Presentation on theme: "Intravenous Fluids Some slides were taken from:"— Presentation transcript:
1Intravenous Fluids Some slides were taken from: Fluid Management OnlineIntravenous Fluids: A Clinical ApproachJAI RADHAKRISHNAN, MDDivision of NephrologyA knowledge of the principles of Intravenous fluid therapy is central to the practice of inpatient medical management, no matter what the specialty of the practitioner. In this review, the physiological principles behind intravenous fluid prescription is discussed.Other references:The Washington Manual of Medical Therapeutics
2OutlineReview of normal physiology of fluid and electrolyte flux: Volume of distributionConcepts of osmolality and tonicityTypes of Intravenous FluidsComposition of IV FluidsTypes of fluid depletionSpecific clinical examples and treatment
3Composition of Body Fluids Total Body WaterMale: 60% Female: 50% Difference due to adiposityExtracellular Fluid %Plasma (intravascular) 25%Interstitial (extra-vascular) 75%Na, Cl, HCO3Intracellular Fluid %K, organic phosphate estersThus, sodium for volume, potassium for cell function!
4Volume of Distribution of Water Solids60%-Males50%-FemalesH2OTo begin this discussion, one needs to know what the volume of distribution of water is. Water accounts for 50% of total body weight in females and up to 60% in males. Thus if one administers 1 liter of water to a 70 kg female, it will be diluted 1 in 35 liters (total body water= 0.5 x body weight in females).
5H2O H2O Na Solids 40% of Wt Intracellular (2/3) Extracellular (1/3) Total body water is further divided in to 2 basic compartments: Intracellular (2/3) and extracellular (1/3). The cell membrane is freely permeable to water but dissolved electrolytes do not share the same permeability.Examples1. 5% Dextrose in water (D5W) is handled just as free water is (since dextrose is metabolized).2. Intravenous 0.9% saline (isotonic) does not diffuse through all compartments since the cell membrane is impermeable to sodium.3. If 1 liter 0.45% saline is administered, ½ behaves as free water and ½ as saline.Na
6E.C.F. COMPARTMENTS Interstitial 3/4 Intra-vascular1/4 H2O Na Na H2O Extracellular water is further divided into intravascular and extravascular (interstitial) compartments. The distribution of IV fluids may be further restricted by the capillary membrane, thus:5% albumin is restricted to the intravascular spaceIsotonic saline can easily cross the capillary membrane and disperse throughout the extravascular (interstitial) space.H2OH2ONaNaColloids & RBC
7“Third Space”Acute sequestration in a body compartment that is not in equilibrium with ECFExamples:Intestinal obstructionSevere pancreatitisPeritonitisMajor venous obstructionCapillary leak syndromeBurnsThird space (not intra- or extra-cellular) refers to collection of fluid (usually isotonic) that is sequestered in potential spaces. This situation is not normal and the fluid is derived from extracellular fluid.Since this fluid accumulates under conditions when patients are ill and thereby are not able to take in enough fluids, IV replacement frequently becomes necessary to prevent/treat extracellular volume depletion.
