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Biomedical subjects

M J Gordon

Publications and source records attributed to M J Gordon.

At least 55 records · Page 3Linked to original sources
PubMed1990

pH-balanced solutions with superoxide dismutase (SOD): an attempt to increase island groin flap survival in rats.

Balanced salt solution (BSS) and balanced salt solution plus (BSS+), alone and in combination with heparin or superoxide dismutase (SOD), were used as irrigation solutions for rat groin flaps after prolonged ischemia. SOD always improved flap survival when it was present in solution, although when combined with BSS and BSS+, it was less effective than when combined with Ringer's lactate. The physiological pH solutions BSS and BSS+ had no advantages over Ringer's lactate in any of the tested combinations.

Administration, Topical↗
PubMed1989

Comparison of high-frequency oscillatory ventilation and high-frequency jet ventilation in cats with normal lungs.

Four adult cats received alternating high-frequency oscillatory ventilation (HFOV) and high-frequency jet ventilation (HFJV) at equivalent proximal airway pressures. Physiologic measurements were made before and after each ventilator change. Proximal airway pressures were then adjusted as necessary to reestablish normal pH and PaCO2 values. Aortic, pulmonary artery, and central venous pressures were monitored. Cardiac outputs were measured. Pulmonary and systemic vascular resistance, intrapulmonary shunt, and alveolar-arterial oxygen gradient were determined. Following the change from HFOV to HFJV at similar proximal airway pressures, HFJV always produced higher pH values (P less than 0.0001), higher PaO2 values (P less than 0.05), lower PaCO2 values (P less than 0.0001), as well as higher cardiac outputs (P less than 0.01), lower pulmonary artery pressures (P less than 0.001), and lower pulmonary vascular resistances (P less than 0.001). Following the reciprocal crossover, from HFJV to HFOV, HFJV pH values were again higher (P less than 0.001), and PaCO2 values were again lower (P less than 0.001). A comparison of HFOV and HFJV at similar pH and PaCO2 values showed that HFOV consistently required higher peak inspiratory pressures (P less than 0.001), higher mean airway pressure (P less than 0.001), and higher pressure wave amplitudes (P less than 0.001). Under the circumstances of this study, HFJV produced better gas exchange at lower proximal airway pressures.

Airway Resistance↗
PubMed1987

"No suture" microanastomosis using Vicryl rings and fibrin adhesive system: an unsuccessful attempt.

Vascular repairs using a combination of Vicryl rings to evert vessel edges and the Tisseel two-component fibrin adhesive system failed to achieve patent microanastomosis without using stay sutures. The bonding force of Tisseel alone was not sufficient to hold the cut ends of rat femoral arteries and veins together. All 10 arterial and 8 venous end-to-end anastomoses separated under normal intraluminal pressure immediately after the removal of microclamps. This method was found to be an unacceptable alternative to the conventional suturing method.

Animals↗
PubMed1987

Diagnosis of alcoholism in a simulated patient encounter by primary care physicians.

Although early detection and treatment of alcoholism have been shown to be efficacious, it is widely accepted that primary care physicians often fail to diagnose alcoholism. In this study, a computerized, simulated encounter with an alcoholic patient was used to assess the performance of a randomly selected sample of primary care physicians in diagnosing alcoholism. Of 95 physicians in this study, only 32 percent diagnosed alcoholism with maximal certainty. There was great variability among physicians in the threshold of information needed to diagnose alcoholism. One third of subjects misinterpreted symptoms of alcoholism and erroneously made other psychiatric diagnoses, chiefly anxiety or depression. Results of this pilot study were not associated with the physicians' age, sex, specialty, duration of training, or reported personal impact of alcoholism. This study provides further evidence of the need for additional education of primary care physicians if such physicians are to succeed in reducing the dramatic impact of alcoholism and alcohol abuse on public health.

Alcoholism↗
PubMed1986

Necrotizing tracheobronchitis: a complication of high-frequency ventilation.

