Clinical trial NCT03144609: Mechanical Ventilation of Obese Patients During Oral Surgical Procedures
Official title: Impact of Protective Mechanical Ventilation of Obese Patients on the Postoperative Respiratory Function During Oral Surgical Procedures
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Obesity
Keywords: mechanical ventilation, obesity, oral-surgical procedures
Lead sponsor: Klarić, Vlasta, M.D.
Sponsor class: INDIV
First posted: 2017-05-09
Enrollment: 75
Sex: ALL
Minimum age (years): 30
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The prevalence of obese patients in a great number of patients scheduled for elective surgery under general anesthesia has been on the increase. Recent studies suggest an intraoperative protective mechanical ventilation for the obese. Surgical procedures in the oral cavity increase the risk of perioperative complications of obese patients. By making this randomized clinical study, investigators want to determine whether the protective intraoperative ventilation with the use of higher positive end-expiratory pressure and recruitment maneuvers compared to ventilation with low positive end-expiratory pressure and without recruitments cause better postoperative respiratory function parameters of obese patients during oral surgical procedures. Investigators also aim to establish the fact which value of a positive end-expiratory pressure has a favorable impact on the respiratory function without negative hemodynamic effect.

Detailed description: Oral surgeries of obese patients in general endotracheal anesthesia are a special challenge as in the most extensive types of interventions any form of regional anesthesia is inadequate, duration of surgery is short but requires deep level of anesthesia after which a quick awakening and most rapid release from hospital are expected, with a known high perioperative risk complications of obese patients.

Oral surgical procedures in the oral cavity due to possible postoperative upper airway oedema increase the risk of postoperative hypoxia in obese patients. Therefore, it is important to intraoperatively mechanically ventilate obese patients with the aim of good ventilation-perfusion ratio without creating new atelectasis, to minimize the risk of postoperative respiratory decompensation and to provide rapid recovery.

As the prevalence of obesity in the world increases as chronic diseases, the number of obese patients scheduled for oral surgery is growing. Studies involving different ways of intraoperative mechanical ventilation of obese patients are mostly processed laparoscopic abdominal studies that can not exclude the additional effect of intraabdominal pressure on the formation of pulmonary atelectasis.

Eligibility criteria: Inclusion Criteria:

* body mass index greater than 30 kg / m2
* surgical operation in the area of the oral cavity in general endotracheal anesthesia - cystectomy, alveotomy, mandible and maxilla osteosynthesis after jaw trauma, operation of retained and affected teeth, orthodontic surgical treatment of jaw deformity, benign tumor surgery
* ASA (American Society of Anesthesiologists) Classification of Patients 2-3
* duration of general endotracheal anesthesia from 1 to 2.5 hours

Exclusion Criteria:

* Allergy to anesthetics
* previous lung operations
* documented heart disease (NYHA II, III)
* Pulmonary disease (asthma, COPD)
* Obstructive pulmonary function disorders according to spirometry: FVC(forced vital capacity) may and may not be normal, FEV1(forced expiratory volume at one second) \<80%, FEV1 / FVC \<80%)
* neuromuscular disease
* clinical sign of cardiovascular disease established during preoperative treatment
* pregnancy
* Patients who, for some reason after surgery, have to remain intubated and mechanically ventilated in the Intensive Medicine Unit
* refuse to sign informed consent

Primary outcomes:
measure: preoperative and postoperative change in arterial blood gas analysis within and between groups of patients
timeFrame: Preoperative parameters were compared with change in early postoperative parameter. Early postoperative measurements were measurements after 15 minutes from the operation, then in the first and third hours, and 24 hours after the operation.
Secondary outcomes:
measure: change in preoperative and postoperative degree of dyspnoea measured on Visual Analog Scale
timeFrame: 25 perioperative hours.Preoperative degree was measured one hour before the start of the operation. Early postoperative measurements were measured 15 min after the operation started, then in the first, third and 24th hours after surgery
measure: The connection between the various risks of difficult intubation and obesity.
timeFrame: up to 1 day:Visual Scale Cormack- Lehane classification was measured at laryngoscopy for intubation by investigator, all other measurements were measured once at preoperative Anesthetic examination
measure: PEEP effects on MAP
timeFrame: 1-2,5 intraoperative hours.Intraoperative measurements were performed 5 min before and 5 min after induction, then every 30 minutes during operation.Change in MAP includes only period from the beginning operation to the end of surgery and extubation.
measure: ARM(alveolar recruitment maneuver) effects on MAP
timeFrame: 1-2,5 intraoperative hours.Intraoperative measurements were performed 5 min before and 5 min after induction, then every 30 min during operation, and 5 min after ARM is performed. Change in MAP includes period from the beginning to the end of operation
Other outcomes:
Locations:
Study officials:
name: Vlasta Klarić, M.D.
role: PRINCIPAL_INVESTIGATOR
References: