The Effects of Hyperventilation Prior to CO2 Insufflation During Laparoscopic Cholecystectomy

NCT ID: NCT01182545

Last Updated: 2010-11-19

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE1
• Total Enrollment: 100 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2008-12-31
• Study Completion Date: 2010-09-30

Brief Summary

The investigators postulated that the use of hyperventilation after induction of anesthesia before CO2 insufflation for laparoscopic surgery in Trendelenburg position would maintain normocapnia and reduce the hemodynamic percussion response of CO2 insufflation.

Detailed Description

The use of laparoscopic techniques has become common in clinical practice. Absorption of carbon dioxide (CO2) from the peritoneal cavity is the potential mechanism for hypercapnia and a rise in the end-tidal carbon dioxide (EtCO2). Mild hypercarbia causes sympathetic stimulation which results in a fivefold increase in arginine vasopressin (AVP), tachycardia, increased systemic vascular resistance, systemic arterial pressure, central venous pressure and cardiac output.1 Severe hypercarbia exerts a negative inotropic effect on the heart and reduces left ventricular function.2 Hemodynamic alterations occur only when the PaCO2 is increased by 30 per cent above the normal levels.

Clearance of CO2 is a function of the adequacy of alveolar ventilation with respect to pulmonary perfusion. Controlled hyperventilation has proved to be superior over spontaneous respiration or controlled normo-ventilation for maintaining normal PCO2 during laparoscopy. During pelvic laparoscopy there was a rapid rise of about 30% in the CO2 load eliminated by the lungs. This quickly reached a plateau and could be compensated by hyperventilation of the lungs with a 30% increase in minute ventilation.

Papadimitriou and co' workers concluded that under sevoflurane anesthesia MAC, prophylactic hyperventilation to ensure mild hypocapnia, (around 33 mmHg) limits the cerebral blood flow velocities enhancing effect of CO2 insufflation, compared with permissive hypercapnia (up to 45 mmHg), during gynecological laparoscopies. However, others advocated that hyperventilation and the head-up position before CO2 insufflation are not sufficient to prevent the CO2-mediated cerebral hemodynamic effects of low-pressure pneumoperitoneum (5-8 mmHg) in children, underwent laparoscopic fundoplication.

Conditions

Laparoscopic Cholecystectomy

Keywords

Anaesthesia; laparoscopic cholecystectomy; CO2 insufflation; hemodynamic; hyperventilation

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: TRIPLE

Study Groups

The normoventilation group

15 minutes prior to CO2 insufflation, the patients' lungs were ventilated with a tidal volume (TV) of about 8 mL.kg-1 and respiratory rate (R.R) owas adjusted to maintain an end-tidal CO2 (ETCO2) of 4.6-6 kPa throughout the procedure.

Group Type: PLACEBO_COMPARATOR

Ventilation

Intervention Type: PROCEDURE

Mechanical ventilation was conducted in all the patients with a Datex-Ohmeda Aestiva/5 Smart Ventilator (Madison, WI) through a rebreathing circuit incorporating a CO2 absorber, a heat and moisture exchanger using volume-controlled mode with an inspiratory to expiratory ratio of 1:2.5, and positive end-expiratory pressure (PEEP) of 5 cm H2O. Plateau pressure was kept as low as possible with an upper limit of 30 cm H2O, and the absence of auto-PEEP was ensured by a drop of the expiratory flow to zero on the flow-time curve.

The hyperventilation group

15 minutes prior to CO2 insufflation, the patients' lungs were ventilated with a TV of 8 mL.kg-1 with the adjustment of the R.R to maintain an ETCO2 of 4-4.6 kPa, until the end of anaesthesia.

Group Type: ACTIVE_COMPARATOR

Ventilation

Intervention Type: PROCEDURE

Mechanical ventilation was conducted in all the patients with a Datex-Ohmeda Aestiva/5 Smart Ventilator (Madison, WI) through a rebreathing circuit incorporating a CO2 absorber, a heat and moisture exchanger using volume-controlled mode with an inspiratory to expiratory ratio of 1:2.5, and positive end-expiratory pressure (PEEP) of 5 cm H2O. Plateau pressure was kept as low as possible with an upper limit of 30 cm H2O, and the absence of auto-PEEP was ensured by a drop of the expiratory flow to zero on the flow-time curve.

Interventions

Ventilation

Mechanical ventilation was conducted in all the patients with a Datex-Ohmeda Aestiva/5 Smart Ventilator (Madison, WI) through a rebreathing circuit incorporating a CO2 absorber, a heat and moisture exchanger using volume-controlled mode with an inspiratory to expiratory ratio of 1:2.5, and positive end-expiratory pressure (PEEP) of 5 cm H2O. Plateau pressure was kept as low as possible with an upper limit of 30 cm H2O, and the absence of auto-PEEP was ensured by a drop of the expiratory flow to zero on the flow-time curve.

Intervention Type: PROCEDURE

Eligibility Criteria

Inclusion Criteria

• ASA I & II
• aged 18-45 years
• undergoing elective laparoscopic cholecystectomy

Exclusion Criteria

• history of cardiovascular disease
• respiratory diseases
• neurological disease
• renal disease
• liver disease
• hormonal disease
• pregnancy
• obesity (defined as a body mass index> 29)
• smokers

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 45 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

King Faisal University

OTHER

Sponsor Role: lead

Responsible Party

King Faisal University

Principal Investigators

Mohamed R El Tahan, M.D.

Role: STUDY_DIRECTOR

King Faisal University

Locations

King Faisal University

Khobar, Eastern Province, Saudi Arabia

Countries

Saudi Arabia

Other Identifiers

23-10-2007

Identifier Type: -

Identifier Source: org_study_id