8Daily Fluid Balance Insensible Losses (approx 500mL) -Lungs 0.3L IntakeInsensible Losses(approx 500mL) -Lungs 0.3L-Sweat 0.1 LTo begin this discussion, one needs to know what the volume of distribution of water is. Water accounts for 50% of total body weight in females and up to 60% in males. Thus if one administers 1 liter of water to a 70 kg female, it will be diluted 1 in 35 liters (total body water= 0.5 x body weight in females).Urine: 1.0 to 1.5L
9Daily Fluid BalanceSum of the- Urine output (500-1,500 ml/day) necessary to excrete the daily solute load +- the insensible water losses from the skin and respiratory tract MINUS- Amount of water produced from the endogenous metabolism ( ml/day)[UO + Insensible water loss] – endogenous metab= [1, ] – 250 = 1750 mLIT IS NOT UNCOMMON TO ADMINISTER 2-3 LITERS WATER PER DAY TO PRODUCE A URINE VOLUME > ML/DAY
10More on Insensible Losses Insensible losses from skin and respiratory tract depend on respiratory rate, ambient temperature, humidity and body temperatureWater losses increase by ml/day for each degree of body temperatureFluid loss from sweating: highly variable (100- 2,000 mL/hour) depending on physical activity, ambient and body temperaturesMechanical ventilation with humidified gases may minimize losses from the respiratory tract
11Other causes of water loss Gastrointestinal Losses: vary in composition and volume depending on their sourceRenal losses of sodium are usually minimal, but maybe significant in diuretic therapy, recovery phase of acute tubular necrosis (ATN), post- obstructive diuresis or mineralocorticoid deficiencyRapid internal fluid shifts: peritonitis, pancreatitis, extensive burns, severe nephrotic syndrome, ileus or intestinal obstruction, crush injuries, rhabdomyolysis [3rd SPACING]
12MATH-70 kg male Total body water=60% body wt =0.6X70=42 liters ECF=1/3 ICF=2/30.6 X42=25 litersThis slide demonstrates the amount of fluid in each compartment in a hypothetical 70kg male.Blood=1/4 (ECF)0.25X13=3. 3 liters
13Principles of Treatment How much volume?Need to estimate the fluid deficitWhich fluid?Which fluid compartment is predominantly affected?Need evaluation of other acid/base/electrolyte/nutrition issues.
14Indications for Prescription of IV Fluids Highest prioritya) Defend haemodynamics1. Re-expand a severely contracted ECF volume2. Prevent a fall in BP when venous tone islow (e.g., anesthesia)b) Return the ICF volume towards normalb) Return the ICF volume towards normal1. Acute hyponatraemia that is symptomatic: Infusehypertonic saline to raise the PNa by 5 mM in 1–2 h2. Chronic hyponatraemia with a seizure: Infuse hypertonicsaline to raise the PNa by 5 mM, but maximum is 8 mM/day;3. Chronic asymptomatic hyponatraemi: Raise thePNa by up to 8 mM/day, slower rate if the PK is lowin a malnourished patient
15Indications for Prescription of IV Fluids Moderate priorityRe-expand a modestly contracted ECF volumeReplace ongoing lossesAvoid oliguriaGiving maintenance fluids to match insensible losses : Match estimated electrolyte-free water loss in sweat and in the GI tract2. To provide glucose as fuel for the brain e.g. during hypoglycemia
16The IV Fluid Supermarket CrystalloidsDextrose in waterD5WD10WD50WSalineIsotonic (0.9% or “normal”)Hypotonic (0.45%, 0.25%)HypertonicComboD5NM/D5NRD5NSSD10NSRinger’s lactate “physiologic” (K, HCO3, Mg, Ca)ColloidsAlbumin5% in NS25% (Salt Poor)DextransHydroxyethyl starch (HES); HetastarchHaemaccelGelofusineBloodA wide variety of fluids are available. In addition, one may need to make a customized solution starting with a base solution.It is important to note that some fluids when given inappropriately make cause complications:Giving Ringer’s lactate in a patient with renal failure may cause hyperkalemiaGiving hypotonic solutions to a patient with extracellular volume depletion (e.g post-surgical) may cause symptomatic hyponatremia.Giving high concentrations of dextrose to a diabetic, without insulin may cause osmotic diuresis and worsen extracellular volume depletion.
