Minimizing Lung Injury During Laparoscopy in Steep Trendelenburg Position

NCT ID: NCT04900714

Last Updated: 2022-01-26

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 23 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2021-06-21
• Study Completion Date: 2021-09-23

Brief Summary

The investigators hypothesize that the level of PEEP is often suboptimally applied in certain operative conditions, such as in laparoscopy with head down (Trendelenburg) positioning. This can result in excessive levels of lung stress and postoperative pulmonary complications.

In patients with steep Trendelenburg and a pneumoperitoneum, the investigators aim to

1. measure apical versus basal atelectasis using the lung ultrasound score

2. compare lung ultrasound scores at different PEEP levels

3. compare respiratory mechanics at the different PEEP levels

4. contrast the optimal PEEP level to standard practice

5. provide guidance to optimal PEEP titration in this setting for the clinician

Detailed Description

The investigators hypothesize that the level of positive end-expiratory pressure (PEEP) is often incorrectly applied in certain operative conditions, such as in laparoscopy with head down (Trendelenburg) positioning. This can result in excessive levels of lung stress and postoperative pulmonary complications.

Incorrect intra-operative ventilator management can be harmful for the patient, potentially leading to postoperative pulmonary complications and ventilator-induced lung injury. During routine anesthesia procedures, most anesthetists will set the ventilator by rule of thumb with a PEEP of 4-6 cmH2O, a tidal volume of 6-8 ml/kg of ideal body weight and a frequency of 10-15 breaths per minute in order to provide lung protective ventilation. However, due to recent advances in surgical practice, patients are more frequently placed in non- physiological states, such as Trendelenburg position up to 30° with concurrent pneumoperitoneum and intra-abdominal pressures of 15mmHg or higher, as in for example robot-assisted radical prostatectomy or gynecological procedures. This extreme positioning and increased intra-abdominal pressure can have a significant effect on respiratory mechanics and can potentially result in excessive lung stress. The changes in applied positive pressure ventilation will result in changes of regional ventilation: both an increased amount of atelectasis and an increased amount of regional hyperinflation are observed in this setting. The ideal PEEP level balances the recruitment of atelectasis versus excessive hyperinflation. These changes in regional ventilation can be assessed by lung ultrasound. The lung ultrasound score can distinguish atelectasis from normal aeration in the different lung regions of interest.

This project is designed as a single center cohort study. Non-obese (BMI < 30kg/m2), lung-healthy non-pregnant, non-smoking individuals without right sided heart failure, scheduled for elective laparoscopy of the lower abdomen, will be recruited. Standardized induction and maintenance with propofol TCI (3-6μg/l plasma concentration as calculated by the Marsh model), sufentanil (0.2μg/kg) and rocuronium (0.6mg/kg) will be provided. Neuromuscular blockade will be monitored using a train-of-four (TOF) monitor and kept with a TOF count < 1 throughout the study using additional doses if indicated. A radial arterial line will be placed. Mechanical ventilation will be provided in volume control mode with a tidal volume of 4-6 ml/kg of ideal body weight (IBW) aiming for a driving pressure ≤ 15cmH2O, a starting PEEP of 5cmH2O, a frequency of 12-18 breaths per minute titrated to the end-tidal CO2 measurement and an initial FiO2 of 0.4. An esophageal balloon catheter with pressure sensor will be used to calculate transpulmonary pressures. The balloon and pressure sensor will be calibrated as per manufacturers guideline. Respiratory parameters will be recorded and saved for later evaluation using the FluxMed GrT monitor and software (MBMED, Argentina). After inflation of the pneumoperitoneum, lung ultrasound will be performed bilaterally at the midclavicular line between the second and third ribs, at the posterior axillary line above the level of T4 and at the posterior axillary line closely superior to the diaphragm, thus retaining 6 ultrasound loops which will be saved for post-hoc lung ultrasound scoring. The lung ultrasound measurements will be repeated at different decremental levels of PEEP: 15, 10, 5 and 0 cmH2O respectively. Arterial blood gas analysis will be performed before insufflation of the pneumoperitoneum and repeated at each level of PEEP. A minimum of 4 minutes equilibration time will be provided after changing PEEP.

Conditions

Atelectasis

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: PREVENTION
• Blinding Strategy: NONE

Study Groups

Decremental PEEP

Every participant will be exposed to a stepwise decremental PEEP.

Group Type: EXPERIMENTAL

Decremental PEEP

Intervention Type: PROCEDURE

High PEEP to low PEEP.

Lung ultrasound score

Intervention Type: DIAGNOSTIC_TEST

lung ultrasound to determine the extend of atelectasis. Uses validated lung ultrasound score.

Blood gas analysis

Intervention Type: DIAGNOSTIC_TEST

Blood gas analysis to determine arterial oxygen tension

Registration of respiratory mechanics

Intervention Type: DIAGNOSTIC_TEST

Pressures and volumes will be registered by the Fluxmed respiratory monitor (MBMED, Argentina)

Evaluation of dead space

Intervention Type: DIAGNOSTIC_TEST

Dead space will be measured non-invasively using volumetric capnography on the FluxMed respiratory monitor (MBMED, Argentina)

Interventions

Decremental PEEP

High PEEP to low PEEP.

Intervention Type: PROCEDURE

Lung ultrasound score

lung ultrasound to determine the extend of atelectasis. Uses validated lung ultrasound score.

Intervention Type: DIAGNOSTIC_TEST

Blood gas analysis

Blood gas analysis to determine arterial oxygen tension

Intervention Type: DIAGNOSTIC_TEST

Registration of respiratory mechanics

Pressures and volumes will be registered by the Fluxmed respiratory monitor (MBMED, Argentina)

Intervention Type: DIAGNOSTIC_TEST

Evaluation of dead space

Dead space will be measured non-invasively using volumetric capnography on the FluxMed respiratory monitor (MBMED, Argentina)

Intervention Type: DIAGNOSTIC_TEST

Eligibility Criteria

Inclusion Criteria

• Elective laparoscopy in the Trendelenburg (head-down) position

Exclusion Criteria

• smoker
• lung disease (e.g. asthma, COPD, emphysema)
• BMI > 30 kg/m2

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 80 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University Hospital, Antwerp

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Vera Saldien, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

Head of the department of anesthesiology

Tom Schepens, MD, PhD

Role: STUDY_CHAIR

Anesthetist/intensivist

Gregory De Meyer, MD

Role: STUDY_CHAIR

Anesthetist in training

Stuart G Morrison, MD

Role: STUDY_DIRECTOR

Staff anesthetist

Locations

Antwerp University Hospital

Edegem, Antwerp, Belgium

Countries

Belgium

References

De Meyer GRA, Morrison SG, Saldien V, Jorens PG, Schepens T. Minimizing Lung Injury During Laparoscopy in Head-Down Tilt: A Physiological Cohort Study. Anesth Analg. 2023 Oct 1;137(4):841-849. doi: 10.1213/ANE.0000000000006325. Epub 2022 Dec 14.

Reference Type: DERIVED

PMID: 36729514 (View on PubMed)

Other Identifiers

1378

Identifier Type: OTHER

Identifier Source: secondary_id

20/40/516

Identifier Type: OTHER

Identifier Source: secondary_id

20/40/516

Identifier Type: -

Identifier Source: org_study_id