Optimizing effective dose and image quality in cone beam CT sialography.

OBJECTIVES: The purpose of this study was to develop protocols that optimize patient radiation dose and image quality for cone beam computed tomographic (CBCT) sialography for the major salivary glands. STUDY DESIGN: Radiation absorbed dose measurements were repeated in triplicate using 25 sites in the head and neck of a Radiation ANalog DOsimetry system (RANDO) phantom, and effective doses were calculated across a range of peak kilovoltage (kVp) and milliamperage (mA) settings using an 8 cm (diameter) by 5 cm (height) field of view (FOV) for submandibular imaging and an 8 cm (diameter) by 8 cm (height) FOV for parotid imaging. Image signal difference-to-noise ratio (SDNR) was determined, and the figure-of-merit (FOM), a measure of image quality, was calculated. RESULTS: For submandibular sialography, 85 kVp and 6 mA were chosen as the optimal exposure parameters, resulting in a mean effective dose of 82.47 µSv and a mean SDNR of 13.86, with a mean FOM of 2.33 µSv-1. For parotid sialography, 70 kVp and 6 mA were chosen, and these settings resulted in a mean effective dose of 39.99 µSv, a mean SDNR of 17.43, and a mean FOM of 7.60 µSv-1. CONCLUSIONS: Low-dose 3-dimensional sialography with high image quality and minimal effective dose can be delivered using CBCT with localized, small FOVs.

Pediatric poisonings in children younger than five years responded to by paramedics.

BACKGROUND: Treatment of poisonings in children has been well studied, but few data are available on the various causes of the poisoning episodes in the pediatric population. OBJECTIVES: To describe the incidence and demographics of accidental poisonings incurred by children<5 years old in the County of San Diego, California who accessed paramedics through the 9-1-1 system. METHODS: Eight years of prehospital records for children<5 years of age were searched for poisoning cases. Detailed narrative information was abstracted to determine the circumstances surrounding the incident. RESULTS: There were more than 40,000 paramedic transport calls for patients 5 years and younger over the study period; 996 (2.5%) of these calls had the chief complaint of poisoning. Of the calls classified as poisonings, 38% involved a 1-year-old and 35% involved a 2-year-old. Fifty-six percent of these poisonings involved either prescription or over-the-counter medications. An additional 16% were due to household cleaners. Eighty-eight percent of all calls were classified as mild in acuity, with 13% of poisoning calls for children under a year of age classified as moderate or acute; 50% of moderate or acute poisoning calls were to children 2 years of age. July and March were the months with the highest incidence of poisoning calls. The fewest calls were received on Saturdays and Sundays. CONCLUSIONS: Children 1 year of age had the highest incidence of unintentional poisonings. Among all age groups, medications were the number one cause of unintentional poisonings. Other unintentional poisonings could be prevented if hazardous materials were out of reach of children; many of the cases in this study happened in front of the parent with the parent watching.

End-tidal partial pressure of carbon dioxide and acute mountain sickness in the first 24 hours upon ascent to Cusco Peru (3326 meters).

OBJECTIVE: To explore the association of end-title partial pressure (Petco(2)) and oxygen saturation (Spo(2)) with the development of AMS in travelers rapidly ascending to Cusco, Peru (3326 m). METHODS: Using the 715 TIDAL WAVE Sp handheld, portable capnometer/oximeter, we measured Spo(2) and Petco(2) in 175 subjects upon ascent to Cusco, Peru (3326 m) from Lima (sea level) (a mean time of 3.9 hours.) Symptoms of AMS were recorded at the same initial time on arrival to altitude and 24 hours later using the Environmental Symptoms Questionnaire (ESQ). RESULTS: This study showed that no subjects with the lowest Petco(2) of 23 to 30 mm Hg had AMS (P <.044). The data also demonstrate that subjects with a higher Petco(2) (36-40 mm Hg) and lower Sao(2) (72%-86%) have a higher incidence of AMS. CONCLUSION: The most important finding of this study is that Petco(2) upon ascent was found to have a more significant effect than Spo(2) on a subject's ultimate ESQ score. This study demonstrates that those individuals with a brisk ventilatory response upon ascent to moderate altitude, as measured by Petco(2), did not develop AMS, whereas a blunted ventilatory response, as reflected in the highest Petco(2), was related to the subsequent development of AMS.

