690
P A R T 8
Drugs acting on the cardiovascular system
comfort; and frequent rest periods
to balance
supply and demand of oxygen
.
■
■
Offer support and encouragement
to help the
person deal with the diagnosis and the drug
regimen.
■
■
Provide thorough teaching, including the name
of the drug, dosage prescribed, technique for
monitoring pulse and acceptable pulse parameters,
dietary measures if appropriate, measures to avoid
adverse effects, warning signs of possible toxicity
and need to notify healthcare provider and the
need for periodic monitoring and evaluation,
including ECGs and laboratory testing,
to enhance
knowledge about drug therapy and to promote
compliance.
Evaluation
■
■
Monitor response to the drug (improvement in
signs and symptoms of HF, resolution of atrial
arrhythmias, serum digoxin level of 0.5 to
2 ng/mL).
■
■
Monitor for adverse effects (vision changes,
arrhythmias, HF, headache, dizziness, drowsiness,
GI upset, nausea).
■
■
Monitor the effectiveness of comfort measures and
compliance with the regimen.
■
■
Evaluate the effectiveness of the teaching
plan (person can name drug, dosage, proper
administration, adverse effects to watch for,
specific measures to avoid them and the importance
of continued follow-up).
■■
TABLE 44.2 Congestive heart failure and response to cardiac glycosides
Response
Signs and symptoms*
During congestive heart failure
After full digitalisation
+
Heart rate, rhythm
and size
Heart hypertrophied, dilated; rate rapid,
irregular; “palpitations”; auscultation—S
3
Dilatation decreased, hypertrophy remains;
rate, 70–80 beats/minute, may be regular;
auscultation—no S
3
Lungs
Dyspnoea on exertion; orthopnoea;
tachypnoea; paroxysmal nocturnal dyspnoea;
wheezing, rales, cough, haemoptysis
(pulmonary oedema)
↓
Rate of respiration; wheezes, rales gone
Peripheral
congestion
Pitting oedema of dependent parts;
hepatomegaly;
↑
jugular venous pressure;
cyanosis; oliguria; nocturia
↑
Cardiac output and renal blood flow leads
to
↑
urine flow,
↓
oedema,
↓
signs and
symptoms of poor perfusion
Other
Weakness, fatigue, anorexia, insomnia, nausea,
vomiting, abdominal pain
↑
Appetite:
↑
strength, energy
*Because the clinical picture in heart failure varies with the stage and degree of severity, the signs and symptoms may vary considerably in different
people.
+Digitalisation will not overcome similar symptoms when they are caused by conditions other than heart failure. Overdosage may actually cause
symptoms similar to those of heart failure (e.g. anorexia, nausea, vomiting, cardiac arrhythmias, peripheral congestion).
CRITICAL THINKING SCENARIO
Inadequate digoxin absorption
THE SITUATION
G.J. is an 82-year-old Caucasian woman with a 50-year
history of rheumatic mitral valve disease. She has been
stabilised on digoxin for 10 years in a compensated state
of heart failure (HF). G.J. recently moved into an extended
care facility because she was having difficulty caring
for herself independently. She was examined by the
admitting facility doctor and was found to be stable. Note
was made of an irregular pulse of 76 beats/minute with
electrocardiographic documentation of her chronic atrial
fibrillation.
Three weeks after her arrival at the nursing home,
G.J. began to develop progressive weakness, dyspnoea on
exertion, two-pillow orthopnoea and peripheral 2+ pitting
oedema. These signs and symptoms became progressively
worse, and 5 days after the first indication that her HF was
returning, G.J. was admitted to the hospital with a diagnosis
of HF. Physical examination revealed a heart rate of 96
beats/minute with atrial fibrillation, third heart sound, rales,
wheezes, 2+ pitting oedema bilaterally up to the knees,
elevated jugular venous pressure, cardiomegaly, weak
pulses and poor peripheral perfusion. G.J.’s serum digoxin
level was 0.12 ng/mL (therapeutic range, 0.5 to 2 ng/mL).
