Sequential Posture Change Fastens Gastric Emptying of Large Volume Bolus Intake of Normal Saline: A Pilot Study

The physiology of gastric emptying (GE) is complex and incompletely understood due to the interplay of several factors such as age, sex, volume, pH, temperature, osmolality, ion and energy content, gravity, posture, physical activity, and food consistency [1–6]. It is well known that posture and gravity affect GE mainly via changes in gastric configuration, which changes the intra-gastric distribution and ultimately the pressure gradient (pressure pump mechanism of GE) across the gastroduodenal segment [7]. Postural changes are also associated with changes in gastric motility (peristaltic pump mechanism of GE) and intragastric distribution of liquid meals [7, 8]. The pattern of GE is known to vary among individuals, but remain consistent within individuals [9]. The post-gastrografin pictures of the author (V.A.) (Fig. 1) illustrate the actual changes in gastric configuration accomplished by the sequential posture changes (SPC) described in the present study. The SPC include mindful relaxation, deep breathing, arm elevation, stretching of the body, and tilting of the upper torso. Deep breathing stimulates the parasympathetic nervous system via the vagus nerve, which is known to increase the gastrointestinal motility [10, 11]. The SPC (‘‘Appendix’’) can be labeled as ‘‘specific’’ to enhance GE for several reasons. Arm elevation in normal subjects increases end-inspiratory gastric and trans-diaphragmatic pressure [12]. All postures are associated with auditory–vestibular stimulation, which is known to affect GE [13]. The SPC used in this study are mild to moderate intensity exercises (MET: 3–5) which also enhances GE [14, 15] as opposed to strenuous exercises which is known to delay GE [16]. Vagotomy is known to delay gastric emptying of both liquids and solids [17]. Shudh colon cleanse (SCC) is a meditation-based bowel prep, which uses lukewarm normal saline (average 2–3 L) consumed orally in large volume boluses alternating with SPC condition for colon prep [18, 19]. This method was as efficacious as NuLytely, and the bowel prep time was less than 2 h. Similar to the pharmacokinetics of an orally ingested medicine, bowel prep outcomes for colonoscopy can vary and depend on the GE of the solution ingested. The role of manipulating the GE via changing gastric configuration was never studied in conjunction with bowel preps. Normal saline (NS) is a non-nutrient liquid and follows first-order kinetics of GE. We propose that faster GE plays a major role in the rapid action of SCC. We conducted this study to see the effect of SPC on GE of 480 mL of NS consumed as single bolus. In experimental studies, real-time ultrasonography has been used for the measurement of liquid GE [20, 21]. It is the least invasive, and it is not associated with any radiation exposure as in nuclear scintigraphic studies of GE. The gastric antrum is the most dependent part of the stomach with no gas interference. Therefore, the measurement of the antral surface area provides more accurate information on GE than the measurement of the entire muscular sac (Bolondi method) [21]. The ultrasonography method also shows good V. Arya (&) A. Valluri Wyckoff Heights Medical Center, Brooklyn, NY, USA e-mail: varyamd@yahoo.com