Sedation Safety During Interventional Pain Procedures
Many interventional pain procedures, such as epidural injections, facet procedures, and nerve ablations, are done with local anesthetic alone. Others are done with sedation to reduce anxiety and discomfort. Sedation is often given in a pain clinic, an office procedure suite, or an ambulatory surgery center rather than a hospital operating room. It may be directed by the proceduralist and given by a nurse, or provided by an anesthesia professional.
Sedation complications are usually about breathing. A patient who becomes more deeply sedated than planned can stop breathing adequately, and oxygen levels can fall quickly. When evaluating such a case, a physician expert looks at patient selection, the planned and actual depth of sedation, monitoring, and rescue. This article walks through each.
Sedation is a continuum
Sedation is often described in levels: minimal sedation, moderate sedation, deep sedation, and general anesthesia. A patient under moderate sedation should respond purposefully to voice or light touch and breathe adequately without help. Under deep sedation, a patient may need help keeping the airway open. These levels are not fixed. The same dose can affect two patients very differently, and a patient can drift from one level to the next. For that reason, a central principle in sedation practice is that the team should be able to rescue a patient who becomes more deeply sedated than intended.
The American Society of Anesthesiologists, together with several other specialty organizations, published Practice Guidelines for Moderate Procedural Sedation and Analgesia 2018 (Anesthesiology, 2018). It is intended to guide clinicians who provide moderate procedural sedation and addresses patient evaluation, preparation, monitoring, staffing, and recovery. An expert should identify which version of the guideline, and which facility policy, applied on the date of care.
Patient selection
Some patients are at higher risk for breathing problems under sedation. Review questions include:
- Sleep apnea. Was obstructive sleep apnea known or suspected, and was it considered in the plan?
- Chronic opioid use and other sedatives. Patients on long-term opioids, benzodiazepines, gabapentinoids, or similar medications may respond unpredictably to added sedatives.
- Lung and heart disease, obesity, and frailty. Was the patient's overall health assessed, and was the setting appropriate for that level of risk?
- Airway. Was the airway evaluated in case rescue became necessary?
- Fasting and aspiration risk. Were fasting status and aspiration risk considered?
Dr. Urits co-authored Management of Patients With Chronic Pain in Ambulatory Surgery Centers (Charipova and colleagues, Cureus, 2020). The review explains that chronic pain and substance use disorders present unique challenges in perioperative planning and are associated with worse postoperative outcomes. It describes preoperative risk stratification and the integration of pain specialists into the ambulatory surgery team.
Planned versus actual depth of sedation
Some procedures depend on the patient being awake enough to give feedback. For example, guidance for spinal cord stimulator lead placement has recommended that the patient be able to respond during the procedure. In a survey Dr. Urits co-authored (Hasoon and colleagues, Pain Therapy, 2021), 77% of physicians reported using deep sedation for permanent stimulator implants at times, and 45% reported using general anesthesia for 10 kHz implants. The authors noted that the guidance and reported practice remain at odds. When deeper sedation is used, the record should explain who provided it and how the patient was monitored.
Monitoring
Monitoring questions often include:
- Was a person other than the proceduralist assigned to monitor the patient?
- Were oxygen saturation, heart rate, blood pressure, and level of consciousness recorded at regular intervals?
- Was breathing monitored, including by capnography where the guidance or facility policy called for it?
- Was supplemental oxygen used, and did it delay recognition of poor breathing?
- Do the documented vital signs match any downloaded monitor data?
Rescue and recovery
- Were reversal agents, airway equipment, suction, and oxygen immediately available?
- Was a person trained in airway management and resuscitation present or immediately available?
- When oxygen levels dropped, how quickly were stimulation, airway support, reversal agents, and a call for help used?
- Was the patient recovered and monitored until discharge criteria were met?
- Was the patient discharged with a responsible adult and clear instructions?
Causation questions
When a patient suffers a hypoxic brain injury or cardiac arrest during or after sedation, an expert considers whether the event was caused by sedation, by an underlying cardiac or neurologic condition, or by something else, such as local anesthetic toxicity (local anesthetic systemic toxicity) or an allergic reaction. The timeline from first abnormal vital sign to intervention is often the key.
Records that usually matter
- The pre-procedure history and physical, including sleep apnea screening and medication list
- The sedation record with drug doses, times, and vital signs
- Monitor downloads and capnography data, if available
- Staffing records showing who monitored the patient
- Recovery and discharge notes
- Facility sedation policies and credentialing records on the date of care
- Emergency response and transfer records
Key takeaways
- Sedation is a continuum, and patients can become more deeply sedated than intended.
- Patient selection, especially sleep apnea and chronic opioid or sedative use, is often central.
- Monitoring, staffing, and rescue capability are usually measured against the ASA guidance and facility policy in effect.
- A time-stamped reconstruction of doses and vital signs is usually the core of the review.
References
- Practice Guidelines for Moderate Procedural Sedation and Analgesia 2018: A Report by the American Society of Anesthesiologists Task Force on Moderate Procedural Sedation and Analgesia, the American Association of Oral and Maxillofacial Surgeons, American College of Radiology, American Dental Association, American Society of Dentist Anesthesiologists, and Society of Interventional Radiology. Anesthesiology. 2018;128(3):437-479. Abstract: https://pubmed.ncbi.nlm.nih.gov/29334501/
- Charipova K, Gress KL, Urits I, Viswanath O, Kaye AD. Management of Patients With Chronic Pain in Ambulatory Surgery Centers. Cureus. 2020;12(9):e10408. Abstract: https://pubmed.ncbi.nlm.nih.gov/33062525/
- Hasoon J, Urits I, Viswanath O, et al. Percutaneous Spinal Cord Stimulation Lead Placement Under Deep Sedation and General Anesthesia. Pain Ther. 2021;10(2):1719-1730. Abstract: https://pubmed.ncbi.nlm.nih.gov/34652716/
Related: Sedation and MAC Cases
Educational information only. Not legal or medical advice.
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