Event duration Rule 2: When baseline breathing amplitude cannot be determined(and when underlying breathing variability is large) events can also be determined when either there is:
1. A clear and sustained increase in breathing apmlitude.
2. In the case where a desaturation has occured, there is event-associated resaturation of at least 2%.
A small bias i.e., more events in reporting hypopneas at the flow threshold recoommended for scoring hypopneas(< 50% of baseline) may be corrected by:
square root transformation
Scoring of apneas Rule 1: Score an apnea when all of the following criteria are met:
1. There is a drop in the peak thermal sensor excursion by >90% of baseling.
2. The duration of the event lasts at least 10 seconds.
3. At least 90% of the event's duration meets the amplitude reduction criteria for apnea.
The alternative signal to detect absence of airflow for identification of an apnea when the thermistor signal is unreliable is:
A nasal air pressure transducer
Event duration Rule 1: for scoring either an apnea or a hypopnea, the event is measured from the:
Nadir preceding the first breath that is clearly reduced to the beginning of the first breath that aproximated the baseling breathing amplitude.
The sensor for detection of blood oxygen is:
Pulse oximetry with a maximum acceptable signal averaging time of 3 seconds.
Score Hypopnea Rule if all of the following criteria are met:
1. Nasal pressure signal excurions (or those of the alternative hypopnea sensor) drop by >30% of baseline.
2. The duration of this drop occurs for a period lasting at least 10 seconds.
3. There is a >4% desaturation from pre-event baseline.
4. At least 90% of the vent's duration must meet the amplitude reduction of criteria for hypopneas.
For scoring of hypopneas when the nasal pressure device is not functioning, alternative sensores include:
A uncalibrated or calibrated inductnace plethysmography or an oronasal thermal sensor.
Cheyene stokes breathing has variable cycle length that is most commonly in the range of:
What is an oronasal thermal sensor?
the sensor to detect abscence of airflow for identification of an apnea.
The sensor for detection of respiratory effort is:
Either esophageal manometry or calibrated or uncalibrated inductance plethysmongraphy.
Evaluating A rhythm
1. Is the rhythm regular?
3. What are atria doing?
4.What are ventricles doing? QRS.
5.Relationship between atria and ventricles
Normal Sinus rhythm
1. PR Interval 0.12-0.20 seconds
2. QRS Complex 0.04-0.10 seconds
3. QT Interval 0.36-0.44 seconds
4. A heart rate of 60-90 beats per minute
5. P waves Uniform and upright in appearance
is of no concern during a sleep study. Only profound bradycardia warrants waking the patient or contacting the medical director.
is of no concern during a sleep study can be accompanied by chest pain, SOB and it may trigger a severe cardiac or pulmonary compromise- If the patient is woken up and tachycardia persists the doctor should be called.
Second degree AV block Mobitz type 1
are suffering from myocardial ischemia= arrhythmia will be brief= monitor closely= If arrhythmia develops into a more sever heart block=more likely to happen with mobitz type II= Notify the doctor immediatly.
Third degree or complete AV block
The patient should be woken up and Basic cardiac life support should be administered . Doctor should be called.
Paroxysmal supraventricular tachcardia (PSVT)
if a patient develops PSVT and rythm is sustained= wake patient and notify Dr.
give patient O2 and ask Pt to perform a valsalva maneuver= exhale against airway.
1. if sustained for a long period of time- may be life threating,
the cardiac arrest team of the medical center or the paramedics may need to be alerted.
2. the patient may quickly loose consciousness
3. can quickly degenerate into ventricular fibrillation which can cause death.
4.BCLS or ACLS should be administered if patient looses consciousness.
5. Should notify physician
6. In hospital code
7. CPR initiated give O2
Ventricular ectopies (PVCS)
1.Not cause for concern
2. Contact physician if premature beats are associated with chest pain, light headedness, palpitations, or nausea, or if the patient becomes confused and uncooperative.
3. Or has more than 6 PVCs in a minute.
4. Or the PVCS occur in couplets or groups of three at least once a minute or the patient has four or more PVC in a row.