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Biomedical subjects

R E Jackson

Publications and source records attributed to R E Jackson.

At least 37 records · Page 2Linked to original sources
PubMed1995

Bystander vs EMS first-responder CPR: initial rhythm and outcome in witnessed nonmonitored out-of-hospital cardiac arrest.

OBJECTIVES: To assess whether outcome and first-monitored rhythm for patients who sustain a witnessed, nonmonitored, out-of-hospital cardiac arrest are associated with on-scene CPR provider group. METHODS: A retrospective, cohort analysis was conducted in a suburban, heterogeneous EMS system. Patients studied were > or = 19 years of age, had had an arrest of presumed cardiac origin between July 1989 and January 1993, had gone into cardiac arrest prior to ALS arrival, and had received CPR on collapse. First-monitored rhythms and survival rates were compared for two patient groups who on collapse either: 1) had received CPR by nonprofessional bystanders (BCPR) or 2) had received CPR by on-scene EMS system first responders (FRCPR). RESULTS: Of 217 cardiac arrest victims, 153 (71%) had received BCPR and 64 (29%) had received FRCPR. The BCPR patients were slightly younger (62.4 vs 68.4 years, p = 0.01) and had slightly shorter ALS response intervals (6.4 vs 7.7 minutes, p = 0.02). There was no difference in BLS response time intervals or automatic external defibrillator (AED) use rates. The percentage of patients with a first-monitored rhythm of pulseless ventricular tachycardia/ventricular fibrillation (VT/VF) and the percentage of patients grouped by CPR provider who survived to hospital admission or to hospital discharge were: [see text]

Adult↗
PubMed1992

Long-term monitoring of aldicarb residues in groundwater beneath a Canadian potato field.

Four shallow monitoring wells beneath a potato field to which Temik (active ingredient--aldicarb) had been applied were sampled up to 19 times over six years. These samples were regularly analyzed for aldicarb sulfoxide, aldicarb sulfone and nitrate and less frequently for major ions and for pH, EH, dissolved oxygen and alkalinity. Pesticide residue concentration in groundwater was related both to time after application and to the elevation of the water table, a measure of groundwater recharge. This dependence on recharge indicates storage in the unsaturated zone. The presence of relatively high residues four years after the last application is due to this storage phenomenon and to water and soil conditions, particularly low temperature, that inhibit the hydrolysis of the active species.

Aldicarb↗
PubMed1992

Massive splenomegaly in sarcoidosis.

We have presented a case of massive splenomegaly. Our patient was initially thought to have lymphoma, but at operation she was found to have sarcoidosis with splenic involvement. At 2250 g, the spleen was one of the largest recorded in the literature on sarcoidosis. Although the spleen is frequently involved in sarcoidosis, a review of 6074 cases showed that the incidence of actual splenomegaly is only 10%. In 628 of these cases the authors described various degrees of splenomegaly, but the incidence of massive splenomegaly was only 3%. We conclude that sarcoidosis must be considered in the differential diagnosis of splenomegaly.

Adult↗
PubMed1991

A selective approach to operative cholangiography.

The value of operative cholangiography in the detection of common bile duct stones has been documented in a number of studies. This study suggests that operative cholangiography can be-used successfully on a more selective basis when used in conjunction with laboratory and operative criteria. One hundred and fifty patients who underwent routine cholecystectomy were retrospectively evaluated. Seventy-five percent had a normal cholangiogram and normal levels of bilirubin and alkaline phosphatase. The remaining 25% had abnormal cholangiograms as well as abnormal laboratory chemistry values. It was noted that if selective operative cholangiography had been performed only on those patients with indications for common bile duct exploration, no ductal stones would have been omitted. Based on these data, a selective approach to operative cholangiography is advocated.

Cholangiography↗
PubMed1988

Hypertension in the emergency department.

Hypertensive emergencies are now rare and are recognized by the deleterious effect on end-organs. Prompt, efficacious treatment is critical, and the current drug of choice for most episodes is sodium nitroprusside. Hypertensive urgencies are more common than are emergencies, and are distinguished by diastolic pressures greater than 115 mm Hg without end-organ dysfunction. Although there are many efficacious agents, one excellent choice is nifedipine.

