Procedural Sedation and Analgesia - Indications, Contraindications and Procedure

Introduction

Procedural sedation and analgesia (PSA) are "regular procedures performed daily in the emergency department (ED) to relieve pain, anxiety, and discomfort while undergoing medical interventions." PSA practice is now safe with the advent of ultra-short-acting sedatives, analgesics, and noninvasive monitoring instruments such as capnography (monitors the concentration of carbon dioxide in the respiratory gasses). Sedation enhances various treatments' effectiveness while improving the patient and medical practitioner experience. Procedural sedation includes the administration of sedative or dissociative drugs with or without the concurrent administration of analgesics. The availability and widespread usage of sedative and analgesic drugs vary by location and practice.

Emergency physicians typically do "unplanned" PSA in the emergency department, which has challenges. The emergency physicians must handle not only the operation and PSA but also acute pain, anxiety, an unstable physiological condition, an ambiguous diagnosis, a limited health history, and other complications. In addition, emergency medicine demands physicians be skilled in critical care techniques such as advanced airway management, cardiovascular management, ventilator resuscitation methods, and anesthesia. These treatments are typically brief and comprise joint dislocation reduction, cardioversion, and imaging tests, but no anesthesia for tracheal intubation.

Procedural sedation (PS) also raises the chance of a successful surgery while shortening the time necessary to complete it. PS also improves patient and caregiver safety. These procedures may include drugs, psychological tactics, and physical actions to produce the desired impact.

What Are the Indications of Procedural Sedation and Analgesia?

PSAs are recommended whenever a patient requires an intervention that will cause considerable discomfort. The dosage of sedation needed is determined by the pain the patient is anticipated to suffer and the need for the patient to maintain the anesthesia effect still during the treatment. Decisions should be based on the patient's vital signals of stability. To estimate the risk of injury during the recommended sedation and procedure, a review of the patient's history of chronic conditions (for example - cardiovascular or respiratory disorders) and their stability, medication history, and allergies are required.

What Are the Contraindications of Procedural Sedation and Analgesia?

• Operator Expertise (Training): PSA is not a viable choice if the individual administering the sedation lacks the experience required to secure an unstable airway, from intubation through cricothyrotomy. Proper monitoring and resuscitation equipment are not present.

• Patient Requirements: If the patient needs a brief unpleasant operation, general anesthesia in an operating room may be more appropriate.

• Patient Circumstances: Patients with a high ASA risk score may benefit from the services of an experienced anesthetist. PSA is especially contraindicated in individuals with an ASA classification of unstable class II or class IV (except for immediate intervention such as for ventricular tachycardia conversion).

• Patients Allergic History: Patients with a known history of hypersensitivities or intolerance to PSA medicines.

• Preparation of the Patient for the Procedure: Aspiration risk is very high (for example, acute alcohol intoxication). Fasting times before surgical sedation can be based on general anesthesia standards, which advise not to drink any liquids before two hours and not to take any solids before six hours. Infants can consume breast milk up to four hours before the operation. If the patient consumes a high-protein diet, it may require additional fasting time (eight hours or more).

What Are the Equipment Required to Perform PSA?

Before beginning Procedural sedation and analgesia (PSA), the operator should have the following items ready,

• IV (intravenous line), operational, or flowing saline lock.

• Cardiopulmonary resuscitation medications and oxygen delivery equipment, varying from nasal cannulas to high-flow oxygen masks, should be available.

• Suction apparatus.

• Bag valve mask, laryngeal mask airway, bougie, direct or video-assisted laryngoscopy with correct blades, properly sized oral airways and endotracheal tubes, and surgical needles airways are all examples of airway equipment.

• When administering drug-reversible agents such as opioids and Benzodiazepines, reversal medications are required. Flumazenil and Naloxone successfully reverse the effects of Fentanyl (or other opioids) and Midazolam (or other benzodiazepines). It should be noted that Flumazenil usage has been linked to status epilepticus, most notably in individuals with undiagnosed benzodiazepine misuse or those suffering from a seizure disease.

• Monitoring devices often include cardiac, blood pressure, pulse-oximetry (SaO2), and respiratory monitors. The use of an end-tidal carbon dioxide monitor is strongly recommended.

How Is PSA Performed?

In an ideal scenario, two operators should be present to perform PSA. One physician will carry out the targeted surgery, while the other will be responsible for sedation, patient monitoring, and team coordination. However, there are numerous situations in which having two operators is not practically possible, particularly for unscheduled procedures.

The physicians performing PSA are well trained in the following areas:

• Patient selection.

• Airway management strategies (a mandatory requirement to carry out these techniques).

• Evaluation and control of the drugs administered.

• Patient monitoring.

• Addressing the potential difficulties.

Preparation for PSA:

• A standard operating checklist format from the World Health Organization (WHO) is followed.

• The monitoring equipments such as electrocardiogram, arterial oxygen saturation (SaO2), and end-tidal carbon dioxide (EtCO2) (preferred if available because it is more sensitive to hypoventilation than SaO2), are used to analyze probable device mistakes, and examine all allergies.

• The contact lenses from patients (especially for Nitrous oxide use) should be removed.

• The essential photographs are displayed

The ideal PSA agent should include sedative, analgesic, and amnestic characteristics and a fast onset and shorter duration of action to allow for a safe and speedy healing and discharge. Although PSA is often achieved by combining a short-acting Benzodiazepine (Midazolam) (sedative, amnestic, and anxiolytic properties but no analgesic effects) with an opioid (Fentanyl), many medications are also available, either alone or in combination.

The combination of Fentanyl and Midazolam is among the most commonly used techniques for performing PSA. Still, other combinations (for example, Propofol and Fentanyl or Propofol and Ketamine) are also used.

What Are the Drugs Used in PSA?

The following drugs are either used alone or in combinations:

• Midazolam.

• Fentanyl.

• Ketamine.

• Etomidate.

• Propofol.

• Dexmedetomidine.

• Methohexital.

Naloxone and Flumazenil are used as reversal agents.

Conclusion

Procedural sedation and analgesia have become gold standard in the emergency department. PSA is a gentle way of assisting patients in enduring short and unpleasant operations. Furthermore, the surgery takes place in a secure atmosphere with physicians available to recover the patient from the ill effects of sedation.