HYPERNATREMIA and hypotension) may be present, as well as the unique Ø Urine sodium concentration → ?@ ST= >W XQ% LC Z@>[ \LM] K>WW D[ K@[ >[M naman they are given high solute contents so mataas din electrolytes, PQ% D[ ^LK@[ tapos low water dahil sa dialysis. KUMUNOY’S IMPROPERTY 7  BASIC SURGERY LECTURER: DR. JEREMY TAN Ø Rate of fluid administration Ø Increased release (mas tumaas extracellularly) Acute Symptomatic Hypernatremia → decrease in o Acidosis serum Na of no more than 1 mEq/h and 12 mEq/d. o Rapid rise of ECF osmolality (hyperglycemia or IV Chronic Hypernatremia → Even slower correction mannitol → shift of K+ to ECF) (0.7 mEq/h). Ø Impaired excretion § Overly rapid correction → cerebral edema o K-sparing diuretics, ACE inhibitors, NSAIDs and herniation. § Spironolactone and ACE inhibitors interfere with Ø Type of fluid used depends on the severity and ease of aldosterone activity, inhibiting normal renal K correction. excretion Oral or enteral replacement → acceptable in most o Renal insufficiency/failure (acute and chronic) cases. Ø SYMPTOMS IV replacement with half- or quarter-normal saline. o Primarily GI, neuromuscular, and cardiovascular o GI: nausea, vomiting, intestinal colic, and diarrhea NOTE o NM: range from weakness to ascending paralysis to Ø Caution also should be exercised when using 5% respiratory failure dextrose in water to avoid overly rapid correction. o CV: ECG changes and eventually to hemodynamic symptoms of arrhythmia and cardiac arrest Ø Frequent neurologic evaluation and frequent evaluation § ECG changes: high peaked T waves (early), of serum sodium levels also should be performed. widened QRS complex, flattened P wave, prolonged PR interval (first-degree block), sine wave COMPOSITION CHANGES: ETIOLOGY AND DIAGNOSIS formation, and ventricular fibrillation. POTASSIUM ABNORMALITIES Ø Treatment Ø Average dietary intake of K: 50-100 mEq/d o Goal: reduce total body K, shift K from the extracellular Ø Excretion: renal excretion (10-700 mEq/d) to the intracellular space, and protect the cells from its Ø Only 2% of the total body K (4.5 mEq/L × 14 L = 63 mEq) is effects in the extracellular compartment → critical to cardiac and o Exogenous sources of K should be removed neuromuscular function. (supplementation in IV fluids and enteral and Ø 98% of total body K is in the ICF parenteral solutions) Ø Potassium distribution is affected by surgical stress, injury, o Cation-exchange resin (e.g.Kayexalate) → binds K in acidosis, and tissue catabolism. (potassium nag leak to exchange for Na extracellular compartment) § Oral Kayexalate → 15-30g in 50-100mL of 20% sorbitol; Alert patients What is the average dietary intake of 50 to 100 § Rectal Kayexalate → 50g in 200mL 20% sorbitol potassium per day in mEq? o Immediate measures attempt to shift K intracellularly a. 25 to 50 b. 75 to 150 § Nebulized albuterol (10-20 mg) ↓ c. 50 to 100 d. 80 to 100 What is the normal range of serum 3.5 to 5.0 § Glucose → 1 ampule of D50 and regular insulin 5-10 units IV potassium in meq/L? § Bicarbonate → 1 ampule IV J a. 1.3 to 5.0 b. 3.5 to 5.0 § Use of glucose alone → rise in insulin secretion. This c. 2.5 to 5.3 d. 1.3 to 2.5 response may be blunted. Both glucose and insulin may be necessary HYPERKALEMIA § Circulatory overload and hypernatremia may be Ø Above the normal range of 3.5 to 5.0 mEq/L. due to administration of Kayexalate and Ø Causes bicarbonate → monitor patients with fragile cardiac o Excessive intake function o Oral or IV K supplementation) o When ECG changes are present o Blood transfusions § Immediate administration of CaCl2 or calcium o Endogenous load/destruction → hemolysis, gluconate (5–10 mL of 10% sol’n) to counteract rhabdomyolysis, crush injury, GI hemorrhage myocardial effects of hyperkalemia. KUMUNOY’S IMPROPERTY 8  BASIC SURGERY LECTURER: DR. JEREMY TAN Ø Calcium infusion is used cautiously in patients receiving § Asymptomatic, not tolerating enteral nutrition: digitalis → digitalis toxicity may be precipitated KCl 20 mEq IV q2h x 2 doses Ø Dialysis consideration for severe hyperkalemia when § Symptomatic: KCl 20mEq IV 1qh x 4 doses conservative measures fail. § Recheck K level 2h after end of infusion § If 4.8 mg/dL o Asymptomatic hypocalcemia → hypoproteinemia Ø Primary hyperparathyroidism results in a normal ionized calcium level Normal o Outpatient setting and malignancy in hospitalized o Symptoms can develop with a normal serum calcium ↓ patients ↑ PTH +Ca in blood level during alkalosis → decreased& ionized calcium o Bony metastasis or secretion of PTH–related protein → o NM and CV symptoms do not occur until the ionized most cases of symptomatic hypercalcemia & fraction falls 12 inversion, heart block, and ventricular fibrillation. mg/dL (CL: serum calcium - 15 mg/dL → may rapidly Ø Treatment progress to death o Asymptomatic hypocalcemia → oral or IV Ca o Initial treatment: repleting associated volume deficit o Acute symptomatic → IV 10% calcium gluconate to and then inducing a brisk diuresis with normal saline achieve a serum concentration of 7-9 mg/dL. o Deficits in Mg, K, and pH must also be corrected. HYPOCALCEMIA § Hypocalcemia will be refractory to treatment if Ø Serum Ca