Antihypertensive Agents↗
PubMed1987

Safety evaluation of nabumetone in United States clinical trials.

A total of 1,924 persons (rheumatoid arthritis, 835; osteoarthritis, 1,073; volunteers, 16) received nabumetone in United States clinical trials. Nine hundred eighty-eight patients have received nabumetone treatment for periods of more than one year, and 375 patients have received treatment for longer than two years. Four hundred eighty patients over 65 years of age have received treatment with nabumetone, and 224 of these elderly patients have received treatment for periods of more than one year. The nabumetone dose most commonly used in all double-blind trials was 1,000 mg at night. In long-term, open-label studies, which were usually extensions of the double-blind trials, patients could increase the dose to 2,000 mg per day. Nine hundred nineteen patients received doses of more than 1,000 mg per day. Adverse experience information was collected at each visit, including information for some patients receiving treatment for more than three years. Laboratory data were collected periodically throughout the trials, and the data were assessed for trends over time. The adverse experience pattern observed for nabumetone is similar to that described for clinical trial data for other nonsteroidal anti-inflammatory drugs. However, it is noteworthy that the pattern observed for nabumetone is from clinical trials with approximately 1,000 patients receiving treatment for periods of one year or more. This long-term patient exposure in clinical trials far exceeds long-term clinical trial data for other agents. The types and frequencies of adverse experiences reported by persons treated with nabumetone are relatively constant over the long time period covered by these trials. Also, the adverse experience patterns remained generally constant over time for various populations: all patients, patients 65 or older, female patients, male patients, and patients who received an increased dose of nabumetone. Although some statistically significant trends were detected for some laboratory parameters, there was little indication of significant clinical patterns. Although there were patients with individually important laboratory values, nabumetone was not associated with clinically important adverse laboratory patterns. Overall, the adverse experience data and laboratory data indicate that nabumetone is safe for the treatment of adult patients with rheumatoid arthritis or osteoarthritis.

Adult↗
PubMed1987

Efficacy of benzathine penicillin G in group A streptococcal pharyngitis: reevaluation.

The rate of streptococcal eradication after intramuscular administration of benzathine penicillin G in 66 children with acute group A streptococcal pharyngitis was determined and possible reasons for treatment failure explored. Bacteriologic treatment failure, defined as isolation of the same serotype at 3- or 6-weeks follow-up, occurred in eight (12%) patients. The treatment failure rate was 21% in those with immunologically significant infection, versus 8% in those without antibody rises (P greater than 0.1). All group A beta-hemolytic streptococcal (GABS) strains isolated from patients with treatment failure, both before and after benzathine penicillin G therapy, were exquisitely susceptible to penicillin G (minimum inhibitory concentration less than or equal to 0.02 microgram/mL), and none showed evidence of tolerance (minimum bactericidal concentration less than or equal to 0.04 microgram/mL). Thus, we found GABS eradication rates to exceed 10% in children given benzathine penicillin G. The failure rate did not appear to be related to enrichment of the patient population with a high proportion of asymptomatic carriers nor to the presence of penicillin-tolerant GABS.

Child↗
PubMed1987

The incidence of AIDS among blacks and Hispanics.

Compared with whites, the acquired immune deficiency syndrome (AIDS) has affected blacks and Hispanics disproportionately. The cumulative incidence (CI) for black men was 2.6, and for Hispanic men 2.5, times the rate for white men. Intravenous (IV) needle use alone does not account for this difference. Not counting IV needle-using cases, the CIs for black and Hispanic men were 1.7 times the CI for white men. Although there were fewer cases in women than men, the white-to-minority disparity was greater for women. The CIs for black and Hispanic women were 12.2 and 8.5 times, respectively, the CI for white women. Prevention programs are urgently needed and should focus on risky behavior (IV needle sharing and receptive anal intercourse), not just risk groups.

Acquired Immunodeficiency Syndrome↗
PubMed1986

The value of obtaining renal images following brain scintigraphy with technetium-99m glucoheptonate.