17Types of Intravenous Fluids 2 types of fluids that are used for intravenous infusions: crystalloids and colloids.Crystalloids are aqueous solutions of mineral salts or other water soluble molecules.Colloids contain larger insoluble molecules (particles suspended in solution), such as gelatin; blood itself is a colloid
18CrystalloidsIntravenous infusion fluids which are composed of solutions of crystalline substances, such as sodium chloride, potassium chloride or glucose.(Water and salts = water and electrolytes)
19What are Colloids?Colloid is the name given to a microparticulate dispersal of one substance in another.Colloid vs solution? Colloids are physically separable (they may be separated by ultra- filtration or centrifugation), whereas a solution requires chemical separation such as evaporation or chemical reaction (you cannot filter the sugar out of your tea, nor centrifuge it out).What differentiates a colloid from a mixture is that the dispersal is so fine that the particles are kept suspended in perpetuity by Brownian motion.
20Colloids in MedicineIn medicine, the term "colloids” refers to IV fluids formed by a colloidal suspension of large molecules in a water- or saline-based medium.Suspensions of macromolecules, usually in a saline medium.These may be physiological (such as 4.5% albumin), semi-synthetic such as succinylated gelatine (which in turn is solubilised bovine), or semi-synthetic such as hydroxyethyl starch
21ColloidsContain particles which do not readily cross semi-permeable membranes such as the capillary membraneThese large molecules tend to remain in the vascular compartment after infusion > exert an osmotic pressure which tends to keep water in the vascular compartment, thereby helping to expand the circulating blood volume and resist redistributionThus the volume infused stays (initially) almost entirely within the intravascular space
22ColloidsStay in the intravascular compartment for a prolonged period compared to crystalloidsHowever, leak out of the intravascular space when the capillary permeability significantly changes e.g. severe trauma or sepsis, burnsUntil recently they were regarded as the gold standard for intravascular resuscitation (see next slide)Because of their gelatinous properties they cause platelet dysfunction and interfere with fibrinolysis and coagulation factors (factor VIII) – thus they can cause significant coagulopathy in large volumes.
23Efficacy & Safety of Colloids Conflicting evidence about their efficacy;Consensus view: in acute volume replacement, they are no better than crystalloids, and may be harmful in some circumstances.Foreign proteins such as gelatin or HES may provoke anaphylaxis in rare circumstances.However, there are strong adherents to their use.
24Colloids versus Crystalloids Colloids preserve a high colloid osmotic pressure in the blood, while, on the other hand, this parameter is decreased by crystalloids due to hemodilution.However, there is still controversy to any actual difference in efficacy.Another difference is that crystalloids generally are much cheaper than colloids.
25Colloids versus Crystalloids for Fluid Resuscitation Evidence BaseColloids have no clinical advantage compared to crystalloids for fluid resuscitation in critically ill adult or childrenHypo-volemic patients given albumin instead of saline does not reduce mortalityAlbumin does not reduce mortality in critically ill patients with burns and hypo-albuminemia
26Colloids versus Crystalloids for Fluid Resuscitation In children with severe malaria, resuscitation with albumin has lower mortality than resuscitation with saline infusion or Gelofusine/ Gelafundin (HES)In critical traumatic brain injury treatment with albumin compared to saline is likely to be ineffective or harmfulintensive care serum albumin concentration is irrelevant, outcome is the same with saline or albumin
27Properties of IV Fluids The amount of solute in a solution influences two related, but subtly different properties: osmolality and tonicityOsmolality versus tonicityOsmolality refers to the amt of solute= solute or particle concentrationTonicity: osmotic effect of the solution in relation to another solution across a semi-permeable membrane.Osmolality is independent of the context whereasTonicity is defined relative to a reference point (usually blood or intracellular osmolality); dependent on whether the solute can pass freely through the cell membrane.
