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Biomedical subjects

D E Fry

Publications and source records attributed to D E Fry.

At least 19 recordsLinked to original sources
PubMed2000

Emergency department discharge of patients with a negative cranial computed tomography scan after minimal head injury.

OBJECTIVE: To determine the negative predictive value of cranial computed tomography (CT) scanning in a prospective series of patients and whether hospital admission for observation is mandatory after a negative diagnostic evaluation after minimal head injury (MHI). SUMMARY BACKGROUND DATA: Hospital admission for observation is a current standard of practice for patients who have sustained MHI, despite having undergone diagnostic studies that exclude the presence of an intracranial injury. The reasons for this practice are multifactorial and include the perceived false-negative rate of all standard diagnostic tests, the belief that admission will allow prompt diagnosis of occult injuries, and medicolegal considerations about the risk of early discharge. METHODS: In a prospective, multiinstitutional study during a 22-month period at four level I trauma centers, all patients with MHI were evaluated using the following protocol: a standardized physical and neurologic examination in the emergency department, cranial CT scanning, and then admission for observation. MHI was defined as either a documented loss of consciousness or evidence of posttraumatic amnesia and an emergency department Glasgow Coma Scale score of 14 or 15. Outcomes were measured at 20 hours and at discharge and included clinical deterioration, need for craniotomy, and death. RESULTS: Two thousand one hundred fifty-two consecutive patients fulfilled the study protocol. The CT was interpreted as negative for intracranial injury in 1,788, positive in 217, and equivocal in 119. Five patients with CT scans initially interpreted as negative required intervention. There was one craniotomy in a patient whose CT scan was initially interpreted as negative. This patient had facial fractures that required surgical intervention and elevation of depressed intracranial fracture fragments. The negative predictive power of a cranial CT scan based on the preliminary reading of the CT scan and defined by the subsequent need for neurosurgical intervention in the population fully satisfying the protocol was 99.70%. CONCLUSIONS: Patients with a cranial CT scan, obtained on a helical CT scanner, that shows no intracerebral injury and who do not have other body system injuries or a persistence of any neurologic finding can be safely discharged from the emergency department without a period of either inpatient or outpatient observation. Implementation of this practice could result in a potential decrease of more than 500,000 hospital admissions annually.

Adolescent↗
PubMed2000

Sepsis syndrome.

A clinical syndrome including fever, leukocytosis, elevated cardiac output, and reduced systemic vascular resistance has been associated with severe infection (i.e., sepsis). However, during the last 15 years, many patients have demonstrated all of the findings that have traditionally been associated with "sepsis" but have not had demonstrated sources of infection. This led to the term "sepsis syndrome" to refer to that population of patients who appeared to have a physiologic and metabolic response associated with, but who did not have, severe infection. More commonly called the systemic inflammatory response syndrome (SIRS), the sepsis syndrome is now associated with the nonspecific systemic activation of the human inflammatory cascade by any of a number of clinical events. The management of the SIRS patient has been ineffective because of incomplete definition of the mechanisms responsible for the syndrome. It is argued that all of the biological mechanisms that are operative in a simple wound and are beneficial are negative for the host when activated systemically. Thus, SIRS is seen in three separate scenarios at present: (1) invasive infection; (2) dissemination of microbes secondary to failure of host defense mechanisms; and (3) severe activation of inflammation by injury, shock, severe soft tissue inflammation, and other noninfectious but proinflammatory events. Newer treatment strategies will need to focus not on the inciting event itself but on better control of the complex responses of the host.

Chemokines↗
PubMed2000

Hepatitis: risks for the surgeon.

Six different hepatitis viruses have now been characterized. Hepatitis B and C are the two hepatitis infections that are of greatest concern for surgeons. Hepatitis B and C share several features that have led to this concern. Both are blood-borne infections. Both are associated with chronic infection ultimately leading to cirrhosis, portal hypertension, and hepatocellular carcinoma, and both can be occupational infections for the surgeon after percutaneous injury associated with infected blood. Chronic hepatitis B infection is seen in 1.25 million people in the U.S. It is associated with a transmission rate to healthcare workers of 25 to 30 per cent following a hollow needle stick injury. Five per cent of acute infections result in chronic disease. It can be effectively prevented as an occupational infection by vaccination with the highly effective hepatitis B vaccine. Chronic hepatitis C infection is present in nearly 4 million people in the U.S. It has a lower rate of transmission than hepatitis B following needle stick injury, but it has a 50 to 80 per cent rate of chronic disease after acute infections. There is no vaccine for hepatitis C, and only prevention of blood exposure will avoid the risks of this occupational infection. Other hepatitis viruses are likely to be identified. Prevention of blood exposure, by the better use of barriers in the operating room and modification of surgical techniques, is recommended to prevent occupational infection from both known and unknown blood-borne viruses from the surgical patient.

