Chewing gum for 1 h does not change gastric volume in healthy fasting subjects. A prospective observational study.

STUDY OBJECTIVE: Perioperative fasting guidelines differ in their approaches to chewing gum in the preoperative period. Current recommendations range from canceling the surgery to proceeding with it. Given this lack of consensus, we performed gastric ultrasound assessments in healthy volunteers before and after a standardized period of chewing gum. The objective of our study was to determine if chewing gum for 1 h change the gastric volume. DESIGN: Observational prospective analytical study. SETTING: Bedside gastric ultrasound. PATIENTS: Following institutional Review Board approval, 55 healthy (American Society of Anesthesiologists class I to II) fasted (non-surgical research) volunteers provided written informed consent to participate in the study. Morbid obesity, renal failure, diabetes mellitus, pregnancy and previous upper abdominal surgery were exclusion criteria. INTERVENTIONS: Volunteers chewed gum for 1 h between the first and second assessment. MEASUREMENTS: Four gastric ultrasound assessments were performed, the first one at baseline and then hourly thereafter. MAIN RESULTS: Fifty-five healthy volunteers were studied. The proportion of subjects who presented a completely empty stomach (Grade 0 antrum) was similar at baseline and after 1 h of gum-chewing [81% vs. 84%, p = 0.19, CI 95% (-12%, 16%)]. Among those subjects who had visible fluid at baseline, the volume remained unchanged throughout the study period. CONCLUSIONS: One hour of gum-chewing had no significant effect on the gastric fluid volume of healthy volunteers, suggesting that it may be safe for healthy subjects to chew gum prior to elective surgery.

Ultrasound-Guided Percutaneous Dilatational Tracheostomies in 2 Difficult Airways.

Ultrasound has become a rapid, safe, and easy-to-use tool for anesthesiologists. It reduces complications, morbidity, and mortality, especially in patients with anatomic abnormalities in whom a traditional approach may be both difficult and risky. We report 2 cases of symptomatic patients with a difficult airway due to displacement of the trachea by a neck mass. Real-time ultrasound imaging was performed for percutaneous dilatational tracheostomies, identifying important structures, without any complications.

A comparison of King Vision video laryngoscopy and direct laryngoscopy as performed by residents: a randomized controlled trial.

STUDY OBJECTIVE: For more than 40 years, direct laryngoscopy (DL) has been used to assure the airway during endotracheal intubation. The King Vision video laryngoscope is one of the latest devices introduced for endotracheal intubation. We hypothesize that, relative to direct laryngoscopy, it improves the intubation success rate with fewer intubation attempts and no difference in intubation time or complications. DESIGN: This randomized controlled clinical trial included. SETTING: The operating room and postanesthesia care unit of an academic hospital. PATIENTS: Eighty-eight patients with American Society of Anesthesiologists status I to II and aged ≥18 years who were scheduled for elective surgery under general anesthesia and had no predictors of difficult airway. Patients were randomized (44 per group) to undergo intubation using either DL or King Vision video laryngoscopy (KVVL) performed by first year residents in anesthesia and intensive care. MEASUREMENTS: During endotracheal intubation by residents, measurements were success rate, number of attempts, time to intubation, visualization of the glottis, and presence of complications. MAIN RESULTS: Both groups had a 100% success rate. A greater frequency of grade 1 laryngoscopy was reported with KVVL (86.4%) relative to DL (59.1%) (P < .05). There were no differences in time to intubation or the number of attempts between the groups (P = .75 and P = .91, respectively). Complications after intubation were low and included oral trauma, esophageal intubation, and sore throat. CONCLUSIONS: The use of KVVL by residents with less than 1 year of training (considered nonexperts) significantly improves visualization of the glottis in patients without predictors of difficult airway. The incidence of complications was too low to draw conclusions.

Volumetric electromagnetic phase-shift spectroscopy of brain edema and hematoma.

Motivated by the need of poor and rural Mexico, where the population has limited access to advanced medical technology and services, we have developed a new paradigm for medical diagnostic based on the technology of "Volumetric Electromagnetic Phase Shift Spectroscopy" (VEPS), as an inexpensive partial substitute to medical imaging. VEPS, can detect changes in tissue properties inside the body through non-contact, multi-frequency electromagnetic measurements from the exterior of the body, and thereby provide rapid and inexpensive diagnostics in a way that is amenable for use in economically disadvantaged parts of the world. We describe the technology and report results from a limited pilot study with 46 healthy volunteers and eight patients with CT radiology confirmed brain edema and brain hematoma. Data analysis with a non-parametric statistical Mann-Whitney U test, shows that in the frequency range of from 26 MHz to 39 MHz, VEPS can distinguish non-invasively and without contact, with a statistical significance of p<0.05, between healthy subjects and those with a medical conditions in the brain. In the frequency range of between 153 MHz to 166 MHz it can distinguish with a statistical significance of p<0.05 between subjects with brain edema and those with a hematoma in the brain. A classifier build from measurements in these two frequency ranges can provide instantaneous diagnostic of the medical condition of the brain of a patient, from a single set of measurements. While this is a small-scale pilot study, it illustrates the potential of VEPS to change the paradigm of medical diagnostic of brain injury through a VEPS classifier-based technology. Obviously substantially larger-scale studies are needed to verify and expand on the findings in this small pilot study.