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Biomedical subjects

D Dodd

Publications and source records attributed to D Dodd.

At least 19 recordsLinked to original sources
PubMed2005

Clinical significance of superficial vein thrombosis.

OBJECTIVE: To evaluate the clinical implications of superficial thrombophlebitis (STP) including its demographic characteristics, distribution, risk factors, relationship with deep vein thrombosis (DVT), pulmonary embolism (PE), diagnosis and management. METHODS: Data were collected from relevant papers using a MEDLINE search and an extensive bibliography review. Studies were considered only when they contained pertinent material to STP. Thirty-seven papers were analysed. RESULTS: The diversity of patients and methods used in the different studies made the comparison among them difficult. STP is a common condition with an underestimated prevalence. There are many risk factors associated with STP but the strongest relation was seen with hypercoagulable states. Malignancy may be another important factor but the strength of this association remains unknown. Coexistence with DVT was found in 6-53%. PE occurred in 0-33.3%. Propagation to DVT ranged from 2.6 to 15%. Treatment has not been standardised and may include elastic compression, anti-inflammatory drugs, anticoagulation and surgery. CONCLUSION: The limited number of prospective randomised studies on STP does not allow strong recommendations to be given. Although STP most often is perceived as benign, it can coexist with or progress to DVT, and even give rise to PE. It is also associated with hypercoagulability and malignancy.

Humans↗
PubMed2003

Proximal arterial occlusion protects the distal lower limb vessels.

PURPOSE: To test the hypothesis that chronic arterial occlusion protects the distal vessels from disease progression. METHODS: Peripheral angiograms from the radiology film store filed under 1997-1999 were reviewed. Those showing unilateral iliac occlusion and those showing unilateral femoro-popliteal occlusion were selected. The severity of arterial disease distal to the occlusion was compared with the patent side. Subsequently, in a subgroup of patients undergoing repeat angiography, the frequency and distribution of disease progression was recorded and related to the initial disease distribution. RESULTS: In the presence of a unilateral iliac occlusion, femoro-popliteal occlusion was less likely on the side of the iliac occlusion than on the opposite side (difference in proportion 10%. 95% C.I.: 1-18%). In the presence of a unilateral occlusion proximal to the knee joint, there were more patent calf vessels on the side of the occlusion than on the opposite side (difference in proportion 9%. 95% C.I.: 4-14%). When angiography was repeated, progression of calf vessel disease was less common in the limbs with untreated proximal occlusion than in those with no proximal occlusion. CONCLUSION: Proximal arterial occlusion protects the distal vessels from the risk of progressive arterial disease.

Angiography, Digital Subtraction↗
PubMed2001

Modified Norwood operation for hypoplastic left heart syndrome.

BACKGROUND: We examined early results in infants with hypoplastic left heart syndrome undergoing the Norwood operation with perioperative use of inhaled nitric oxide and application of extracorporeal membrane oxygenation. METHODS: Medical records were reviewed retrospectively. RESULTS: Between April 1997 and March 2001, 50 infants underwent a modified Norwood operation for hypoplastic left heart syndrome. Mean age at operation was 7.5 +/- 5.7 days, and mean weight was 3.1 +/- 0.5 kg. Five infants had a delayed operation because of sepsis. The mean diameter of the ascending aorta by echocardiography was 3.6 +/- 1.8 mm. Ductal cannulation was used to establish cardiopulmonary bypass in all patients. Mean circulatory arrest time was 39.4 +/- 4.8 minutes. The size of the pulmonary-systemic shunt was 3.0 mm in 6 infants, 3.5 mm in 37, and 4.0 mm in 7. Infants with persistent hypoxia (partial pressure of oxygen < 30 mm Hg) received nitric oxide after they were weaned from cardiopulmonary bypass. Extracorporeal membrane oxygenation was initiated in 8 infants in the pediatric intensive care unit primarily for low cardiac output and in 8 in the operating room because of the inability to separate them from cardiopulmonary bypass. The 30-day mortality rate was 22% (11 of 50 patients), and the hospital mortality rate was 32% (16 of 50 patients). Mean follow-up was 17 months. Ten patients (20%) underwent stage-two repair, with one operative death. One survivor had a Fontan procedure, and 2 underwent heart transplantation, with one death. CONCLUSIONS: Early application of extracorporeal membrane oxygenation for hemodynamic instability and selective use of nitric oxide for persistent hypoxia in the immediate postoperative period may improve survival of patients with hypoplastic left heart syndrome. Renal failure requiring hemofiltration during extracorporeal membrane oxygenation (p < 0.05) and cardiopulmonary arrest in the pediatric intensive care unit (p < 0.05) were predictors of hospital mortality.