Blood-Borne Pathogens↗
PubMed1999

Differential effects of heparin on the early and late phases of hepatic ischemia and reperfusion injury in the pig.

The mechanisms by which heparin protects the liver during induced episodes of liver ischemia-reperfusion are poorly understood. Previous work in a swine model demonstrated that serum levels of glycohydrolases and lipid peroxide peaked within 3 h after 45 minutes of hepatic ischemia followed by reperfusion. Serum levels of lactate dehydrogenase and aspartate aminotransferase peaked 20-24 h later. The aim of this study was to evaluate the effect of heparin on these two-phases of enzyme release, using a pig model of hepatic ischemia-reperfusion injury. Twenty male swine were divided into control (n = 8) and heparin (n = 12) groups. In the heparin group, heparin was administered prior to and concurrent with ischemia-reperfusion. Following 45 min of hepatic ischemia, the levels of beta-galactosidase, beta-glucosidase, acid phosphatase, purine nucleoside phosphorylase, lipid peroxides, lactate dehydrogenase, and aspartate aminotransferase in serum were monitored for up to 166 h and compared to pre-ischemic and control levels. With heparin infusion, the peak levels of beta-galactosidase, beta-glucosidase, and the lipid peroxide were reduced to 50-60% of the control levels. Acid phosphatase and purine nucleoside phosphorylase activities in serum were reduced to 25% and 60%, respectively. The peak concentrations of lactate dehydrogenase and aspartate aminotransferase were reduced to about 25% of the control level. In addition, the serum enzymes of control pigs did not return to pre-ischemic levels until 2 weeks after hepatic ischemia, while they normalized in less than 1 week in the heparin-treated animals. Systemic heparinization had different protective effects on the first and secondary phases of liver injury. These differences may reflect heparin protection of different types of liver cells. The protection of the parenchymal cells may be the combined result of reduced sinusoidal cell injury and the anticoagulant properties of heparin.

Acid Phosphatase↗
PubMed1999

Clinical and scientific importance of source control in abdominal infections: summary of a symposium.

In May 1997, a panel of surgeon-investigators met to discuss the clinical importance and research implications of controlling the source of abdominal infections. It was concluded that source control is critical to therapeutic success and that antimicrobial therapy and other adjunctive interventions will fail if the source of infection is not controlled by resection, exteriorization or other means. The panelists presented different definitions of source control, depending on the scientific purpose of the definition. All participants agreed that failure to consider the adequacy of source control of infection has limited the value of most clinical trials of therapeutic anti-infective agents. Besides recognizing source control as an essential goal of patient care, the panelists emphasized the need for further investigative work to define, record and stratify the adequacy of source control in clinical trials of therapeutic agents for abdominal infections.

Abdomen↗
PubMed1999

Stab wounds to the back/flank in hemodynamically stable patients: evaluation using triple-contrast computed tomography.

Triple-contrast computerized tomography (3CT) has been proposed as a method to detect high-risk injuries in hemodynamically stable patients with stab wounds (SWs) to the back/flank and to successfully triage patients with low-risk scans into a potentially cost-effective treatment algorithm. The purpose of this study was to retrospectively review our experience with the use of 3CT for diagnostic accuracy of SWs to the back/flank and to evaluate potential decreased length of stay (LOS) in the hospital for patients with low-risk scans and no associated injuries. Seventy-nine hemodynamically stable patients met criteria for inclusion in this review. Fifty-eight 3CTs were performed for initial evaluation, 44 low risk and 14 high risk, and 21 patients underwent mandatory laparotomy. The accuracy of 3CT was found to be 97.9 per cent. The LOS was significantly less in patients who had no associated injuries and a low-risk 3CT (16.5 hours), as compared with all other treatment groups. Hemodynamically stable patients with SWs to the back/flank may be safely triaged using 3CT. Patients with low-risk scans and no associated injuries may be discharged immediately, and those with potential delayed associated injuries should be observed for 6 to 24 hours. This strategy significantly decreases LOS in patients with low incidence of significant injury.

