John Hedley-Whyte
Harvard University
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Featured researches published by John Hedley-Whyte.
The Lancet | 1982
GaryC. Du Moulin; John Hedley-Whyte; DanielG. Paterson; Alan Lisbon
The gastric and upper-airway flora of 60 consecutive patients treated with antacids or cimetidine in a respiratory/surgical intensive-therapy unit were studied. In 52 (87.0%) patients one or more organisms were cultured simultaneously from both upper airway and stomach. A sequence of transmission was clear in 17 of these patients. Pneumonia due to gram-negative bacilli developed in 31 patients; in most cases the causative organisms were of gastric origin. No pneumonia developed in the 8 patients whose gastric and upper-airway flora were different. The number of gram-negative bacilli in gastric aspirates correlated with the pH of the gastric aspirate. Treatment of seriously ill patients with antacids or cimetidine may encourage airway colonisation and predispose the patients to pneumonia caused by gram-negative bacilli.
The New England Journal of Medicine | 1975
Thomas W. Feeley; G C du Moulin; John Hedley-Whyte; Leonard S. Bushnell; John P. Gilbert; David S. Feingold
Pneumonia caused by Pseudomonas aeruginosa occurs frequently in critically ill patients and is associated with a mortality rate of 70 per cent. An aerosol of polymyxin B was administered (2.5 mg per kilogram per day) to the upper airways of 292 patients in a respiratory-surgical intensive-care unit during a seven-month period, in an attempt to prevent Ps. aeruginosa pneumonia. Although only one of the patients studied acquired pneumonia due to Ps. aeruginosa, 10 others acquired pneumonia caused by a polymysinx-resistant organism. Seven pneumonias were caused by organisms not frequently pathogenic to man (flavobacteria, serratia and Streptococcus faecalis). The mortality rate for acquired pneumonia in this study, 64 per cent, is greater than that in previous studies in which either no polymyxin or cyclic polymyxin therapy was used. Continuous use of polymyxin B aerosol appears to be a dangerous form of therapy.
JAMA | 1979
Jovan L. Djokovic; John Hedley-Whyte
We studied the outcome of surgery in 500 patients over 80 years of age. Hospital mortality within one month of surgery was 6.2%. The American Society of Anesthesiologists class 1 to 5 preoperative evaluation scale was useful in predicting death--less than 1% of class 2 patients died, 4% of class 3, and 25% of class 4. Six of seven perioperative deaths were caused by mesenteric infarction. Myocardial infarction was the leading cause of postoperative death. Twenty-four percent of 141 patients who underwent upper abdominal surgery required controlled endotracheal ventilation for more than 24 hours postoperatively; 57% after intrathoracic surgery; and only 2% after surgery that did not enter pleura or peritoneum. Forty-seven patients underwent gallbladder surgery, and 27 peripheral underwent vascular surgery without any hospital fatality. Enflurane appears to be a safe general anesthetic for sick, elderly patients.
JAMA | 1988
Gary C. du Moulin; Kurt D. Stottmeier; Pierre A. Pelletier; Anna Y. Tsang; John Hedley-Whyte
Water from 34 sites on two temporarily vacant hospital floors was analyzed for the presence of mycobacteria. These sites included 18 cold water taps and 16 hot water taps, including shower heads. A total of 14 sites (41%) demonstrated the presence of Mycobacterium avium as confirmed by biochemical characterization, DNA/rRNA probe analysis, and seroagglutination. Of positive sites, 11 were hot water sources with an average temperature of 55 degrees C and yielding up to 500 colony-forming units per 100 mL. Seven of 11 strains analyzed for glycolipid antigens were identified with the type 4 serovar, the preponderant serovar of M avium in patients with acquired immunodeficiency syndrome from the Boston area. Potable hot water systems, particularly those that generate aerosols, may contain concentrations of M avium greater than those found in cold water systems and could serve as an environmental source for colonization and infection of immunocompromised persons.
Anesthesiology | 1974
Stephen V. Hall; E. Ernest Johnson; John Hedley-Whyte
Renal blood flow obtained by a square-wave electromagnetic flowmeter and intrarenal distribution of blood flow assessed by 3Kr washout-curve analysis were measured in ten dogs lightly anesthetized with pentobarbital. Creatinine clearance, sodium excretion, and fractional sodium reabsorption were measured in ten dogs, including four of the dogs studied for renal hemodynamics. Comparisons were made between the effects of intermittent positive-pressure ventilation (IPPV) and continuous positive-pressure ventilation (CPPV) with 10 cm H2O positive end-expiratory pressure (PEEP). A 29 per cent decrease in cardiac index caused by CPPV was associated with a 9 mm Hg decrease in mean renal arterial pressure (P < 0.02) and only a 7 per cent decrease in total renal blood flow (N.S.). With CPPV, fractional perfusion of outer cortex decreased, while perfusion of inner cortex and outer medullary tissue increased, urinary output decreased 40 per cent (P < 0.01), creatinine clearance declined 23 per cent (P < 0.001), sodium excretion decreased 63 per cent (P < 0.005), and fractional reabsorption of sodium increased (P < 0.005). All changes were reversible. The response to the decreases in cardiac index and intrathoracic blood volume during CPPV results in redistribution of intrarenal blood flow and a marked decrease in renal excretion of sodium and water, while total renal blood flow remains essentially unchanged.
