Objective. To compare the speeds and success rates of placement for percutaneous cricothyrotomy versus surgical or open cricothyrotomy. Methods. Twenty-two paramedics (mean 9.7 years of experience), with training in both methods, were timed using a pig trachea in a crossover model. An emergency physician performed timing and documentation of success; timing commenced after the equipment was ready and the membrane was identified. Paramedics were randomly assigned by a coin toss to start in either group. All were actively employed by a municipal third-service emergency medical services (EMS) agency. Paramedics who did not complete one of the methods correctly were excluded from speed analysis. Data were analyzed using descriptive statistics, a t-test of paired samples, and confidence intervals for matched samples. Results. Placement of a surgical cricothyrotomy was significantly faster (mean 28 seconds, range 10-78 seconds) than the percutaneous method (mean 123 seconds, range 58-257 seconds) (p < 0.001). Mean difference between the 20 matched percutaneous versus surgical pairs was 93.75 seconds (95% CI 72.3, 115.2). The surgical route had a 100% success rate at obtaining airway control, whereas the percutaneous method had a 90.9% success rate (p = 0.1). Conclusion. In an animal model, surgical cricothyrotomy appeared to be a preferable method for establishing a definitive airway over the percutaneous method. Further research is required to define the optimal approach in the prehospital setting for the invasive airway.

We have studied by Raman spectroscopy the thermal behavior of associated polyguanylic acid [poly(G)] and polyguanylic–polycytidylic acid [poly(G) · poly(C)] in self-pressurized aqueous solutions contained in sealed capillary tubes. The associated polynucleotides were found to be very resistant to heat, but evidence of thermal degradation was observed after melting of the helical structures. The cooperative melting transition of the four-stranded complex of poly(G) was located at 141°C in 0.5M KCl, 135°C in 0.5M NaCl, 129°C in 0.5M LiCl, 123°C in 0.1M tetramethylammonium perchlorate, and 105°C in 0.1M tetraethylammonium bromide solutions. The transition was observed at 130°C in poly(G) · poly(C) (in 0.5M NaCl). The results in this case show that a four-stranded poly(G) complex is formed following the melting of the double helix. © 1999 John Wiley & Sons, Inc. Biopoly 49: 21–28, 1999

Surgical causes of abdominal pain are always the entities to exclude before considering non-operative conditions; however, the spectrum of non-operative disease is greater and far more diverse. The purpose of this article is to present these diseases in an organized fashion, grouped by abdominal location and mechanism. The emphasis is on providing reasonable, clear and rapid clinical ways to distinguish these conditions from operative counterparts. Information regarding diagnostic studies is included where appropriate. Focus is not only on common processes, but also on those rarely seen by general surgeons, and therefore poorly covered in general surgical education. Range of topics includes abdominal wall pathology toxicology, hematology, urology infectious disease, immunology, rheumatology, pediatrics, neurology and cardiopulmonary medicine. When combined with traditional surgical education material, this information will allow a more informed approach to abdominal pain.