Phenobarbital sedation via subcutaneous infusion in a palliative medicine unit: retrospective review

Phenobarbital for inpatient palliative sedation-a clinical audit

OBJECTIVES

Identify the indication, route of administration and dose for phenobarbital continuous subcutaneous infusion (CSCI) in palliative sedation therapy (PST).Assess the dosing and continuation of midazolam and levomepromazine in conjunction with phenobarbital.

METHODS

This clinical audit examined inpatient phenobarbital CSCI use for PST from January 2021 to April 2024. Data were retrospectively extracted from electronic medical records (n=23).

RESULTS

The most common indication for phenobarbital CSCI was agitation, followed by sedation for non-invasive ventilation withdrawal. Phenobarbital was administered subcutaneously in all cases without adverse systemic or site reactions.The most common loading dose was 200 mg (50-200 mg), and the most common initiating CSCI dose was 800 mg/24 hours (400-1200 mg/24 hours). The maximum dose was 1800 mg/24 hours. The average time to death following start of phenobarbital was 52 hours (4-123 hours). Most patients (n=22) were described as comfortable at death.Before starting phenobarbital CSCI, all patients were on midazolam CSCI (mean dose 50 mg), which was continued in 14 patients. Seventeen patients received levomepromazine CSCI (mean dose 137 mg), which was continued in 12 patients.

CONCLUSION

Phenobarbital appears to be an effective medication for PST. However, inconsistencies in dosing, concurrent sedative medication use and standardised protocols highlight areas for improvement in clinical guidelines.

Successful Use of Propofol After Failed Palliative Sedation in Patients With Refractory Symptoms

Context: Propofol is a general anesthetic used in multiple clinical scenarios. Despite growing evidence supporting its use in palliative care, propofol is rarely used in palliative sedation. Reluctance toward the adoption of propofol as a sedative agent is often associated with fear of adverse events such as respiratory arrest. Objectives: We aimed to describe efficacy and safety of palliative sedation in refractory sedation with propofol using a protocol based on low, incremental dosing. Methods: A retrospective observational study featuring inpatients receiving sedative treatment with propofol in our palliative care unit in Madrid (Spain) between March 1, 2018 and February 28, 2023, following a newly developed protocol. Results: During the study period, 22 patients underwent sedation with propofol. Propofol was used successfully to control different refractory symptoms, mainly psychoexistential suffering and delirium. All patients had undergone previous failed attempts at sedation with other medications (midazolam or lemovepromazine) and presented risk factors for complicated sedation. All patients achieved satisfactory (profound) levels of sedation measured with the Ramsay Sedation Scale, but total doses varied greatly between patients. Most patients (17, 77%) received combined therapy with propofol and other sedative medications to harness synergies. The median time between start of sedation with propofol and death was 26.0 hours. No cases of apnea or death during induction were recorded. Conclusion: A protocol for palliative sedation with propofol based on low, incremental dosing, with the option of administering an initial induction bolus, shows excellent results regarding adequate levels of sedation, without observing apnea or respiratory depression. Our results promote the use of propofol to achieve palliative sedation in patients with refractory symptoms and risk factors for complicated sedation at the end of life.

Use of Phenobarbitone for Palliative Sedation in Dyspneic Crises Due to COVID-19 Pneumonia - A Case Series

Patients who suffer from dyspnea while dying from COVID-19 are treated with opioids and benzodiazepines. In some instances, patients may experience refractory dyspnea at the end of life. Palliative sedation can be prescribed to alleviate such patients' suffering. We describe two patients being treated for severe COVID-19 pneumonia in a tertiary hospital. Both developed intractable dyspneic crises despite high-dose opioids and benzodiazepines. This led to their requirement of palliative sedation in the general ward using subcutaneous phenobarbitone (phenobarbital). We outline clinical considerations for the use of palliative sedation in COVID-19 related dyspnea. In particular, we discuss the evidence for, benefits and limitations of using phenobarbitone for palliative sedation in COVID-19 patients.