2011-08-Surgery-Body Fluids Composition, Volume Deficit and Fluid Resuscitation

Case 1:A 27 year old male patient, weighing 65 kg., is admitted due to right upper quadrant pain, with a

diagnosis of acute cholecystitis. He undergoes cholecystectomy. After the operation, he was place on NPO.

Compute for the following:1. Total Body Water

a. TBW = body wt. (kg) x 60% = 65 kg. x 60% = 39 L2. Extracellular Fluid Volume

a. ECF Volume = body wt. (kg) x 20% = 65 kg. x 20% = 13 L3. Intracellular Fluid Volume

a. ICF Volume = body wt. (kg) x 40% = 65 kg. x 40% = 26 L4. Intravascular Fluid Volume / Plasma

a. Body wt. (kg) x 5% = 65 kg. x 5% = 3.25 L5. Extravascular Extracellular Fluid Volume / Interstitial

a. Body wt. (kg) x 15% = 65 kg. x 15% = 9.75 L

Note: In Schwartz’s it says that the ECF is 1/3 of the TBW while the ICF is 2/3. This poses no problem when the patient is a male since in males 1/3 of the TBW=20% of Total Body Weight and 2/3 of the TBW=40% of the Total Body Weight. However in females this is not true (as you no doubt have seen in page 52 of Schwartz’s); 1/3 of the TBW is not equal to 20% of Total Body Weight and 2/3 of the TBW is not equal to 40% of the Total Body Weight for females. This is why Dr. Versoza advised us to stick to the 20% and 40%/30%.

Objectives:1. To understand fluid distribution in the body according to the various compartments.2. To understand the clinical features of fluid derangement following various surgical conditions.3. To understand the concepts of fluid resuscitation in these surgical conditions.

Importance:1. Fluid replacement is one of the things that are ordered first by physicians.2. One of the most common causes of negligence in hospitals is attributable to a physician not

knowing how to compute for the appropriate amount of fluid to give to a patient. This may lead to volume overload, eventually causing cardiac failure.

Determinants of TBW:1. Sex (M/F)2. Weight

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Subject: SurgeryTopic: Body Fluids: Composition, Volume Deficit & Fluid ResuscitationLecturer: Dr. Jesus L. Versoza Jr. MD, DPBS, FPCSDate of Lecture: July 26, 2011Transcriptionist: Maebritt & JCEditor: JCPages: 10

Table 1. Functional Compartments of Body Fluids

Fluid Male FemaleTotal Body Water 60% 50%Extracellular Fluid

Blood volume Plasma

Cell mass Interstitial

20% 8%

5 % 3%

15%

20% 8%

5% 3%

15%Intracellular 20% 30%

Extracellular fluid volume has 2 components: Plasma / Intravascular fluid, which is 5% of the total body weight, and Interstitial fluid, which is 15%. The values of these components are the same for both males and females.

The Interstitial fluid compartment is the compartment most often affected by various surgical conditions. Fluid derangements in this compartment are referred to as “Third Spacing”. Third spacing is given more specific names on the basis of where they occur, e.g. ascites is the abdomen.

The volume of the Intracellular fluid compartment is different in males and in females. This is due to males having more muscle mass than females, since most of the Intracellular fluid can be found within muscles. Males are assumed to be more muscular because they secrete more androgens, particularly testosterone; higher testosterone levels usually equates with higher muscle mass in males. Females, on the other hand, secrete more estrogen; estrogen facilitates fat deposition.

Blood is made up of Plasma and Formed elements, which includes WBC, RBC and platelets. Since plasma is 5% of the total body weight and fluid volume within the formed elements of blood (i.e. Cell Mass) is 3% of the total body weight, the Blood Volume is 8% of the total body weight. Changes in vital signs are often dependent on the amount of blood a patient will lose. For example, if a girl, who weighs 30kg (2.4 L blood volume) and a man who weighs 100 kg (8L blood volume) got into a car accident and lost 1 L of blood, the girl is more likely to be more compromised than the man because the man has a greater blood volume.Neonates contain more water than adults: 75-80% water with proportionately more extracellular fluid (ECF) than adults. At birth, the amount of interstitial fluid is proportionally three times larger than in an adult. By the age of 12 months, this has decreased to 60% which is the adult value.Total body water as a percentage of total body weight decreases progressively with increasing age. By the age of 60 years, total body water (TBW) has decreased to only 50% of total body weight in males mostly due to an increase in adipose tissue.

