Fluid and Electrolytes Flashcards
Vascular Access Overview
- Required to administer IV fluids and medications
- Useful in obtaining blood sampling for lab tests
- Types of access depends on medications that need to be administered and anticipated length of use
- Central vs. peripheral
- Vascular acces can be utilized for invasive monitoring in critically ill patients
Peripheral catheters
Complications?
- Most commonly used catheter in the acute care setting
- Usually placed in a vein of the hand or arm, placed distally if possible
- CDC Guidelines recommend changing of catheter every 96 hours
- Infection, Phlebitis, Extravasation, Infiltration, Air embolism, Hemorrhage, Hematoma
Peripherally Inserted Central Catheters (PICC)
- Good for patietns who are staying long IV acces
- Alternative to Subclav lines, internal jugular lines or femoral lines, which have higher rates of infection
- Insertions requires specialised training
- Complications
- Catheter occlusion, phlebitis, hemorrhage, thrombosis, infection
Central Venous Catheters
- Allows administrations of large volumes of fluid, blood products, TPN, caustics, vasopressors, chemo
- Capabe of monitoring hemodynamics CVP
- Placed into a large vein in the neck (internal jugular vein). chest or groin
- Complications
- Pneumothorax, Thrombosis, Infections, Air embolism
Intraosseous
- Entry into the bone marrow to provide a non-collapsible entry point into the systemic venous system
- Any medication that can be administered via IV can be administered via IO
- Useful in emergency situations when IV access cannot be obtained
- Requires specialized training
- EM nurses, EMT
- Can be utilized for ~24 hours
- Complicatons
- Fat embolism, fracture, osteomyelitis, compartment syndrome, Abscess, skin necrosis
Complications of IV therapy
- Infiltration
- Non-vesicant fluid leaks into surrounding tissue
- Infections
- Punture interrupts skin integrity
- Phlebitis
- Inflammation of the vein
- Thromophlebitis
- Irritation of vein with clot formation
- Extravascation
- Leakage of vesicant fluid into surrounding tissue
Comparison fo Options for Vascular Access
Total Body Water
1 liter of fluid =?
70 kg male =
- For clinical purposes, total body fluids = 60% body weight for adults
- Percent decreases as body fat increases
- decreases with Age
- For calculations, use hydrated (normal) weight unless patient is obese (>20% of IBW) use IBW
- 2.2Ibs(1 kg)
- 42 liters
Intracellular fluid
- Water within cells
- 2/3 of TBW
- 40% of body weight
- Rich in electrolytes
- K, Mg, Phosphates, Proteins
Extracellular fluid (ECF)
- Fluid outside cell
- Rich in Sodium, Chloride, bicarb
- 1/3 of TBW
- Made up of two major fluid sub compartements
- Interstitual/ lymph
- Fluid space between cells
- Intravascular
- Interstitual/ lymph
Fluids, Electrolytes, Acid-Base losses
- Sensible
- Urine, stool
- Water, sodium, K
- Insensible
- Lung, evaporation through skin, fever
- Mostly water and a little Na+
- Other
- Nasogastric tube suction
- Nasojejunal tubes
- Drains
- Fistula tracts
- Burns
Intravascular Depletion Acute problem
Signs/Symptoms and causes
TBW depletion Chronic problem
Replacement therapy Determining the Needs
- Ongoing exceptional loss
- If ongoing problems are not accounted for, a second insufficiency will develop soon after correction of the current deficiency
- Replacement regimen should match as closely as possible both the amount and composition of the exceptional losses
- At minimum, realize that exceptional fluid losses maybe be occuring and be particularly vigilant to monitor these patients for S/S of fluid depletion
Maintenance Basal Requirements
Neonate (1-10 kg)
Child (10-20)
Adults > 20
- 100 ml/kg
- 1000 ml + 50 ml for each kg > 10
- 1500 mL + 20 ml for each kg >20 ‘
- For sensible losses in hospitalized pts not taking much PO
Isotonic fluids
(310 mEq/L)
fluid doesnt shift from ECF to ICF
Hypertonic > 376 can help?
Draws water out of cells into ECF
Help stabalize bp, increase urine output, and reduce edema
Hypotonic < 250
Water is pulled from vascular compartments into interstitial fluid is diluted
Crystalloid solutions
- Electrolyte solutions supply water and sodium to maintain the osmotic gradient between ICF and ECF
- Plamsa volume- expanding capability of crystalloid is directly related to its sodium concentration
- D5W: Free water
IV fluid comparisons
IV fluid comparisons continued
Choice of approptiate fluid?
Define?
Pts with impaired tissue perfusion?
Standard therapy?
- Define primary type of fluid problem
- TBW depletion vs. ECF depletion
- ITP- immediate therpeutic goal
- Return volume to intravascular space and ECF compartment
- Standard therapy is to administer normal saline quickly (150-500 mL/hr) until S/S of impaired tissue perfusion have minimized or disappeared
- Pt may be switched to a more hypotonic solution
In pts demonstrating impaired tissue perfusion?
- LR is an alternative, however, lactate may be problematic during massive prolonged infusions
- In severe cases, a solution may be indicated that increases in oncotic pressire within the vasculature space
- Colloid
- blood cells (specially indacted if oxygen-carrying capacity of blood is compromised)
In patients with elevated plasma osmolarity and serum sodium concentrations
- In patients demonstrating elevated plasma osmolality and serum sodium concentrations
- Virtually always have a water-deficit problem and, in the absence of S/S of impaired tissue perfusion, primarily need hydration (water) therapy
- Hypotonic solutions: more efficient at replenishing the ICF than do isotonic solutions and reduce the plasma osmolality more quickly
- Solution should have a lower sodium concentration than the patient’s serum, but do not drop the serum sodium too quickly (CAUTION - cerebral edema)
- D5½ NS is a commonly-used general rehydration solution; hypertonic or colloidal solutions have no role in treating TBW depletion
Monitoring therapy
Parameters?
Therapuetic goal: resolve S/S of fluid deficit and normalize lab values as much as possible
- Physical S/S (thirst, sunken fontanelles, CNS problems)
- Orthostatic blood pressure
- Pulse rate
- Wt changes
- Blood chnages
- Blood chemistries
- FLuid input vs. fluid output
- CVP, PCWP, cardiac output (ICU pts)
Monitoring therapy?
Replenish fluids ______ in conditions that may?
Failure?
- more cautiously in conditions that may predispose a pt to fluid overload
- Renal failure
- Cardiac failure
- Hepatic failure
- Elderly
Fluid deficiency summary?
Summary - fluid overload
- Excess intake
- Excess IV fluids
- Blood/plasma use
- hypertonic fluids
- Excess dietary sodium
- Water intoxication
- Remobilization of edema
- Inadequate Output
- CHF
- Cirrhosis
- Nephrotic syndrome
- Hyperaldosteronism
- Low dietart protein
- Steroid use