Effect of Dexmedetomidine on Lung Protection in Elderly Patients Undergoing Laparoscopic Surgery for Colorectal Cancer (Dex)

The primary change in aging lung tissue among older people is atrophy, leading to a significant decline in ventilatory function. Intraoperative mechanical ventilation further decreases lung compliance and ventilatory function in elderly patients, making them more susceptible to respiratory dysfunction and postoperative pulmonary complications, which severely affects patient safety and postoperative recovery. Dexmedetomidine is a highly selective α2-adrenergic receptor agonist, and several studies have found that intravenous infusion of dexmedetomidine exerted lung protective effects during single-lung ventilation thoracic surgery. However, one study found that continuous intravenous dexmedetomidine infusion during low-temperature cardiac arrest aortic surgery did not improve perioperative respiratory mechanics and oxygenation. Therefore, this project aims to investigate the lung protective effects of continuous intravenous infusion of dexmedetomidine during laparoscopic surgery for elderly patients with rectal or sigmoid colon cancer.

Study Overview

• Status: Completed
• Conditions: Lung Injury; Dexmedetomidine; Rectal Tumors; Surgery, Laparoscopic; Tumor of Sigmoid Colon
• Intervention / Treatment: Drug: Dexmedetomidine; Other: Normal saline

Detailed Description

As the body ages, all organs and tissues gradually undergo aging. Research has found that aging becomes increasingly significant after age 60, with the main change in pulmonary tissue aging being atrophy and a substantial decrease in ventilatory function. In elderly patients undergoing surgery, mechanical ventilation during surgery further reduces lung compliance, leading to an increased risk of respiratory dysfunction and postoperative pulmonary complications, which severely affect patient safety and postoperative recovery. Furthermore, due to its advantages, such as minimal trauma, less postoperative pain, and faster wound recovery, laparoscopic surgery has gradually become an essential surgical approach. However, during surgery, pneumoperitoneum and head-down position can cause diaphragmatic elevation, increased thoracic pressure, increased airway pressure, decreased lung compliance, and further aggravation of respiratory dysfunction and postoperative pulmonary complications. Therefore, exploring effective measures to protect the lungs during the perioperative period has always been a critical research direction for anesthesiologists.

Dexmedetomidine is a highly selective α2-adrenergic receptor agonist that mainly functions as a sedative and hypnotic, often used as an adjuvant in anesthesia. In recent years, some studies have found that intravenous infusion of dexmedetomidine during single-lung ventilation in thoracic surgery can play a lung-protective role by reducing the inflammatory response, improving oxidative stress, improving respiratory mechanics, increasing oxygenation, and reducing postoperative pulmonary complications. In obese patients undergoing laparoscopic sleeve gastrectomy, continuous intravenous infusion of dexmedetomidine can improve respiratory mechanics and increase oxygenation. However, some studies have also found that constant intravenous infusion of dexmedetomidine during chest aortic surgery with low-temperature cardiac arrest does not improve perioperative respiratory mechanics and oxygenation. In addition, it is unclear whether dexmedetomidine also has a lung-protective effect in elderly patients undergoing laparoscopic surgery in the head-down position.

According to the latest data statistics, the incidence and mortality of colorectal cancer rank among the top five malignant tumors globally, making it one of the primary cancers that endanger life and health. Although colorectal cancer is showing a trend toward younger age, it is still predominantly seen in elderly patients. Laparoscopic surgery for tumor resection is the primary treatment method, and during the surgery, a head-down position is required to expose the surgical field fully. As the head-down angle is the same for rectal cancer and sigmoid colon cancer laparoscopic surgery, this project focuses on elderly patients undergoing laparoscopic rectal or sigmoid colon cancer surgery. It explores the lung-protective effect of continuous intravenous infusion of dexmedetomidine during surgery, providing guidance for anesthesia management in this patient population.

• Study Type: Interventional
• Enrollment (Actual): 64
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Chongqing Municipality
    • Chongqing, Chongqing Municipality, China, 400000
      • The Second Affiliated Hospital of Chongqing Medical University

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Patients undergoing elective laparoscopic surgery for rectal or sigmoid colon cancer.
2. American Society of Anesthesiologists (ASA) physical status classification I-III.
3. Age ≥60 years and <85 years.
4. Voluntary participation and ability to understand and sign the informed consent form.

