Analgesic Consumption in the Early Postoperative Period: A Prospective Observational PACU Study

Factors Influencing Analgesic Consumption in the Early Postoperative Period: A Prospective Observational Study in the Post-Anesthesia Care Unit

Postoperative pain remains a significant clinical challenge that directly affects patient recovery, functional outcomes, and overall quality of care. Inadequate pain control in the early postoperative period is associated with delayed mobilization, increased risk of complications, prolonged hospital stay, and the development of chronic pain. The post-anesthesia care unit (PACU) represents a critical phase in which pain is actively assessed and managed, and analgesic consumption during this period serves as an objective indicator of analgesic requirements and effectiveness of perioperative pain strategies.

This prospective observational study aims to identify patient-related, surgical, and anesthesia-related factors influencing analgesic consumption in the early postoperative period among adult patients admitted to the PACU following elective surgery. No additional interventions will be performed, and all perioperative management will follow routine clinical practice. Data will be collected prospectively from clinical records, anesthesia charts, and PACU monitoring forms.

The primary outcome is total analgesic consumption during the PACU stay. Secondary outcomes include pain intensity assessed using a standardized pain scale at PACU admission and discharge, requirement for rescue analgesia, incidence of postoperative nausea and vomiting, and length of stay in the PACU.

The findings of this study are expected to contribute to the identification of patients at higher risk for increased analgesic requirements and to support the development of individualized pain management strategies, ultimately improving perioperative care quality and patient outcomes.

Study Overview

• Status: Recruiting
• Conditions: Postoperative Pain; Pain Management; Analgesic Consumption
• Intervention / Treatment: Other: Observational Assessment

Detailed Description

Postoperative pain is a major clinical concern that significantly affects recovery, patient satisfaction, and overall perioperative outcomes. Inadequate pain control in the early postoperative period is associated with delayed mobilization, increased risk of complications, prolonged hospital stay, and the development of chronic postoperative pain. Therefore, early identification of factors influencing analgesic requirements is essential for optimizing individualized pain management strategies.

The post-anesthesia care unit (PACU) represents a critical period during which patients are closely monitored following surgery, and pain management is actively adjusted. Analgesic consumption during this phase provides an objective and clinically relevant measure of pain management adequacy. However, analgesic requirements may vary widely depending on patient-related factors (such as age, sex, and body mass index), surgical characteristics (type and duration of surgery), and anesthesia-related variables (anesthetic technique, intraoperative analgesic administration, and use of regional anesthesia).

This study is designed as a single-center, prospective observational study conducted in the post-anesthesia care unit of a tertiary oncology hospital. Adult patients undergoing elective surgical procedures will be included. No additional interventions will be performed, and all perioperative care will be administered according to routine clinical practice. Data will be collected prospectively from anesthesia records, PACU monitoring forms, and hospital electronic systems.

The primary outcome is total analgesic consumption during the PACU stay. Secondary outcomes include pain intensity at PACU admission and discharge, requirement for rescue analgesia, incidence of postoperative nausea and vomiting, and length of stay in the PACU.

The findings of this study are expected to contribute to the identification of patients at higher risk for increased analgesic requirements in the early postoperative period. These results may support the development of individualized and more effective pain management strategies and improve overall perioperative care quality.

• Study Type: Observational
• Enrollment (Estimated): 254

Contacts and Locations

• Study Contact: Name: Mustafa Kemal Şahin; Phone Number: +905075800976; Email: mksahin@msn.com

Study Locations

• Turkey (Türkiye)
  • Yenimahalle
    • Ankara, Yenimahalle, Turkey (Türkiye), 06200
      • Recruiting
      • Dr. Abdurrahman Yurtaslan Ankara Oncology Education and Research Hospital Clinic of Anesthesiology and Rea
      • Contact: Mustafa Kemal SAHIN, Dr; Phone Number: +905075800976; Email: mksahin@msn.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Adult patients undergoing elective surgical procedures and admitted to the post-anesthesia care unit (PACU) in a tertiary oncology hospital. The study population represents a heterogeneous surgical cohort managed under routine perioperative care conditions.

