Lower oesophageal sphincter tone increases after induction of anaesthesia in pigs with full stomach

Improvement of atropine on esophagogastric junction observation during sedative esophagogastroduodenoscopy

BACKGROUND AND STUDY AIMS

Although sedation esophagogastroduodenoscopy (EGD) is now widely used, previous research has reported that sedation during EGD exhibits a negative effect on esophagogastric junction (EGJ) exposure. Atropine might improve EGJ exposure, as noted in clinical practice. The aim of this study was to examine whether sedation had a negative effect on EGJ observation in the Chinese population, and whether atropine had some ability to act as an antidote to this unexpected secondary effect of sedation.

PATIENTS AND METHODS

In this cross-sectional study, subjects were divided into the following three groups according to the methods of EGD examination: the non-sedation group, the propofol-fentanyl combined sedation group and the combined sedation with atropine administration group. The EGJ observation was assessed by a key photograph taken with the endoscopic camera 1 cm from the EGJ, which was rated on the following four-degree scale: excellent (score = 4), good (score = 3), fair (score = 2) and poor (score = 1).

RESULTS

The EGJ exposure was better in the sedation group administered atropine (score = 2.64±1.05) than in the sedation group (score = 1.99±1.08, P<0.05) but not as good as in the non-sedation group (score = 3.24±1.12, P<0.05). Reduced detection of EGJ diseases in the sedation group was also found, compared to the non-sedation group (P<0.05). Only the use of atropine (OR = 2.381, 95%CI: 1.297-4.371, P = 0.005) was independently associated with excellent observation of the EGJ during sedation EGD.

CONCLUSIONS

Combined propofol-fentanyl sedation reduces the extent of exposure of the EGJ during EGD and reduces the detection of EGJ diseases. The application of atropine in the sedation endoscopy examination helped to achieve better EGJ observation, but still cannot achieve an equal extent of exposure compared to non-sedation EGD.

The Rapid Sequence Induction Revisited: Obesity and Sleep Apnea Syndrome

Pulmonary aspiration is a cause of anesthesia-related morbidity and mortality, with little change in incidence over the past 20 years. Rapid sequence induction is a common procedure in obese patients, who appear to be more at risk for both pulmonary gastric aspiration and difficult airways, and is required in obese and sleep apnea syndrome patients with symptomatic gastroesophageal reflux or other predisposing conditions. In the elective obese or sleep apnea patient with no other risk factors for pulmonary aspiration, the risks and benefits of rapid sequence induction and cricoid pressure should be weighed. If rapid sequence induction is required, succinylcholine remains the neuromuscular blocking agent of choice, if there are no contraindications.

Esophageal Acid clearance: more volume-dependent than motility-dependent in healthy piglets

BACKGROUND/AIMS

The present study investigates manometrically in healthy piglets whether esophageal clearance after distension with different volumes of acid is volume-dependent.

METHODS

Sedated, non-intubated piglets (n = 22) underwent stationary manometry of the esophagus with a 4-probe perfused assembly after successive injection of 1, 2, and 3 mL of saline and acid. Simultaneous pH metering allowed assessment of acid clearance. Wave features and clearance times after saline and acid were compared by paired non-parametric tests and Friedman analysis of variance. The linearity of the relationships between the clearance times and the volumes of acid infused were tested after square root transformations by one-way ANOVA repeated measures. The significance level was set at < 0.05.

RESULTS

The motor response was identical after distension with saline and acid except for the largest amount of acid used, which elicited more waves during the first 5 minutes after infusion. Time elapsed until regaining pH4 was longer after higher amounts of acid, but not significantly, whereas that necessary to regain baseline pH was significantly longer after such challenge. Esophageal motility was practically identical after 1 and 2 mL of acid, but it was slightly less effective in the first minute after the 3 mL challenge. There was a linear correlation between clearance times and volumes of acid infused.

CONCLUSIONS

Up to a certain volume, the motor responses of the healthy esophagus to distension with neutral or acid fluids were similar. Acid clearance was more a function of the amount of acid present than of the motor response elicited by its presence. Only when the amount of acid was large, esophageal motor response was worse than that elicited after equivalent volumes of neutral fluid. The present evidence suggests that long episodes of reflux in pH tracings might reflect large volumes of refluxate as well as disturbed motor function.