Effect of Perioperative Dexmedetomidine on Chronic Post-Surgical Pain

Phone interviews were conducted at 3 months after surgery by trained pain physicians following a standardized protocol at each participating centre. Primarily, the question was asked: "Do you currently have persisting pain related to your thoracoscopic surgery ?" If the answer is "YES", the BPI and DN-4 (Douleur Neuropathique4 questions, as Neuropathic pain four questions in English) were applied for pain evaluation. After that, CPSP will be finally diagnosed focusing on key diagnostic criteria including: (1) Pain arises or intensifies following surgery; (2) Pain persists for at least three months and impacts quality of life; (3) Pain occurs after a pain-free interval or evolves from ongoing acute postoperative pain; (4) Pain is localized to the surgical site or radiates to areas corresponding to the relevant nerve distribution; and (5) Other potential causes of pain have been excluded.

The Pittsburgh Sleep Quality Index (PSQI), developed by Dr. Daniel J. Buysse and his colleagues at the University of Pittsburgh in 1989, contains 19 self-rated and 5 observer-rated questions grouped into 7 components including subjective sleep quality and sleep latency etc., with each component scored 0 - 3 and total score 0 - 21, where 5 or less means good sleep quality and 5 or more indicates poor sleep quality, and it's widely used in sleep medicine, psychology and clinical research to evaluate sleep problems, monitor treatment effects and conduct epidemiological investigations, being a reliable and valid tool for assessing sleep quality and crucial for understanding and managing sleep-related issues.

The Richards-Campbell Sleep Questionnaire (RCSQ) is a prominent tool in sleep research and clinical practice for gauging sleep quality. It comprehensively evaluates sleep aspects from respondents' subjective views.

Comprising multiple items, it covers sleep onset latency (time to fall asleep), sleep depth, sleep duration, and wake-up frequency at night. It may also involve related factors like sleep environment quality and sleep's impact on daily life.

With specific questions and response options, individuals rate sleep experiences numerically or descriptively. Data from the RCSQ aids in diagnosing sleep disorders, evaluating treatment efficacy, and conducting sleep-related epidemiological studies. It is mainly intended for the assessment of short-term sleep conditions during hospitalization.

We will use Huawei smart wearable devices to assess the objective sleep conditions of patients. The definition of total sleep duration is as follows: Before the sleep on the first night before their surgery, a wearable sleep monitoring device was placed on the non-dominant wrist of each participant. The patients wore this sleep monitoring device throughout their hospitalization. The sleep monitoring period is from 20:00 to 20:00 the next day.

The indicator of Wake-up time during sleep refers to the total time a person is awake after initially falling asleep.

The deep sleep duration: According to Huawei's scientific sleep (TruSleep™) technology, the sleep status of patients is determined by analyzing data such as the patients' heart rate and body movements, and it is recorded.

The Hospital Anxiety and Depression Scale (HADS) is a widely utilized psychological assessment tool. It aims to screen and evaluate anxiety and depression levels of patients in hospital or clinical settings. Comprising 14 items split into an Anxiety Subscale and a Depression Subscale with 7 items each, it assesses symptoms related to both. Respondents rate items based on their past week's feelings. Proven reliable and valid across diverse populations and cultures, it's handy in medical settings for differentiating coexisting mental symptoms with physical illnesses. Easy to administer and score, it's crucial for early detection, treatment planning, and monitoring, aiding comprehensive mental health management.

The Numerical Rating Scale (NRS) for pain is a commonly used tool in healthcare to gauge patients' pain intensity. It's a subjective measure where patients rate pain on a 0 - 10 scale. 0 means no pain; 10 is the worst imaginable pain. Scores 3 and below suggest mild pain with little impact, 4 - 6 moderate pain affecting daily life somewhat, and 7 and above severe pain needing prompt attention.

It's practical for its simplicity. Medical staff can administer it quickly during consultations. Patients can easily understand and use it to convey pain feelings. This helps professionals evaluate pain severity, plan treatments, and monitor pain relief. Overall, the NRS is vital in pain assessment and management, enhancing medical care quality and patient comfort.

The Quality of Recovery-15 (QoR-15) assessment scale is a professional tool for evaluating the recovery quality of patients post-surgery or after certain medical interventions. It is composed of 15 items, with each item scored from 0 to 10 points, and the total score ranges from 0 to 150 points. The higher the score, the better the quality of recovery.

These 15 items cover five dimensions: physical comfort, emotional state, physical independence, psychological support, and pain. The QoR-15 scale is recognized for its high reliability and validity. It is easy to administer and score, which is of great significance in assessing patients' recovery status and guiding medical staff to formulate appropriate treatment and care plans.

Short Form-36 Health Survey Questionnaire (SF-36) The SF-36 is a widely recognized and commonly used instrument for assessing quality of life. It consists of 36 questions covering eight domains, such as physical functioning, role limitations due to physical problems, social functioning, and mental health.The scale provides a comprehensive view of an individual's quality of life, generating scores that help healthcare providers understand patients' well-being and make more informed decisions in diagnosis, treatment, and care, with good reliability and validity demonstrated in various studies.

Phone interviews were conducted at 3 months after surgery by trained pain physicians following a standardized protocol at each participating centre. Primarily, the question was asked: "Do you currently have persisting pain related to your thoracoscopic surgery ?" If the answer is "YES", the BPI and DN-4 (Douleur Neuropathique4 questions, as Neuropathic pain four questions in English) were applied for pain evaluation. After that, CPSP will be finally diagnosed focusing on key diagnostic criteria including: (1) Pain arises or intensifies following surgery; (2) Pain persists for at least three months and impacts quality of life; (3) Pain occurs after a pain-free interval or evolves from ongoing acute postoperative pain; (4) Pain is localized to the surgical site or radiates to areas corresponding to the relevant nerve distribution; and (5) Other potential causes of pain have been excluded.