N202 - Exam 1 Questions and Answers Latest Version 2025 Graded A+
Regulation of Acid/Base - Answers - 3 systems works together in the body to maintain the pH despite
continuous acid production
1.) Buffers
2.) Respiratory system
3.) Renal system
Buffer system - Answers - Prevents major changes in pH by removing or releasing hydrogen ion
- Excess acid: buffers bind with hydrogen ions to minimize the change in pH
- Excess alkalinity: buffers release hydrogen ions restoring pH
- Major buffer system are the bicarbonate-carbonic acid buffer system
Buffer system: respiratory - Answers - Respiratory system and the medulla regulate carbonic acid in the
body by retaining or eliminating CO2
- Can occur within minutes
- Becomes less effective over time
- COPD patients have chronically high CO2
- Alkalosis depresses the respiratory center resulting in a decrease in the rate and depth of respiration
- CO2 is retained and combined with water, the pH then falls to a more normal level
Buffer system: renal - Answers - Responsible for long term regulation of acid base balance
,- Excess acids are eliminated by the kidneys
- Regulates bicarbonate levels in extracellular fluids by regenerating bicarboate ions and reabsorbing
them in the renal tubules
- In acidosis: kidneys excrete H+ ions and RETAIN bicarb
- In alkalosis: kidneys RETAIN H+ ions and excrete bicarb
Obtaining ABGs - Answers - Wash hands, if radial artery is being used, perform a modified Allen test
prior to puncture
-A pre-heparinized syringe is used with an attached 22G needle
- Don goggles and non-sterile gloves
- Prepare the site with 2% chlorhexidine antiseptic solution, using friction for 30 secs
- Allow antiseptic to dry
- Palpate and stabilize the selected artery with index and middle fingers of non-dominant hand
- With bevel up and syringe at a 30 degree angle, puncture the skin
- Observe for flashback of blood
- Pulsation of the blood into the syringe indicates the artery has been punctures
- Allow the syringe to self fill to obtain at least 1 ml of blood, withdraw syringe
- Place gauze pad firmly over the puncture site and hold pressure for 5 mins
, - Secure dressing with tape once bleeding has stopped
- Seal needle/tip of syringe immediately
- Immerse sample in ice and label specimen with pt name, room #, ID #
- Send specimen to lab within 10 mins
- Properly dispose of used supplies and wash hands
Allen test - Answers - Test used before taking ABGs, used to find out if the blood flow to your hand is
normal
- Have the pt. hold over their head and open and close several times
- With fist clenched, apply direct pressure to the radial and ulnar arteries
- Instruct the pt. to lower and open the hand
- Release pressure over the ulnar artery and observe for return of hand color
- Return of color within 7 seconds indicates patency of ulnar artery and intact superficial and palmar
arch and a positive Allen's test
- The nurse or RT may then proceed with obtaining the arterial blood specimen from the RADIAL artery
Normal ABG values - Answers - pH: acid 7.35-7.45 base
- PaCO2: base 35-45 mmHg acid
- HCO3: acid 22-26 mEq/L base
- PaO2: 80-100
Regulation of Acid/Base - Answers - 3 systems works together in the body to maintain the pH despite
continuous acid production
1.) Buffers
2.) Respiratory system
3.) Renal system
Buffer system - Answers - Prevents major changes in pH by removing or releasing hydrogen ion
- Excess acid: buffers bind with hydrogen ions to minimize the change in pH
- Excess alkalinity: buffers release hydrogen ions restoring pH
- Major buffer system are the bicarbonate-carbonic acid buffer system
Buffer system: respiratory - Answers - Respiratory system and the medulla regulate carbonic acid in the
body by retaining or eliminating CO2
- Can occur within minutes
- Becomes less effective over time
- COPD patients have chronically high CO2
- Alkalosis depresses the respiratory center resulting in a decrease in the rate and depth of respiration
- CO2 is retained and combined with water, the pH then falls to a more normal level
Buffer system: renal - Answers - Responsible for long term regulation of acid base balance
,- Excess acids are eliminated by the kidneys
- Regulates bicarbonate levels in extracellular fluids by regenerating bicarboate ions and reabsorbing
them in the renal tubules
- In acidosis: kidneys excrete H+ ions and RETAIN bicarb
- In alkalosis: kidneys RETAIN H+ ions and excrete bicarb
Obtaining ABGs - Answers - Wash hands, if radial artery is being used, perform a modified Allen test
prior to puncture
-A pre-heparinized syringe is used with an attached 22G needle
- Don goggles and non-sterile gloves
- Prepare the site with 2% chlorhexidine antiseptic solution, using friction for 30 secs
- Allow antiseptic to dry
- Palpate and stabilize the selected artery with index and middle fingers of non-dominant hand
- With bevel up and syringe at a 30 degree angle, puncture the skin
- Observe for flashback of blood
- Pulsation of the blood into the syringe indicates the artery has been punctures
- Allow the syringe to self fill to obtain at least 1 ml of blood, withdraw syringe
- Place gauze pad firmly over the puncture site and hold pressure for 5 mins
, - Secure dressing with tape once bleeding has stopped
- Seal needle/tip of syringe immediately
- Immerse sample in ice and label specimen with pt name, room #, ID #
- Send specimen to lab within 10 mins
- Properly dispose of used supplies and wash hands
Allen test - Answers - Test used before taking ABGs, used to find out if the blood flow to your hand is
normal
- Have the pt. hold over their head and open and close several times
- With fist clenched, apply direct pressure to the radial and ulnar arteries
- Instruct the pt. to lower and open the hand
- Release pressure over the ulnar artery and observe for return of hand color
- Return of color within 7 seconds indicates patency of ulnar artery and intact superficial and palmar
arch and a positive Allen's test
- The nurse or RT may then proceed with obtaining the arterial blood specimen from the RADIAL artery
Normal ABG values - Answers - pH: acid 7.35-7.45 base
- PaCO2: base 35-45 mmHg acid
- HCO3: acid 22-26 mEq/L base
- PaO2: 80-100
