Despite Differences in Cytosolic Calcium Regulation, Lidocaine Toxicity Is Similar in Adult and Neonatal Rat Dorsal Root Ganglia In Vitro
BACKGROUND:: Neuraxial local anesthetics may have neurological complications thought to be due to neurotoxicity. A primary site of action of local anesthetics is the dorsal root ganglia (DRG) neuron. Physiologic differences have been noted between young and adult DRG neurons; hence, the authors examined whether there were any differences in lidocaine-induced changes in calcium and lidocaine toxicity in neonatal and adult rat DRG neurons. METHODS:: DRG neurons were cultured from postnatal day 7 (P7) and adult rats. Lidocaine-induced changes in cytosolic calcium were examined with the calcium indicator Fluo-4. Cells were incubated with varying concentrations of lidocaine and examined for viability using calcein AM and ethidium homodimer-1 staining. Live imaging of caspase-3/7 activation was performed after incubation with lidocaine. RESULTS:: The mean KCl-induced calcium transient was greater in P7 neurons (P < 0.05), and lidocaine significantly inhibited KCl-induced calcium responses in both ages (P<0.05). Frequency distribution histograms of KCl-evoked calcium increases were more heterogeneous in P7 than in adult neurons. With lidocaine, KCl-induced calcium transients in both ages became more homogeneous but remained different between the groups. Interestingly, cell viability was decreased by lidocaine in a dose-dependent manner similarly in both ages. Lidocaine treatment also activated caspase-3/7 in a dose- and time-dependent manner similarly in both ages. CONCLUSIONS:: Despite physiological differences in P7 and adult DRG neurons, lidocaine cytotoxicity is similar in P7 and adult DRG neurons in vitro. Differences in lidocaine- and KCl-evoked calcium responses suggest the similarity in lidocaine cytotoxicity involves other actions in addition to lidocaine-evoked effects on cytosolic calcium responses.
Trichobezoars as a cause of upper gastrointestinal bleeding: A case presentation [Meeting Abstract]
Case Presentation: A 39-year-old African American woman presented with nausea, postprandial emesis, early satiety, abdominal distension/pain for 1 week, and 2 days of hematemesis. Physical exam revealed a diffusely distended, tender abdomen and a firm, immobile 8 x 12 cm abdominal mass in the left upper quadrant. A complete blood count was significant for a hemoglobin and hematocrit of 6.5 and 21.5, respectively. She was transfused 2 units of packed red blood cells. CT revealed gastric trichobezoars. On further questioning, she revealed a 28-year history of trichotillomania and trichophagia and reported consuming a quart-sized bag of hair daily that she obtained from barber shops. Esophagogastroduodenoscopy demonstrated 3 large trichobezoars within the stomach and a 1-cm nonbleeding ulcer on the greater curvature, without evidence of complete gastric outlet obstruction or Rapunzel syndrome (tracking beyond the pylorus). The trichobezoars were deemed too large to be removed endoscopically. She was started on Prozac 20 mg by mouth daily to decrease the compulsion to consume hair, Coca-Cola 300 mL 3 times a day to decrease the size of the trichobezoars in anticipation of surgical removal, and metoclopramide 10 mg by mouth twice a day. Psychiatric management was initiated. Discussion: Trichobezoars are accumulations of hair typically located in the stomach that may track beyond the pylorus into the small bowel. This finding is associated with the psychiatric disorders trichotillomania and trichophagia, which usually occur in young females. When not recognized early, trichobezoars may continue growing because of persistent hair consumption and cause gastric erosion, ulceration, or gastric outlet obstruction (Gorter RR, Kneepkens CMF, Mattens ECJL, Aronson DC, Heij HA. Management of trichobezoar: case report and literature review. Ped Surg Int. 2010;26:457-463). In this case, the significant size of this patient's trichobezoars resulted in partial pyloric obstruction, leading to gastrointestinal (GI) symptoms. We propose that the trichobezoars eroded the gastric mucosa causing ulceration. During 1 week of vomiting, the marked increase in intra-abdominal pressure was transmitted to the esophagus, which likely caused Mallory-Weiss syndrome, manifesting as hematemesis. The patient's malnutrition resulted in severe iron -deficiency anemia, which was exacerbated by hematemesis and gastric ulceration. Conclusions: Although a rare occurrence, trichobezoars must be considered in a differential diagnosis of a patient, especially in young females presenting with either an abdominal mass or nonspecific GI symptoms in the context of an upper GI bleed. We also highlight the importance of managing trichobezoars medically and with psychiatric counseling prior to surgical removal in order to alleviate GI symptoms and prevent reoccurrence. 1