28Osmolality versus tonicity Solutes that are restricted to the ECF (Na+ and accompanying anions) or the ICF (K+ salts and organic phosphate esters) determine the effective osmolality or tonicity of the compartmentOsmolality and osmolarity are units of measurement.Osmolality is the number of osmoles of solute in a kilogram of solvent, while osmolarity is the number of osmoles of solute in a litre of solution.An osmole is one mole of any non-dissociable substance. It will contain 6.02 x 1023 particles.Osmolarity is the concentration of an osmotic solution. This is usually measured in osmoles. Osmolarity is also used to determine certain medical conditions, like the dissolved particles in urine. The volume of a solution will change with the addition of solutes, and also with any change in the temperature or pressure. Therefore, osmolarity is sometimes difficult to determine.Osmolality deals with the concentration of the particles that is dissolved in a fluid. In medical science, osmolality is used to determine several conditions like diabetes, dehydration and shock. For the detection of these conditions, the osmolality of the serum is checked, and is known as plasma osmolality. The concentration of the substances like chloride, sodium, potassium, glucose and urea are calculated.Read more: Difference Between Osmolality and Osmolarity | Difference Between | Osmolality vs Osmolarity
29TonicityA complex concept because cell permeability varies with cell type and circumstances.For example, in a non-diabetic, glucose is s rapidly transported into cells and so exerts little persisting osmotic effect, whereas in an insulin- deficient Type 1 diabetic glucose cannot enter the cells and remains in the intravascular space where it exerts a hypertonic effect.
30Tonicity and Osmolality Most solutions aim to be iso-osmolar to reduce osmotic damage to blood cells and irritation to the veinsHowever, a hyperosmolar solution such as 5% glucose with 20mmol KCl can actually be effectively hypotonic as the glucose is rapidly absorbed into the cells leaving only the 20mmol KCl and electrolyte-free water
31Water Balance [N] Plasma Osmolarity: 285-295 mOsm/kg Works within a narrow rangeSenses 1-2% tonicity changeTo achieve steady stateINTAKE should approximately equal EXCRETIONIntake regulated by thirst receptorsExcretion regulated by AVP
33CrystalloidsThe most commonly used crystalloid fluid is normal saline, a solution of sodium chloride at 0.9% concentration, which is close to the concentration in the blood (isotonic)Ringer’s lactate or Ringer's acetate is another isotonic solution often used for large-volume fluid replacement
34CrystalloidsA solution of 5% dextrose and water, sometimes called D5W, is often used instead if the patient is at risk for having low glucose or high sodiumThe choice of fluids may also depend on the chemical properties of the medications being given.
36Commonly Used Parenteral Solutions IV SolutionOsmolality (mOsm/kg)[Glucose](g/L)[Sodium] (mmol/L)[Cl-] (mmol/L)5% D/W2785010% D/W55610050% D/W27785000.45% NaCl *154-----770.9% NaCl*3083% NaCl1026513Lactated Ringer’s**274130109* also available with 5% dextrose** also contains 4 mmol K+, 1.5 mmol Ca++, 28 mmol lactate
37Saline solutions 0.9% Normal Saline – ‘Salt and water’ Principal fluid used for intravascular resuscitation & replacement of salt loss e.g diarrhea and vomitingContains: Na+ 154 mmol/l, K+ - Nil, Cl mmol/l; But K+ is often addedIsoOsmolar compared to normal plasmaDistribution: Stays almost entirely in the Extracellular spaceOf 1 litre – 750ml ECF; 250ml intravascular fluidSo for 100 ml blood loss – need to give 400ml normal saline [only 25% remains intravascular]
381 Liter 0.9% saline Total body water ECF=1 liter ICF=0 Interstitial=3/4 of ECF=750mlIsotonic (normal, 0.9%) saline is distributed in extracellular fluid since the cell membrane is not permeable to sodium.Thus, of 1 liter of NS in our hypothetical 70 kg male:250ml will remain in the intravascular space and the remainder 750ml will exit into the interstitial space.In a patient with shock from fluid depletion, 1 liter of intravascular saline = 4 liters total saline may be required to restore hemodynamicsIntravascular=1/4 ECF=250 ml
390.45 NSS= Half normal saline HYPOtonic salineReserved for severe hyperosmolar states (for maintenance fuids) e.g. H.H.S or DKA and severe dehydrationLeads to HYPOnatremia if plasma sodium is normalMay cause rapid reduction in serum sodium if used in excess or infused too rapidly. This may lead to cerebral edema and rarely, central pontine demyelinosis ; Use with caution!
