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Biomedical subjects

T Vargish

Publications and source records attributed to T Vargish.

At least 37 records · Page 2Linked to original sources

Myocardial opiate receptor activity is stereospecific, independent of muscarinic receptor antagonism, and may play a role in depressing cardiac function.

Earlier work has shown that morphine sulfate can produce a dose-related decrease in heart rate (HR) and cardiac output (CO) in isolated working rat hearts. This response is preventable with the use of the opiate receptor antagonist, naloxone hydrochloride. In this study, the stereospecificity of the opiate response was tested with the use of levorphanol tartrate and its d-isomer, dextrorphan, in our Langendorff rat heart model. The interaction of muscarinic receptor activity with the opiate response was tested by first adding bethanechol chloride to the perfusate in the presence and absence of atropine (5 X 10(-9) mmol/L). Our earlier studies with morphine sulfate were then repeated in the presence of the same concentration of atropine. At a concentration of 5 X 10(-6) mmol/L, levorphanol tartrate produced a significant decrease in CO (p less than 0.05), while a similar concentration of dextrorphan produced little change in either HR or CO. Bethanechol chloride, in a concentration of 3 X 10(-6) mmol/L, produced a significant decrease in HR and CO (p less than 0.05), which was prevented by atropine. When morphine sulfate was added to the standard perfusate (3 X 10(-4) mmol/L), HR and CO were significantly decreased (p less than 0.05). This change was not prevented by the addition of atropine. The opiate effect on myocardial function is mediated by a stereospecific opiate receptor, which acts independently of muscarinic receptor antagonism.

Animals↗

Hemodynamic evaluation of ibuprofen in canine hypovolemic shock.

This study was done to evaluate the role of ibuprofen, a cyclooxygenase inhibitor, in a standard model of hypovolemic shock. Fifteen dogs were subjected to fixed mean arterial blood pressure (MABP) shock (40-45 mmHg) for 45 min and then treated with physiologic saline (NS), low-dose ibuprofen (6.25 mg/kg), and high-dose ibuprofen (12.5 mg/kg) by IV bolus and continuous IV infusion. After 60 min of treatment, the shed blood was returned. Survival was monitored for 72 h. Both dose levels resulted in a significant increase in MABP and total peripheral resistance over NS during the infusion period but heart rate, cardiac output, and left ventricular contractility were similar for all groups. Survival at 72 h was also similar for the three groups. Ibuprofen treatment, while increasing MABP and total peripheral vascular resistance did not seem to alter cardiac function or improve survival when compared to NS in this model of hypovolemic shock.

Animals↗

Early diagnosis and outcome of pancreatic abscesses in pancreatitis.

During the past 3.5 years the authors have evaluated 191 patients, both retrospectively and prospectively, to establish factors which might help to identify those patients at higher risk of developing pancreatic abscesses. Those factors included etiology of pancreatitis, number of severity indices present, and specific indices present. Once an abscess developed, severity indices, etiology, and bacteriology were examined as factors in mortality. Six specific severity indices occurred more often (P less than 0.05) in patients developing abscesses. These indices were lactate dehydrogenase evaluation, leukocytosis, metabolic acidosis, hypoxemia, hypocalcemia, and fluid sequestration. In addition, seven of 18 abscess patients had six or more indices present as opposed to five of 161 pancreatitis patients. This was significant at P less than 0.05 level. The etiology of the pancreatitis was not a significant factor. Once an abscess developed, gram-negative infections were polymicrobial (8 of 9 patients) and were associated with a 56 per cent mortality. The gram-positive abscesses (6 patients) were all monomicrobial and none of these patients died. In addition, age greater than 55 years, serum glucose greater than 200 mg%, hematocrit decrease of 10 per cent, and fluid sequestration greater than 6 L were associated with a 50 per cent or greater mortality. The authors believe that patients presenting initially with six or more severity indices, especially the six mentioned above, are at significantly increased risk for developing a pancreatic abscess and those abscess patients with gram-negative abscesses, as well as having any of the four severity indices previously mentioned, have a much worse prognosis.

Abscess↗

Effect of methylprednisolone on naloxone's hemodynamic response in canine hypovolemic shock.

