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Biomedical subjects

J A Barrett

Publications and source records attributed to J A Barrett.

At least 73 records · Page 4Linked to original sources
PubMed1991

The utility of cardiac evaluation in the hemodynamically stable patient with suspected myocardial contusion.

Myocardial contusion following isolated blunt thoracic trauma (BTT) remains a diagnostic and therapeutic dilemma. To identify the presence of cardiac abnormality following BTT, 123 hemodynamically stable patients were prospectively evaluated with serial electrocardiograms (ECG) and cardiac enzymes (total CPK and CPK-MB). Gated cardiac radionuclide angiography (MUGA) scans were performed within 48 hours following admission. Patients included in the study sustained significant thoracic trauma identified by physical findings or mechanism of injury. Sixty-three patients (51%) were identified with either abnormal ECG, or abnormal total CPK, CPK-MB, MUGA scan, or combination of the above. Thirty-seven patients (58.7%) manifested an ECG abnormality defined as ST-segment or T-wave abnormality. Twenty-two patients (34.9%) had total CPK value greater than or equal to 50 International Units (I.U.) or CPK-MB fractions greater than or equal to five per cent. MUGA scan was abnormal (right ventricular ejection fraction less than 40 per cent and/or wall motion abnormality) in 12 patients (19%). Eight patients with MUGA scan abnormality had normal ECG and/or normal total CPK, CPK-MB values. Evaluation of all patients up to six months revealed no mortality, malignant arrhythmias, or cardiac failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Intrahypothalamic injections of norepinephrine facilitate feline affective aggression via alpha 2-adrenoceptors.

The purpose of this study was to investigate the effects of noradrenergic agents infused into the anterior hypothalamus on feline affective defense responses elicited by electrical stimulation of the ventromedial hypothalamus. Anterior hypothalamic sites which are known to receive inputs from both the ventromedial hypothalamus and ascending noradrenergic pathways were selected for pharmacological analysis. Intracerebral infusions of NE (1.2-2.4 nmol) into the anterior hypothalamus significantly reduced the threshold current required to elicit the hissing component of affective defense via electrical stimulation of the ventromedial hypothalamus. Maximal threshold reductions (17 +/- 3% to 20 +/- 3%) were observed 30 min following infusion. Anterior hypothalamic infusions of clonidine facilitated feline affective defense by reducing hissing current thresholds by 18 +/- 4%. Clonidine-induced changes in response thresholds parallel those obtained with NE. Both NE-induced and clonidine-induced reductions in current thresholds were reversible by pre- and post-treatment of the anterior hypothalamic sites with yohimbine. These results demonstrate that the reductions in response thresholds are mediated by post-synaptic alpha 2-adrenoceptors located within the anterior hypothalamus. Thus the noradrenergic system may play an important role in the regulation of affective aggressive behavior.

Affect↗
PubMed1990

Prospective study of the effect of safety belts in motor vehicle crashes.

Trauma resulting from motor vehicle crashes (MVCs) is the leading cause of death in persons 1 to 38 years old. The following prospective study was undertaken to assess the effect of safety belts on the types of injuries sustained in MVCs. A total of 1,364 patients from four Chicago-area hospitals were evaluated prospectively during a six-month period. Safety belts reduced the incidence of head, facial, thoracic, abdominal, and extremity injuries sustained in MVCs. Spinal injuries comprised the only group in which safety belt wearers sustained injuries more frequently than safety belt nonwearers. Further research on the different safety belt designs and effects of air bags is needed to reduce the incidence of cervical and lumbar strain in restrained patients.

Abbreviated Injury Scale↗
PubMed1990

Rectal motility studies in faecally incontinent geriatric patients.

