Laryngoscope plastic blades in scheduled general anesthesia patients: a comparative randomized study.

STUDY OBJECTIVE: To compare two brands of disposable plastic laryngoscope blades, Vital View plastic blades and Heine XP plastic blades, with the reusable Heine Classic+ Macintosh metal blades. DESIGN: Prospective randomized, controlled, single-blinded study. SETTING: Operating room of a university-affiliated hospital. PATIENTS: 519 patients without criteria for predicted difficult intubation, undergoing scheduled surgery during general anesthesia. INTERVENTIONS: Patients were randomized to three groups according to laryngoscope blade brand. MEASUREMENTS: Difficult tracheal intubation was evaluated by the Intubation Difficulty Scale (IDS) (IDS > 5 = procedure involving moderate to major difficulty). MAIN RESULTS: The percentage of intubations with an IDS > 5 was 3.1% in Group M (metal blade group), 5.1% in Group V (Vital View plastic blade group), and 10.0% in Group H (Heine plastic blade group). A significant difference was noted between Groups M and H (P = 0.02) but not between Groups M and V. CONCLUSIONS: Intubation may be more challenging when using Heine XP plastic blades but no significant difference exists between Vital-View plastic blades and Heine Classic+ metal blades.

Video-assisted versus conventional tracheal intubation in morbidly obese patients.

BACKGROUND: We compared tracheal intubation characteristics and arterial oxygenation quality during airway management of morbidly obese patients whose trachea was intubated under video assistance with the LMA CTrach (SEBAC, Pantin, France) or the Airtraq laryngoscope (VYGON, Ecouen, France) with that of the conventional Macintosh laryngoscope. METHODS: After standardized induction of anesthesia, 318 morbidly obese patients scheduled for elective morbid obesity surgery received tracheal intubation with the LMA CTrach, the Airtraq laryngoscope, or the conventional Macintosh laryngoscope. Duration of apnea, time to tracheal intubation, and oxygenation quality during airway management were compared between the LMA CTrach and the laryngoscope groups. RESULTS: Patients' characteristics were similar in the three groups. The success rate for tracheal intubation was 100% with the LMA CTrach and the Airtraq laryngoscope. One patient of the Macintosh laryngoscope group received LMA CTrach intubation because of early arterial oxygen desaturation associated with unstable facemask ventilation. The duration of apnea was shorter with the LMA CTrach than that of the Airtraq laryngoscope and the Macintosh laryngoscope. The duration tracheal intubation was shorter with the Airtraq laryngoscope than with the Macintosh laryngoscopes and the LMA CTrach. During airway management, arterial oxygenation was of better quality with the LMA CTrach and the Airtraq laryngoscope than that of the Macintosh laryngoscope. CONCLUSION: Because LMA CTrach promoted short apnea time and the Airtraq laryngoscope allowed early definitive airway, both video-assisted tracheal intubation devices prevented most serious arterial oxygenation desaturation evidenced during tracheal intubation of morbidly obese patients with the conventional Macintosh laryngoscope.

Isoflurane, 0.5 minimum alveolar concentration administered through the precardiopulmonary bypass period, reduces postoperative dobutamine requirements of cardiac surgery patients: a randomized study.

OBJECTIVE: Cardioprotective properties have been shown with halogenated volatile agents. It was hypothesized that low-dose isoflurane administered before aortic cross-clamping may reduce the amount of dobutamine required to improve impaired postoperative cardiac function after various types of cardiac surgery. DESIGN: A prospective, randomized trial. SETTING: An anesthesia and intensive care unit, university hospital. PARTICIPANTS: Two hundred eighty cardiac surgery patients. INTERVENTIONS: All patients allocated to either isoflurane treatment (T) or no treatment (control group [C]) received total intravenous anesthesia. In the treatment group, isoflurane was administered at a 0.5 minimum alveolar concentration (MAC) from tracheal intubation to initiation of cardiopulmonary bypass (CPB). During weaning from CPB, dobutamine was introduced by using a hemodynamically driven decision tree. MEASUREMENTS AND MAIN RESULTS: The number of patients receiving dobutamine was comparable (66 v 78, p = 0.07, in T and C groups, respectively). The total amount of postoperative dobutamine indexed to patient weight, considered as the primary endpoint, was reduced in the isoflurane-treated group (4.2 +/- 8 v 7.2 +/- 15, p < 0.02, in T and C, respectively). Isoflurane was identified as an independent variable significantly (odds ratio [confidence interval]) influencing the total amount of postoperative dobutamine (0.53 [0.31-0.92], p < 0.02). Postoperative troponin I release at 20 hours was not affected by isoflurane treatment. CONCLUSIONS: This study revealed that exposure to 0.5 MAC isoflurane before CPB reduced the total amount of dobutamine required to normalize postoperative cardiac dysfunction in various types of cardiac surgical patients.