Previous studies have suggested that methylprednisolone (MP) pretreatment attenuates the usual hemodynamic response to naloxone (NAL) treatment of hypovolemic shock. In this study, both drugs were given concurrently during shock to evaluate hemodynamic changes, plasma endorphin-like activity (PELA), and survival. Twenty-six dogs were bled to a mean arterial pressure (MAP) of 40 to 45 mm Hg, which was maintained for 45 min. Animals were then treated with iv 0.9% NaCl (NS), 5 ml; NAL, 4 mg/kg; MP, 30 mg/kg; or NAL, 4 mg/kg, plus MP, 30 mg/kg. Animals treated with NAL and/or MP had significantly (p less than .05) improved MAP, cardiac output, and myocardial contractility compared with NS-treated animals. NAL and MP each significantly lowered PELA levels and both NAL and NAL plus MP significantly improved survival.

Animals↗

Ruptured right atrium from nonpenetrating trauma of the chest.

As with our case, patients with rupture of the atrium may survive untreated for prolonged periods. Although three survivors have been reported after rupture of the right or left ventricle, ventricular injuries are usually fatal. With improvements in transportation methods, rapid recognition and diagnosis, and early operative intervention, we would expect more patients with this type of injury to survive.

Accidents, Traffic↗

Biliary tract injuries following routine cholecystectomy.

This retrospective study was done to review the epidemiology, etiology, method of treatment, and results of repairs of biliary tract injuries following routine cholecystectomy. Fourteen patients have been treated at our hospital for biliary tract injuries during a 10-year period (January 1974-December 1983). One injury occurred at our institution. During this same time span, 941 cholecystectomies were performed at our hospital giving an incidence of 0.11 per cent for the injury. Trained surgeons were responsible for nine injuries, family practitioners for two injuries, and a surgery resident for one injury. Two injuries were caused by individuals whose level of training could not be determined. In only one case was massive hemorrhage associated with the injury. Four patients had their injuries diagnosed and treated at the time of their original surgery. Two had successful initial repairs. The other two required further reconstructive surgery with good results. Ten patients had a delay in diagnosis, and nine required biliary tract reconstruction. Four of these had good results. Combining both groups, 13 patients required 20 procedures. Stents were used in 14 procedures with good results in 43 per cent. Stents were left in place 6.9 months. Five procedures were done without stents and four resulted in failure. Biliary tract injuries are devastating problems caused by trained surgeons through lack of attention. Better results can be obtained if the injury is recognized early and treated. The overall success rate was 62 per cent. The use of stents improved the success rate.

Adult↗

Morphine depression of myocardial function.

A modified Langendorff rat heart preparation with an isolated working rat heart was used to establish the presence of opiate receptors in the myocardium and to demonstrate the effects of an opiate agonist on myocardial function in the absence of neuronal and humoral factors. Twenty-five Sprague-Dawley rats weighing 400-500 gm were anesthetized and had their hearts excised and attached to the Langendorff perfusion apparatus. After a 30 min control period, the Krebs-Henseleit Buffer (KHB) perfusion solution was altered by the addition of 0.9% NaCl (S) or morphine sulfate (MS), which resulted in a final concentration of 2 X 10(-4) M or 3 X 10(-4) M MS in the KHB. Temperature, preload, and afterload were kept constant while heart rate (HR), cardiac output (CO), and aortic dP/dtmax were measured. Significant dose-related depression of HR, CO, and less significantly, aortic dP/dtmax were demonstrated. The data suggest that opiate receptors are present in the myocardium and that morphine sulfate directly effects the myocardium causing a significant decrease in HR, CO, and aortic dP/dtmax. These changes are a result of opiate receptor agonism, which seems to be primarily a negative chronotropic effect and might explain the mechanism for the role of endogenous opiates during shock.

Animals↗

Late administration of methylprednisolone does not enhance naloxone effect in hypovolemic shock.

