Advanced endoscopic gastrointestinal techniques for the bariatric patient: implications for the anesthesia provider.

PURPOSE OF REVIEW: The incidence of obesity and the use of endoscopy have risen concurrently throughout the 21st century. Bariatric patients may present to the endoscopy suite for primary treatments as well as preoperatively and postoperatively from bariatric surgery. However, over the past 10 years, endoscopic bariatric and metabolic therapies (EBMTs) have emerged as viable alternatives to more invasive surgical approaches for weight loss. RECENT FINDINGS: The United States Food and Drug Administration (FDA) has approved several different gastric EBMTs including aspiration therapy, intragastric balloons, and endoscopic suturing. Other small intestine EBMTs including duodenal mucosal resurfacing, endoluminal magnetic partial jejunal diversion, and Duodenal-Jejunal Bypass Liner are not yet FDA approved, but are actively being investigated. SUMMARY: Obesity causes anatomic and physiologic changes to every aspect of the human body. All EBMTs have specific nuances with important implications for the anesthesiologist. By considering both patient and procedural factors, the anesthesiologist will be able to perform a safe and effective anesthetic.

Modulation of murine Alzheimer pathogenesis and behavior by surgery.

OBJECTIVE: Previous research suggests that a link between anesthetic exposure and Alzheimer disease exists. Because anesthetics are rarely given alone, we ask whether addition of surgery further modulates Alzheimer disease. BACKGROUND: Cognitive dysfunction occurs after surgery in humans. Anesthesia alone produces cognitive decline in both older wild-type (WT) mice and rats, and the addition of surgery produces transient decline in young, adult WT mice. Because neuroinflammation has been implicated and occurs early in Alzheimer disease, we hypothesized that the neuroinflammatory stress associated with surgery would accelerate the progression of Alzheimer disease. METHODS: Cecal ligation and excision were performed on presymptomatic 5- to 11-month-old triple-transgenic Alzheimer disease (3×TgAD) and C57BL/6 WT mice under desflurane anesthesia. Surgery animals were compared with aged-matched 3×TgAD and WT mice exposed to air or desflurane alone. Cognitive function was assessed via Morris water maze at 2 and 13 weeks postoperatively. Amyloid and tau pathology and inflammation and synaptic markers were quantified with immunohistochemistry, Luminex assay, enzyme-linked immunosorbent assay, or Western blot assays. RESULTS: A significant cognitive impairment in 3×TgAD mice that underwent surgery compared with air or desflurane controls persisted to at least 14 weeks after surgery. Microglial activation, amyloidopathy, and tauopathy were enhanced by surgery as compared with desflurane alone. No differences between surgery, anesthetic, or air controls were detected in WT mice CONCLUSIONS: Surgery causes a durable increment in Alzheimer pathogenesis, primarily through a transient activation of neuroinflammation.

Is hydrogen sulfide-induced suspended animation general anesthesia?

Hydrogen sulfide (H(2)S) depresses mitochondrial function and thereby metabolic rates in mice, purportedly resulting in a state of "suspended animation." Volatile anesthetics also depress mitochondrial function, an effect that may contribute to their anesthetic properties. In this study, we ask whether H(2)S has general anesthetic properties, and by extension, whether mitochondrial effects underlie the state of anesthesia. We compared loss of righting reflex, electroencephalography, and electromyography in mice exposed to metabolically equipotent concentrations of halothane, isoflurane, sevoflurane, and H(2)S. We also studied combinations of H(2)S and anesthetics to assess additivity. Finally, the long-term effects of H(2)S were assessed by using the Morris water maze behavioral testing 2 to 3 weeks after exposures. Exposure to H(2)S decreases O(2) consumption, CO(2) production, and body temperature similarly to that of the general anesthetics, but fails to produce a loss of righting reflex or muscle atonia at metabolically equivalent concentrations. When combined, H(2)S antagonizes the metabolic effects of isoflurane, but potentiates the isoflurane-induced loss of righting reflex. We found no effect of prior H(2)S exposure on memory or learning. H(2)S (250 ppm), not itself lethal, produced delayed lethality when combined with subanesthetic concentrations of isoflurane. H(2)S cannot be considered a general anesthetic, despite similar metabolic suppression. Metabolic suppression, presumably via mitochondrial actions, is not sufficient to account for the hypnotic or immobilizing components of the anesthetic state. Combinations of H(2)S and isoflurane can be lethal, suggesting extreme care in the combination of these gases in clinical situations.

Anesthesia in presymptomatic Alzheimer's disease: a study using the triple-transgenic mouse model.

BACKGROUND: Experimental evidence suggests that anesthetics accelerate symptomatic neurodegenerative disorders such as Alzheimer's disease (AD). Because AD pathology precedes symptoms, we asked ourselves whether anesthetic exposure in the presymptomatic interval accelerated neuropathology and appearance of symptoms. METHODS: Triple-transgenic AD mice were exposed to general aesthetics, either halothane or isoflurane, at 2, 4, and 6 months of age, they then underwent water maze cognitive testing 2 months later, and subsequently their brains were analyzed using enzyme-linked immunosorbent assay, immunoblots, and immunohistochemistry for amyloid and tau pathology and biomarkers. RESULTS: Learning and memory improved after halothane exposure in the 2-month-old group relative to controls, but no changes were noted in the isoflurane group. When gender was examined in all age groups, females exposed to halothane performed better as compared with those exposed to isoflurane or controls. Therefore, improvement in the 2-month exposure group is most likely because of a gender effect. Level of phospho-tau in the hippocampus was significantly increased 2 months after anesthesia, especially in the 6-month exposure group, but changes in amyloid, caspase, microglia, or synaptophysin levels were not detected. CONCLUSIONS: These results indicate that exposure to two different inhalation-type anesthetics during the presymptomatic phase of AD does not accelerate cognitive decline, after 2 months, and may cause a stress response, marked by hippocampal phosphorylated tau, resulting in preconditioning against the ongoing neuropathology, primarily in female mice.