Exclusion Criteria:

1. Patients with obesity (BMI>28 kg/m2)
2. Grade 3 hypertensive patients (systolic blood pressure ≥180 mmHg and/or diastolic blood pressure ≥110 mmHg)
3. Patients with acute coronary syndrome, sinus bradycardia (heart rate <45 beats/minute), II or III degree atrioventricular block, or NYHA heart failure class III or IV
4. Patients with a history of severe chronic obstructive pulmonary disease (COPD) (GOLD stage III or IV), severe or uncontrolled bronchial asthma, lung infections, bronchiectasis, thoracic deformities, and chest diseases (such as mediastinal tumors and thoracic tumors)
5. Pulmonary artery pressure ≥ 60 mmHg
6. Patients with Child-Pugh Class B or C liver function
7. Patients with stage 4 or 5 chronic kidney disease
8. Patients with hyperthyroidism, pheochromocytoma
9. Patients with hearing, intellectual, communication, or cognitive impairments
10. Patients who cannot cooperate with the study for any reason, or whom the investigator deems unsuitable for inclusion in this trial.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Health Services Research
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dexmedetomidine; After anesthesia induction, intravenous infusion of dexmedetomidine at 1μg/kg was administered and completed within 20 minutes, followed by continuous infusion at 0.3μg/kg/h until 30 minutes prior to the end of surgery.	Drug: Dexmedetomidine; After anesthesia induction, intravenous infusion of dexmedetomidine at 1μg/kg was administered and completed within 20 minutes, followed by continuous infusion at 0.3μg/kg/h until 30 minutes prior to the end of surgery.; Other Names: Dexmedetomidine Hydrochloride
Placebo Comparator: Control; After anesthesia induction, 0.25 ml/kg of normal saline was infused within 20 minutes, followed by a continuous infusion of 0.075 ml/kg/h until 30 minutes before the end of surgery.	Other: Normal saline; After anesthesia induction, 0.25 ml/kg of normal saline was infused within 20 minutes, followed by a continuous infusion of 0.075 ml/kg/h until 30 minutes before the end of surgery.; Other Names: Saline