The tracheobronchial histopathologic findings in eight neonates who died after treatment with high-frequency jet ventilation (HFJV) were compared with those in eight similar infants who died after treatment with conventional mechanical ventilation. The HFJV and conventionally treated groups were matched as closely as possible for birth weight, gestational age, and duration of mechanical ventilation. A 4-point, nine-variable histologic scoring system was used to grade tissue changes in the trachea, carina, and mainstem bronchi. The patients who received HFJV had significantly more histologic damage in their tracheas, carinas, and right and left mainstem bronchi. At all levels of the airway examined, HFJV was associated with more inflammation, greater losses of ciliated epithelium, and more mucus within the lumen of the airway than was conventional mechanical ventilation.

Bronchi↗
PubMed1986

High-frequency ventilation and tracheal injuries.

Recent reports linking serious tracheal injuries to various forms of high-frequency ventilation prompted this study. We compared the tracheal histopathology seen following standard-frequency, conventional mechanical ventilation with that seen following high-frequency, conventional mechanical ventilation, and two different forms of high-frequency jet ventilation. Twenty-six adult cats were examined. Each was mechanically ventilated for 16 hours. Seven received standard-frequency, conventional mechanical ventilation at 20 breaths per minute. Seven received high-frequency, conventional mechanical ventilation at 150 breaths per minute. Six received high-frequency jet ventilation at 250 breaths per minute via the Instrument Development Corporation VS600 jet ventilator (IDC). Six received high-frequency jet ventilation at 400 breaths per minute via the Bunnell Life Pulse jet ventilator (BLP). A semiquantitative histopathologic scoring system graded tracheal tissue changes. All forms of high-frequency ventilation produced significant inflammation (erosion, necrosis, and polymorphonuclear leukocyte infiltration) in the trachea in the region of the endotracheal tube tip. Conventional mechanical ventilation produced less histopathology than any form of high-frequency ventilation. Of all of the ventilators examined, the BLP, the ventilator operating at the fastest rate, produced the greatest loss of surface cilia and depletion of intracellular mucus. IDC high-frequency jet ventilation and high-frequency, conventional mechanical ventilation produced nearly identical histologic injuries. In this study, significant tracheal damage occurred with all forms of high-frequency ventilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Ophthalmology training in US family practice residencies.

Training in office ophthalmology is important in family practice residencies, especially because ophthalmology problems are common in family practice and only one quarter of medical students take structured ophthalmology clerkships in US medical schools. A joint committee of the American Academy of Family Physicians (AAFP) and the American Academy of Ophthalmology (AAO) has developed for family practice residents a core curriculum in ophthalmology listing essential cognitive knowledge and psychomotor skills. A national study on the extent and type of training currently available in US family practice residencies was performed. Based on a response rate of 82 percent, structured ophthalmology training experiences are provided on a required basis by 93 percent of the programs. Of these, 63 percent offer block rotations normally of two or four weeks' duration. Although a majority of the cognitive areas and psychomotor skills recommended by the AAFP-AAO joint committee are likely to be covered in existing family practice residencies, gaps identified in both categories call for closer attention to improving the learning experiences of residents in this field.

Curriculum↗
PubMed1985

Neonatal high-frequency jet ventilation: four years' experience.

During a 4-year period, 34 neonates were treated with high-frequency jet ventilation (HFJV) using two different HFJV systems. Twenty-three of the neonates had severe pulmonary air leaks, five had congenital left-sided diaphragmatic hernias, and six had end-stage respiratory failure without pulmonary air leaks. The two HFJV systems performed similarly in all pathologic conditions. Following HFJV, arterial blood gas values improved in 28 of the 34 patients (82%). Eleven patients (32%) ultimately survived. Of 23 patients with pulmonary air leaks, 17 (74%) improved, nine (39%) survived. One infant with diaphragmatic hernia and one with end-stage respiratory failure survived. Ten of 12 patients (85%) who died following eight or more hours of HFJV had significant tracheal histopathology in the region of the endotracheal tube tip. The lesions ranged from moderate erythema to severe necrotizing tracheobronchitis with total tracheal obstruction. HFJV can be useful in the treatment of severe pulmonary air leaks in neonates and may prove useful in the treatment of congenital diaphragmatic hernias. However, HFJV produces inflammatory injuries in the proximal trachea. More clinical and laboratory studies are needed to define the relative risks and benefits of this new therapy.