The late addition of methylprednisolone (MP) in our canine hypovolemic shock protocol was evaluated to determine whether any hemodynamic enhancement of the naloxone (NAL) effect might be present. Thirty-four dogs were bled to a mean arterial pressure (MAP) of 40-45 mm Hg and held there for 45 minutes. All animals were then treated (T = 0) with 0.9% NaCl (NS) or NAL. In two groups of animals, MP (30 mg/kg) was given as an IV bolus 30 minutes after initiating NS or NAL therapy. At 60 minutes, the infusions were stopped and the shed blood was returned. Animals treated with NAL with or without MP showed improvement in MAP, maximal left ventricular contractility (LVdP/dt max), and cardiac output (CO) compared to NS. We found little hemodynamic improvement with the addition of MP at T = 30 for either the NAL or NS. Plasma endorphinlike activity (PELA) values decreased during treatment in the groups receiving NAL. Survival was improved in all groups except those receiving NS, but survival was statistically better only in the group that received NAL.

Animals↗

Opiate agonist depression of myocardial function is dose related and independent of pentobarbital or chloral hydrate anesthesia.

Previous work has demonstrated that a common opiate agonist, morphine sulfate (MS), causes significant depression of myocardial performance when added to the perfusate of a modified Langendorff isolated rat heart preparation. The same model has been used in this study with the addition of higher concentrations of MS to demonstrate that the aforementioned effects occur in a dose-related fashion. In addition, different anesthetics, sodium pentobarbital (P) or chloral hydrate (CH), were compared and demonstrated that there was no significant difference in results. This implies that there is not an anesthetic-morphine interaction occurring. These results suggest opiate agonist depression of myocardial function acts on opiate receptors, causing primarily a chronotropic effect.

Anesthesia, General↗

Hemodynamic effects of naloxone in early canine hypovolemic shock.

The contribution of endorphins (endogenous opiates) to the pathophysiology of shock was evaluated by the administration of naloxone (NAL) at different time intervals after inducing hypovolemia. Forty-four dogs were bled into a reservoir to a mean arterial pressure (MAP) of 40-45 mmHg and maintained at this pressure for 30, 45, or 60 minutes. The animals were then given either intravenous 0.9% NaCl (S) or NAL. Animals treated after 30 minutes of hypovolemia at a fixed MAP had similar hemodynamic responses to both NAL or S. After 45 minutes, the NAL-treated animals showed significant improvement in MAP, cardiac output (CO), and survival (P less than 0.05) when compared with S-treated animals. Animals treated with NAL after 60 minutes showed little significant hemodynamic difference from animals treated with S but all S-treated animals died during the 60-minute treatment period. Plasma endorphinlike activity (PELA) rose with hypovolemia and then returned toward control levels in all NAL treated animals before reinfusion of shed blood while it remained elevated in S-treated animals until after reinfusion.

Animals↗

Management of nonfamilial adenomatous polyps and colon cancers.

There is evidence that patients with adenocarcinoma of the colon and synchronous adenomatous polyps are at an increased risk for developing metachronous colon cancer. A retrospective study was made of all patients with colon cancer at our institution and the associated Veterans Administration Hospital between 1974 and 1983 to help assess the need for more extensive colon resection in patients with colon cancer and synchronous adenomatous polyps. At our hospitals 470 new cases of colon cancer were identified. Nine percent (44/470) had colon cancer and concurrent adenomatous polyps. Seven (16%) of these 44 patients developed metachronous colon cancer, as compared with four of 426 patients without polyps at the initial surgery (p less than 0.001). Four patients without polyps at the initial surgery developed polyps at a later date; three of the four patients developed metachronous colon cancer. We believe that more extensive colon resection, such as total colectomy and ileoproctostomy, may play a role in preventing the occurrence of metachronous colon cancer in patients with colon cancer and synchronous adenomatous polyps. In addition, if adenomatous polyps develop after colon surgery, close endoscopic follow-up is required.

Adenocarcinoma↗

Rural trauma care: a study of trauma care in a rural emergency medical services region.