Table 2. Distribution of Normal Fluid and ElectrolyteLosses and Requirements

Substance Total Losses Requirement/24 hr( Per kg/BW)Water 2300-2600 ml 35.0 ml

Sodium (major extracellular cation)

80-100 mEq 1.0 mEq

Potassium (major intracellular cation)

80-100 mEq 1.0 mEq

Chloride (major extracellular anion)

100-150 mEq 1.5 mEq

Bicarbonate (major intracellular anion)

- 0.5 mEq

Table 3. Sources of Normal Fluid and Electrolyte LossesSources Insensible or Sensible Losses/24 hrs.?

Urine 1200-1500 ml (25 ml./kg BW)Skin 200-400 ml (10 ml./kg BW)

Lungs 500-700 ml (10.5 ml./kg BW)Feces 100-200 ml

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In total, you are losing about 2-2.5 Liters a day. Insensible losses are normal losses. It is from the urine that majority of our fluid losses come from (obviously), however fluid can also be lost from the body through other means like perspiration through the skin, evaporation of fluid found in the respiratory passages (which increases when one is hyperventilating), and the small amount of fluid that is lost whenever we defecate. A patient who is hooked to a mechanical ventilator will have more insensible fluid losses through the lungs, one who is at the desert or is highly febrile through the skin and someone who’s diarrheic through the feces. Conditions that cause increased urination, such as Diabetes Insipidus or Diabetes Mellitus, do not contribute to Insensible fluid losses. These cause pathologic fluid losses.

Table 4. Electrolyte Composition of Body FluidsParameters used to determine what type of fluid to give for a particular form of fluid loss.

Ways to determine hydration status of patient:1) Physical Examination – Subjective data2) Laboratory Findings - Objective data

Physical Examination (subjective):a. Skin turgor – Assessed by pinching the patient’s skin. Loss of elasticity indicates dehydration.b. Moistness of mucous membrane* – lips, gingiva and buccal mucosa, tongue; dryness indicates

dehydration.c. Venous fillingd. Blood pressure and pulsee. Ocular tensionf. Urine output (1-2 ml/kg/hr) – most important parameter in determining hydration statusg. Weight

*This is not 100% reliable. For example, a patient who is talkative is expected to have a dry mouth even though he’s not dehydrated.

Normal urine output is 1-2ml/kg/hr. Example: A girl weighing 30kg, is expected to void 30cc of urine/hr. In 24 hrs, her normal urine output would be 30cc x 24 = 720cc/day.

Note: Bates’ page 6 says that subjective data is what the patient tells you, which is essentially the History, from the Chief Complaint to the Review of Systems. In contrast objective data is what you detect during the examination and includes all physical examination findings

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Substance Na+ K+ H+

Cl - HCO3-

Plasma 142 4.5 - 100 25

Gastric Juice 45 30 70 120 25

Intestinal Juice Bile Pancreatic Juice

120140130

205

15

--

110--

304080

Laboratory (objective):a. Hematocrit b. Urine specific gravityc. BUN/Creatinine d. Urine and serum sodiume. Central venous pressure – cathether is inserted to the brachial plexus, pass though the vena

cava, until to the right side of the heart.f. Pulmonary capillary wedge pressure

Measured by wedging a pulmonary catheter with an inflated balloon into a small pulmonary arterial branch.

Most accurate way of determining hydration because it measures the left side of the heart. Measuring the left side of the heart allows one to measure the cardiac output, giving him an idea of what the total volume of the patient is.

If determination of the Pulmonary Capillary Wedge Pressure is no possible, the next best laboratory value that should be determined would be the Central Venous Pressure (CVP), which measures the pressure within the right side of the heart. The only problem with CVP is that other conditions (e.g bronchectiasis, cor pulmonale) may cause an increase in the CVP. In PCWP results remain constant regardless of the disease of the patient, unless there is a change in body fluid or TBW.

Pulmonary Wedge Capillary Pressure: Central Venous Pressure:

Principles of managing fluid, electrolyte, acid-base imbalances

a. Correct shock and restore blood volume to normal:b. Restore colloid osmotic pressurec. Correct acid-base imbalanced. Restore blood osmolality e. Correct electrolyte deficitsf. Establish F/E daily maintenanceg. Establish daily caloric maintenance

Basic categories of fluid and electrolyte disorders:1. Alterations in volume

a. volume excess b. volume deficit – more commonly encountered in the surgical setting

2. Alterations in osmolality or solute concentrationa. hyponatremia b. hypernatremia

3. Composition abnormalities 4. Alterations in acid-base balance

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This is an example of alteration in volume: volume deficit. Rupture of the inflamed appendix, as can be seen here, has led to the edema of the small intestine (as evidenced by its shininess). Fluid that has caused the swelling is from the interstitial fluid compartment resulting in a depletion of the amount of fluid normally present in this compartment.