40Hypertonic Saline 1.8, 3.0, 7.0, 7.5 and 10% Saline Reserved for plasma expansion with colloidsIn practice rarely used in general wards; Reserved for high dependency, specialist areasDistributed almost entirely in the ECF and intravascular space. This leads to an osmotic gradient between the ECF and ICF, causing passage of fluid into the EC space. This fluid distributes itself evenly across the ECF and intravascualr space, in turn leading to intravascular repletion.Large volumes will cause HYPERnatraemia and Intracelullar dehydration.
42Glucose solutions 5% Dextrose (often written D5W) – ‘Sugar and Water’ Primarily used to maintain water balance in patients who are not able to take anything by mouth;Commonly used post-operatively in conjunction with salt retaining fluids i.e salineProvides some calories [ 10% of daily requirements]Regarded as ‘electrolyte free’ – contains NO Sodium, Potassium, Chloride or Calcium
43D5W Distribution: <10% Intravascular; > 66% intracellular When infused is rapidly redistributed into the intracellular space; Less than 10% stays in the intravascular space therefore it is of limited use in fluid resuscitation.For every 100ml blood loss – need 1000ml dextrose replacement [10% retained in intravascular space]Common cause of iatrogenic hyponatremia in surgical patient
44Total body water=1 liter 1 liter 5% Dextrose (D5W)Total body water=1 literECF=1/3 = 300mlICF=2/3 = 700mlSolutions containing dextrose in water are handled like free water (although dextrose enters cells, it is metabolized).Thus 1 liter of D5W in a 70kg male will diffuse throughout body water60ml will remain in the intravascular space, 240 will be in interstitial fluid and,700ml will enter cellsDextrose in water is obviously not an efficient method to treat someone with shock.Intravascular=1/4 of ECF~75ml
451 Liter D5NM/D5NR Total body water ECF=1 liter ICF=0 Interstitial=3/4 of ECF=750mlIsotonic (normal, 0.9%) saline is distributed in extracellular fluid since the cell membrane is not permeable to sodium.Thus, of 1 liter of NS in our hypothetical 70 kg male:250ml will remain in the intravascular space and the remainder 750ml will exit into the interstitial space.In a patient with shock from fluid depletion, 1 liter of intravascular saline = 4 liters total saline may be required to restore hemodynamicsIntravascular=1/4 ECF=250 ml
46Colloid: 1 liter 5% Albumin 5% Albumin will remain in the intravascular space, at least acutely. It is the most efficient way to treat shock.However, this effect is not permanent and, paradoxically in patients who are hypoalbuminemic (cirrhosis, nephrotic syndrome), albumin eventually enters the interstitial space because the integrity of the capillary barrier is not intact.Intravascular=1 liter
47A Comparison of Albumin and Saline for Fluid Resuscitation in the Intensive Care Unit ABSTRACTBackground It remains uncertain whether the choice of resuscitation fluid for patients in intensive care units (ICUs) affects survival. We conducted a multicenter, randomized, double-blind trial to compare the effect of fluid resuscitation with albumin or saline on mortality in a heterogeneous population of patients in the ICU.Methods We randomly assigned patients who had been admitted to the ICU to receive either 4 percent albumin or normal saline for intravascular-fluid resuscitation during the next 28 days. The primary outcome measure was death from any cause during the 28-day period after randomization.Results Of the 6997 patients who underwent randomization, 3497 were assigned to receive albumin and 3500 to receive saline; the two groups had similar baseline characteristics. There were 726 deaths in the albumin group, as compared with 729 deaths in the saline group (relative risk of death, 0.99; 95 percent confidence interval, 0.91 to 1.09; P=0.87). The proportion of patients with new single-organ and multiple-organ failure was similar in the two groups (P=0.85). There were no significant differences between the groups in the mean (±SD) numbers of days spent in the ICU (6.5±6.6 in the albumin group and 6.2±6.2 in the saline group, P=0.44), days spent in the hospital (15.3±9.6 and 15.6±9.6, respectively; P=0.30), days of mechanical ventilation (4.5±6.1 and 4.3±5.7, respectively; P=0.74), or days of renal-replacement therapy (0.5±2.3 and 0.4±2.0, respectively; P=0.41).Conclusions In patients in the ICU, use of either 4 percent albumin or normal saline for fluid resuscitation results in similar outcomes at 28 days.N Engl J Med May 27;350(22):