The value of adding an extra view of the kidneys immediately following brain imaging with Tc-99m glucoheptonate was investigated in a two-year retrospective study at our institution. Between October 1982 and October 1984, 561 individuals underwent Tc-99m glucoheptonate brain imaging with the added renal view. Twenty-nine of these individuals (5.2%) demonstrated renal abnormalities. The abnormal renal findings were clinically correlated in 24 of these persons. Sixteen (67%) of these 24 individuals were unaware of any renal abnormality. Useful information can be obtained from renal images incidental to brain imaging at no added expense or radiation exposure to the patient, and at a minimal cost in time to the imaging clinic.

Adolescent↗
PubMed1985

Dose-related response of centrally administered epinephrine on the change in aortic diastolic pressure during closed-chest massage in dogs.

The current recommendation of the American Heart Association is to give 0.5 to 1.0 mg (7.5 to 15 micrograms/kg in a 70-kg man) of epinephrine intravenously every five minutes during cardiac arrest. The optimal dose of epinephrine to augment the aortic diastolic pressure (ADP) is not known. The effect of various doses of central bolus epinephrine on the ADP during closed-chest massage was studied. A group of 25 large dogs was divided equally into five groups: control and 15, 45, 75, and 150 micrograms/kg. After three minutes of cardiac arrest, closed-chest massage was initiated, and the study drug was given two minutes later. The ADP and right atrial pressures were monitored for 15 minutes. Changes in ADP peaked at two minutes after injection in all groups receiving epinephrine, and the drop in ADP over time noted in the control group was prevented by increasing doses of epinephrine. Among the groups receiving epinephrine, however, there was no difference in the absolute ADP and diastolic coronary perfusion pressure.

Animals↗
PubMed1984

Blood flow in the cerebral cortex during cardiac resuscitation in dogs.

Regional cerebral cortical blood flow (rCCBF) in 15 large dogs was determined using the double thermistor dilution method during standard closed-chest massage (CCM), CCM with an epinephrine infusion at 30 micrograms/kg/min (CCM + Epi), and open-chest cardiac massage (OCCM). As a percentage of prearrest flow values, the rCCBF was 9.8% with CCM, 35% with CCM + Epi, and 156% with OCCM. The rCCBF was reduced significantly with CCM (P less than .005) and CCM + Epi (P less than .01). OCCM generated flows indistinguishable from prearrest values. The use of high-dose epinephrine significantly increased the rCCBF during CCM. The implications for intact neurologic resuscitation of these reductions in rCCBF with CCM are important.

Animals↗
PubMed1983

Cerebral cortical perfusion during and following resuscitation from cardiac arrest in dogs.

Perfusion of the cerebral cortex during closed chest CPR in dogs, generating systolic pressures of 60 to 70 mmHg, is only 10% of pre-arrest blood flow. In contrast, internal cardiac massage produces normal cortical perfusion rates. Following a 20-min perfusion arrest, during pressure controlled reperfusion, cortical flow rates decay to less than 20% normal after 90 min of reperfusion. This appears to be due to increasing cerebral vascular resistance, and is not due to rising intracranial pressure. The post-arrest cortical hypoperfusion syndrome is prolonged with cortical flow remaining below 20% normal up to 18 hr post arrest. The use of a variety of calcium antagonists, including flunarizine, lidoflazine, verapamil, and Mg2+, immediately post-resuscitation maintains cerebral vascular resistance and cortical perfusion at normal levels. A prospective blind trial of the calcium antagonist lidoflazine following a 15-min cardiac arrest in dogs and resuscitation by internal massage, demonstrates amelioration of neurologic deficit in the early postresuscitation period.

Adenosine Triphosphate↗
PubMed1983

Prolonged hypoperfusion in the cerebral cortex following cardiac arrest and resuscitation in dogs.

