Effects of Alveolar Recruitment Strategies on Arterial Oxygenation and Postoperative Inflammatory Response During Laparoscopic Bariatric Surgery: A Randomised Control Trial.
Condition: Bariatric Surgery Candidate
Study type: Interventional

Summary: 
      even though the advancement of ambulatory bariatric surgeries, yet the precise spot of
      recruitment manoeuvres as a secure and efficient approach to enhance the respiratory efficacy
      of obese patients is still obscured. Previous research have extensively focused their
      attention towards alveolar recruitment with various positive end-expiratory pressure (PEEP)
      levels to alleviate anaesthesia induced pulmonary collapse and enhance arterial oxygenation.

      Patients and methods: a prospective randomized study involved 60 adult obese patients (18-65
      years), with American Society of Anaesthesiologists physical Status classification 1-2,
      enrolled in 2 groups; Group S: received protective lung strategy with recruitment manoeuvre
      (RM) every 30 minutes and steady PEEP (10) cm H2o in between RM till end of surgery. Group D:
      received protective lung strategy with recruitment manoeuvre (RM) every 30 minutes and
      decreasing PEEP (15, 10, and 5) cm H20 (10 minutes for each level) in between RM till end of
      surgery.
    

Detailed description: 
      -  Atelectasis arises shortly following onset of anaesthesia even among a healthy
           volunteer, and is closely correlated to escalation of intrapulmonary hypoxemia and
           inevitable gas exchange derangement .

        -  sixty adult obese patients (body mass index more than 35 kg/m2), of both sexes, aged
           from 18-65 years old, with American Society of Anaesthesiologists physical Status
           classification scores of 1-2, scheduled for laparoscopic bariatric procedures. Exclusion
           criteria were patients refusal, history of significant pulmonary disease (obstructive or
           restrictive), previous pneumothorax, significant cardiac dysfunction (arrhythmias ±
           unstable haemodynamics, left ventricular ejection fraction < 40%), difficult intubation
           as well as those suffering from significant hepatic or renal impairment. Furthermore,
           patients developed episodes of hemodynamic instability (like desaturation (Sp02< 90 %)
           or mean blood pressure (MAP) < 60 mmHg) during recruitment manoeuvre were omitted from
           the study.

        -  Subjects were randomly assigned -via closed envelopes technique opened immediately
           before induction- into 2 equal groups (n=30 each) to receive 1 of the following
           ventilatory regimens:

             -  Group S: patients received protective lung strategy with recruitment manoeuvre (RM)
                every 30 minutes and steady PEEP (10) cm H2o in between RM till end of surgery.

             -  Group D: patients received protective lung strategy with recruitment manoeuvre (RM)
                every 30 minutes and decreasing PEEP (15, 10, and 5) cm H20 (10 minutes for each
                level) in between RM till end of surgery.

        -  Anaesthesia was induced with lidocaine (1mg/kg) followed by (1.5 - 2 mg/kg) propofol
           (ideal body weight) and (1-1.5 μg/kg) fentanyl. Endotracheal intubation was accomplished
           with rocuronium (1mg/kg) and a suitable sized tube (8.0 ID). Anaesthesia was maintained
           with sevoflurane (1-2 %) with (50 %) oxygen in air. Neuromuscular block was continued
           with rocuronium boluses monitored by train-of four along with additional doses of
           opioids given as required to achieve a suitable clinical depth of anaesthesia. Precise
           fluid replacement was administrated consistent with the standard administration
           guidelines during anaesthesia.

        -  Patients were ventilated using Datex-Ohmeda Aestiva/5 (Madison, WI) anaesthesia machine,
           (volume controlled mode) with lung protective strategy using a tidal volume of 6- 8
           ml/kg ideal body weight, (5-10 cm H20) PEEP and 50 % O2 in air adjusted to reach Spo2 ≥
           95 %. The respiratory rate was adjusted to keep end - tidal Co2 level between (35 -45
           mmHg), and inspiratory to expiratory times at a ratio 1:2.

        -  Measurements

             1. Hemodynamic parameters: HR and MAP.

             2. Respiratory mechanics: Peak airway pressure (Paw-peak) and Plateau pressure
                (Paw-plat).

             3. Oxygenation parameters: Partial arterial tension of oxygen (PaO2), PaO2/FiO2 ratio
                and oxygen saturation (SpO2).

                All the previous measurements were recorded at the following time points: T0
                (baseline value on room air), T5 (5 minutes after pneumoperitoneum), T30 (30
                minutes after first RM), T6o (60 minutes after first RM), T90 (90 minutes after
                first RM), TE (20 minutes after the end of surgery on nasal cannula 3 L /min).
                Additional arterial blood gases analysis was performed in the PACU after 30 mins
                and 1 hr postoperatively.

             4. Serum interleukins (IL)-6 and (IL)-8, using enzyme-linked immunosorbent assay
                (ELISA) (Biosource, Biosite, Germany) in (pg/ml) were measured as baseline
                preoperative value and after 24 hr postoperatively. Validation of methods and
                degrees of concentrations was done following to the accompanied instructions.

             5. Postoperative pulmonary and non-pulmonary complication - (if any) - were assessed
                and reported in the PACU.

             6. Other variables like: duration of anaesthesia, duration of surgery,
                pneumoperitoneum time, number of patients needed vasopressors, length of ICU stay
                and hospital stay.
    

Intervention name(s): protective lung strategy with recruitment manoeuvre (RM) - steady PEEP; protective lung strategy with recruitment manoeuvre (RM) - decreasing PEEP
Intervention type(s): Procedure; Procedure
Intervention description(s): protective lung strategy with recruitment manoeuvre (RM) every 30 minutes and steady PEEP (10) cm H2o in between RM till end of surgery.; protective lung strategy with recruitment manoeuvre (RM) every 30 minutes and decreasing PEEP (15, 10, and 5) cm H20 (10 minutes for each level) in between RM till end of surgery.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: 60 adult obese patients (18-65 years), with American Society of Anaesthesiologists physical Status classification 1-2, enrolled in 2 groups; Group S: received protective lung strategy with recruitment manoeuvre (RM) every 30 minutes and steady PEEP (10) cm H2o in between RM till end of surgery. Group D: received protective lung strategy with recruitment manoeuvre (RM) every 30 minutes and decreasing PEEP (15, 10, and 5) cm H20 (10 minutes for each level) in between RM till end of surgery.
Masking: Single (Participant)
Primary purpose: Prevention
Keywords: bariatric; atelectasis; alveolar recruitment