Administration, Inhalation↗
PubMed1999

Prescribing controlled substances in Tennessee: progress, not perfection.

BACKGROUND: In the 1980s, Tennessee ranked among the top 10 states in per capita consumption of several controlled substances. We describe efforts designed to reduce non-criminally motivated misprescribing in Tennessee, present Tennessee's recent Drug Enforcement Administration (DEA) rankings, and suggest how physicians may reduce misprescribing. METHODS: Tennessee's Board of Medical Examiners (BME) consults with Tennessee Physician Health Program (PHP) and refers selected physicians to a continuing medical education (CME) program offered at Vanderbilt University School of Medicine. The BME has also published a clear set of prescribing guidelines. RESULTS: Of more than 160 CME participants, only two have reappeared before the BME for prescribing infractions. Tennessee's overall DEA ranking improved from 7th highest to 17th from 1994 to 1997. CONCLUSIONS: The reasons the rankings improved cannot be established, but the changes occurred at the same time as the BME, PHP, and Vanderbilt CME collaborations. We will continue to promote professional and patient health throughout the region.

Drug and Narcotic Control↗
PubMed1999

Management of acute nontraumatic upper limb ischemia.

A retrospective review of all patients presenting to a tertiary referral center with acute nontraumatic upper limb ischemia between January 1992 and June 1997 was undertaken to examine the role of intraarterial thrombolysis in the management of such cases. Twenty-one patients were identified in the radiology and vascular surgery departments' registers. Twenty (95%) underwent angiography, demonstrating subclavian artery occlusion in four, axillary in two, brachial in 13, and one at the digital level. Intraarterial thrombolysis was attempted in 12 patients. There were three technical failures, all requiring embolectomy. Six had complete lysis and resolution of their symptoms. One patient had partial lysis but experienced no further rest pain. Thrombolysis was unsuccessful in two cases with one subsequently requiring embolectomy and the other surgical bypass. Three patients had surgical intervention as their primary procedure with two favorable outcomes and one ending in above-elbow amputation. Five patients were treated conservatively with heparin, resulting in three partial and two full recoveries. One patient experienced complete resolution of symptoms with an intravenous prostacyclin infusion. Both electrocardiograms (ECG) and echocardiograms (ECHO) were of limited diagnostic aid, and long-term warfarin anticoagulation was prescribed to all patients. There was no recurrence of upper limb ischemia at a median follow up of 18 months. Intraarterial thrombolysis is an effective first line treatment for acute nontraumatic upper limb ischemia in selected cases.

Acute Disease↗
PubMed1991

Current issues in burn wound infections.

As we have emphasized, the diagnosis of burn wound infections in the high-risk burned child can be difficult and depends on a very high degree of suspicion and daily clinical evaluation of the burn wound site by consistent observers. Appropriate precautions include meticulous hand-washing and the use of gloves when handling the wound site and prophylactic application of a topical antibacterial agent such as SSD cream. Wound therapy should include routine vigorous surgical débridement. Surveillance wound cultures should be done weekly to determine the emergency of colonization and aid in the selection of empiric antimicrobial regimens when these are appropriate. Wound biopsy for histological examination and quantitative culture is highly recommended in the severely ill child with an unclear etiology or site of infection. If, despite these measures, sepsis ensues, then systemic antibiotics must be started empirically as an adjuctive therapy to surgical débridement. Knowledge of the organisms colonizing a wound will prove useful in choosing an antibiotic regimen while awaiting definitive results of blood and wound biopsy cultures. Without this information, early burn sepsis therapy should focus on gram-positive organisms, while infection later in the course should raise suspicion of nosocomial pathogens such as P. aeruginosa, other enteric bacilli, and C. albicans. An initial regimen might include nafcillin plus ceftazidime or an aminoglycoside, with anaerobic coverage depending on considerations noted previously. Once the causative agent is identified, therapy must be modified accordingly. Amphotericin B and acyclovir use should be guided by positive cultures from the burn wound site along with systemic evidence of dissemination. Available studies do not yet make clear the role of empiric immunotherapy with intravenous gamma globulin in the burned child. Therefore, its use cannot be recommended at the present time, although the development of specific immunoglobulins (P. aeruginosa, S. aureus) may prove useful in the future. In view of the multiplicity of organisms that may colonize burn wounds, it is likely that passive immunization may be more useful in the treatment of infection than in its prevention. The switch from P. aeruginosa to, for example, Klebsiella pneumoniae or E. cloacae, is not apt to be particularly beneficial in most circumstances. Similarly, an increased understanding of the role of the immune system in the propensity to burn sepsis may guide the development of vaccines or immunomodulators that decrease the risk of infection in seriously burned children and adults.