48Volume Deficit-Clinical Types Total body water:Water loss (diabetes insipidus, osmotic diarrhea)Extracellular:Salt and water loss (secretory diarrhea, ascites, edema)Third spacingIntravascular:Acute hemorrhageFluid deficits may occur across all compartments, or may occur in any one of them:Water loss (dehydration) depletes all compartments equally. This leads to hypernatremic dehydration.Common examples include diabetes insipidus, osmotic diuresis (e.g. uncontrolled hyperglycemia), osmotic diarrheas.A tendency towards hypernatremia is usually followed by intense thirst and rapid restoration of the fluid deficit. However, when access to free water is restricted (demented or ventilated patients), hypernatremic dehydration develops.2. Salt and water loss (isotonic loss) may lead to depletion of extracellular fluid.Examples include burns, ascites, secretory diarrheas (cholera), diuretic therapy and third spacing.3. Intravascular fluid loss is seen with acute hemorrhage
49Clinical Diagnosis Intravascular depletion Hemodynamic effects BP HR JVPCool extremitiesReduced sweatingDry mucus membranesThe physical examination is the cornerstone for diagnosing fluid deficits.With dehydration (free water deficit), thirst and hypernatremia may be the only manifestations.With intravascular depletion (e.g. hemorrhage) hemodynamic effects are predominantIntitially postural hypotension,then supine hypotension. Flat jugular veins.Sympathetic stimulation leads to peripheral vasoconstriction and decreaesd axillary sweating and dry mucus membranes.With extracellular fluid depletion, a decrease in body weight precedes physical signs such as decreased skin turgor and sunken eyeballs. With ongoing losses, hemodynamic effects (as described above) superveneE.C.F. depletionSkin turgor, sunken eyeballsWeightHemodynamic effectsWater DepletionThirst Hypernatremia
50Example- GI BleedA 55 year old patient presents with massive hematemesis (vomiting blood) x 1 hour. He has a history of peptic ulcer disease.Exam: Diaphoretic, normal skin turgor.Supine BP: 120/70 HR 100Sitting BP: 90/50 HR=140Lab: Serum Na=140What is the nature of his fluid deficit ?What IV fluid resuscitation would you prescribe ?What do you expect the hematocrit to be :- at presentation ?- after 12 hours of Normal Saline treatment?
51Example-Diarrhea and Vomiting A 23 year old previously healthy medical student returns from vacation in Boracay with a healthy tan and severe diarrhea and vomiting x 48 hours.Sunken eyeballs, poor skin turgor and dry mucus membranesBP 80/70 HR 130 supine.Labs: Na 130 K=2.8HCO3 =12ABG: 7.26/26/100What is the nature of his fluid deficit ?What fluid will you prescribe ?What would happen if D5W were to be used?There is severe extracellular fluid depletion.In addition, because of GI losses, the patient has low potassium, and bicarbonate.Hyponatremia is present because of free water intake in the presence of elevated ADH levels (from hypovolemia).Isotonic saline or Ringer’s lactate will be useful here.Remember to independently correct the potassium deficit (which may be > 100meq)
52Example-Hyperosmolar State An 85 year old nursing home resident with dementia, and known diabetes was admitted with confusion.Exam: Disoriented, restless initially; then stuporousBP: 110/70 supine 90/70 sitting. Decreased skin turgor.Labs: Na= 150meq/L Wt=50kgsBUN/Cr=50/1.8 = 27Blood sugar= 1200 mg/dl Hct=45What is the pathogenesis of her fluid and electrolyte disorder ?How would you treat her ?
