Subanesthetic ketamine: the way forward for pain management in sickle cell disease patients?

ABSTRACT

Introduction

Patients with sickle cell disease (SCD) present recurrent episodes of acute pain, the hallmark of the disease, and some will also develop chronic pain. Currently, the treatment of SCD acute pain only targets its symptoms, rather than underlying mechanisms, and is directed by expert and consensus guidelines.

Areas covered

While opioids remain the mainstay of therapy for acute pain and are also used to treat SCD-related chronic pain, in some patients, opioids are ineffective or are associated with severe undesirable side effects. In those instances, clinicians caring for patients with SCD face an unmet need for effective non-opioid analgesics. Recently, the use of subanesthetic ketamine has been explored as a strategy to meet this need. While definitive evidence of its efficacy is lacking, some information exists suggesting that subanesthetic ketamine improves pain control and may have opioid-sparing effects in SCD-related acute pain. However, ketamine can also yield undesirable psychotomimetic and cardiovascular effects.

Expert opinion

After weighing potential risks and benefits, in the absence of better alternatives and in settings where it can be administered safely, ketamine may be a reasonable option for patients with SCD-related acute refractory pain.

KEYWORDS:

• Ketamine
• sickle cell
• pain
• NMDA receptor
• acute

Article highlights

• In sickle cell disease (SCD), pain is a complex entity and, in some cases, its underlying mechanisms are incompletely understood.

• Opioids are the mainstay of therapy for acute pain, but in some patients with SCD opioids are ineffective and can be associated with refractory and inadequately treated pain.

• Subanesthetic ketamine has been used to treat refractory SCD-related pain based on retrospective case reports and series suggesting that ketamine improves pain control and has opioid-sparing effects.

• While definitive evidence of its efficacy is lacking, there has been a surge on the use of subanesthetic ketamine for the treatment of acute sickle pain.

• In settings where it can be administered safely, ketamine may be a reasonable option for patients with SCD-related acute refractory pain.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This work was supported by the Intramural Research Program of the National Institutes of Health Clinical Center and National Heart Lung and Blood Institute, National Institutes of Health (Grant numbers 1ZIACL090052-05, 1ZIACL090053-05, 1ZIACL090054-05, and 1ZIAHL006233-05).