This is an example of volume deficit resulting from acute blood loss. The patient has a gunshot wound that has resulted in a hemothorax. Blood is being evacuated from the pleural cavity.

This is an example of a volume deficit resulting from a 3rd degree burn. This leads to loss of fluid and colloid through skin.

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This is an example of volume deficit from an acute blood loss. The patient is exhibiting the Grey Turner’s Sign i.e., bluish discoloration of the flanks indicating an intra-abdominal hemorrhage.

This is an example of volume deficit resulting from edema of incarcerated bowels.

Table 5. Volume Deficit (Hypovolemia)

Type of dehydration Definition Results from: Ideal Replacement

Isotonichypohydration

Proportionate loss of water and salt, most common type of deficit.

GI losses without renal compensation

Sweating not compensated by adequate hypotonic fluid replacement

Vomiting Losses from gastric

tubes

Isotonic salt solutions

Hypertonic hypohydration –

majority of medicine patients present with

this.

Loss of water in excess of salt; more water is lost as compared to salt.

Diarrhea (i.e. cholera) Inadequate water intake Corticosteroid therapy Diabetes insipidus Late phase of burns-

after 48 hours, there is evaporation from the burn area.

Hypotonic salt solution (more water but less salt)

Hypotonic hypohydration –

majority of surgical patients present with

this.

Loss of salt in excess of water; more salt is lost as compared to water.

GI losses Addison’s disease Excessive diuretic

therapy Extravasation of fluid (ex.

Early phase of burns, ascites, peritonitis) Acute blood loss Hypoalbuminemia

Hypertonic salt solution (more electrolytes than water)

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Degree of hypovolemia:1. Mild

lose of 4% total body water(TBW), manifested by thirst

2. Moderate lose of 8% of the TBW; manifested by:

o marked thirst o no groin or axillary sweato loss of skin turgor

3. Severe lose of 10% TBW; manifested by:

o marked hypotension, o confusiono delirium

Degree of hypovolemia (in terms of blood volume):

1. Mild lose of 10% total blood volume(TBV), manifested by thirst

2. Moderate lose of 20% of the TBV; manifested by marked thirst tachycardia

3. Severe lose of 30% TBV; manifested by marked hypotension confusion delirium

Type of fluid deficit correction:

1. Maintenance therapy - normal requirements in the absence of abnormal losses (physiologic losses from urine, sweat, etc.). In other words, dealing with fluids lost normally.

2. Replacement therapy – includes not only those needed to replace insensible fluid losses but also those needed to replace abnormal (continuing) losses from the body (ex. via NGT, GI fistula, diarrhea, febrile etc.).

Fluid Correction based on the following criteria:

1. Weight: especially for children (<10) and elderly (>70 y.o)

1st 10 kg. BW = 100 mL/kg.2nd 10 kg. BW = 50 mL/kg.Additional kg. BW = 20 mL/kg.

2. Temperature:Maintenance therapy + (10% X difference in temperature X Maintenance therapy)

3. Type/amount of losses

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Signifies decrease in blood volume; not enough blood is getting to the heart to be pumped hence not enough blood reaches the brain.

Table 6. Commercially available Intravenous Fluids (IVF and their composition)

Solution Na+ K+(in mEq) Ca++ Mg+ Cl-a. Lactated

Ringer’s130 4 3 - 109

b. Normosol R 140 13 - 3 98c. Normosol M 40 13 - 3 40d. 0.45 NaCl 51 - - - 51e. 0.45 NaCl 77 - - - 77f. 0.9 NSS or

NaCl154 - - - 154

A, B and F are hypertonic solutions or crystalloids while the rest are isotonic solutions. NOTE: WHAT WILL FOLLOW IS A VERY CONFUSING DISCUSSION ON HOW TO DETERMINE IF A

SOLUTION IS HYPOTONIC OR ISOTONIC. To determine the range of Sodium concentrations that is considered isotonic, divide 130 (I think this is from the sodium concentration of Lactated Ringer’s above) by 2. This will give you 65. Thus anything having a sodium concentration of 60-70 mEq is considered isotonic while those having concentrations of 50 mEq and below are considered hypotonic (I don’t know how he was able to make this connection he just said that it was so)

Ideal replacement for acute blood loss (see table 5): hypertonic salt solution Ideal replacement for GI losses without renal compensation (see table 5): isotonic solution

specifically 0.5 Nacl or D5.45 NaCl; If the patient has diarrhea of cholera type, the ideal IVF would be the hypotonic salt solution

D5.3 Remember: D5.9 is hypertonic; D 5.45 is isotonic ; and D5.3 is hypotonic; D means Dextrose There are instances that you must not give a solution with dextrose, like in patients with

Diabetes.