A randomized, double-blind study comparing morphine with fentanyl in prehospital analgesia.

STUDY OBJECTIVE: The aim of this study was to compare, by a randomized double-blind method, morphine (M) and fentanyl (F) in a prehospital setting. METHODS: Consecutive patients with severe, acute pain defined as a visual analog scale score (VASS) of 60/100 or higher were included. The M group received an initial intravenous M injection of 0.1 mg/kg then of 3 mg every 5 minutes. The F group received an initial intravenous F injection of 1 microg/kg then of 30 microg every 5 minutes. The goal of analgesia was a VASS of 30/100 or lower. The end point was the VASS measured 30 minutes after initial administration (VAS [T30]). RESULTS: There were 26 patients included in the M group and 28 in the F group. Initial VASS(T0) and VASS(T30), mean (95% CI), were 83 (78-88) and 40 (28-52) in the M group and 77 (72-82) and 35 (27-43) in the F group (P=NS). Sixty-two percent of patients in the M group described analgesia as excellent or good vs 76% of those in the F group who did (P=NS). There were no differences in the incidence of side effects in the 2 groups. CONCLUSION: This study demonstrates that M and F were comparable in treating severe, acute pain in a prehospital setting during the first 30 minutes in spontaneous breathing patients.

Tracheal ring fracture during a PercuTwist tracheostomy procedure.

UNLABELLED: Because of difficult weaning from mechanical ventilation, a 59-yr-old man admitted for emergency cardiac surgery underwent a bedside PercuTwist tracheostomy on day 14 of his intensive care unit stay. We observed a double fracture of the second tracheal ring during the initial dilation process with the PercuTwist dilator, associated with distal migration of a cartilage fragment, which was avulsed from the anterior portion of the second cartilaginous ring. IMPLICATIONS: Like other antegrade single-step techniques, the PercuTwist tracheostomy presents the risk of anterior tracheal wall damage during the initial stage of the dilation process. Antegrade forces applied to the trachea should be minimized by sufficiently deep skin incision and both slow and smooth initial rotation of the dilator.

Effects of nifedipine-induced pulmonary vasodilatation on cardiac receptors and protein kinase C isoforms in the chronically hypoxic rat.

In chronic hypoxia, pulmonary hypertension induces a right ventricular (RV) hypertrophy (RVH) and the catecholamine-activated adrenergic system modulates cardiovascular responses through alpha- and beta-adrenergic pathways. The alpha(1)-adrenergic receptor (alpha(1)-AR) and protein kinase C (PKC) may play an important role in the signaling pathway leading to RVH. The aim of this study was to examine the relationship between nifedipine-induced pulmonary vasodilatation, the blunting of RVH and the modifications in the density of alpha(1)-AR, PKC activity and expression of PKC isoforms. In rats exposed to 15 days of hypoxia (380 torr, 50.66 kPa), RV pressure increased and RVH developed. Nifedipine, a calcium antagonist, given through gastric administration, partially decreased RV pressure and RVH. In both ventricles, hypoxia decreased alpha(1)-AR and beta-AR density and increased muscarinic acetylcholine receptor density. Nifedipine decreased alpha(1)-AR density only in normoxia. Expression of epsilon, delta and zeta PKC isoforms increased with RVH and normalized with nifedipine treatment. In conclusion, in this in vivo model of hypoxic rat, no relation was found between a RVH decrease and cardiac receptor densities. However, the development and regression of pulmonary hypertension and RVH were related to the expression of some PKC isoforms suggesting that pathways other than alpha(1)-AR might be involved in hypoxia-induced ventricular hypertrophy.