Cellular Environment 2023 PDF
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Uploaded by ComprehensiveMagnolia
Moreno Valley College
2023
Steve Casarez
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Summary
This document provides an overview of cellular environments, including intracellular and extracellular fluids, plasma, interstitial fluid, and alterations in fluid movements. The presentation also describes different types of fluid, osmosis, diffusion, and mediated transport. It covers various related concepts such as hydrostatic pressure, oncotic pressure, and osmotic pressure.
Full Transcript
By Steve Casarez RN, MICN, Paramedic Update 2023 ▪ Needs a functioning system to distribute nutrients to the right place so it can carry out its duties and functions. Intracellular (ICF) Fluid inside the cell Extracellular (ECF) Fluid outside the cell. There are two types: 1. Intr...
By Steve Casarez RN, MICN, Paramedic Update 2023 ▪ Needs a functioning system to distribute nutrients to the right place so it can carry out its duties and functions. Intracellular (ICF) Fluid inside the cell Extracellular (ECF) Fluid outside the cell. There are two types: 1. Intravascular Fluid in arteries and veins carrying plasma, blood products, and nutrients. 2. Interstitial Fluid or 3rd Space commonly seen as Edema Both ICF and ECF should have the same concentration or (Osmolarity). Permeable Membranes are: ▪ A delicate membrane that separates the two and allows fluid to move in and out. Extracellular Fluid Intravascular Interstitial Intracellular Fluid Note: Elderly patients' total body% of water drops too around 45-40% estimated TOTAL The body moves fluid and nutrients in three ways, and diseases and trauma can alter these normal processes: 1. Osmosis 2. Diffusion 3. Mediated Transport Insensible Fluid Loss (approx. 1,600 mL in 24 hours) From the skin Respiratory tract Urine output Sweating (approx. 100mL) Fecal loss (approx. 200mL) Replacement comes from three primary sources Oral intake of fluids like water, commonly called hydration Metabolic water production from oxidation of food And with medical interventions of intravenous (IV) fluids Both are Solute Concentrations Is the number of active particles in a kilogram or liter of water Salt (Sodium) is the most abundant in ECF NA+ = 135 – 145 mEq/ dL Serum Osmolality Serum Osmo 280 – 295 mEq/ dL FUN FACT: Why do we call 0.9% sodium chloride Normal Saline? It is because of Osmolality! 0.9% sodium chloride is 308 Circulating blood is 275-299 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4794509/ 1st is Osmosis Defines the movement of water between ICF / ECF that moves from Hypo to Hyper solutes Isotonic ▪ Equal balance concentration between ICF / ECF Hypertonic ▪ Higher concentration in ECF than in ICF ▪ Example: seawater Hypotonic ▪ Lower concentration in ICF than in ECF ▪ Example: distilled water ▪ Water moves from lower solute concentration to a higher solute concentration Equal balance concentration between ICF / ECF Blood has approx. 290-300 mOsm/L Equal solutes Common Isotonic IV Fluids 0.9% Sodium Chloride Lactated Ringers D5W (5% dextrose in water) as free water ONLY Treatment Goals Hydration Increase Preload in Shock Hypoglycemia Hypertonic More solutes outside the cell Pulls fluid from IC to EC Common Hypertonic IV fluids D5NS D5LR D5 0.45% 10% Dextrose 3.0% Sodium Chloride TX Goals Pull excess fluid off to treat edema Used in TBI when herniation is present Hypotonic More solutes in the cell Pulls fluid from EC to IC Common Hypotonic IV fluids ▪ D5W (5% dextrose in water) when dextrose is metabolized ▪ 0.25% sodium chloride ▪ 0.45% sodium chloride ▪ 0.225% sodium chloride TX Goals ▪ Aggressive Cellular hydration ▪ Pulls fluid from the vascular system into the ICF 2nd is the Diffusion of Solids and Gases Spreading of molecules from a higher concentration to a lower concentration Bodies’ way to keep equilibrium by keeping the concentration gradient equal as possible Example of locations: Lungs and Kidneys Diffusion of Gases Diffusion of Solids ▪ Measures Expired Carbon Dioxide (Co2) ▪ Co2 is a byproduct of cellular respiration ▪ eTCO2 can assess patient