53Calculation of Water Deficit HealthyDehydratedOsm (P Na) x volumeOsm (P Na) x volumeA 50 kg female with Na=150Na x Normal Body Water = Na x Current Body Water(140) (NBW?) = 150 x (0.5 x 50=25 liters)NBW (X) = 26.8 litersWater deficit = NBW-CBW= =1.8 litersThe basis of calculating free water deficit lies in the fact that the product of osmolality and volume in extracellular fluid is constant.Thus, when there is loss of free water, there is an increase in extracellular fluid osmolarity (reflected in the serum sodium).Known parameters:Current serum NaCurrent body water (½ body weight)Serum Na in normal circumstancesFrom the equation PNa x volume (healthy) = PNa x volume (healthy), we can calculate the body water (dehydrated)The water deficit is the difference (healthy – dehydrated).
54A CirrhoticA 40-year-old patient with known alcoholic cirrhosis, portal hypertension and ascites is admitted with a rising creatinine.Exam: BP 100/70 (no orthostasis), JVP 5cms, +++ascites, no peripheral edema, +asterixis.BUN=12mg/dL Creat=2mg/dL Alb=2.0g/dLUrine volume has been 200cc/24h.Comment on his fluid statusIf volume-depleted how would you treat him?A very difficult situation:There is intravascular volume depletion because Starling forces are reversed:Increase portal vein (hydrostatic) pressureDecreased colloid osmotic pressure from hypoalbuminemia.Although intravascularly volume depleted, saline will cause temporary restoration of intravascular volume. In a short time, this saline will extravasate into ascitic fluid and worsen peripheral edema. Intravenous albumin, too, is effective transiently, as the half life in cirrhotics is markedly reduced.
55Example-Post Op Abdominal Distension A 60 year old male with pancreatic carcinoma has undergone total pancreaticoduodenectomy and gastrojejunal bypass.On post-operative day-3 he develops abdominal distension.BP= 110/60 and HR increases from 100 to 130 on sitting. Bowel sounds are absent.Abd XRay reveals multiple fluid levels in the abdomen. N-G suction is initiated.This patient has “third spacing”; ECF is being driven into dilated intestinal loops leading to progressive ECF depletion.The treatment is to institute nasogastric suction and replace losses with isotonic saline or Ringer’s lactate.What is the nature of his fluid deficit ?How will you treat ?
56Example-Intubated ptA 64 year old male with severe pneumonia has just been intubated. You were asked to give IVF orders since he has several IV meds.BP= 120/70 and HR – 91 bpmPlasma sodium = 128 mmol/LPotassium – 3.6 mmol/LAdequate urine outputIs there a fluid deficit ?What will be your IVF order ?While he is still NPO?On NGT OF feeding?
57Case scenariosUnconscious 25 year old, previously healthy, found inside a locked roomUnconscious, known diabetic, diaphoretic, tachycardic, afebrile, BP= 150/90 mm HgPt with a Stab wound on the abdomen, BP=80/60 mm Hg, awake, restlessIVF to follow for a patient with urosepsis, sodium is 150 mmol/L, weak, BP= 100/70 mm Hg
58A Nutritional Dilemma **Use D10W-NS instead** The patient is being treated with 100ml/hour(5% dextrose in 0.9% saline)Is the caloric supply adequate ?Total volume=100mlx24h=2400mlTotal dextrose (5g/100ml)= 5x24=120g/dayTotal calories=120g x 4kcals/g=480 kcals.**Use D10W-NS instead**
59ConclusionsCrystalloids are generally adequate for most situations needing fluid management.The composition of the solution and rate of administration are important when addressing a specific situation.Colloids may be indicated when more rapid hemodynamic equilibration is required (inadequate data).