Hypokalemia can occur after cardiac surgery because of the high urine output
associated with hemodilution during CPB. The major adverse effects of hypokalemia
after cardiac surgery are:
A. Respiratory muscle weakness delaying extubation, and cardiac arrhythmias.
B. Acute renal failure and delirium.
C. Increased incidence of stroke and delirium.
D. Increased incidence of perioperative MI and arrhythmias.
Give this one a try later!
, A. Hypokalemia can cause muscle weakness when K+ level is < 2.5 mEq/L.
Respiratory muscle weakness can delay time to extubation. Muscle
weakness can also involve the GI tract and skeletal muscles, leading to ileus
and delaying ambulation. The most common manifestation of hypokalemia
is cardiac arrhythmias, including both atrial and ventricular arrhythmias.
Hypokalemia is a common cause of torsades de pointes.
Potassium level is not directly related to the incidence of perioperative MI,
stroke, or delirium.
Acute renal failure would cause hyperkalemia, not hypokalemia.
You are caring for a patient who returned from CABG surgery 4 hours ago. You
expect drainage from the mediastinal chest tubes to:
A. Be at least 200 ml/hr for the first 2 hours.
B. Drainage should have stopped by now.
C. Be bright red with clots present.
D. Be <100 ml per hour.
Give this one a try later!
D. Drainage from chest tubes should be no more than 100 ml/hr on return
from surgery and should gradually decrease over the first 3-4 hours. Bright
red blood and clots or drainage >200 ml/hr can indicate surgical bleeding
and should be reported. The patient will probably need to return to
surgery if drainage is > 400 ml/hr, or > 300 ml/hr for 2-3 hours, or >200ml/hr
for 4 hours. A sudden decrease in drainage can indicate the presence of
clots obstructing chest tubes or can be a sign of tamponade. Chest tubes
are usually removed in about 24 hours if drainage is <20 ml/hr
Which of the following are true about the surgical MAZE procedure:
A. It involves ablation of the AV node and permanent pacemaker insertion.
B. It is surgical amputation of the left atrial appendage.
C. It is done to correct severe mitral stenosis.
D. It is done to prevent recurrent atrial fibrillation.
,Give this one a try later!
A. The MAZE procedure creates multiple incisions in the right and left atria
in order to interrupt the reentry pathways responsible for maintenance of
atrial fibrillation. It usually includes amputation of the left atrial appendage
as well, since this is the site of most thrombus formation in atrial fibrillation.
AV node ablation with permanent pacemaker insertion is an
electrophysiology procedure that can be performed in patients with
chronic atrial fibrillation who are unresponsive to or intolerant of drug
therapy. AV node ablation prevents the atrial fibrillation from conducting
into the ventricle but requires a ventricular pacemaker to maintain an
adequate ventricular rate.
You are admitting a cardiac surgery patient from the OR to the ICU. After the patient
has been transferred to the ICU bed, you note that the arterial line BP displayed on
the monitor is 80/56. You have verified that the arterial line is not kinked and the
tubing is free of air and blood, and that the transducer is correctly located at the
patient's phlebostatic axis and has been correctly zeroed after connection to the
bedside monitor. Which of the following should be evaluated to determine the cause
of this patient's hypotension:
A. Verify that chest tube drainage is not excessive.
B. Verify that medication infusions have not become disconnected during transport
and transfer to the ICU bed.
C. Evaluate CVP, PWP (or PA diastolic pressure), CO, SVR, SaO2.
D. Verify an adequate cardiac rhythm on the bedside monitor.
E. All of the above.
Give this one a try later!
, E.Immediate postoperative hypotension is commonly due to inadvertent
vasopressor infusion termination (i.e. disconnected lines or wrong infusion
rate due to switching from one infusion pump to another) or hypovolemia
due to excess bleeding. The nurse must make sure that all medication
infusions are intact and running at the correct rate. If a vasodilator
(nitroglycerin or nitroprusside) is running it should be turned off.
Excessive chest tube drainage can indicate bleeding as a cause of
hypotension. Other causes of postoperative hypotension can include
cardiac arrhythmias, myocardial dysfunction or ischemia, cardiac
tamponade, pneumothorax or hemothorax, or ventilation problems.
Evaluation of hemodynamic monitoring parameters can help determine if
hypotension is due to preload problems (low CVP and PWP), cardiac
tamponade (equalization of CVP, PA diastolic, and PWP), or myocardial
dysfunction (low cardiac index in presence of adequate preload and
afterload). Bilateral breath sounds should be present and ventilator settings
and function verified. A postoperative chest X-ray should be obtained to
verify ET tube placement and absence of pneumothorax or hemothorax.
You are caring for a patient with an intra-aortic balloon pump and note blood in the
tubing. Your initial action should be:
A. Stop the balloon pump and notify the physician.
B. Administer 100% oxygen to help displace the helium and notify the physician
C. Leave the IABP running and notify the physician.
D. Purge the IABP manually to clear the blood from the tubing.
Give this one a try later!
A. Blood in the IABP tubing indicates a balloon rupture which can cause
gas embolus. However, helium is thought to be easily absorbed in the
presence of balloon rupture and oxygen is not generally indicated. The
appropriate action is to disconnect the balloon from the console or turn it
on standby so the movement of helium is stopped and notify the physician.
