Question

Choose one of the hormonal fluid regulators in the body and give an overview of how it works. Discuss how the lungs or the kidneys compensate for acid-base imbalance. Give numbers. Why is the nurse’s role critical in infusion therapy? Choose one type of infusion of interest.

Answer 1

1. Antidiuretic Hormone (ADH):

-Regulates blood osmolarity (most important function)

-Causes kidneys to reabsorb water into the blood, < which decreases blood osmolarity

-Regulates blood pressure (minor function)

-Increases blood volume, which increases blood pressure

-Causes vasoconstriction, which increases blood pressure

Hypothalamus Secretion triggers: 1 osmolality plasma volume 1 CCK (sm intestine) 1 Ang 11 Anterior pituitary Posterior pituitary ADH into Renal V, receptors: circulation 14,0 permeability in collecting duct retain H2O Vascular V, receptors: (high doses) TPR 1 Arterial BP

2. Kidneys compensate acid base imbalance bythw following ways :-

-Fixed acid excretion

-Normal regulation of bicarbonate concentration in the blood

Kidney Regulation of Acid-Base Balance

Renal Regulation :-

-Regulation of Fixed Acids in Blood

AKA: nonvolatile acids

Produced via normal body metabolism

Cannot be converted into gases and excreted via the lungs; must go through kidneys to leave the body

Conditions that cause an abnormal increase in fixed acid production (e.g., DKA, hypoxia) leads to accelerated acid excretion to maintain homeostasis

Excretion of Fixed Acids

Since the normal amount of fixed acids is relatively small, the kidneys are able to maintain homeostasis with no problems

If the amount of organic acids is large (e.g., DKA), even healthy kidneys can't keep up over the short term

This leads to a buildup of hydrogen ion in the blood, leading to a drop in pH

#. Bicarbonate Buffer System

Step 1:

-Sodium ions are reabsorbed from the filtrate in exchange for H+ by an antiport mechanism in the apical membranes of cells lining the renal tubule

Step 2:

-The cells produce bicarbonate ions that can be shunted to peritubular capillaries

Step 3:

-When CO2 is available, the reaction is driven to the formation of carbonic acid, which dissociates to form a bicarbonate ion and a hydrogen ion

H2O + CO2 ↔ H2CO3 ↔ HCO3- + H+

Step 4:

-Bicarbonate ion passes into the peritubular capillaries and returns to the blood

-Hydrogen ion is secreted into the filtrate, where it becomes part of new water molecules and be reabsorbed as such, or removed in the urine.

3. Nurses role is very critical in infusion therapy because she is the one who calculates the dose for infusion prescribed ,does the dilution , set the flow rate etc . Any up or down will have severe effects to the patient. For example if a patient is getting TPN infusion ,and the nurse have increased the flow rate without checking glucose levels of the patient ,then the patient might go in hyperglycemia . Second example , consider a patient is getting insulin infusion , and the nurse have have increased the flow rate based on previous glucose measurements can lead to hypoglycemia .