Abdominal Injuries↗
PubMed1999

The ABCs of hepatitis.

There are potentially seven hepatitis viruses in existence. Because hepatitis C and G do not fully explain the previous syndrome of non-A, non-B hepatitis, it is likely that at least one additional blood-borne hepatitis virus has yet to be identified. The consequences of the chronic hepatitis syndrome in the United States and around the world will be significant in coming decades. More patients with end-stage liver disease, portal hypertension, and hepatocellular carcinoma may be expected. The implication for surgeons is that there will be more patients with hepatitis. More importantly, the risk of hepatitis as an occupational infection will be with the current generation of surgeons for the rest of their careers. Effective hepatitis B vaccination and application of uniform practices for avoiding blood exposure and percutaneous injury become the hallmark in preventing the occupational transmission of these viruses.

General Surgery↗
PubMed1998

Infection in the ischemic lower extremity.

Infections in the lower extremity of the patient with ischemia can cover a broad spectrum of different diseases. An understanding of the particular pathophysiologic circumstances in the ischemic extremity can be of great value in understanding the natural history of the disease and the potential complications that may occur. Optimizing blood flow to the extremity by using revascularization techniques is important for any patient with an ischemic lower extremity complicated by infection or ulceration. Infections in the ischemic lower extremity require local débridement and systemic antibiotics. For severe infections, such as necrotizing fasciitis or the fetid foot, more extensive local débridement and even amputation may be required. Fundamentals of managing prosthetic graft infection require removing the infected prosthesis, local wound débridement, and systemic antibiotics while attempting to preserve viability of the lower extremity using autogenous graft reconstruction.

Amputation, Surgical↗
PubMed1998

Decreased polyunsaturated fatty acids in sickle cell anaemia.

The purpose of this study was to determine if the growth retardation often associated with sickle cell anaemia could be related in part to a deficiency of essential fatty acids. We reported recently that children with sickle cell disease in Jos, Nigeria have lower levels of serum amino acids and higher levels of urinary amino acids than their healthy counterparts. In the current study, we determined that the serum phospholipids of children with sickle cell anaemia did not deviate in the proportions of the essential fatty acids, linoleic and alpha-linolenic they contain compared to controls. However, their serum phospholipid profiles were significantly different in the proportions of four other fatty acids. Specifically, the phospholipids of children with sickle cell anaemia contained 19 per cent more palmitic acid (P = 0.006), 22 per cent more oleic acid (P = 0.014), 18 per cent less arachidonic acid (P = 0.008), 51 per cent less eicosapentaenoic acid (P = 0.0008), and 43 per cent less decosahexaenoic acid (P = 0.001). These data show that children with sickle cell anaemia are not deficient in essential fatty acids, but that the fatty acid elongation and desaturation pathway is somehow disturbed in this disease.

Anemia, Sickle Cell↗
PubMed1998

Admission or observation is not necessary after a negative abdominal computed tomographic scan in patients with suspected blunt abdominal trauma: results of a prospective, multi-institutional trial.

