Monitoring Vital Signs During Sedation For Optimal Patient Safety

By Genni Burkhart, DOCS Incisor Editor

This topic is included in DOCS Education's top 25 Safety Statements, compiled by our esteemed faculty. The first ten, by Dr. Leslie Fang, can be found here.

To ensure patient safety, continuous monitoring of vital signs is essential in assessing their response to sedation and preventing potential emergencies. Monitoring should include oxygenation, ventilation, circulation, and temperature. Patient consciousness, however, must always be prioritized, as it's the foundation of their well-being and safety throughout the procedure.

Three critical factors must be considered to ensure patient safety. Let's explore these elements to ensure your patient's safety is never compromised. They include:

1. Patient selection.
2. Avoid sedating the very young, the very old, and the very sick.
3. Keep your patient conscious. (DOCS only teaches conscious sedation)

Risks inherently grow as your patient becomes increasingly sedated. It's imperative to monitor vital statistics and the patient’s airway, as well as support the natural characteristics that help them breathe and maintain their life functions. Maintaining verbal responsiveness with your patient throughout the procedure should be a top priority.

Goals of Monitoring

• Observe consciousness
• Verbal responsiveness
• Monitor physiological parameters
• Heart rate
• Oxygen saturation
• Blood pressure
• End-tidal carbon dioxide (ETCO2)

When monitoring a patient during sedation, focusing on the machine that measures vital statistics is common. However, the most crucial factor to keep track of is the patient's consciousness, which can only be done by direct interaction with the patient rather than relying solely on the readings from monitors.

Pre-Sedation Baselines

The patient's "normal" BP range should fall within the ASA 1 and ASA 2 categories.

• Preferred heart rate of: >60 and <100
• Preferred blood pressure of: <120 systolic and <80 diastolic
• Preferred 02 saturation of: > 96%
• Preferred ETCO2 of: 40mm HG +/- 5 mm

When the preoperative heart rate and blood pressure are above these preferred levels, the patient’s anxiety is often contributing. Sometimes, taking readings without the doctor present can provide a more reliable and consistent measurement of the patient.

Lower-than-normal heart rate and blood pressure readings are often found in patients in excellent physical condition. When abnormal baseline cardiovascular values cannot be explained by anxiety or excellent physical condition alone, patients should seek medical consultation before sedating them.

As with any atypical measurement, the inaccuracy of the monitoring equipment must also be ruled out. Key points to remember include:

• Do not sedate without high-quality monitoring equipment. It’s also essential that all team members know how to use the equipment and how to set the alarms.
• Pulse, blood pressure, oxygen saturation, and end-tidal CO2 measurements must be measured, monitored, and recorded throughout the treatment.

Monitoring Heart Rate

When a patient is sedated, their heart rate may slow down due to the activation of the parasympathetic system, the release of acetylcholine, and the activation of its receptors.

This decrease in heart rate is to be expected and less of a concern compared to tachycardia, which increases the risk of an adverse cardiovascular event. Additionally, there is particular concern when an absence of a P wave on an EKG accompanies the tachycardia, which can be a sign of heart block, ventricular tachycardia, or fibrillation.

Certain medical conditions can affect the patient’s heart rate. Examples of ailments that can increase heart rate include:

• Atherosclerosis
• Congestive Heart Failure
• Myocardial Infarction
• Congenital Heart Defects
• Inflammatory or Degenerative Heart Disease
• Myocarditis (Infection of the Heart)
• Chronic Lung Disease
• Hypertension
• Hyperthyroidism
• Electrolyte Imbalance
• Emotional Stress

Medications that can cause tachycardia include:

• Asthma Medicines
• Antibiotics
• Cough, Cold, and Allergy Medicines
• Thyroid Medicine
• Antidepressants
• Supplements

Monitoring Blood Pressure

Patients diagnosed with regular or prehypertension are acceptable candidates for sedation. Given all other health conditions the patient might have, it’s acceptable for a patient with stage 1 hypertension also to be sedated, provided the consult with their PCP or cardiologist determines their hypertension to be under acceptable control.

However, patients with stage 2 hypertension are not candidates for sedation until their condition is successfully managed.

Abnormal Blood Pressure During Sedation

The blood pressure of a sedated patient should be lower than their baseline blood pressure, but significant differences may still occur. This is due to the following reasons:

• Sedation medications
• Existing medications
• Skipped or missed medication dose
• Patient discomfort
• Indication of a possible cardiovascular event
• Monitoring equipment

It’s important to remember the blood pressure cuff size you’re using for each patient. For instance, if the cuff is too small for the patient, the BP reading will be artificially high. Conversely, if the cuff is too large for the patient, the BP reading will be artificially low. If the BP is taken on an extremity above the level of the heart, the reading will also be artificially low.

Monitoring Oxygenation

Oxygenation is the most critical factor among the various physiological measurements assessed during conscious sedation. While heart rate and blood pressure are also monitored, they are typically supported by the sedation process, making them less critical than oxygenation.

Although end-tidal CO2 measures ventilation, oxygenation is a more revealing number in conscious sedation patients. Since they are not intubated, capnography/capnometry measurement reliability is less pertinent. Therefore, monitoring oxygenation to detect any potential negative impacts of conscious sedation is crucial.

The pulse oximeter measures oxygenation by reflecting the percentage of available hemoglobin sites occupied by oxygen. The difference between the percentage of oxygenated hemoglobin and the tissues that need it determines the efficiency of oxygen delivery. Therefore, it is most desirable that the percentage of oxygenated hemoglobin measured by the pulse oximeter be as high as possible to ensure optimal tissue oxygenation.

Monitoring End-Tidal CO2

End-tidal CO2 Monitoring (ETCO2) measures a patient's exhaled carbon dioxide, which reflects the metabolic processes of ventilation. Oxygenation measures how much oxygen the blood carries, while ventilation measures the carbon dioxide produced by oxygenating tissues (cellular metabolism).

As a result, it can be used to determine the effectiveness of ventilation and oxygenation in a patient's body.

ETCO2 also has the advantage of being a more real-time measurement than SpO2. As a general rule, expired CO2 rises before oxygen saturation decreases.

In Conclusion

Maintaining patient consciousness is of the utmost importance during sedation. Therefore, dentists must start by selecting patients who are appropriate candidates for sedation.

While monitoring equipment is essential, direct interaction with the patient and verbal responsiveness are critical in assessing consciousness and ensuring patient safety throughout the procedure. Properly trained dental professionals prioritize monitoring procedures to mitigate risks and ensure the patient's wellbeing during sedation.

This proactive approach ensures that emergencies and complications are avoided during sedation appointments. As a result, patients will be satisfied and safely treated, and staff will be prepared to provide excellent patient care.

For a more in-depth review, join world-class educator Dr. Anthony Feck, DMD, here for an informative DOCS Education course on the important components you and your team need for safe and effective sedation. This course is worth 3 CE credit hours.

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Author: With over 14 years as a published journalist, editor, and writer, Genni Burkhart's career has spanned politics, healthcare, law, business finance, technology, and news. She resides in Northern Colorado, where she works as the editor in chief of the Incisor at DOCS Education.