The nurse will need to prepare for IABP removal and replacement if
needed.
associated with hemodilution during CPB. The major adverse effects of hypokalemia
after cardiac surgery are:
A. Respiratory muscle weakness delaying extubation, and cardiac arrhythmias.
B. Acute renal failure and delirium.
C. Increased incidence of stroke and delirium.
D. Increased incidence of perioperative MI and arrhythmias.
Give this one a try later!
, A. Hypokalemia can cause muscle weakness when K+ level is < 2.5 mEq/L.
Respiratory muscle weakness can delay time to extubation. Muscle
weakness can also involve the GI tract and skeletal muscles, leading to ileus
and delaying ambulation. The most common manifestation of hypokalemia
is cardiac arrhythmias, including both atrial and ventricular arrhythmias.
Hypokalemia is a common cause of torsades de pointes.
Potassium level is not directly related to the incidence of perioperative MI,
stroke, or delirium.
Acute renal failure would cause hyperkalemia, not hypokalemia.
You are caring for a patient who returned from CABG surgery 4 hours ago. You
expect drainage from the mediastinal chest tubes to:
A. Be at least 200 ml/hr for the first 2 hours.
B. Drainage should have stopped by now.
C. Be bright red with clots present.
D. Be <100 ml per hour.
Give this one a try later!
D. Drainage from chest tubes should be no more than 100 ml/hr on return
from surgery and should gradually decrease over the first 3-4 hours. Bright
red blood and clots or drainage >200 ml/hr can indicate surgical bleeding
and should be reported. The patient will probably need to return to
surgery if drainage is > 400 ml/hr, or > 300 ml/hr for 2-3 hours, or >200ml/hr
for 4 hours. A sudden decrease in drainage can indicate the presence of
clots obstructing chest tubes or can be a sign of tamponade. Chest tubes
are usually removed in about 24 hours if drainage is <20 ml/hr
Which of the following are true about the surgical MAZE procedure:
A. It involves ablation of the AV node and permanent pacemaker insertion.
B. It is surgical amputation of the left atrial appendage.
C. It is done to correct severe mitral stenosis.
D. It is done to prevent recurrent atrial fibrillation.
,Give this one a try later!
A. The MAZE procedure creates multiple incisions in the right and left atria
in order to interrupt the reentry pathways responsible for maintenance of
atrial fibrillation. It usually includes amputation of the left atrial appendage
as well, since this is the site of most thrombus formation in atrial fibrillation.
AV node ablation with permanent pacemaker insertion is an
electrophysiology procedure that can be performed in patients with
chronic atrial fibrillation who are unresponsive to or intolerant of drug
therapy. AV node ablation prevents the atrial fibrillation from conducting
into the ventricle but requires a ventricular pacemaker to maintain an
adequate ventricular rate.
You are admitting a cardiac surgery patient from the OR to the ICU. After the patient
has been transferred to the ICU bed, you note that the arterial line BP displayed on
the monitor is 80/56. You have verified that the arterial line is not kinked and the
tubing is free of air and blood, and that the transducer is correctly located at the
patient's phlebostatic axis and has been correctly zeroed after connection to the
bedside monitor. Which of the following should be evaluated to determine the cause
of this patient's hypotension:
A. Verify that chest tube drainage is not excessive.
B. Verify that medication infusions have not become disconnected during transport
and transfer to the ICU bed.
C. Evaluate CVP, PWP (or PA diastolic pressure), CO, SVR, SaO2.
D. Verify an adequate cardiac rhythm on the bedside monitor.
E. All of the above.
Give this one a try later!
, E.Immediate postoperative hypotension is commonly due to inadvertent
vasopressor infusion termination (i.e. disconnected lines or wrong infusion
rate due to switching from one infusion pump to another) or hypovolemia
due to excess bleeding. The nurse must make sure that all medication
infusions are intact and running at the correct rate. If a vasodilator
(nitroglycerin or nitroprusside) is running it should be turned off.
Excessive chest tube drainage can indicate bleeding as a cause of
hypotension. Other causes of postoperative hypotension can include
cardiac arrhythmias, myocardial dysfunction or ischemia, cardiac
tamponade, pneumothorax or hemothorax, or ventilation problems.
Evaluation of hemodynamic monitoring parameters can help determine if
hypotension is due to preload problems (low CVP and PWP), cardiac
tamponade (equalization of CVP, PA diastolic, and PWP), or myocardial
dysfunction (low cardiac index in presence of adequate preload and
afterload). Bilateral breath sounds should be present and ventilator settings
and function verified. A postoperative chest X-ray should be obtained to
verify ET tube placement and absence of pneumothorax or hemothorax.
You are caring for a patient with an intra-aortic balloon pump and note blood in the
tubing. Your initial action should be:
A. Stop the balloon pump and notify the physician.
B. Administer 100% oxygen to help displace the helium and notify the physician
C. Leave the IABP running and notify the physician.
D. Purge the IABP manually to clear the blood from the tubing.
Give this one a try later!
A. Blood in the IABP tubing indicates a balloon rupture which can cause
gas embolus. However, helium is thought to be easily absorbed in the
presence of balloon rupture and oxygen is not generally indicated. The
appropriate action is to disconnect the balloon from the console or turn it
on standby so the movement of helium is stopped and notify the physician.
The nurse will need to prepare for IABP removal and replacement if
needed.