Blood Gas Analysis↗
PubMed1984

A systems perspective on clinical management.

A process-tracing descriptive approach is described which is aimed at understanding the clinical management of diabetes mellitus both from the physician's and the patient's perspective. Physician/patient pairs were interviewed about their views of diabetes management. Content analysis and statement classification were used to develop a four-stage model for clinical management which successfully classified 98% of physician statements and 97% of patient statements. Both four-stage models can be combined with a simplified systems description of clinical diabetes to form a unitary systems model for clinical management. Video recording of routine clinic visits with stimulated recall by physicians suggests this systems view of management has considerable heuristic and explanatory potential. A case analysis is presented to illustrate the explanatory value of the systems perspective on difficult management problems.

Clinical Competence↗
PubMed1984

Tracheobronchial histopathology associated with high-frequency jet ventilation.

We compared the tracheobronchial histopathology seen after conventional mechanical ventilation (CMV) and high-frequency jet ventilation (HFJV) in 44 adult cats. Two different HFJV humidity systems were examined: one used entrained mist alone, and the other infused 3 ml/kg X h of 0.45% NaCl directly into the jet stream. HFJV produced more tracheal damage than CMV. This damage occurred at the endotracheal tube tip. The pattern of injury was acute inflammation, with erosion, necrosis, and infiltration of polymorphonuclear (PMN) leukocytes. The HFJV humidity system using entrained mist alone produced more damage than the HFJV infusion-pump humidity system. HFJV also produced more luminal mucus at all airway levels. Lower airways had different injury patterns. After 16 h, CMV produced more histopathology in the carina and mainstem bronchi. Here, the injuries were losses of surface cilia, losses of epithelial goblet cells, and inflammation. The dissimilar histologic injury patterns seen with 2 different forms of mechanical ventilation suggest different mechanisms of injury.

Animals↗
PubMed1984

Using conventional infant ventilators at unconventional rates.

The effect of progressive increases in ventilator rate on delivered tidal and minute volumes, and the effect of changing peak inspiratory pressure (Pmax), positive end-expiratory pressure (PEEP), and inspiration to expiration (I:E) ratio at different ventilator rates were examined. Five different continuous-flow, time-cycled, pressure-preset infant ventilators were studied using a pneumotachograph, an airway pressure monitor, and a lung simulator. As rates increased from 10 to 150 breaths per minute, tidal volume stayed constant until 25 to 30 breaths per minute; then progressively decreased. In all, tidal volume began to decrease when proximal airway pressure waves lost inspiratory pressure plateaus. As rates increased, minute volume increased until 75 breaths per minute, then leveled off, then decreased. Substituting helium for O2 increased the ventilator rate at which this minute volume plateau effect occurred. Increasing peak inspiratory pressure consistently increased tidal volume. Increasing positive end-expiratory pressure decreased tidal volume. At rates less than 75 breaths per minute, inspiratory time (inspiration to expiration ratio) had little effect on delivered volume. At rates greater than 75 breaths per minute, inspiratory time became an important determinant of minute volume. For any given combination of lung compliance and airway resistance: there is a maximum ventilator rate beyond which tidal volume progressively decreases and another maximum ventilator rate beyond which minute volume progressively decreases; at slower rates, delivered volumes are determined primarily by changes in proximal airway pressures; at very rapid rates, inspiratory time becomes a key determinant of delivered volume.

Humans↗