OBJECTIVES: Hospitalization for observation is the current standard of practice for patients who have sustained blunt abdominal trauma and who do not require emergent operation, despite having undergone diagnostic studies that exclude the presence of an intra-abdominal injury. The reasons for this practice are multifactorial and include the perceived false-negative rate of all standard diagnostic tests, the belief that hospitalization will allow for the prompt diagnosis of occult injuries, and medicolegal considerations about the risk of early discharge. The focus of this study was to determine whether hospitalization for observation is necessary after a negative diagnostic evaluation after blunt abdominal trauma, to determine the negative predictive value of abdominal computed tomographic (CT) scanning in a prospective series of patients, and to identify which patients can be safely released from the emergency department without observation or hospitalization after blunt abdominal trauma. METHODS: In a prospective, multi-institutional study over 22 months at four Level I trauma centers, all patients with blunt abdominal trauma suspected by either physical examination or mechanism of injury were evaluated using the following protocol: physical examination in the emergency department, followed by abdominal CT scanning, followed by hospitalization for observation. The standardized physical examination was repeated between 4 and 8 hours. Outcomes were measured at 20 hours and at discharge and included clinical deterioration, the need for celiotomy, and mortality. Other data collected included demographics, mechanism of injury, and findings on physical examination and abdominal CT scanning. RESULTS: Three thousand eight hundred twenty-two consecutive patients with suspected abdominal trauma presented to the four trauma centers. Two thousand seven hundred seventy-four of these met study eligibility criteria and were prospectively enrolled. Of these, 2299 fulfilled the entire study protocol. CT scan was negative in 1,809 patients, positive for organ injury or abdominal fluid in 389 patients, and nondiagnostic in 78 patients. Abdominal tenderness or bruising was present in 1,380 patients (61%), but only 22% had a positive CT scan. Nineteen percent of patients with a positive CT scan had no tenderness. Computed tomography detected 22 of the 25 blunt intestinal injuries in this series. Free intraperitoneal fluid without solid visceral injury was present in 90 patients, and but only 7 patients had intestinal injuries. There were nine celiotomies in patients whose CT scan was initially interpreted as negative: six were therapeutic (intestine in three, bladder in one, kidney in one, and diaphragm in one), two were nontherapeutic, and one was negative. The negative predictive power of an abdominal CT scan based on the preliminary reading and as defined by the subsequent need for a celiotomy in the population fully satisfying the protocol was 99.63% (lower 95 and 99% confidence bounds of 99.31 and 99.16%, respectively). CONCLUSION: These data indicate that abdominal tenderness is not predictive of an abdominal injury and that patients with a negative CT scan after suspected blunt abdominal trauma do not benefit from hospital admission and prolonged observation.

Abdominal Injuries↗
PubMed1997

Treatment of pneumonia in mechanically ventilated trauma patients. Results of a prospective trial.

OBJECTIVES: To determine the efficacy and magnitude of associated adverse effects of 2 different antibiotic regimens for the treatment of pneumonia in intubated surgical patients and to assay and compare blood samples and bronchoalveolar lavage fluid with respect to some host-defense parameters, especially in patients with unilateral pneumonia. DESIGN: Randomized, prospective, unblinded clinical comparison of 2 treatment arms with respect to intent to treat and clinical and microbiologically evaluable patients. SETTING: Six university surgical services in teaching hospitals with modern and well-staffed intensive care units. INTERVENTIONS: The consistency and objectively of the diagnosis of pneumonia was improved by the use of a grid of diagnostic parameters. Aggressive mechanical approaches to pneumonia in intubated surgical patients were supplemented by therapeutic use of aztreonam and vancomycin hydrochloride or combined imipenem and cilastatin sodium. RESULTS: Patients randomized to the aztreonam-vancomycin group were somewhat more ill, fared slightly better, and had fewer serious drug-related side effects than did those treated with imipenem-cilastatin (all P > .05). Immunologic parameters assessed by evaluation of bronchoalveolar lavage fluid showed differences between infected pulmonary lobes and noninfected ones; some changes were also noted in patients who recovered compared with those whose pneumonia persisted or recurred. CONCLUSIONS: Clinical studies of pneumonia in surgical patients need to be stratified to assure comparability, to identify patients in whom treatment is likely to fail, and to display differences between more and less effective therapies. Studies of blood and bronchoalveolar lavage samples showed that certain local and systemic immunologic parameters correlate with clinical status and outcome.

Aztreonam↗
PubMed1996

The reemergence of mycobacterial infections.

In the early half of this century, infections due to Mycobacterium tuberculosis were quite common and were frequent causes of death and morbidity among the world population. Surgeons in the 1930s were quite sensitive to making the diagnosis of tuberculosis. All surgeons had considerable experience with thoracic surgical procedures for pulmonary tuberculosis. Moreover, tuberculosis was a significant cause of occupational infection among surgeons and other physicians. Thus, being able to diagnose the disease quickly and accurately was not only in the patient's best interest, but also allowed appropriate precautions to be exercised so that occupational infections of the health care team could be minimized.

Antitubercular Agents↗
PubMed1996

Glycohydrolases as markers of hepatic ischemia-reperfusion injury and recovery.