Hyperventilation following aero-medical rapid sequence intubation may be a deliberate response to hypoxemia.

BACKGROUND: Recent studies document a high incidence of hyperventilation by prehospital providers, with a potentially detrimental effect on outcome in traumatic brain injury (TBI). PURPOSE: To document the incidence of hyperventilation by aero-medical providers and explore a possible relationship between hyperventilation episodes and desaturations or impending hypoxemia. METHODS: This was a prospective, descriptive study using TBI patients undergoing prehospital RSI by aero-medical crews. Continuous data regarding end-tidal CO2 (EtCO2), ventilatory rate, and oxygen saturation (SpO2) were downloaded from hand-held oximeter-capnometer devices. Two investigators independently assessed oximetry/capnometry data to identify the following occurrences: desaturation during RSI (SpO2 < 90%), impending hypoxemia (SpO2 decrease by >or=3% to a value <95%) following intubation, loss of SpO2 signal, hyperventilation (EtCO2<30 mm Hg), and severe hyperventilation (EtCO2 < 25 mm Hg). Covariate analysis was used to explore the possible association between hyperventilation episodes and either desaturation, impending hypoxemia, or loss of SpO2 signal. RESULTS: A total of 32 aero-medical patients were enrolled with a mean duration of ventilation monitoring of 14.8 min. The incidence of hyperventilation or severe hyperventilation was substantially lower than previously documented with ground paramedics. A total of 28 hyperventilation episodes were identified in 16 patients; 13 of these were associated with impending hypoxemia following intubation, five were associated with desaturation during RSI, and seven were associated with loss of SpO2 signal. The remaining three occurred immediately following intubation without desaturation during RSI. Desaturation was observed in 62% of patients; of note, desaturation was recorded on the quality improvement document in only 23% of these. Covariate analysis revealed an association between hyperventilation episodes and either desaturatios during RSI, impending hypoxemia following intubation, or loss of SpO2 signal. CONCLUSIONS: The incidence of hyperventilation by aeromedical crews was lower than reported for ground paramedics and appears to occur in response to desaturation, impending hypoxemia, or loss of SpO2 signal.

Traumatic brain injury outcomes in pre- and post- menopausal females versus age-matched males.

Gender differences in outcomes from major trauma have been described previously, and exogenous female hormone administration appears to be neuroprotective following traumatic brain injury (TBI). This analysis explored outcomes in pre- and post-menopausal females versus age-matched males. A total of 13,437 patients (n = 3,178 females, n = 10,259 males) with moderate-to-severe TBI (head AIS > or = 3) were identified from our county trauma registry. Overall mortality was similar between males and females (22% for both). Logistic regression was used to compare gender outcome differences, with a separate analysis performed for premenopausal (< 50 years) versus postmenopausal (> or = 50 years) patients, and after stratification by decade of life. No statistically significant difference in outcomes was observed for pre-menopausal females versus males (odds ratio [OR] 1.06; 95% confidence interval [CI] 0.83, 1.35; p = 0.633), but outcomes were significantly better in postmenopausal females versus males (OR 0.63, 95% CI 0.48-0.81, p < 0.001) after adjusting for age, mechanism of injury, Glasgow Coma Scale (GCS), hypotension (SBP < or = 90 mm Hg), head Abbreviated Injury Score (AIS), and Injury Severity Score (ISS). Stratification by decade of life revealed the gender survival differential inflection point to occur between ages 40-49 (OR 1.06, 95% CI 0.66-1.71, p = 0.798) and ages 50-59 (OR 0.38, 95% CI 0.20-0.74, p = 0.005). In addition, Revised Trauma Score and Injury Severity Score (TRISS) was used to calculate probability of survival (PS); all patients were then stratified by decade of life, and males and females were compared with regard to mean survival differential (outcome - PS). The identical pattern of improved outcomes in post-menopausal but not pre-menopausal females versus age-matched males was observed. These data suggest that endogenous female sex hormone production is not neuroprotective.