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
oxygenation index	oxygenation index is the ratio of partial pressure of O2 in arterial blood to fraction of inspired oxygen, namely PaO2/FiO2 ratio.	When patients enter the operation room (T0), 5 minutes after completion of pneumoperitoneum and trendelenburg position (T1), 30 (T2) and 60 (T3) minutes after trendelenburg position, when extubate the endotracheal tube (about 30 min postoperatively, T4)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
PaCO2	arterial carbon dioxide pressure assessed by arterial blood gas measurement.	When patients enter the operation room (T0), 5 minutes after completion of pneumoperitoneum and trendelenburg position (T1), 30 (T2) and 60 (T3) minutes after trendelenburg position, when extubate the endotracheal tube (about 30 min postoperatively, T4)
EtCO2	end-tidal carbon dioxide pressure assessed by arterial blood gas measurement.	5 minutes after establishment of pneumoperitoneum and trendelenburg position (T1), 30 minutes after trendelenburg position (T2), 60 minutes after trendelenburg position (T3)
Pplat	plateau pressure (Pplat) is the end-inspiratory airway pressure and is measured just after airflow has ceased, which is displayed automatically on the anesthesia machine.	5 minutes after establishment of pneumoperitoneum and trendelenburg position (T1), 30 minutes after trendelenburg position (T2), 60 minutes after trendelenburg position (T3)
Ppeak	peak airway pressure is the highest pressure measured during the respiratory cycle and is a function of both the resistance of the airways and the compliance of the respiratory system, which is displayed automatically on the anesthesia machine.	5 minutes after establishment of pneumoperitoneum and trendelenburg position (T1), 30 minutes after trendelenburg position (T2), 60 minutes after trendelenburg position (T3)
lung compliance	lung compliance is defined as the change in lung volume for a unit change in transalveolar pressure, which is displayed automatically on the anesthesia machine.	5 minutes after establishment of pneumoperitoneum and trendelenburg position (T1), 30 minutes after trendelenburg position (T2), 60 minutes after trendelenburg position (T3)
Vd/Vt	Vd/Vt represents dead space ventilation, which is the volume of ventilated air that does not participate in gas exchange. Vd/Vt = 1.14 × (PaCO2-EtCO2) / PaCO2-0.005.	5 minutes after establishment of pneumoperitoneum and trendelenburg position (T1), 30 minutes after trendelenburg position (T2), 60 minutes after trendelenburg position (T3)
Qs/Qt	Qs/Qt is a measurement of pulmonary shunt. It describes the percentage of blood that reaches the left side of the heart without picking up oxygen. Qs/Qt = (CcO2 - CaO2) / (CcO2 - CvO2), where CcO2 = pulmonary end-capillary O2 content, same as alveolar O2 content, CaO2 = arterial O2 content, CvO2 = mixed venous O2 content.	When patients enter the operation room (T0), 5 minutes after completion of pneumoperitoneum and trendelenburg position (T1), 30 (T2) and 60 (T3) minutes after trendelenburg position, when extubate the endotracheal tube (about 30 min postoperatively, T4)
PA-aO2	alveolar-arterial oxygen gradient measures the difference between the oxygen concentration in the alveoli and arterial system, which can be obtained from the arterial blood gas measurement.	When patients enter the operation room (T0), 5 minutes after completion of pneumoperitoneum and trendelenburg position (T1), 30 (T2) and 60 (T3) minutes after trendelenburg position, when extubate the endotracheal tube (about 30 min postoperatively, T4)
SPO2	oxygen saturation refers to the amount of oxygen bound to hemoglobin in arterial blood.	When patients enter the operation room (T0), 5 minutes after trendelenburg position (T1), 30 (T2) and 60 (T3) minutes after trendelenburg position, when extubate the endotracheal tube (about 30 min postoperatively, T4), postoperative day 1-3
Blood pressure	Systolic blood pressure, diastolic blood pressure, mean arterial pressure	When patients enter the operation room (T0), 5 minutes after trendelenburg position (T1), 30 (T2) and 60 (T3) minutes after trendelenburg position, when extubate the endotracheal tube (about 30 min postoperatively, T4), postoperative day 1-3
HR	hear rate	When patients enter the operation room (T0), 5 minutes after trendelenburg position (T1), 30 (T2) and 60 (T3) minutes after trendelenburg position, when extubate the endotracheal tube (about 30 min postoperatively, T4), postoperative day 1-3
Lac	lactic acid in blood	When patients enter the operation room (T0), 5 (T1), 30 (T2) and 60 (T3) min after trendelenburg position, and when the tracheal tube was extubated (T4)
WBC	White blood cell counting in blood	before surgery, postoperative day 1
NEU	neutrophil counting in blood	before surgery, postoperative day 1
NEU(%)	percentage of neutrophil in blood	before surgery, postoperative day 1
TV	Tidal Volume	before surgery, postoperative day 1
MVV	minute ventilation volume	before surgery, postoperative day 1
RR	respiration rate	before surgery, postoperative day 1
Postoperative pulmonary complications	The incidence of postoperative pulmonary complications was assessed according to the Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) definition.	postoperative day 1, 2, and 3
The length of postoperative hospital stay	The days stayed in hosptial after surgery	From the first day after surgery until the date of discharged from the hospital, assessed up to 1 months.
Postoperative hospitalization costs	All fees cost postoperatively	From the first day after surgery until the date of discharged from the hospital, assessed up to 1 months.

