Reconsideration of the nomadic condition of the southernmost Guachichiles based on the relationship with their environment.

BACKGROUND: The Guachichiles were a group of Chichimeca people that inhabited the southern and central parts of the Mexican Plateau. In the southern area of their distribution, they occupied and used the tunales, extensive forests of arborescent nopales (Opuntia spp.). Their pre-Columbian distribution was dissected by the Royal Silver Road established by the Spaniards, and this lead to them being main protagonists in the so-called Chichimeca War, during the sixteenth century. With very little first-hand documentation, the Guachichiles were described as savage, warring, primitive, hunting nomads, but little efforts have been done to understand their daily life habits. Based on the relationship of pre-Columbian southern Guachichiles with their environment, we re-valuate whether they were nomads, as the Chichimecas collectively have been labeled, or whether those living in tunales could live year-round in this habitat. As part of our analysis, we propose the primary plant and animal species that integrated their diet. METHODS: We draw information from a review of bibliographic sources, complemented with extensive searches in all pertinent Mexican archives. We carried out field work to define the geographical extent of the pre-Columbian territory of the southernmost Guachichiles, based on the Spanish Chronicles, remnant fragments of vegetation, landscape characteristics, and geographic names related with nopales. Using approaches from wildlife ecology, historical sciences and ethnobiological information on wild resources currently or recently used in the area, we proposed which resources were available to the southernmost Guachichiles, and how their primary diet might have been. RESULTS: The habitat of the southern Guachichiles, the tunal forest, was exuberant and rich in resources, having provided numerous plant products, of which tunas (prickly pears) and mesquite pods were of uttermost importance. At least 10 plant foods were available within the tunales. They would have consumed at least seven birds (including their eggs), six mammals, four reptiles, grubs, and honey, in addition to at least six vertebrate species hunted at the edges of the tunal with grasslands and shrublands or in more open patches of tunal. In addition to food, they prepared at least three alcoholic beverages, had access to two species of probable psychoactive beehive cacti and to one hallucinogenic mushroom species, and might have traded peyote from the north with outside-tunal Guachichiles. CONCLUSIONS: The rich habitat in which southern Guachichiles lived allowed them to be largely sedentary, but this required that they prevented other groups from gathering and hunting in their habitat. As a result of them living in and defending the tunales, the Guachichiles could have been divided into two or three habitat-driven groups: Tunal Guachichiles, and grassland and, or shrubland Guachichiles.

Perioperative determinants of transient hypocalcemia after pediatric total thyroidectomy.

PURPOSE: We seek to identify risk factors associated with hypocalcemia after pediatric total thyroidectomy. METHODS: We retrospectively reviewed patients younger than 21years undergoing total thyroidectomy between January 2002 and January 2016. We defined hypocalcemia as any serum calcium <8mg/dl or ionized calcium <1.0mmol/L. Perioperative risk factors were identified through multivariate logistic regression. RESULTS: Ninety-one children underwent total thyroidectomy. The average age was 13.7±4.4years, and 77% were female. Transient hypocalcemia was diagnosed in 34% (n=31) of patients. There was one case of permanent hypoparathyroidism. Predictors of transient hypocalcemia included age (OR 0.87, 95% CI 0.8-0.97, p=0.01), lymphadenectomy (OR 6.6, 95% CI 1.7-31.6, p=0.01), and hyperthyroidism (OR 13.3, 95% CI 1.3-1849, p=0.03). Patients with malignancy undergoing central (OR 7.1, 95% CI 1.5-33.4, p=0.01) or central plus lateral lymphadenectomy (OR 6.33, 95% CI 1.0-40.1, p=0.05) had significantly increased risk for transient hypocalcemia. Malignancy, MEN2A/B, goiter, preoperative calcium supplementation, incidental parathyroid removal, and postoperative PTH <15pg/ml were not associated with transient hypocalcemia. CONCLUSIONS: Younger age, hyperthyroidism, and concomitant lymphadenectomy during total thyroidectomy increase risk of developing transient hypocalcemia. Malignant cases with central or central plus lateral lymphadenectomy are also at increased risk. Aggressive perioperative management of hypocalcemia should be initiated in patients with these risk factors. LEVEL OF EVIDENCE: 2b.

