Paramedic contact to balloon in less than 90 minutes: a successful strategy for st-segment elevation myocardial infarction bypass to primary percutaneous coronary intervention in a canadian emergency medical system.

INTRODUCTION: Few systems worldwide have achieved the benchmark time of less than 90 minutes from emergency medical services (EMS) contact to balloon inflation (E2B) for patients sustaining ST-segment elevation myocardial infarction (STEMI). We describe a successful EMS systems approach using a combination of paramedic and 12-lead electrocardiogram (ECG) software interpretation to activate a STEMI bypass protocol. OBJECTIVES: To determine the proportion of patients who met the benchmark of E2B in less than 90 minutes after institution of a regional paramedic activated STEMI bypass to primary PCI protocol. METHODS: We conducted a before-and-after observational cohort study over a 24-month period ending December 31, 2009. Included were all patients diagnosed with STEMI by paramedics trained in ECG acquisition and interpretation and transported by EMS. In the "before" phase of the study, paramedics gave emergency departments (EDs) advance notification of the arrival of STEMI patients and took the patients to the ED of the PCI center. In the "after" phase of the study, paramedics activated a STEMI bypass protocol in which STEMI patients were transported directly to the PCI suite, bypassing the local hospital EDs. Transmission of ECGs did not occur in either phase of the study. RESULTS: We compared the times for 95 STEMI patients in the before phase with the times for 80 STEMI patients in the after phase. The proportion for whom E2B was less than 90 minutes increased from 28.4% before to 91.3% after (p < 0.001). Median E2B time decreased from 107 minutes (interquartile range [IQR] = 30) before to 70 minutes (IQR = 24) after. Median D2B time decreased from 83 minutes (IQR = 34) before to 35 minutes (IQR = 19) after. Median E2D time increased from 21 minutes (IQR = 8) before to 32 minutes (IQR = 17) after. Median differences between phases were significant at p < 0.001. The rate of false-positive PCI laboratory activation during the after phase of the study was 12.4%. CONCLUSIONS: The proportion of patients with E2B times less than 90 minutes significantly improved through the implementation of a paramedic-activated STEMI bypass protocol. Further study is required to determine whether these benefits are reproducible in other EMS systems.

Characterization of basal hepatic bile flow and the effects of intravenous cholecystokinin on the liver, sphincter, and gallbladder in patients with sphincter of Oddi spasm.

The major objectives of this project were to establish the pattern of basal hepatic bile flow and the effects of intravenous administration of cholecystokinin on the liver, sphincter of Oddi, and gallbladder, and to identify reliable parameters for the diagnosis of sphincter of Oddi spasm (SOS). Eight women with clinically suspected sphincter of Oddi spasm (SOS group), ten control subjects (control group), and ten patients who had recently received an opioid (opioid group) were selected for quantitative cholescintigraphy with cholecystokinin. Each patient was studied with 111-185 MBq (3-5 mCi) technetium-99m mebrofenin after 6-8 h of fasting. Hepatic phase images were obtained for 60 min, followed by gallbladder phase images for 30 min. During the gallbladder phase, 10 ng/kg octapeptide of cholecystokinin (CCK-8) was infused over 3 min through an infusion pump. Hepatic extraction fraction, excretion half-time, basal hepatic bile flow into the gallbladder, gallbladder ejection fraction, and post-CCK-8 paradoxical filling (>30% of basal counts) were identified. Seven of the patients with SOS were treated with antispasmodics (calcium channel blockers), and one underwent endoscopic sphincterotomy. Mean (+/-SD) hepatic bile entry into the gallbladder (versus GI tract) was widely variable: it was lower in SOS patients (32%+/-31%) than in controls (61%+/-36%) and the opioid group (61%+/-25%), but the difference was not statistically significant. Hepatic extraction fraction, excretion half-time, and pattern of bile flow through both intrahepatic and extrahepatic ducts were normal in all three groups. Gallbladder mean ejection fraction was 9%+/-4% in the opioid group; this was significantly lower (P<0.0001) than the values in the control group (54%+/-18%) and the SOS group (48%+/-29%). Almost all of the bile emptied from the gallbladder refluxed into intrahepatic ducts; it reentered the gallbladder after cessation of CCK-8 infusion (paradoxical gallbladder filling) in all eight patients with SOS, but in none of the patients in the other two groups. Mean paradoxical filling was 204% (+/-193%) in the SOS group and less than 5% (P<0.05) in both the control and the opioid group. After treatment, six of the SOS patients had complete pain relief and one, partial pain relief. The basal tonus of the sphincter is variable in patients with SOS, and allows relatively more of the hepatic bile to enter the GI tract than the gallbladder. Due to simultaneous contraction of the sphincter and gallbladder in response to CCK-8, most of the bile emptied from the gallbladder refluxes into intrahepatic ducts, and reenters the gallbladder immediately after cessation of hormone infusion. The characteristic features of gallbladder filling, emptying, and paradoxical refilling with cholecystokinin provide objective parameters for noninvasive diagnosis of SOS by quantitative cholescintigraphy.