Differences in Incidence of Common Side Effects Between Young Adults and Elderly Patients While Using IV-PCA

In this retrospective study, postoperative pain score, PCA-related complications, the risk factors for requirement of rescue analgesics and antiemetics will be evaluated in young and elderly patients, respectively, using fentanyl-based IV PCA during postoperative 48 hours after various surgeries.

Since 2010, A PCA service team in the investigators' hospital have collected multidisciplinary clinical data from all the patients who used IV-PCA postoperatively in aim of the assessment of clinical outcome. The investigators reviewed the collected data from the patients who had used IV-PCA for pain control after an elective surgery under general or spinal anesthesia between Sep. 2010 and March. 2014. The need for informed consent was waived for this study. The investigators have used a disposable PCA pump (Ambix Anaplus®; E-Wha Fresenius Kabi, Korea or accufuser plus®; Woo Young Medical, Korea) and fentanyl was diluted in 100mL with saline for 48 hrs PCA infusion. The pump was set as follows: infusion rate as 2 ml/hr, bolus dose as 0.5 ml or 1 ml, lockout time as 15 min. It was decided at the anesthesiologist's option whether the additional analgesic drug (ketorolac or nefopam) and the antiemetic drug (ondansetron, ramosetron or palonosetron) would be added in PCA or not. The anesthesiologist who performed the anesthesia decided the amount of chosen drugs. Exclusion criteria were as following: age \< 20 years old, age 40 to 69, postoperative ventilator support or intensive care, and imperfect data. The data of the PCA regimen which has been decided were recorded and analyzed. Demographic variables including age, sex, body mass index, American Society of Anesthesiologists (ASA) physical status and history of smoking, motion sickness, postoperative nausea/vomiting, hypertension and diabetes mellitus have been analyzed. Anesthesia and surgery-related variables including the duration of anesthesia, the type of anesthesia (general or spinal), laparoscopy and the operation site (categorized in abdominal, thoracic, upper \& lower extremities, head \& neck, spine and others) were also been analyzed. PCA-related variables included total dose of fentanyl for two days (µg/kg), use of mixed additional analgesics and antiemetics in PCA and discontinuation of PCA. When the patient requested the discontinuation of IV-PCA, the reason and the time have been recorded. Postoperative variables including the numeric rating scale (NRS, 0-10, 0 = no symptom; 10= unthinkable worst pain) for pain, requirements of rescue analgesics and antiemetics were analyzed. And the postoperative complications including nausea, vomiting, headache, dizziness, and sedation were analyzed. All the postoperative variables were recorded at postoperative 0-6 hrs including stay at post-anesthesia care unit, 6-12, 12-18, 18-24 and 24-48 hrs.

Eligibility Criteria:
Inclusion Criteria:

* Patients who had used IV-PCA for pain control after an elective surgery under general or spinal anesthesia between Sep. 2010 and March. 2014

Exclusion Criteria:

* Age \< 20 years old,
* age 40 to 69,
* postoperative ventilator support or intensive care,
* and imperfect data