Nibp monitoring considerations, Monitoring – Physio-Control LIFEPAK 15 User Manual

Page 83

MONITORING

LIFEPAK 15 Monitor/Defibrillator Operating Instructions

4-39

reach a peak amplitude and then start to decrease. The rising and falling amplitude values form a

curve that is analyzed to yield systolic pressure, diastolic pressure, and mean arterial pressure

(MAP).

The NIBP monitor measures the pulse rate by tracking the number of pulses over time. The NIBP

monitor uses artifact rejection techniques to provide accurate results under most operating

conditions. When a patient is experiencing arrhythmias during a measurement, the accuracy of the

pulse determination may be affected or the time needed to complete a measurement may be

extended. In shock conditions, the low amplitude of blood pressure waveforms makes it difficult for

the monitor to accurately determine the systolic and diastolic pressures.

NIBP Monitoring Considerations

As with any noninvasive oscillometric blood pressure monitor, clinical conditions can affect the

accuracy of the measurements obtained, including the following:

• The patient’s physiological condition. For example, shock may result in a blood pressure

waveform that has a low amplitude, making it difficult for the monitor to accurately determine

the systolic and diastolic pressures.

• The position of the patient.

• Motion may prolong the measurement process since motion artifacts have to be rejected in the

data stream. Motion that affects measurement can include patient movement, patient seizure,

bumping the cuff, and flexing the extremity under the cuff.

• The presence of other medical devices. The NIBP monitor does not operate effectively if the

patient is connected to a heart/lung machine.

• When a patient is experiencing arrhythmias, pulse rate accuracy may be affected or the time

needed to complete an NIBP measurement may be extended. The device automatically deflates

if a blood pressure measurement cannot be obtained in 120 seconds.

• Blood pressure and pulse can fluctuate greatly between measurements; the monitor cannot alert

the operator of changes in vital signs that occur between measurement cycles.

• There may be some difference between readings taken manually and readings from the NIBP

monitor due to the differing sensitivity of the two methods. The NIBP monitor meets the ANSI/

SP10 AAMI standard that requires a mean difference of ±5 mmHg, with a standard deviation no

greater than 8 mmHg, compared to auscultatory readings.

• When using the NIBP monitor during defibrillation, the NIBP monitor is not available when the

defibrillator is being charged. Upon shock, the monitor resets and dashes (– – –) appear in place

of pressure readings. After defibrillation, you can resume blood pressure measurement

• If the blood pressure cuff fails to deflate for any reason or causes undue discomfort to the

patient, remove the cuff from the arm or disconnect the tubing from the defibrillator.