Note: This is taken from http://members.efn.org/~nurses/IVF.html0.9% NaCl (normal saline)  isotonic 0.25% NaCl  hypotonic 0.45% NaCl  hypotonic 2.5% dextrose  hypotonic Lactated Ringer's solution  isotonic D5W (acts as a hypotonic solution in body)

 isotonic

 D5 NaCl  hypertonic D5 in Lactated Ringer's  hypertonic D5 0.45% NaCl  hypertonic

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Case no. 265 kg. male with elective cholecystectomy, no nasogastric tube, placed on NPO

TBW = wt. (kg.) X 60% = 65 kg. X .60 = 39 litersECF = wt. (kg.) X 20% = 65 kg. X .20 = 13 litersICF = wt. (kg.) X 30% = 65 kg. X .40 = 26 litersTBV = wt. (kg.) X 8 % = 65 kg. X .08 = 5.2 liters Maintenance therapy: 35 ml./kg. X 65 kg. = 2275 ml./dayElectrolyte replacement:Na = 1 meq/kg. K = 1meq/kg. Cl = 1.5 meq/kg

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CONSTANT IF COMPUTING FOR MAINTENANCE THERAPY

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Case no. 3Same patient in Case no. 1 but develops ileus w/ NGT output of 1600 mL bile stained

Compute for the following:

1. Replacement and maintenance therapy:= maintenance + output =2275 ml. ( see above answer for maintenance) + 1600 ml. (replacement)= 3875 mL/day; because you need to maintain the fluid loss normally and at the

same time you need to replace what is abnormally lost!

2. Electrolyte replacement:Na = 1 meq/kg K = 2-3 meq/kg Cl = 1.5 meq/kg

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Case no. 4Same patient but develops atelectasis, with temperature a 39.0 C

Compute for the following:

1. Replacement and maintenance therapy:= Maintenance therapy + 10% [temp. difference X maintenance therapy] = 2275 ml. (maintenance) + 10% [(39.0 C - 37.0 C) x 2275]=2275 ml + [10% (2x 2275)]= 2275 + 455= 2730 mL/ 24 hrs.

Note: Patients that have abnormal loss of fluid through the lungs (i.e. from ventilator use) are given a constant volume of 1 Liter in addition to their maintenance therapy volume. This 1 Liter is good for 24 hours.

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Case no. 550 y/o male, 60 kg., (+) Peptic Ulcer Disease, w/ continuous vomiting. NGT output 2500

ml./24 hr.

Compute for the following:

1. TBW: wt.(kg.) X 60% = 60 x .60 = 36 liters2. ECF: wt.(kg.) X 20% = 60 X .20 = 12 liters3. ICF: wt.(Kg.) X 40% = 60 X .40 = 24 liters 4. Replacement and maintenance therapy:

=2100 ml. (maintenance) + 2500 ml. (replacement)= 4600 ml./day

5. Electrolyte Imbalance : hypochloremic, hypokalemic, metabolic alkalosis due to loss of HCl (if there is closure of the pylorus, a.k.a gastric outlet obstruction)

In PUD, if the patient’s pylorus is not closed and he vomits a lot, there is an equal loss of electrolytes. But, if patient’s pylorus closes (as a result of fibrosis) and he vomits a lot, he loses a lot of gastric juices, particularly HCl acid. Loss of acid results in alkalosis. In order to prevent death due to severe alkalosis the body will try to save H+ in exchange for K+. Thus in addition to hypochloremia, patient will also exhibit hypokalemia.

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The IVF needed is D5 NSS ( D5.9 NaCl ). You cannot give KCl to the patient because KCl (bolus), which incidentally is given for lethal injection, causes cardiac stand still. Thus, to correct the electrolyte derangement you need to give NaCl. The Cl- portion of NaCl will correct the hypochloremia. And by giving Na+ in excessive amounts, the kidneys will spare K+ by expelling Na+ in its place. Thus hypochloremia, hypokalemia and metabolic alkalosis are corrected

----------------------------------------------------------------------------------------------------------------------------------------“RULE OF NINES” IN ESTIMATING TBSA

Rule of nines is used for burns. This will be lectured next semester but Dr. Versoza asked us to still take note of this. Replacement depends on the burned area.

(Doc didn’t explain this thoroughly)

PARKLAND FORMULA FOR ESTIMATING FLUID RESUSCITATION TOTAL FLUID REQUIREMENT : WT.(Kg.) x %BURNS x 3-4 ml.

1st 24 hours: Lactated Ringer’s solution half of total fluidrequirement during first 8 hours, half of remainingfluid during last 16 hours

2nd 24 hours: Colloid solution at 250 ml. For each 10% burnsover 20%

D5 Water to maintain sodium at 140 meq/L

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