Rectal motility was assessed in three groups of geriatric patients (faecally incontinent, continent faecally impacted and control patients) to determine whether 'uninhibited' rectal contractions are a cause of faecal incontinence. The incidence of rectal contractions in response to rectal distension did not differ between the three study groups. Two-thirds of the incontinent patients were unable to retain a condom distended with water (soft-stool model) during a proctometrogram. Involuntary expulsion of this device was correlated with the presence of rectal contractions and low anal resting pressure. Involuntary expulsion of an airfilled balloon (firm-stool model) from the rectum occurred less frequently and was correlated with low resting pressure but not with rectal contractions. The contribution of 'uninhibited' rectal contractions to faecal incontinence is insignificant except for a minor role in the expulsion of liquid stool.

Aged↗
PubMed1990

Pharmacology of RG W-2938: a cardiotonic agent with vasodilator activity.

The cardiovascular effects of RG W-2938, 6-[6-(3,4-dihydro-3-methyl-2(1H)-2-oxoquinazolinyl)]-4,5-dihydro-3 (2H-pyridazinone, a new nonglycoside, noncatecholamine cardiotonic/vasodilator agent were examined in vivo in anesthetized and conscious dogs and in vitro in isolated guinea pig hearts; in the latter, RG W-2938 5 nmol-5 mumol increased contractility in a dose-related fashion. RG W-2938 30-300 micrograms/kg administered intravenously (i.v.) to anesthetized dogs increased contractile force while decreasing arterial pressure and total peripheral resistance (TPR) in a dose-related manner. Heart rate (HR) was only slightly increased, and aortic flow was not appreciably altered. A single oral dose of RG W-2938 0.3 mg/kg administered to conscious chronically instrumented dogs produced a marked and sustained increase in contractility 15-240 min after treatment while only slightly increasing HR. The effects of RG W-2938 30-300 micrograms/kg, i.v. were studied in a mecamylamine-propranolol-induced model of heart failure. RG W-2938 effectively reversed the drug-induced heart failure by increasing myocardial contractility and decreasing arterial pressure while only slightly affecting HR. These studies show that RG W-2938 is an orally effective positive inotropic/vasodilator agent.

Analysis of Variance↗
PubMed1990

The impact of volume on outcome in seriously injured trauma patients: two years' experience of the Chicago Trauma System.

The American College of Surgeons has stated that in considering the development of trauma systems it is important to ensure an appropriate volume of seriously injured patients be seen by each trauma center in order to achieve acceptable mortality rates. Clinical data supporting this recommendation are lacking. An analysis was performed on 1,643 seriously injured trauma patients to determine the relationship between volume and mortality rates. Three separate statistical methods were used: Pearson correlation coefficients, mortality odds ratios, and direct pairwise mortality comparisons. In addition, Tobit analysis was introduced as a method to analyze the relationship between volume and mortality. Mortality rates were adjusted for the confounding variable of serious head injury. Pearson correlation coefficients for volume vs. adjusted mortality was -0.65. Mortality odds ratios comparing the low-volume (less than 140 pts) trauma centers vs. the high-volume (greater than 200 pts) trauma centers was 1.3 for adjusted mortality rates (95% CI = 1.01-1.66; p = 0.04). Categorical analysis showed significantly different mortality rates in the centers before and after adjusting for patient mix. Tobit analysis showed the relationship between volume and mortality to be significant, accounting for 30-40% of the observed variation in mortality rates. In addition, Tobit analysis allowed construction of a model to predict mortality rates, given specific volumes of patients. Our data suggest that an inverse relationship exists between volume and mortality, and support the necessity of configuring trauma systems in a manner that will ensure designated trauma centers will see a high volume of seriously injured patients.

Adult↗
PubMed1990

Diagnostic peritoneal lavage: is an isolated WBC count greater than or equal to 500/mm3 predictive of intra-abdominal injury requiring celiotomy in blunt trauma patients?

