Optimal method for selecting PEEP level in ALI/ARDS patients under mechanical ventilation.

The PEEP in ALI/ARDS had been used since its' description (1967). Up-to-date no optimal approach to PEEP setting had been introduced, however common approaches that had been introduced included Pressure volume curves, increasing PEEP trial, decreasing PEEP trial & PEEP/FiO2 tables adopted by ARDS network. The present work assessed the safety and efficacy of three introduced approaches for PEEP setting namely increasing PEEP trial, decreasing PEEP trial and PEEP/FiO2 table. Sixty patients fulfilling the American-European Consensus Conference (AECC) criteria for ALI/ARDS were enrolled in this study, patients were randomly allocated into three equal groups (n = 20) 1, 2 & 3 using closed envelope technique. In GA: patients received an increasing PEEP trial, GB: patients received a decreasing PEEP trial and GC: PEEP was set according to PEEP/FiO2 tables of the ARDS network trial. Hemodynamic parameters (mean arterial blood pressure (MAP) and heart rate (Hr) were recorded. Respiratory & oxygenation parameters (peak airway pressure (Paw), plateau pressure (Pplat), mean airway pressure (Pmean), PEEP, PaO2, PaO2/FiO2 and arterial oxygen saturation (Sao2) were also recorded at eight specific times, prior to randomization (baseline), following PEEP setting and twice daily for 72 hours. Both increasing and decreasing PEEP trials were considered superior to PEEP/FiO2 tables in identifying desired PEEP level. Although increasing and decreasing PEEP trials had demonstrated increased PaO2, and decreased FiO2 and better PaO2/FiO2 ratios compared to baseline values, however increasing PEEP trial was associated with lower Paw and Pplat due to lower PEEP values compared to decreasing PEEP trial. Decremental trial was associated with best PaO2, FiO2, and PaOz/FiO2 compared to increasing PEEP trial and PEEP/FiO2 tables.

Perioperative effects of various anesthetic adjuvants with TIVA guided by bispectral index.

BACKGROUND: This prospective, randomized, double blinded, controlled study was designed to compare effects of intravenous co-administration of clonidine, magnesium, or ketamine on anesthetic consumption, intraoperative hemodynamics, postoperative analgesia and recovery indices during Bispectral Index (BIS) guided total intravenous anesthesia (TIVA). METHODS: After ethical committee approval and written informed consent, 120 adult patients ASA I and II scheduled for open cholecystectomy were randomly assigned to one of 4 equal groups. Group CL received clonidine 3 µg/kg and maintained by 2 µg/kg/h. Group MG received magnesium sulphate 50 mg/kg and maintained by 8 mg/kg/h. Group KET received racemic ketamine 0.4 mg/kg and maintained by 0.2 mg/kg/h. Control group (CT) received the same volume of isotonic saline. Anesthesia was induced and maintained by fentanyl, propofol and rocuronium. Propofol infusion was adjusted to keep the BIS value between 45-55. Intraoperative hemodynamics, induction time, anesthetic consumption, recovery indices, and PACU discharge were recorded. RESULTS: Induction time, propofol requirements for induction and maintenance of anesthesia, intraoperative fentanyl and hemodynamic values were significantly lower with Groups CL and MG compared to Groups KET and CT (P < 0.05). Patients in Group MG showed significantly lower muscle relaxant consumption, delayed recovery and PACU discharge than other groups (P < 0.05). First, analgesic requirement was significantly longer and total postoperative analgesic consumption was significantly lower in the adjuvant groups versus Group CT (P < 0.05). CONCLUSIONS: Clonidine, magnesium, and ketamine can be useful adjuvant agents to BIS-guided TIVA. Pharmacokinetic studies of such drug combinations were recommended to investigate their interaction.

Controlled mechanical ventilation with LMA Sureme versus i-gel in anesthetized adult patients.

The efficacy, safety and ease of insertion of LMA Supreme and the i-gel in adult cases undergoing elective surgical procedures requiring general anesthesia with controlled mechanical ventilation. This study included 60 ASA physical status I-II adult patients of both sexes scheduled for elective surgical procedures under general anesthesia. Patients were randomly allocated into one of two groups; LMA-S GI (n=30) and i-gel GII (n=30). A size 4 LMA Supreme and a size 4 i-gel were used with standard monitoring. Number of insertion attempts, ease of insertion, presence of gastric insufflation, laryngeal leak, leak pressure, ease of gastric tube insertion, ventilatory parameters, complications as well as hemodynamic variables was recorded. The results showed no clinically significant changes of heart rate, MAP, SpO2 or P(ET)CO2 in GI & GII. The i-gel showed higher frequency of ease of insertion (p=0.048) and gastric tube (p< 0.001). First attempt of insertion was successful in 60% of LMA-S GI and 73.3% of the i-gel GII (p=0.460) without failures in both groups. Leak pressure was significantly higher in the i-gel (25.5 +/- 4.8 cm H2O) compared to the LMA-S (21.1 +/- 7.6 cm H2O) (p=0.010) while both peak and plateau pressures were significantly lower in i-gel GI (19.35 +/- 2.25 cm H2O & 17.75 +/- 2.07 cm H2O) compared to LMA-S GII (30.05 +/- 3.82 cm H2O & 28.80 +/- 3.99cm H2O) (p<0.001) respectively. There was no significant difference between both groups in the frequency of complications encountered during insertion or recovery.

Sub-antibiotic doses of erythromycin as a prokinetic in abdominal surgeries: reviving the old.

All patients undergoing major abdominal procedures have some degree of gastricatony in the immediate postoperative period, presenting mainly with vomiting. Many prokinetic agents have been used in the past, but none is a universal remedy. Studies showed that subantibiotic doses of erythromycin, a macrolide antibiotic and motilin agonist, accelerates gastric emptying. This study investigated whether preoperative subantibiotic dose oral erythromycin (250 mg), altered residual gastric volume and postoperative adverse effects in patients scheduled for abdominal surgeries. Erythromycin was compared with the commonly used prokinetic metoclopramide and antiemetic ondansetron, in terms of prokinetic efficacy, cost and adverse effects. In a double-blind study, eighty patients (20 each) were allocated randomly to receive orally, either erythromycin 250 mg (E250) or erythromycin 500 mg (E500), or 10 mg metoclopramide (M), or 4 mg ondansetron (Z), an hour pre-induction of anesthesia. Preoperative oral erythromycin in subantibiotic dose 250 mg elicited a significntly lower residual gastric volume (P < 0.001) and a lower VAS for vomiting, compared with ondansetron. As for metoclopramide and erythromycin 500, residual gastric volume was comparable, but E 250 had a lower VAS for vomiting than both groups. Rescue remedy for vomiting was required for groups E500, M and Z (100, 10 and 10%) compared to 0% in group E250. Ultimately, subantibiotic oral dose of erythromycin (250 mg), given 1 hr preoperatively, is an inexpensive prokinetic alternative with a promising post-operative profile which may be superior to the inexpensive prokinetic metoclopramide with known adverse effects, and the expensive antiemetic ondansetron.