Preoperative Toxicological Screening on Perioperative Anesthetic Management

NCT07100314 | Completed

• 1 other identifier: Preoperative Toxicology
• Study Type: observational
• Target: 1,260
• Locations: 1 country
• Sites: 1

Brief Summary

Background: Preoperative substance use is a growing concern in patients undergoing metabolic bariatric surgery (MBS), but its impact on short-term outcomes remains debated. This study evaluated the association between preoperative toxicological screening test (TST) results and perioperative outcomes, including anesthesia requirements, postoperative recovery, complications, and one-year weight loss in patients undergoing MBS. Key Points

1. 1.Preoperative toxicological screening identifies a significant proportion (15.1%) of patients undergoing metabolic bariatric surgery with recent substance use that may not be disclosed through self-reporting.
2. 2.Patients with positive toxicological screening tests require significantly higher anesthesia doses, experience more severe postoperative pain, and have higher rates of complications and readmissions within 30 days.
3. 3.While short-term weight loss outcomes at one year show modest differences between toxicological screening test-positive and negative patients, the perioperative risk profile suggests the need for tailored management strategies for patients with recent substance use.

Conditions

Toxicology; Bariatric Surgery Analgesia; Bariatric Surgery; Substance Use

Keywords

Metabolic bariatric surgery; toxicological screening; substance use; short-term outcomes; pain management; anesthesia requirements; postoperative complications; weight loss

Outcome Measures

Primary Outcomes (3)

• history of specific substance use and /or detected by toxicological screening

  To determine the prevalence and patterns of substance use detected by preoperative toxicological screening tests (TST) in patients undergoing metabolic bariatric surgery (MBS) in the MENA region. Additional information regarding prescription status (prescribed versus self-prescribed) was obtained through structured patient interviews conducted by trained clinical staff for differentiation between legitimate medical use and recreational or non-prescribed substance use.

  within 30 days post operative

• Anesthesia-related outcomes included dosages of induction agents (specifically propofol) and perioperative opioid consumption (intraoperative fentanyl dose and postoperative morphine consumption).

  Recovery parameters were assessed, including recovery time (measured in minutes from extubation till meeting discharge criteria from the operative theatre (OR) to the post-anesthesia care unit (PACU)) and recovery status evaluated through Richmond Agitation-Sedation Scale (RASS). The RASS is a 10-point scale that ranges from -5 to +4, designed to evaluate a patient's level of alertness and agitation during recovery. Levels -1 to -5 denote 5 levels of sedation; levels +1 to +4 describe increasing levels of agitation. RASS level 0 is "alert and calm.

  within 30 days post operative

• Pain assessment

  was conducted using the Visual Analog Scale (VAS), measured multiple times during the first postoperative day: baseline, 1 hour, 6 hours, 12 hours, and 24 hours post-surgery. The VAS is a validated tool for pain assessment that consists of a 10-cm horizontal line with endpoints representing "no pain" (0) and "worst possible pain" (10). Patients were given 3 mg morphine if VAS scores reached ≥ 4. The time to first opioid request was also recorded as an indicator of pain onset and severity.

  within 30 days post operative

Secondary Outcomes (4)

• postoperative recovery parameter

  during the first 24 hours after surgery.

• postoperative recovery parameter

  during the first 24 hours after surgery

• postoperative recovery parameter

  during the first 24 hours after surgery.

• preoperative substance use affects short-term weight loss

  12 months postoperative

Study Arms (2)

TST-positive

The toxicological panel tested for seven major categories of substances: 1. COC (Cocaine): Detection of cocaine metabolites indicating recent cocaine use 2. AMP (Amphetamines): Screening for amphetamine and methamphetamine compounds 3. THC (Tetrahydrocannabinol): Detection of cannabis metabolites 4. MOP (Morphine/Opiates): Screening for morphine, codeine, and related opiate compounds 5. TRA (Tramadol): Specific detection of tramadol, a commonly prescribed analgesic in the region 6. BAR (Barbiturates): Detection of barbiturate compounds 7. BZO (Benzodiazepines): Screening for benzodiazepine medications

Diagnostic Test: Multi-Drug One Step Screen Test Panel (Urine)

TST-negative

patients that tested negative in the dipstick test.

Diagnostic Test: Multi-Drug One Step Screen Test Panel (Urine)

Interventions

Multi-Drug One Step Screen Test Panel (Urine) DIAGNOSTIC_TEST

Tested positive

TST-positive

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

A total of 1,260 patients were enrolled in the study and underwent preoperative toxicological screening tests (TST). The study population had a mean age of 38.4 ± 9.7 years, with a predominance of female patients (72.3%). The mean preoperative BMI was 44.2 ± 6.8 kg/m². Laparoscopic sleeve gastrectomy (LSG) was the most common procedure (68.3%), followed by one-anastomosis gastric bypass (OAGB, 21.4%) and Roux-en-Y gastric bypass (RYGB, 10.3%). Of the 1,260 patients, 190 (15.1%) tested positive on preoperative TST for at least one substance. The most detected substances were tramadol (52.6% of positive tests), cannabis (28.4%), benzodiazepines (15.8%), opiates (10.5%), amphetamines (7.9%), barbiturates (5.3%), and cocaine (2.6%). Multiple substances were detected in 18.4% of TST-positive patients. Figure 1 illustrates the distribution of substances detected in the TST-positive group.

You may qualify if:

• adult patients (≥18 years) with obesity who were scheduled to undergo primary MBS, including laparoscopic sleeve gastrectomy (LSG), Roux-en-Y gastric bypass (RYGB), or one-anastomosis gastric bypass (OAGB)
• Patient selection followed the 2022 American Society for Metabolic and Bariatric Surgery (ASMBS) and International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) guidelines for MBS

You may not qualify if:

• previous bariatric or major abdominal surgery
• emergency procedures
• chronic pain syndromes
• severe psychiatric illness
• patient refusal that would impair informed consent or compliance with study protocols
• inability to complete follow-up assessments

Sponsors & Collaborators

• General Committee of Teaching Hospitals and Institutes, Egypt: lead

Study Sites (1)

The surgical department of Medical Research Institute Hospital, Alexandria University

Alexandria, 21531, Egypt

Location

Biospecimen

Retention: SAMPLES WITH DNA

clinical utility of routine preoperative toxicological screening tests (TST) in patients undergoing primary metabolic bariatric surgery (MBS). (Urine) All participants underwent comprehensive urine toxicological screening using a standardized multi-drug panel. The screening was performed using the Multi-Drug One Step Screen Test Panel (Urine) with reference number DOA-174, lot number 0000661863, with an expiry date of December 17, 2024. This dipstick test provided rapid, point-of-care screening for a comprehensive range of substances commonly encountered in clinical practice.

MeSH Terms

Conditions

Substance-Related Disorders; Agnosia; Postoperative Complications; Weight Loss

Interventions

Urination

Condition Hierarchy (Ancestors)

Chemically-Induced Disorders; Mental Disorders; Perceptual Disorders; Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Pathologic Processes; Body Weight Changes; Body Weight

Intervention Hierarchy (Ancestors)

Urinary Tract Physiological Phenomena; Reproductive and Urinary Physiological Phenomena

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of General surgery

Study Record Dates

• First Submitted: July 17, 2025
• First Posted: August 3, 2025
• Study Start: December 1, 2023
• Primary Completion: May 1, 2024
• Study Completion: June 1, 2024
• Last Updated: August 3, 2025

Record last verified: 2025-07

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR, ANALYTIC CODE
• Time Frame: whole study period
• Access Criteria: Ask contact person

Locations

EG (1)