A 5-year retrospective review of 3,503 diagnostic peritoneal lavage (DPL) patients was conducted, identifying 48 (13%) blunt trauma patients who had a DPL WBC count greater than or equal to 500/mm3. The mean DPL WBC count was 1,646 +/- 2,275. Twenty (42%) of these patients were observed and discharged without subsequent operation or morbidity. Laparotomy was performed on 28 (58%) patients; 17 (61%) had a negative lap, 11 (39%) had intra-abdominal injuries requiring surgical repair or drainage (54% solid organ, 27% hollow viscus, 18% diaphragmatic). There were no significant differences between the three subgroups with regards to age, injury severity, time interval between injury and DPL, or mean DPL WBC count (p greater than 0.05). The negative-lap and no-lap groups had a significantly larger number of females; one presented with PID. The positive predictive value (PPV) of an isolated lavage WBC count of greater than or equal to 500/mm3 for intra-abdominal injury was 23% (11/48). The PPVs for DPLs performed less than and greater than or equal to 3 hours or those recalculated using WBC values higher than 500/mm3 were not significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Injuries↗
PubMed1989

The appreciation of rectal distention in fecal incontinence.

The subjective response to rectal balloon sensation was assessed with anorectal manometry and pudendal nerve terminal motor latency measurement (PNTML) in three groups of patients. There were 37 healthy subjects, 54 patients with idiopathic fecal incontinence (IFI), and 36 with complete rectal prolapse and incontinence (CRP). There was no significant difference for any parameter of rectal balloon sensation between patients with IFI and normals. Patients with CRP differed only in onset (P = .001). The results show that the appreciation of rectal distention is maintained in IFI.

Action Potentials↗
PubMed1989

The effect of urban trauma system hospital bypass on prehospital transport times and Level 1 trauma patient survival.

We studied the influence of hospital bypass on prehospital times and Level 1 trauma patient survival. During the nine-month study period, 251 Level 1 trauma patients were transported to the Cook County Hospital trauma unit by Chicago Fire Department (CFD) paramedics. The prehospital times and survival rates in the 203 (81%) patients who arrived with vital signs were analyzed. In this group, 64 (32%) had a hospital Trauma Score (TS) of 12 or less, 74 (39%) had at least one Abbreviated Injury Score (AIS) of 4 or more, and 58 (30%) had an Injury Severity Score (ISS) of more than 20. There were 66 (32%) directly transported patients and 137 (68%) patients who required hospital bypass. The time from CFD contact (by 911) to trauma center arrival (total run time) was on the average three minutes longer in the bypass group than in the direct group (36 +/- 11 vs 33 +/- 10 minutes, P less than .05). The travel time from the scene to the hospital (transport time) also was three minutes longer in the bypass group (7 +/- 3 vs 4 +/- 2 minutes, P less than .005). The need for bypass did not significantly influence survival. Survival was 86% in the bypass group and 85% in the direct group. The elapsed time between the injury and CFD contact (delay time) averaged 27 +/- 26 minutes and contributed 43% to the 63-minute mean overall time from the injury event to arrival at the trauma center. Total run time in directly transported patients accounted for 52% of the mean overall prehospital time.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Selective management of anterior abdominal stab wounds.

A policy of selective management of anterior abdominal stab wounds was evaluated in 333 consecutive patients. Laparotomy was performed based upon initial clinical assessment in 165 patients. There were six deaths (3.6%), major complications in 23 patients (14%), and 28 negative laparotomies (17%). Eighteen patients developed indications for laparotomy after 10.7 +/- 2.2 hours of observation. There were no deaths, major complications in two patients (11%), and four negative laparotomies (22%). One hundred fifty patients were observed and discharged after 1.8 +/- 0.1 days. Sensitivity, specificity, and positive and negative predictive values for initial clinical evaluation were 91%, 85%, 92%, and 83%, respectively. Length of hospitalization in the initially operated and in the delayed group was 9.5 +/- 0.6 and 10.6 +/- 2.6 days (NS), respectively. Most serious intra-abdominal injuries will declare themselves on initial clinical assessment. The remainder are less severe injuries and these patients can be safely observed without undue sequelae due to delay. The use of clinical assessment alone to prompt laparotomy is also cost effective based on analysis of hospital days for initial illness. No procedures are necessary to define penetration.