Burns↗
PubMed1988

Infection of a human leukemia K-562 cell line with Semliki Forest virus.

Infection of the human leukemia hematopoietic stem cell line, K-562, with Semliki Forest virus (SFV) can be characterized by three stages: (1) an early virus-proliferating stage lasting 1 to 4 days post-infection (pi) in which infectious virus is produced in high titers (10(3)pfu/cell) but in which there is minimal cytopathic effect. All cells appear viable by trypan blue dye exclusion, although they do not proliferate, and DNA and cell protein synthesis decrease to less than 3% of uninfected controls within 24 hours; (2) an intermediate stage extending from day 5 to about day 24-30 pi in which the amount of infectious virus declines to low levels. During this stage, viral protein synthesis decreases to undetectable levels, although viral gylcoproteins are readily demonstrated by immunofluorescence and by immunoblot; however, capsid protein appears to degrade within 21 days pi. Cell numbers remain constant but the viability of the non-proliferating cells determined by trypan blue exclusion could not be determined with confidence; (3) a final long-term stage in which viral glycoproteins, E1 and E2, are detectable by immunoblots and immunofluorescence for many months but the cells are metabolically inactive and do not synthesize viral proteins. These non-viable cells do not lyse for as long as 2 years.

Antigens, Viral↗
PubMed1985

Myxomatosis.

Explore the source record for details and available documents.

Letter↗
PubMed1985

Backscattering from dental restorations and splint materials during therapeutic radiation.

Models were constructed to simulate as closely as possible the human oral cavity. Radiation absorbed doses were determined for controls and various test situations involving the presence of dental restorative and splint materials during cobalt-60 irradiation of the models. Adjacent gold full crowns and adjacent solid dental silver amalgam cores both increased the dose to the interproximal gingivae by 20%. Use of orthodontic full bands for splinting the jaws increased the dose to the buccal tissues by an average of 10%. Augmentation of dose through backscatter radiation was determined to be only slight for intracoronal amalgam fillings and stainless steel or plastic bracket splints.

Crowns↗
PubMed1983

Changes in rib cage shape during quiet breathing, hyperventilation and single inspirations.

We measured the relative changes in upper and lower rib cage volume (delta RCU and delta RCL, respectively) using an induction coil plethysmograph (Respitrace) in seven normal seated subjects during relaxed passive expiration from total lung capacity, during quiet breathing, rapid breathing at 60 breaths/min (RB), during exercise-induced hyperventilation (EH) and during single fast inspirations. The plot of the RCU vs RCL was slightly curvilinear during relaxation from total lung capacity in all subjects. However, the inferred changes in rib cage shape were similar during RB and EH to those observed during quiet breathing and the relaxation manoeuvres. In contrast, single rapid inspirations were associated with marked and variable changes in rib cage shape, being most prominent in the first part of the breath. Our results suggest that during cyclic breathing respiratory muscle activity is so co-ordinated that the pattern of rib cage shape change is similar to that observed during relaxation. In contrast, single rapid inspirations are associated with markedly different and variable shape changes of the rib cage, presumably due to different patterns of inspiratory muscle recruitment. The results are consistent with the observation that during tidal breathing regional ventilation distribution is flow independent.

Adult↗
PubMed1983

Factors influencing glottic dimensions during forced expiration.

To examine the relationship between expiratory effort, expiratory flow, and glottic aperture, we compared the effects of actively and passively produced changes in flow in six normal subjects. During flow transients of 1.08 +/- 0.08 l/s produced by voluntary expiratory effort, glottic width (dg) increased by 54 +/- 13% (mean +/- SE). In contrast transient increases in expiratory flow, produced passively by chest compression, were not accompanied by increases in glottic dimensions. Similarly, when subjects expired through a resistance, transient passive increases in mouth pressure of 8.1 +/- 0.8 cmH2O failed to increase glottic width. However, when similar positive-pressure transients were produced actively, dg increased by 97 +/- 36% even though the expiratory efforts were accompanied by relatively small increases in flow (0.20 +/- 0.05 l/s). During tidal breathing glottic widening commenced 160 +/- 60 ms before the onset of inspiratory flow, whereas the widening associated with active flow and pressure transients did not measurably precede the onset of the change in flow or pressure. Our results indicate that transient expulsive efforts are associated with synchronous increases in dg, regardless of whether expiratory flow increases. The findings are most readily explained by a centrally determined synchronous recruitment of intrinsic laryngeal and expiratory muscles that facilitates lung emptying by minimizing airway resistance during forced exhalation.

Adult↗