Motor vehicle-related trauma deaths in a 21-county rural emergency medical services (EMS) system are reviewed. Injury severity scores (ISS) and Glasgow coma scores (GCS) were recorded to provide baseline data for future comparison as the system progresses. The majority of deaths (67%) were related to CNS injuries. ISS in this series was similar to data reported from Orange County, California. The average GCS for all patients in this series was 5, indicating the high prevalence and severity of head injuries in motor vehicle deaths. Patients treated only in community hospitals had a low average ISS of 28.5. Those transferred from community hospitals to the regional tertiary care center had an average ISS of 36.2. Those admitted directly to the tertiary center had an ISS of 38.9. The data suggest that the rural trauma system might improve if there were training programs that promote recognition of significant injury, more aggressive resuscitation, and expeditious transfer of the injured patients.

Accidents, Traffic↗

Evaluation of an emergency air transport service as a component of a rural EMS system.

The authors reviewed the records of 569 patients transported by an emergency helicopter service to evaluate its impact on the outcome of patients with multisystemic injuries. A Total Trauma Score for each patient was computed. A number of other factors were also considered, including the nature of the injury, number of systems injured, origin and duration of flight, resuscitative maneuvers, number of blood transfusions given and the timing of operations required to treat the injury. The service was then rated utilizing strict specific guidelines as either essential, helpful or not a factor, in the preservation of life and/or limb in each case. A fourth group was comprised of patients who expired as a result of their injuries. The air transport service was essential to 16.5% and helpful to 10.9% of patients. In spite of rapid evaluation and maximal intervention, 102 (17.9%) of the patients died. The group for which air transport was judged "not a factor" (54.7%) consisted of patients whose injuries would not have proven fatal had their transportation to the tertiary care center been delayed. Retrospective analysis of the data available to the tertiary care center at the time of the decision to transfer the patients by air revealed that it was not possible to differentiate those patients who did not benefit from the service from those for whom the service was judged essential or helpful. Even though 17.9% of the helicopter transported patients died at some time during their period of hospitalization, they did receive the benefit of prompt sophisticated evaluation and management of their injuries.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Hemodynamic changes following corticosteroid and naloxone infusion in dogs subjected to hypovolemic shock without resuscitation.

B-endorphin, which is released concomitantly with ACTH from the pituitary during stress, may also alter cardiac performance in hemorrhagic shock. In this study of 36 dogs subjected to hemorrhagic shock without resuscitation, we demonstrate the interaction of high doses of dexamethasone (DEX) or methylprednisolone (M) and opiate receptor blockade with naloxone (NAL). NAL, when given alone, resulted in the most hemodynamic improvement and the longest survival time while those animals receiving DEX or M, even in combination with NAL, did not do as well. These data suggest that corticosteroids block the NAL effect following hemorrhagic shock.

Adrenal Cortex Hormones↗

The ankle injury--indications for the selective use of X-rays.

The radiograph is rapidly superseding the clinical examination as the diagnostic tool for acute ankle injuries. Twenty-four independent variables which might help distinguish between soft tissue injuries and fractures at the ankle were identified and then used prospectively to study 150 consecutive patients with ankle injuries. Nineteen patients had fractured ankles (12.7 per cent) and 131 (87.3 per cent) had soft tissue injuries. Only the patient's ability to bear weight on the injured ankle and the presence of tenderness over the lateral aspect of the ankle below the malleolus proved to be helpful. When these 2 signs were present together, regardless of all other variables, there was a 97.5 per cent probability of soft tissue injury P less than 0.005). This study suggests that careful patient assessment will permit more discriminating use of ankle X-rays.

Adolescent↗

Adrenalectomy abolishes and cortisol restores naloxone's beneficial effects on cardiovascular function and survival in canine hemorrhagic shock.

Endogenous opioid substances are activated in and may contribute to the cardiovascular depression of hemorrhagic shock. In order to determine the importance of the adrenal gland in the beneficial effects of the opiate antagonist naloxone in shock we studied 23 adrenalectomized dogs subjected to hemorrhagic shock. Adrenalectomy abolished the salubrious cardiovascular responses to naloxone. Naloxone responses (increased mean arterial pressure, cardiac output, and left ventricular contractility) were restored by giving hydrocortisone 50 mg intravenously before naloxone. Survival was also prolonged in animals receiving naloxone and hydrocortisone compared to naloxone or saline alone; hydrocortisone alone decreased survival. The adrenal glands are necessary for naloxone's beneficial effects, probably via adrenal corticosteroid secretion.

Adrenalectomy↗