Advances in liver surgery and transplantation have lead to a steady increase in the number of these interventions. Prompt quantitative assessment of hepatic of hepatic function and a patient's subsequent morbidity and mortality following surgery remain difficult despite the currently utilized historic markers of hepatic parenchymal injury (e.g., aspartate transaminase [AST], lactate dehydrogenase [LDH] gamma-glutamyl transpeptidase [GGT]). Increases in serum glycohydrolase activities appear to provide sensitive and quantitative markers of hepatic ischemia/reperfusion injury. In 10 male swine (25 to 35 kg body weight) following 30, 45, and 90 minutes of acute hepatic ischemia, the systemic release of eight different glycohydrolases and lipid peroxides into serum were determined and compared with pre- and postischemic serum levels of LDH, GGT, and AST. The rapid release of glycohydrolases into serum was directly proportional to the length of the ischemic period from 30 to 90 minutes; e.g., beta-glucosidase, mean 1.9-fold increase at 30 minutes; 8.3-fold at 45 minutes; and 22.8-fold at 90 minutes; P < .002) and the activities peaked within the first 3 hours postischemia. In constrast, AST, LDH, and GGT were released slowly and peaked 20 to 30 hours after hepatic blood flow was restored. In swine with fatal outcomes (90 minutes of ischemia), all enzyme levels increased continuously during the final hours of life. However, in swine that survived hepatic ischemia/reperfusion injury (45 minutes of ischemia) the glycohydrolases, but not AST, LDH, and GGT, declined after 2 to 3 hours' postischemia and the serum lipid peroxide levels followed the same pattern. Serum beta-galactosidase and beta-glucosidase levels are sensitive markers that rise as quickly as traditional enzyme markers (AST, LDH, GGT) following hepatic ischemic injury; moreover, the glycohydrolases have the added value of serving as predictors of survival.

Acid Phosphatase↗
PubMed1996

The importance of antibiotic pharmacokinetics in critical illness.

Antibiotics are the most commonly used drugs in the surgical patient. Pharmacokinetics is the study of processes that result in the delivery of drugs to effector sites. Drug absorption, distribution, biotransformation, and excretion are the critical elements of drug delivery to effector sites. The biologic elimination half-life (t1/2) and the volume of distribution (Vd) are terms used to describe the active processes of pharmacokinetics; t1/2 and Vd are determined for antibiotics by employing healthy volunteers or minimally ill patients. From these data, dosing schedules for each antibiotic are determined. This article reviews the literature on the impact of critical illness and sepsis on antibiotic pharmacokinetics. The data identify that t1/2 may be reduced in the hyperdynamic states of stress and sepsis and that the Vd is expanded. These changes mean that currently accepted dosing regimens of antibiotics in critically ill patients are inadequate. Subtherapeutic antibiotic concentrations in these patients may account for treatment failures and may be of significance in the emergence of bacterial resistance.

Absorption↗
PubMed1995

Effects of oligosaccharide binding on glycogen debranching enzyme activity and conformation.

Glycogen debranching enzyme contains two catalytic activities (4-alpha-glucanotransferase and amylo-1,6-glucosidase) on its single polypeptide chain, and they are affected differently by the binding of oligosaccharides. Glucose, maltose, and maltotriose are competitive inhibitors of the amylo-1,6-glucosidase activity measured by the hydrolysis of alpha-glucosyl fluoride, whereas saccharides with four or more glucose units are activators of the same activity, showing apparent "uncompetitive" kinetics. This suggests that they do not bind until the alpha-glucosyl fluoride is bound. In either case the potency of the effect increases with the length of the oligosaccharide chain. On the other hand, all oligosaccharides tested (maltose to maltohexaose, alpha-cyclodextrin, and beta-cyclodextrin) are competitive inhibitors of the transferase activity and also cause a decrease in the intrinsic fluorescence, both functions again increased by chain length, thus indicating that these saccharides do bind to the free enzyme. These interesting results can be reconciled if the extended main chain resulting from the transferase reaction has to be reoriented into a different binding mode in order to position the alpha-1,6-linked side-chain glucose into the correct position for the glucosidase reaction. Therefore, activating oligosaccharides behave kinetically as if they had not been previously bound. It is concluded that the main chain of the natural limit dextrin substrate has a different mode of binding for the two catalytic reactions in order to position properly first the maltotetraosyl side chain in the transferase catalytic site and then the glucosyl side chain in the glucosidase catalytic site.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