Page 205 - Critical Care Nursing Demystified

190 CRITICAL CARE NURSING DeMYSTIFIED

NURSING ALERT

Always assess the patient first. VF can be mimicked by the patient brushing his or her

teeth or a loose electrode. Since there is no circulation, early defibrillation is important!

Asystole
This is another type of code rhythm, but as the name suggests, it is known by
the absence of systole. There is an extremely poor prognosis with this rhythm;
so finding the cause and treating it is important. Asystole is known by its flatline
appearance.
• RATE: There are sometimes P waves but they are not associated with
anything and will disappear. No QRS complex is seen.
• RHYTHM: None.
• CONDUCTION: None.

NURSING ALERT

Since there is no rhythm, consistently administered, high-quality CPR and identifying Downloaded by [ Faculty of Nursing, Chiangmai University 5.62.158.117] at [07/18/16]. Copyright © McGraw-Hill Global Education Holdings, LLC. Not to be redistributed or modified in any way without permission.
the cause is important. Causes can include hypoxia, hypovolemia, hypothermia, aci-
dosis, electrolyte imbalance, drug overdose, cardiac tamponade, tension pneumotho-
rax, and pulmonary emboli.

Where Do 12-Lead ECGs Enter the Picture?

4 A 12-lead electrocardiogram (ECG) is a noninvasive diagnostic tool that the
critical care nurse and health care providers use to look at the major surfaces
of the heart. Its limitation is that it is only a small space in time we are “seeing,”
so to analyze evolving changes in the heart, ECGs need to be done at spaced-
out time intervals, so evolving changes are not missed. Baseline ECGs are also
done as part of a routine physical, before surgery and any time the patient has
a dramatic change in cardiac status like chest pain or hypotension.
Although only ten electrodes are placed on the chest and limbs, the ECG
machine changes around the polarity (– and + poles) of the electrodes to “see”
12 different views of the heart. This diagnostic tool tells us much more about
what is going on in the heart. It is similar to a car sitting in a valley; if you only