status for: ▪ Metabolic Status ▪ Adequate Circulation ▪ Adequate Ventilation ▪ Perfusion emergencies ▪ All four are independent of one another depending on your goals and outcomes for the patient ▪ THIS IS NOT USED FOR CHECKING OR MONITORING OXYGENATION Moving solutes against a concentration gradient From lower to higher concentration 1st Active Transport 2nd Facilitated Diffusion Active transport Faster then diffusion Uses A GREAT DEAL of energy Example: ▪Sodium/ Potassium pump ▪ATP production Facilitated Diffusion Uses a helper protein to move against the concentration Example: Insulin helps glucose into the cell Arterial Venous High Pressure side Low Pressure side A-line Pressures Cuff Blood Pressure Hydrostatic pressure Hydrostatic pressure 35mmHg 17mmHg Interstitial space Oncotic pressure Oncotic pressure 25mmHg 25mmHg Membrane Capillary bed 1. This movement is related to pressures ▪ Hydrostatic pressures ▪ Pressure to the walls of the vessels ▪ Forces fluids out of capillaries ▪ Osmotic pressures Hemodynamics ▪ Pulls fluid into the capillaries 2. Intravascular ▪ has high pressures 3. Interstitial ▪ has lower pressures Pressure exerted by a fluid because of its weight Weight will be based on the pressure exerted by the pump and by the diameter of the pipe onto the capillary Arterial Hydrostatic pressures 40 mmhg Venous Hydrostatic pressures 10 mmhg Example of this is Blood Pressures Mean Arterial Pressure (MAP) normal at 60-120 mmHg. MAP measures end-organ perfusion pressures. Dependent on Cardiac Output (CO=HRxSV) Dependent on Right Ventricular Filling Dependent on Systemic Vascular Resistance (SVR) or the radius of the blood vessels. Dilation Constriction Normal Tone Dilation Constriction The Patient : = Low Blood Pressure The Patient: = Low Cardiac Output = High Blood Pressure = Low Mean Arterial Pressures = High Cardiac Output = Low Systemic Vascular Resistance = High Mean Arterial Pressures Causes: = High Systemic Vascular Resistance = Loss of vagal tone Causes: = Distributive Shock = Early stages of Shock = Septic Shock = Compensated Shock = Decompensated Shock = Overdose of blood pressure medications What are some other injuries and diseases that may change blood pressure or hydrostatic pressures? Pressure difference between a semipermeable membrane, through which it cannot penetrate Pressures related to the concentration of colloids in the fluid Example: capillary pressures or Cap refill time Edema may be a result of these changes Tonicity Is the minimum pressure needed to prevent inward flow across a semipermeable membrane Alteration in this permeability increases the space for exchange: ▪ Sepsis ▪ Bacterial Infections ▪ Shock ▪ Pneumonia Edema Collection of water in the interstitial space 3rd spacing Causes ▪ Increased Capillary hydrostatic pressure ▪ Decreased Plasma Oncotic pressure (intravascular) ▪ Increased capillary membrane permeability ▪ Histamine Response ▪ Damage to cells make them “leaky” ▪ Lymphatic obstruction Increased hydrostatic pressure Occlusion or Diminish of Venous flow Retention of salt and water Common Causes ▪ CHF ▪ End Stage Renal Disease Decreased Plasma Osmotic Pressures Reduced plasma proteins Not enough pressure to pull fluid through the interstitial space Common Causes ▪ Liver disease ▪ Resuscitation ▪ Hemorrhagic Increased capillary membrane permeability Inflammation and Immune response Histamine response “Leaky” cells Common Causes ▪ Trauma ▪ Burns ▪ Crushing injuries Lymphatic obstruction Lymphedema Blocked or impaired lymphatic system Common Causes ▪ Mastectomy Localized edema can be deadly Cerebral edema Has no space to move the fluids Result is increase in ICP and herniation EMS S/S ▪ Acute decrease in GCS ▪ Cushing's Triad ▪ Unequal or Nonreactive pupils Localized edema can be deadly Compartment Syndrome Increase edema in a compartment Decrease blood flow distal to the injury Sensory damage EMS S/S the 5 P’s ▪ Pain out of proportion to findings ▪ Paresthesia (pins and needles) ▪ Paralysis ▪ Pallor (pale) ▪ Pressure Dependant Edema Pitting edema Is measurable Common areas ▪ Feet / lower extremities ▪ Presacral edema High pressure Hydrostatic Cell Oncotic Low pressure