Acute Surgical and Procedural Pain Christopher L. Wu, MD Professor of Anesthesiology The Johns Hopkins Hospital

Overview Apply 5 dimensions from the chronic pain AAAPT to “acute surgical and procedural pain” Examine possible grouping/diagnostic criteria Propose possible surgeries/procedures to be studied

Dimensions Dimension 1: Core diagnostic criteria Dimension 2: Common features Dimension 3: Common medical comorbidities Dimension 4: Neurobiological, psychosocial and functional consequences Dimension 5: Putative neurobiological and psychosocial mechanisms, risk factors, and protective factors

Dimensions Dimension 1: Core diagnostic criteria –Symptoms, signs, and diagnostic test findings required for the diagnosis of the chronic pain condition. Includes differential diagnosis considerations. Acute Pain: –Symptoms & signs may be more homogenous than chronic pain as we are assuming there is a discrete insult/injury. Diagnostic test findings for acute pain? Diagnosis of the acute surgical/procedural pain condition may be more straightforward than chronic pain due to the presence of a discrete insult/injury.

Dimensions Dimension 2: Common features –Additional information regarding the disorder, including common pain characteristics (e.g. location, temporal qualities, descriptors), non-pain features (numbness, fatigue), the epidemiology of the condition, and life- span considerations, including those specific to pediatric and geriatric populations. These features are important in describing the disorder but are not components of the core diagnostic criteria. Acute Pain –Like that for chronic pain, we may want additional information regarding this disorder, including common pain characteristics (e.g. location, temporal qualities, descriptors), non-pain features (numbness, fatigue).

Dimensions Dimension 3: Common medical comorbidities –Medical and psychiatric disorders that commonly occur with the chronic pain condition. For example, major depression is comorbid with many chronic pain conditions. Also includes chronic overlapping pain conditions, that is, those chronic pain conditions that are comorbid with each other. Acute Pain: –Although there may not be medical and psychiatric disorders that commonly/consistently occur with the acute pain condition, we may need to be aware of risk factors for the development of CPSP. Also acute pain may be more difficult to treat in some populations (eg, opioid-tolerant, OSA).

Dimensions Dimension 4: Neurobiological, psychosocial and functional consequences –Neurobiological, psychosocial, and functional consequences of chronic pain. Examples include sleep and mood disorders and pain-related interference with daily activities. Acute Pain: –Similarly, acute pain from surgery/procedures may result in neurobiological, psychosocial, and functional consequences (eg, sleep and mood disorders and pain-related interference with daily activities) although the temporal nature is expected to the limited in most cases.

Dimensions Dimension 5: Putative neurobiological and psychosocial mechanisms, risk factors, and protective factors –Putative neurobiological and psychosocial mechanisms contributing to the development and maintenance of the chronic pain condition, including risk and protective factors. Examples include central sensitization, decreased descending inhibition, and somatosensory amplification. Acute Pain: –There may be putative neurobiological and psychosocial mechanisms contributing to the development and maintenance of the acute pain condition; however, these may be different than those for chronic pain. There may be interest in who may be “at-risk” for higher levels of acute pain or development of CPSP

Other Possible Dimensions Temporal –Accounts for different timeframes for acute pain –Somewhat one dimensional Anatomic location –Easy to define, account for multiple locations Tissue type –May account for different pain qualities

Acute Pain Procedures/Surgery Which surgeries or procedures should we consider? –Relatively common –Clinically important –Research opportunities –Different age/ethnic groups –Gender

Acute Pain Procedures/Surgery Cesarean delivery –1.3 million/yr US (1/3 of all deliveries); female; visceral- musculoskeletal; ranked #9 (out of 179) as most painful; ?CPSP Thoracotomy –Relatively common procedure; considered a relatively painful procedure; both genders; CPSP Knee arthroscopy/reconstruction –Common procedure; self-limited pain; both genders; adult and children Spine surgery –3 of top most painful surgeries; bone pain/spasm; opioid-tolerant; chronic pain; mostly adults/both genders; long-term pain Anesthesiology Apr;118(4):934-44

Acute Pain Procedures/Surgery Subcutaneous injection –Self-limited; extremely common (eg, vaccines); both genders; adults (all age groups) and children Lumbar puncture –Self-limited; relatively common; both genders; adults (all age groups) and children Biopsy –Self-limited; less common (eg, bone marrow); both genders; adults (all age groups) and children

Anesthesiology Apr;118(4):934-44

Final Thoughts Some of the chronic pain dimensions can be applied to acute surgical and procedural pain but modifications needed Differences include the presumed limited duration of injury