Abdominal Injuries↗
PubMed1989

Anal function in geriatric patients with faecal incontinence.

The association of faecal incontinence with constipation and confusion in the elderly is well recognised but the anal function of faecally incontinent geriatric patients is poorly understood. Anal studies were therefore performed on 99 geriatric patients (49 with faecal incontinence, 19 continent patients with faecal impaction and 31 geriatric control patients with normal bowel habit) and 57 younger healthy control patients. An age related reduction in anal squeeze pressure but not resting pressure was identified. A reduction in anal resting pressure was detected in the faecally incontinent geriatric patients but squeeze pressure did not differ significantly from that found in the other geriatric patients. Anal sensation was impaired in the faecally incontinent patients. No difference was found between the groups as measured by pudendal nerve terminal motor latency. Gross neuropathy of the distal part of the pudendal nerve does not account for the observed external anal sphincter weakness in geriatric patients or for their faecal incontinence. Internal anal sphincter dysfunction is an important factor in faecal incontinence in the elderly.

Aged↗
PubMed1989

Celiprolol, a compound which attenuates myocardial acidosis and improves regional segmental function following ischemia in dogs: a comparison with propranolol.

Celiprolol, propranolol or saline were administered to separate groups (n = 5-6) of anesthetized dogs in which a critical stenosis was applied to the circumflex coronary artery for 90 min and then reperfused for 30 min. Test drugs were administered at 30 min poststenosis and the effects on pH, regional function and endocardiogram were monitored. A reduction in coronary flow of 54 +/- 2% (n = 27) yielded marked increases in hydrogen ion concentration (H+) of 17 +/- 2 X 10(-8) and ischemic endocardial ST segment of 6 +/- 1 mV while ischemic segmental shortening decreased 75 +/- 9%. Heart rate, arterial pressure and normal regional function were not altered. Celiprolol 0.1 and 1 mg/kg, i.v., reversed the alterations in H+ and ischemic ST segment to prestenosis values while improving ischemic segmental shortening 20 and 38%, respectively, and not affecting heart rate. Propranolol 0.1 and 1 mg/kg, i.v., reversed the alterations in H+ and ischemic ST segment to prestenosis values while further decreasing ischemic segmental shortening 66 and 30%, respectively. Upon reperfusion, ischemic segmental shortening returned to prestenosis values in the group treated with celiprolol 1 mg/kg, i.v., while the propranolol- and saline-treated groups further decreased. It is concluded that celiprolol is efficacious in normalizing myocardial function and ischemia-induced electrophysiological changes following coronary artery stenosis.

Acidosis↗
PubMed1989

Elderly female patients in continuing care: why are they hyperosmolar?

We have shown that the majority of elderly female patients in continuing care are in a hyperosmolar state. Thirty-two out of thirty-nine subjects had an osmolality greater than 295 mosm/kg and the mean osmolality was 302 +/- 8 mosm/kg (range 280-317 mosm/kg). No significant relationship was found with the degree of confusion (rs = 0.31; p greater than 0.05). In the second part of the study neither the measured degree of hydration, or any acute, small increases in fluid input influenced the plasma osmolality.

Aged↗
PubMed1989

Toxicology screening in urban trauma patients: drug prevalence and its relationship to trauma severity and management.