Description

Inclusion Criteria:

• Adults aged 18 years and older
• Undergoing elective surgical procedures
• Admitted to the post-anesthesia care unit (PACU) after surgery
• Receiving general and/or regional anesthesia
• Able to provide informed consent

Exclusion Criteria:

• Patients younger than 18 years
• Emergency surgical procedures
• Patients transferred directly to the intensive care unit postoperatively
• PACU stay shorter than 30 minutes
• Patients unable to communicate or assess pain
• Incomplete clinical records
• Refusal to participate in the study

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

PACU Observational Cohort; This study consists of a single observational cohort of adult patients undergoing elective surgery and subsequently monitored in the post-anesthesia care unit (PACU). No intervention is applied as part of the study. All patients receive standard perioperative care according to institutional clinical practice. Data on analgesic consumption, pain scores, and perioperative variables are collected prospectively to evaluate factors influencing analgesic requirements in the early postoperative period.

Other: Observational Assessment; This is a non-interventional observational study. No experimental intervention is applied. All patients receive routine perioperative care according to institutional clinical practice. The study involves prospective collection and analysis of clinical data related to analgesic consumption and associated factors during the early postoperative period in the post-anesthesia care unit (PACU).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total Analgesic Consumption in the PACU	Total amount of analgesic medications administered to patients during their stay in the post-anesthesia care unit (PACU). Analgesic consumption will be recorded and standardized (e.g., converted to morphine equivalents if applicable) to allow comparison across patients.	During PACU stay (from admission to discharge, within approximately 0-4 hours postoperatively)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain Intensity at PACU Admission	Pain intensity assessed at admission to the post-anesthesia care unit (PACU) using a standardized pain scale (e.g., Visual Analog Scale or Numeric Rating Scale, 0-10, where 0 indicates no pain and 10 indicates worst imaginable pain).	At PACU admission (within the immediate postoperative period)
Pain Intensity at PACU Discharge	Pain intensity assessed at discharge from the post-anesthesia care unit (PACU) using a standardized pain scale (e.g., Visual Analog Scale or Numeric Rating Scale, 0-10).	At PACU discharge (within approximately 0-4 hours postoperatively)
Requirement for Rescue Analgesia in the PACU	Need for additional rescue analgesic treatment during PACU stay, recorded as whether rescue analgesia was required.	During PACU stay (from admission to discharge, within approximately 0-4 hours postoperatively)
Incidence of Postoperative Nausea and Vomiting in the PACU	Occurrence of postoperative nausea and/or vomiting during PACU stay, recorded based on routine clinical assessment.	During PACU stay (from admission to discharge, within approximately 0-4 hours postoperatively)
Length of Stay in the PACU	Duration of time spent in the post-anesthesia care unit, measured in minutes from PACU admission to discharge.	During PACU stay (from admission to discharge, within approximately 0-4 hours postoperatively)

Collaborators and Investigators

• Sponsor: Dr Abdurrahman Yurtaslan Ankara Oncology Training and Research Hospital

Publications and helpful links

General Publications

• Apfelbaum JL, Chen C, Mehta SS, Gan TJ. Postoperative pain experience: results from a national survey suggest postoperative pain continues to be undermanaged. Anesth Analg. 2003 Aug;97(2):534-540. doi: 10.1213/01.ANE.0000068822.10113.9E.
• Kehlet H, Dahl JB. Anaesthesia, surgery, and challenges in postoperative recovery. Lancet. 2003 Dec 6;362(9399):1921-8. doi: 10.1016/S0140-6736(03)14966-5.
• Gan TJ, Diemunsch P, Habib AS, Kovac A, Kranke P, Meyer TA, Watcha M, Chung F, Angus S, Apfel CC, Bergese SD, Candiotti KA, Chan MT, Davis PJ, Hooper VD, Lagoo-Deenadayalan S, Myles P, Nezat G, Philip BK, Tramer MR; Society for Ambulatory Anesthesia. Consensus guidelines for the management of postoperative nausea and vomiting. Anesth Analg. 2014 Jan;118(1):85-113. doi: 10.1213/ANE.0000000000000002.

Study record dates

Study Major Dates

• Study Start (Actual): April 5, 2026
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): July 20, 2026

Study Registration Dates

• First Submitted: April 17, 2026
• First Submitted That Met QC Criteria: April 17, 2026
• First Posted (Actual): April 23, 2026

Study Record Updates

• Last Update Posted (Actual): April 30, 2026
• Last Update Submitted That Met QC Criteria: April 26, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Nervous System Diseases; Postoperative Complications; Pathologic Processes; Neurobehavioral Manifestations; Perceptual Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Postoperative; Agnosia
• Other Study ID Numbers: 2026-04/75

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data (IPD) will not be shared due to institutional data protection policies and the need to maintain patient confidentiality. All data collected in this study will be anonymized and used solely for the purposes of this research.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No