The New England Journal of Medicine | 1965
H. Pontoppidan; John Hedley-Whyte; H. H. Bendixen; Myron B. Laver; Edward P. Radford
IN a person with normal lungs the amount of ventilation that is sufficient to eliminate the carbon dioxide produced (and thus to maintain carbon dioxide homeostasis) is predictable with considerabl...
Journal of Clinical Investigation | 1973
Sheldon Greenfield; Daniel Teres; Leonard S. Bushnell; John Hedley-Whyte; David S. Feingold
A prospective study used polymyxin B by aerosol to reduce colonization of the upper respiratory tract with nosocomial gram-negative bacilli. 58 high-risk patients from the Respiratory-Surgical Intensive Care Unit entered the trial. 33 were randomly selected to receive 2.5 mg/kg/day of polymyxin B by hand atomizer into the pharynx, and tracheal tube if present. 17 of 25 control patients became colonized with gram-negative bacilli as compared with 7 of 33 polymyxin-treated patients (p < 0.01). Control patients became colonized with a total of 33 gram-negative bacilli: 3 were Pseudomonas aeruginosa, 21 were species of Enterobacteriaceae. The polymyxin-treated patients became colonized with a total of 11 gram-negative bacilli: no P. aeruginosa and only 3 species of Enterobacteriaceae were recovered. Colonization increased with duration in Respiratory-Surgical Intensive Care Unit and with time of required controlled ventilation. Polymyxin most effectively prevented the increase in colonization in treated patients who stayed in the Respiratory-Surgical Intensive Care Unit for longer than 1 wk and who required controlled ventilation for at least 72 h.
Journal of Clinical Investigation | 1966
John Hedley-Whyte; H. Pontoppidan; M. J. Morris
The purpose of this study was to determine the effect of increasing the tidal volume on pulmonary ventilation-perfusion relations in patients with respiratory failure caused by cardiopulmonary disease. The frequent occurrence of an increased physiologic dead space (2, 3) and of increased physiologic shunting (3) in patients undergoing prolonged artificial ventilation has previously been described. These changes in ventilation-perfusion ratios mean that very large tidal volumes and high percentages of inspired oxygen are often required to maintain life during prolonged intermittent positive pressure ventilation. The aim of our study was to measure the consequences of changing the tidal volume, but not the respiratory frequency, of patients with respiratory failure secondary to either acute intrapulmonary infection or chronic pulmonary emphysema.
Anesthesiology | 1964
H. H. Bendixen; B. Bullwinkel; John Hedley-Whyte; M. B. layer
The hypothesis is tested that progressive atelectasis. with shunting of venous blood into the arterial bloodstream, may occur with ventilation which is normal by the usual criteria, but lacking in periodic deep breaths capable of reinflating collapsed airspaces. A previous study found such shunting to occur in anesthetized patients, ventilated by mechanical respirators; in the present study 25 patients were anesthetized with ether and oxygen and breathed spontaneously for an average period of 130 minutes. At the end of this period of spontaneous ventilation the average arterial oxygen tension was 402 mm. of mercury. Following a period of three to five minutes of controlled ventilation, using large tidal volumes, the average arterial oxygen tension rose to 553 mm. of mercury. The greatest fall in arterial oxygen tension occurred in the patients whose spontaneous tidal volumes were the most shallow. It is concluded that spontaneous ventilation in anesthetized patients, even when adequate in terms of carbon dioxide elimination, should be supplemented with periodic passive hyperinflations.
Brain Research | 1985
Gary C. du Moulin; Daniel Paterson; John Hedley-Whyte; Selwyn A. Broitman
Impaired mental status is a poorly understood manifestation of sepsis and may be associated with altered permeability of the blood-brain barrier. To examine the possibility that sepsis affects permeability of the blood-brain barrier, rats were infected with a peritoneal implant consisting of sterilized feces, barium sulfate, and 10(8) colony forming units (CFU) of Escherichia coli. Using this model, reproducible episodes of peritonitis with bacteremia resulted. Rats were sacrificed hourly after 5 min circulation of 100 mg horseradish peroxidase. Animals were perfused-fixed and the brains removed. Representative coronal sections were stained for peroxidase reaction product and cerebral blood vessels were examined microscopically for evidence of HRP staining and extravasation. The number of stained cerebral vessels from infected rats was increased at all times compared to uninfected control rats. Extravasation of horseradish peroxide within neuropil was significantly higher in hours 1, 4 and 5 as compared to controls. The lack of significant increase in hours 2 and 3 may suggest transient closing or repair of the tight junctions. We conclude that peritonitis and bacteremia are associated with increased permeability of the blood-brain barrier.