Abstract. Objective: To determine whether emergency medicine (EM) resident documentation of procedures, patient encounters, and patient follow-ups improved after implementation of a personal digital assistant (PDA) hand-held recording system. Methods: All first-year EM residents were provided a PalmV (Palm, Inc., Santa Clara, CA) PDA. A customized patient procedure and encounter program was constructed using Pendragon Forms (Pendragon Software Corporation, Libertyville, IL) and loaded into each PDA. Residents were instructed to enter information on patients who had any of 21 procedures performed or were considered to be clinically unstable. These data were downloaded to the residency coordinator's desktop computer. The mean number of procedures, encounters, and follow-ups performed per resident were then compared with those of a group of 36 historical controls from the three previous first-year resident classes who recorded the same information using a handwritten card system. Data from the historical controls were combined and the means of each group were compared by Student's t-test. Results: Mean documentation of three procedures was significantly increased in the PDA group versus the index card system: conscious sedation 5.8 vs. 0.03 (p < 0.000005), thoracentesis 2.2 vs. 0.0 (p = 0.002), ultrasound 6.3 vs. 0.0 (p = 0.002). The mean numbers of pericardiocenteses and unstable pediatric surgical patient evaluations were significantly decreased in the hand-held group [from 1.2 to 0.4 (p = 0.03) and from 9.1 to 2.2 (p = 0.02), respectively]. Patient follow-up documentations were not statistically different between the two groups. Conclusions: Use of a hand-held PDA was associated with an increase in first-year EM resident documentation in three of 20 procedures and a decrease in one procedure and the number of unstable surgical pediatric patient resuscitations. The overall time savings in constructing a resident procedure database, as well as the other uses of the PDAs, may make transition to a hand-held computer-based procedure log an attractive option for EM residencies.

This research was designed to test the hypothesis that ischemic preconditioning can be transferred between animals via whole blood transfusion. Preconditioning at a distance refers to the reduction in myocardial infarct size seen when coronary artery occlusion is preceded by brief ischemic episodes of noncardiac tissue. Isolation of the trigger signal responsible for this effect may be useful in the diagnosis and treatment of acute coronary occlusive syndromes. Rabbits were paired by crossmatching blood samples prior to experimentation. Crossmatched pairs were placed into either preconditioned (P) or control sets. Rabbits in the preconditioned sets were further divided into donor (PD) and acceptor (PA) animals. PD animals underwent five episodes of circumflex and renal artery occlusion followed by reperfusion. Before and after each preconditioning episode, a whole blood exchange was performed between PD and PA animals. Alternatively, control rabbits underwent the same surgical procedures and time-sequenced transfusion without preconditioning. All animals then underwent prolonged circumflex occlusion (60 minutes) followed by reperfusion (30 minutes). The area of myocardium at risk (R) was determined by isotope-labeled microsphere injection. Infarct size (I) was determined by NBT staining. The percent infarct within the risk area (I/R) was then compared. The I/R was significantly lower in the PA (14.0% +/- 12.2) and PD (14.3% +/- 11.2) groups as compared with controls (61% +/- 20. 6). There was no significant difference between the tPA and TPD groups. In conclusion, the ischemic preconditioning effect can be transferred to nonpreconditioned animals via whole blood transfusion, suggesting a humoral mechanism for preconditioning at a distance.

Abstract. Objectives: Advances in the field of cardiopulmonary resuscitation have led to an increasing number of patients initially surviving sudden cardiac arrest. Unfortunately, most of these patients do not recover from the resultant anoxic brain insult. Several animal and human trials have suggested that post-resuscitative brain hypothermia may improve neurologic recovery after cardiopulmonary arrest. Present cooling methods are slow, induce only brain surface cooling, or result in systemic hypothermia. The authors tested the hypothesis that unilateral hypothermic carotid bypass would induce bilateral brain cooling without evoking systemic hypothermia or hemodynamic instability. Methods: Anesthetized, ventilated common swine (n = 6, 24-37 kg) underwent right femoral and carotid artery bypass cannulation. Central and peripheral hemodynamic parameters were recorded every 2 minutes throughout the procedure. Thermodynamic parameters included bilateral frontal lobe, bilateral nasopharyngeal, pulmonary artery, and rectal temperatures. Hypothermic femoral-carotid bypass was accomplished by drawing blood from the right femoral artery, cooling it to 24ЊC, and returning it to the right carotid artery at a flow rate of 5 mL/kg/min for 30 minutes. Results: With initiation of cooling, brain temperatures dropped rapidly from baseline of 37.2ЊC to 30.6ЊC (right frontal lobe) and 33.1ЊC (left frontal lobe) at 30 minutes. Pulmonary artery and rectal temperatures also decreased, but never reached mild hypothermic levels (34ЊC). There was no significant change in any hemodynamic parameters during brain cooling. Conclusions: Femoral-carotid hypothermic bypass rapidly induced a state of selective brain hypothermia without causing systemic hypothermia or hemodynamic instability. Key words: hypothermia; brain; resuscitation; bypass; cerebral ischemia. ACADEMIC EMERGENCY MEDICINE 2001; 8:303-308 I NCREASING numbers of patients experiencing out-of-hospital cardiac arrest are surviving to hospital admission as a result of improvements in resuscitation techniques.1-3 Unfortunately, most of these patients fail to recover to their previous functional status. [4][5][6] Present therapy during the post-resuscitative period remains largely suppor- tive and directed at preventing further anoxic insult and cardiovascular instability.Recent evidence from both laboratory and human trials suggests that post-resuscitative brain hypothermia may improve functional outcome of survivors from out-of-hospital cardiac arrest. [7][8][9][10][11]

Abstract. Objective: Brief myocardial ischemia evokes a cardioprotective response, referred to as ''ischemic preconditioning'' (IP), that limits injury caused by a subsequent prolonged ischemic insult. The myocardial IP effect can be induced by ischemia of ''distant'' cardiac and noncardiac tissue, implicating the involvement of an as-yet-unidentified humoral trigger. If a preconditioning hormone exists, the authors hypothesize that the IP effect should be transferable, via administration of coronary effluent, from a preconditioned donor heart to a virgin nonpreconditioned acceptor heart. Methods: Isolated buffer-perfused rabbit hearts were assigned to one of four treatment groups in a donor/acceptor sequence. Donor hearts underwent either three IP cycles or a matched period of uninterrupted perfusion (control donors). Coronary perfusate collected from IP and control donor hearts was reoxygenated and transfused to virgin acceptor hearts. All hearts then underwent 30 minutes of global ischemia followed by 30 minutes of reperfusion. Left ventricular developed pressure (LVDP) (the authors' index of cardioprotection) was monitored throughout the protocol by a left ventricular (LV) balloon. Results: In donor controls, LVDP assessed at 30 minutes post-reflow was restored to only 49 Ϯ 5% of baseline values. Recovery of LV function was significantly enhanced in both IP donor hearts (69 Ϯ 4%*) and IP acceptor hearts (70 Ϯ 6%*) vs donor controls (*p < 0.05), while, in acceptor controls, intermediate values of LVDP (62 Ϯ 7%) were obtained. Conclusion: The IP effect can be transferred between rabbit hearts, suggesting the presence of a humoral trigger signal for distant preconditioning. Isolating this hormone may have therapeutic and diagnostic implications in the management of acute myocardial ischemia.

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