Increasing cerebral vascular resistance and brain perfusion failure occur within 90 minutes following cardiac arrest and resuscitation. This study followed cortical perfusion for 18 hours after a 15-minute cardiac arrest. Six dogs were anesthetized with ketamine and gallamine and then mechanically ventilated. They were instrumented for arterial pressure, central venous pressure, and regional cerebral cortical blood flow (rCCBF) determined by thermodilution. A left thoracotomy and pericardiotomy were done. Two dogs served as non-arrest controls. Cardiac arrest was produced in four dogs with an intravenous bolus of KCl at 1 mEq/kg. After 15 minutes of cardiac arrest, the animals were resuscitated with internal massage, NaHCO3, epinephrine, and internal defibrillation. Cortical blood flow was followed for 18 hours. Arterial core temperature was never less than 35 C. Pre-arrest cortical blood flows were 0.86 cc/min/g (+/- 0.11). The two control animals had stable rCCBF (0.74 +/- 0.17) for all determinations during the 18-hour follow-up period. Determinations of rCCBF from 6 to 18 hours in post-arrest animals were 7% to 14% of pre-arrest values. We conclude that the post-resuscitation perfusion failure in the cortex is prolonged. Any potential for neuronal recovery, unless perfusion is protected, would not be realized given this phenomenon.

Animals↗
PubMed1983

Early amelioration of neurologic deficit by lidoflazine after fifteen minutes of cardiopulmonary arrest in dogs.

A prospective, controlled, blind study was done to test the effect of a calcium entry blocker on the neurologic integrity of dogs after cardiopulmonary arrest. Ten male mongrel dogs were anesthetized, prepared with sterile technique, and instrumented for pulmonary arterial (PA) and systematic arterial pressure monitoring. A left thoracotomy and pericardotomy were performed. Cardiac arrest was produced by injecting KCl (1 mEq/kg) through the PA line, and the respirator was stopped. Full arrest was maintained for 15 minutes. Thereafter, the dogs were resuscitated with ventilation, internal massage, fluids, bicarbonate, epinephrine, and internal defibrillation. All dogs were resuscitated within 6 to 10 minutes. Five control dogs received saline placebo, and five dogs were treated with lidoflazine (1 mg/kg) IV drip immediately post resuscitation. All dogs were scored neurologically every two hours by a deficit grading scale. All treated dogs had spontaneous ventilation, reactive pupils and corneals, voluntary movements, and responses to tactile stimulation at 12 hours post resuscitation. Four of five control dogs had maximum deficit scores without improvement. The difference in neurologic scores between the treated and control groups became increasingly divergent with time, and was statistically significant (P less than .05) by four hours post resuscitation. Thus the calcium antagonist lidoflazine produces improvement in neurologic recovery in the first 12 hours after cardiopulmonary arrest in dogs.

Animals↗
PubMed1983

A double-blind comparative trial with mianserin and amitriptyline in outpatients with major depressive disorders.

1 A double-blind trial with parallel treatment groups was conducted to compare the safety and efficacy of mianserin with amitriptyline. 2 This was a six week trial with weekly visits. Measurements at each visit included: 21 item Hamilton Depression (HAMD) Scale. Clinical Global Impression (CGI) Scale and Treatment Emergent Symptom Scale (TESS). 3 Mianserin and amitriptyline were comparable with respect to efficacy. 4 More adverse experiences were reported by amitriptyline patients. The predominant amitriptyline adverse experiences were of the anticholinergic type; the predominant mianserin adverse experience was drowsiness/fatigue. 5 The Efficacy Index (EI), a scale combining efficacy and adverse experiences, clearly demonstrated the superiority of mianserin over amitriptyline.

Amitriptyline↗
PubMed1983

Hemodynamics of cardiac massage.

The introduction of closed chest massage in 1960 initiated a widespread interest in cardiopulmonary resuscitation. Until that time, open chest cardiac massage was the standard for CPR. Initial explanations for blood flow during closed chest CPR were based upon direct compression of the heart. This explanation has given way to demonstrations that blood flows during CPR because of changes in intrathoracic pressure. Changes in intrathoracic pressure that create blood flow have been created by simple maneuvers such as coughing. More involved methods of affecting intrathoracic pressure, in an attempt to improve upon standard closed chest massage, have included applying positive pressure to the airway, binding of the abdomen, and the use of MAST. Cardiac output with closed chest massage is approximately one fourth of normal, and cerebral perfusion is approximately one tenth of normal. Cardiac output with open chest massage is approximately double that obtained by closed chest massage. Cerebral blood flow during open chest massage approaches physiologic values. The use of drugs possessing alpha adrenergic activity and maneuvers that augment intrathoracic pressure improve vital organ perfusion.

Animals↗