Modification of an evidence-based protocol for advanced appendicitis in children.

INTRODUCTION: We previously developed an evidence-based clinical pathway for children with advanced appendicitis. The pathway standardized the choice and duration of antibiotic therapy and established discharge criteria. Initially, the pathway led to a 50% decrease in the rate of superficial and deep surgical site infections and a significant decrease in hospital length of stay. Four years after implementation, we noted an increase in the infectious complication rate and the emergence of resistant bacteria to commonly used antibiotics. In this study, we prospectively collected peritoneal fluid cultures at the time of appendectomy in an effort to optimize our antibiotic therapy and decrease complication rates. METHODS: Microbiology analysis of peritoneal fluid cultures obtained at the time of appendectomy was performed in patients with an intraoperative diagnosis of advanced appendicitis. Clinical information, including demographics, laboratory data, and postoperative outcomes were collected and compared to the historic cohort. X(2), Student's t-test, and Fisher exact test were used where appropriate. RESULTS: The historic and prospective cohorts were similar with respect to clinical and demographic data. The postoperative intra-abdominal abscess rate remained unchanged (28% from 24%, P = 0.603). Escherichia coli and Pseudomonas aeruginosa were the most commonly isolated aerobic bacteria from peritoneal fluid in the prospective cohort. Thirty-two percent of these patients had Pseudomonas spp., and 12% had Enterococcus spp. or Escherichia coli resistant to cefoxitin in their peritoneal fluid cultures. DISCUSSION: A significant proportion (40%) of children with advanced appendicitis had organisms either not susceptible or resistant to our first line antibiotic in their peritoneal fluid cultures. Our clinical pathway now recommends piperacillin-tazobactam as the most effective empiric therapy for advanced appendicitis in children. Microbiologic analysis of peritoneal fluid at appendectomy may be used to tailor antibiotic therapy in advanced appendicitis.

Risk factors for surgery in pediatric intussusception in the era of pneumatic reduction.

INTRODUCTION: Surgical treatment is still necessary for intussusception management in a subgroup of patients, despite advances in enema reduction techniques. Early identification of these patients should improve outcomes. METHODS: The medical records of patients treated for intussusception at our institution from 2006 to 2011 were reviewed. Univariate and multivariate analyses, including stepwise logistic regression, were performed. RESULTS: Overall, 379 patients were treated for intussusception, and 101 (26%) patients required operative management, with 34 undergoing intestinal resection. The post-operative complication rate was 8%. On multivariate analysis, failure of initial reduction (OR 9.9,p=0.001 95% CI, 4.6-21.2), a lead point (OR 18.5,p=0.001 95% CI, 6.6-51.8) or free/interloop fluid (OR 3.3,p=0.001 95% CI, 1.6-6.7) or bowel wall thickening on ultrasound (OR 3.3,p=0.001 95% CI, 1.1-10.1), age <1 year at reduction (OR 2.7,p=0.004, 95% CI, 1.4-5.9), and abdominal symptoms>2 days (OR 2.9,p=0.003, 95% CI, 1.4-5.9) were significantly associated with a requirement for surgery. Similarly, a lead point (OR 14.5, p=0.005 95% CI, 2.3-90.9) or free/interloop fluid on ultrasound (OR 19.8, p=0.001 95% CI, 3.4-117) and fever (OR 7.2, p=0.023 95% CI, 1.1-46) were significantly associated with the need for intestinal resection. CONCLUSION: Abdominal symptoms>2 days, age<1 year, multiple ultrasound findings, and failure of initial enema reduction are significant predictors of operative treatment for intussusception. Patients with these findings should be considered for early surgical consultation or transfer to a hospital with pediatric surgical capabilities.