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Flashcards in ABGs Deck (16)
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1
Q

ABGs are most commonly collected from which artery?

Which test must be performed before taking blood from the radial artery for ABGs?

A

Radial artery!! other arteries are femoral and brachial.

Allen test must be done before taking blood from the radial artery to ensure they have collateral circulation to the hand from the ulnar artery. if they dont have this circulation they are at risk of losing their hand.

2
Q

What are the normal ranges of each of the following ABG parameters:

  • pH
  • PaCO2
  • PaO2
  • HCO3
  • anion gap
A

pH: 7.35-7.45

PaCO2: 35-45mmHg

PaO2: above 80mmHg

HCO3: 22-28mmol/L

Anion Gap: 10-16mmol/L or 7-13mmol/L?

3
Q

Decreased force of cardiac contraction, decreased vascular response to catecholamines, and decreased response to the effects/actions of certain medications are consequences of ____?

Decreased tissue oxygenation, neurological and muscle function are consequences of ___?

A

Acidosis.

Alkalosis.

4
Q

T/F, Alterations in homeostasis will affect the rate of unloading of the oxygen from hgb?

A

True,
decreased temp and alkolosis cause a shift to the left on the dissociation curve demonstrating hgbs increased affinity to oxygen, therefore it does not unload it as readily. (a shift to the left = lower PO2)

5
Q

What 3 systems maintain body pH?

How long does it take for these systems to respond to changes in pH?

A

Chemical buffering (carbonic acid, phosphate, plasma proteins) (response is immediate)

Resp center (response in 1-3mins; resp rate & tidal volume)

Kidneys (response in hours to days; excretes either acid or alkaline urine)

6
Q

Cause of respiratory acidosis?

A

Cause:

  • CNS depression (medications, narcotics, sedatives, or anesthesia)
  • impaired muscle function (spinal cord injury, neuromuscular dz)
  • Pulmonary disorders (atelectasis, PNA, pneumothorax, pulm edema)
  • massive PE
  • Hypoventilation d/t pain, chestwall injury, or abd pain.
7
Q

Signs and sx of resp acidosis?

Tx of resp acidosis?

A

Resp acidosis: (hypoventilation)
RESP: dyspnea, respiratory distress and/or shallow respiration

NERVOUS: HA, restlessness, confusion

CV: tachycardia, dysrhythmias

Tx:

  • increase the ventilation
  • treat the underlying cause (ex. pneumothorax, pain and CNS depression d/t medicatino)
  • may require mechanical ventilation
8
Q

Causes of resp alkalosis?

A

resp alkalosis:

  • psychological responses such as fear, anxiety, or pain
  • increased metabolic demands such as fever, sepsis, pregnancy, or thyrotoxicosis
  • Medications such as respiratory stimulants
  • CNS lesions
9
Q

Signs and sx of resp alkalosis?

Tx of resp alkalosis?

A

Signs and sx: (hyperventilation)

  • CNS: light headedness, numbness, tingling, confusion, inability to concentrate, and blurred vision
  • dysrhthmias and palpitations
  • dry mouth, diaphoresis, andd tetanic spasms of the arms and legs **

Tx:
-treat underlying problem
-monitor for respiratory muscle fatigue
-

10
Q

Causes of metabolic acidosis?

When you see metabolic acidosis you need to rule out what three conditions?

A

Renal failure

DKA

Anaerobic metabolism (tissue death, lactic acidosis)

Starvation

Salicylate iintoxication

Sepsis

MUDPILES:

  • methanol
  • uremia
  • dka or alcoholic ketoacidosis
  • paraldehyde/acetaminophen?
  • Isoniazide or iron overdose
  • ethylene glycol intoxication
  • salicylate overdose

Must rule out ischemia, renal failure, and DKA

11
Q

Signs and sx of metabolic acidosis

Tx of metabolic acidosis

A

Signs and sx;
-CNS: HA, confusion, restlessness, lethargy, stupor, coma

CVS: dysrhythmias

Kussmauls respirations* (deep and fast resps)

Warm, flushed skin as well as nausea and vomiting.

Tx:

  • treat the underlying cause
  • use bicarb as indicated
  • hydration
12
Q

Metabolic alkalosis causes

A

Cuases:
-ingestion of antacids, excess use of bicarb, or use of lactate in dialysis*

-protracted vomiting, gastric suction, hypochloremia, excess use of diuretics, high levels of aldosterone*

13
Q

Signs and sx of metabolic alkalosis

A

CNS:dizziness, lethargy, seizure, and coma

MSK weakness, muscle twitching, muscle cramps and tetany*

N/V and resp depression

14
Q

Base Excess:

-used as an estimate of what?

A

used as an estimate of the amount of strong acid or base needed to correct the metabolic component of an acid base disorder.

*a negative base excess indicates a base deficit in the blood.

15
Q

What is the major anion in the ECF?

How do you calculate the anion gap? Why is this helpful?

A

Cl-

Anion Gap = (Na+) - [Cl + HCO3]

Helpful in sorting out causes of metabolic acidosis (MUDPILES) as some causes have an increased anion gap and some have a normal gap.

16
Q

Make sure you….

A

Practice you ABGs!!!