Although toxicology screening is often used when treating trauma patients, its utility and significance remain controversial. Data from 623 toxicology screens performed in urban trauma center patients with mental status alterations are reported. The study patients were predominantly black and male, with a mean age of 32 (+/- 22) years. Overall, 86% of screens were positive. Substances of abuse, including ethanol, were noted in 525 (84%) of urine toxicology screens. Ethanol, cannabinoids, and cocaine were the drugs most commonly found in urine, with positivity noted in 53%, 37%, and 34% of screens. Serum analysis was 44% positive, with ethanol noted in 41% of patients. In blacks, the odds ratio of illicit drug use before trauma ranged from 1.9 to 4.2 (p less than 0.005), and in those aged 17 to 40 years, the odds ratio for illicit urine drugs ranged from 4.7 to 16.8 (p less than 0.001). In patients older than 40 years, the odds of a positive serum ethanol level were 1.7 times greater than in younger patients, and a level above 300 mg% was 3.8 times more likely in this age group (p less than 0.001). When serum ethanol was detected, the odds ratio of a head injury was 1.4 relative to patients without serum ethanol (p less than 0.06), and the odds ratio for abdominal injury was 1.6 for patients with serum ethanol (p less than 0.03). The odds of a TS less than 12 were 1.8 (p less than 0.05), and the odds of a GCS less than 12 were 3.3 (p less than 0.001) with ethanol levels greater than 100 mg%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

The prevalence of psychiatric disorders in a primary care practice.

Using a two-stage case identification process, patients from a rural primary care practice were assessed for psychiatric disorders (Research Diagnostic Criteria [RDC] categories) over a 15-month period. The prevalence of all psychiatric disorders was 26.5%; 10.0% were specific RDC depressive disorders, and 5.3% were disorders without depression, usually anxiety related. Another 11.2% of patients were thought to have a disorder with significant depressive symptomatology that could not be classified into a specific depressive disorder category, a finding that suggests restricted usefulness of specialty-based categories for the range of clinical presentations in primary care. The relationship of demographic variables to specific disorders was examined; there were age, sex, and marital status differences in the rates for certain disorders, although these findings need replication using large patient samples. The prevalence findings emphasize the need for research on outcome and treatment response for depression presentations in primary care.

Adolescent↗
PubMed1988

Peritoneal lavage in penetrating thoraco-abdominal trauma.

Forty-five consecutive patients with penetrating thoraco-abdominal trauma underwent surgical exploration to evaluate the ability of peritoneal lavage to detect peritoneal penetration. Eight patients fulfilled standard criteria for operation and did not undergo lavage. The remaining 37 patients underwent diagnostic peritoneal lavage using a closed technique before exploratory laparotomy. Using 10,000 RBC/mm3 as our previously established criterion for peritoneal penetration, there were seven true positive, one false positive, 28 true negative, and one false negative lavage for an overall accuracy of 94.6% with 87.5% sensitivity and 96.6% specificity as determined by subsequent laparotomy. While 33% of this patient cohort were found to have significant injuries (four had isolated diaphragmatic injuries, all detected by peritoneal lavage), 67% were subjected to negative surgical exploration, as accurately predicted by peritoneal lavage. Negative laparotomy carried a 10.7% operative morbidity. Based on these data we advocate diagnostic peritoneal lavage in patients with thoraco-abdominal penetrating trauma who otherwise lack operative indications.

Abdominal Injuries↗
PubMed1988

The use of absorbable mesh in splenic trauma.

Previous reports from this hospital documented a splenic preservation rate of 50% (18/36) in adults after blunt and penetrating trauma. Recently (January through December 1984), use of an absorbable mesh helped to attain a 67% (22/33) salvage rate. The mesh is applied in such a fashion that it acts by tamponade. It proved useful in patients with bleeding from a large surface area or from deep parenchymal injuries, even those extending into the hilum. No deaths occurred in the splenic salvage patients. There was no difference in postoperative complications among the splenectomy, conventional splenorraphy, or mesh wrap splenorraphy groups. However, workup of persistent postoperative fevers in two splenic wrap patients revealed perisplenic fluid collections on CT scan. Aspiration yielded sterile fluid. Possible cause and effect relationship is being studied in the dog lab. We conclude that splenic wrapping is both a safe and efficacious method of splenic preservation.

Adolescent↗