Monitoring, Bedside

Update December 13, 2018

Bedside monitoring displays, stores, and trends the patient's heart rate, respiratory rate, blood pressure reading (noninvasive and invasive), oxygen saturation, electrocardiographic (ECG) tracing, and pressure waveforms generated from arterial, venous, or bladder catheters to make these information to physicians and nurses.

The individual bedside monitor is connected to a computerized central monitoring system outside of the patient's room that will sound an alarm when abnormal measurements are recorded prompting immediate notification of the staff and evaluation of the patient.

Alarm limits and scales are set by the nursing staff depending on the patient's clinical status. For instance, the ECG scale may be set to amplify the tracing 2- to 4-fold in a low-voltage state. Pressure waveform scales can vary based on the patient's pressure range; generally, the right atrial pressure is set at 20 mm Hg, pulmonary artery systolic pressure is set at 40 mm Hg, and systolic arterial blood pressure is set at 180 mm Hg.1

1. Cardiac Monitoring
- Continuous EKG - Computerized arrhythmia detection systems facilitate rapid detection of rhythm abnormalities and increase the likelihood of successful resuscitation.
2. Blood Pressure
- Intermittent (sphygmomanometer) or continuous (intravascular) assessment of BP (systolic, diastolic, mean arterial, and central venous pressures).
- Assessment of response to treatment and titration of vasoactive drugs. Continuous intravascular methods are warranted in patients with marked hemodynamic instability.
- Over the short term, BP is considered adequate if renal perfusion is maintained (usually MAP > 70 mm Hg in young, previously healthy persons). Premorbid medical problems and aging, however, may mandate a higher MAP.
  
  Note: If the cuff is too small for the arm (ie, the patient is obese), the measured systolic BP will be falsely elevated.
3. Pulse Oximetry
- Continuous, quantitative arterial O2 saturation (SaO2); ensures adequate oxygenation of systemic arterial blood for tissue delivery.
4. Temperature
- Critically ill patients are at high risk of thermoregulatory disorders due to their pathophysiologic condition (eg, fluid resuscitation, burns, sepsis); continuous measurements in the esophagus (esophageal probe) and central venous blood compartment (PA catheter) are accurate methods for monitoring core body temperature. ATLS definitions of hypothermia are mild, 35°C; moderate 32°C; and severe 28°C.
5. Capnography
- Continuous measurement of expired CO2. Changes imply alteration in clinical status (eg, hypoventilation, overfeeding, fever, sepsis).
6. Heart Murmurs
- The presence of a premorbid cardiac murmur and, more important, the interval development of a new cardiac murmur are important in the care of a critically ill patient. In general, diastolic murmurs are usually pathologic.

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