Collaborators and Investigators

• Sponsor: The Second Affiliated Hospital of Chongqing Medical University
• Investigators: Principal Investigator: ling Dan, BD, The Second Affiliated Hospital of Chongqing Medical University

Publications and helpful links

General Publications

• Lee SH, Kim N, Lee CY, Ban MG, Oh YJ. Effects of dexmedetomidine on oxygenation and lung mechanics in patients with moderate chronic obstructive pulmonary disease undergoing lung cancer surgery: A randomised double-blinded trial. Eur J Anaesthesiol. 2016 Apr;33(4):275-82. doi: 10.1097/EJA.0000000000000405.
• Jannu V, Dhorigol MG. Effect of Intraoperative Dexmedetomidine on Postoperative Pain and Pulmonary Function Following Video-assisted Thoracoscopic Surgery. Anesth Essays Res. 2020 Jan-Mar;14(1):68-71. doi: 10.4103/aer.AER_9_20. Epub 2020 Mar 16.
• Jiang H, Kang Y, Ge C, Zhang Z, Xie Y. One-lung ventilation patients: Clinical context of administration of different doses of dexmedetomidine. J Med Biochem. 2022 Apr 8;41(2):230-237. doi: 10.5937/jomb0-33870.
• Xia R, Xu J, Yin H, Wu H, Xia Z, Zhou D, Xia ZY, Zhang L, Li H, Xiao X. Intravenous Infusion of Dexmedetomidine Combined Isoflurane Inhalation Reduces Oxidative Stress and Potentiates Hypoxia Pulmonary Vasoconstriction during One-Lung Ventilation in Patients. Mediators Inflamm. 2015;2015:238041. doi: 10.1155/2015/238041. Epub 2015 Jul 26.
• Kostroglou A, Kapetanakis EI, Matsota P, Tomos P, Kostopanagiotou K, Tomos I, Siristatidis C, Papapanou M, Sidiropoulou T. Monitored Anesthesia Care with Dexmedetomidine Supplemented by Midazolam/Fentanyl versus Midazolam/Fentanyl Alone in Patients Undergoing Pleuroscopy: Effect on Oxygenation and Respiratory Function. J Clin Med. 2021 Aug 9;10(16):3510. doi: 10.3390/jcm10163510.
• Hasanin A, Taha K, Abdelhamid B, Abougabal A, Elsayad M, Refaie A, Amin S, Wahba S, Omar H, Kamel MM, Abdelwahab Y, Amin SM. Evaluation of the effects of dexmedetomidine infusion on oxygenation and lung mechanics in morbidly obese patients with restrictive lung disease. BMC Anesthesiol. 2018 Aug 14;18(1):104. doi: 10.1186/s12871-018-0572-y.
• Kim S, Park SJ, Nam SB, Song SW, Han Y, Ko S, Song Y. Pulmonary effects of dexmedetomidine infusion in thoracic aortic surgery under hypothermic circulatory arrest: a randomized placebo-controlled trial. Sci Rep. 2021 May 26;11(1):10975. doi: 10.1038/s41598-021-90210-w.

Study record dates

Study Major Dates

• Study Start (Actual): April 17, 2023
• Primary Completion (Actual): February 3, 2024
• Study Completion (Actual): February 27, 2024

Study Registration Dates

• First Submitted: December 13, 2023
• First Submitted That Met QC Criteria: January 27, 2026
• First Posted (Actual): February 4, 2026

Study Record Updates

• Last Update Posted (Actual): February 4, 2026
• Last Update Submitted That Met QC Criteria: January 27, 2026
• Last Verified: April 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Wounds and Injuries; Neoplasms by Site; Neoplasms; Intestinal Diseases; Respiratory Tract Diseases; Gastrointestinal Neoplasms; Digestive System Neoplasms; Digestive System Diseases; Gastrointestinal Diseases; Colorectal Neoplasms; Intestinal Neoplasms; Rectal Diseases; Lung Diseases; Colonic Diseases; Sigmoid Diseases; Thoracic Injuries; Colonic Neoplasms; Rectal Neoplasms; Lung Injury; Sigmoid Neoplasms; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Pharmaceutical Preparations; Azoles; Imidazoles; Inorganic Chemicals; Chlorine Compounds; Crystalloid Solutions; Isotonic Solutions; Solutions; Sodium Compounds; Chlorides; Hydrochloric Acid; Dexmedetomidine; Saline Solution; Sodium Chloride
• Other Study ID Numbers: Research NO. 64 for 2023

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Individual participant data (IPD) will be available with the corresponding author when required.
• IPD Sharing Time Frame: The data will be available when published and kept for 5 years.
• IPD Sharing Access Criteria: Researchers who provide a methodologically sound proposal.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE; CSR

Drug and device information, study documents

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