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D F Treacher

Publications and source records attributed to D F Treacher.

At least 19 recordsLinked to original sources
PubMed2000

Effects of glutamine supplementation, GH, and IGF-I on glutamine metabolism in critically ill patients.

During critical illness glutamine deficiency may develop. Glutamine supplementation can restore plasma concentration to normal, but the effect on glutamine metabolism is unknown. The use of growth hormone (GH) and insulin-like growth factor I (IGF-I) to prevent protein catabolism in these patients may exacerbate the glutamine deficiency. We have investigated, in critically ill patients, the effects of 72 h of treatment with standard parenteral nutrition (TPN; n = 6), TPN supplemented with glutamine (TPNGLN; 0.4 g x kg(-1) x day(-1), n = 6), or TPNGLN with combined GH (0.2 IU. kg(-1). day(-1)) and IGF-I (160 microg x kg (-1) x day(-1)) (TPNGLN+GH/IGF-I; n = 5) on glutamine metabolism using [2-(15)N]glutamine. In patients receiving TPNGLN and TPNGLN+GH/IGF-I, plasma glutamine concentration was increased (338 +/- 22 vs. 461 +/- 24 micromol/l, P < 0.001, and 307 +/- 65 vs. 524 +/- 71 micromol/l, P < 0.05, respectively) and glutamine uptake was increased (5.2 +/- 0.5 vs. 7.4 +/- 0.7 micromol x kg(-1) x min(-1), P < 0.05 and 5.2 +/- 1.1 vs. 7.6 +/- 0.8 micromol x kg(-1) x min(-1), P < 0.05). Glutamine production and metabolic clearance rates were not altered by the three treatments. These results suggest that there is an increased requirement for glutamine in critically ill patients. Combined GH/IGF-I treatment with TPNGLN did not have adverse effects on glutamine metabolism.

Adult↗
PubMed1999

A 25-year study of nosocomial bacteremia in an adult intensive care unit.

OBJECTIVE: To identify the organisms, their antibiotic susceptibility, and the associated focus on infection causing nosocomial bacteremia in patients in an adult intensive care unit (ICU) between 1971 and 1995. DESIGN: Prospective observational study. SETTING: A 12-bed general adult ICU in a 1,000-bed tertiary referral teaching hospital. PATIENTS: Four hundred eighty-six episodes of bacteremia involving 570 organisms in 425 patients. MEASUREMENTS AND MAIN RESULTS: Blood cultures taken from patients with suspected nosocomial infection were analyzed. Isolated organisms were identified, and their susceptibility to commonly used antibiotics was determined. Clinical details, including antibiotic treatment, were recorded for all patients. From 1986 to 1995, culture results of samples obtained from other sites were used to help identify the focus of infection causing bacteremia. All results were collected prospectively by clinical microbiologists. Between 1971 and 1990, the number of bacteremias and the relative frequency of isolation of individual organisms changed little, with Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella species predominating. During 1991 to 1995, the number of bacteremias increased two-fold, largely attributable to increased isolation of Enterococcus species, coagulase-negative staphylococci, intrinsically antibiotic-resistant gram-negative organisms (particularly P. aeruginosa), and Candida species. The most commonly used antibiotics for the treatment of bacteremic patients throughout the 1970s were amoxicillin and gentamicin. After the introduction of cephalosporins in the early 1980s, their use increased progressively to equal that of gentamicin in the 1990s, whereas amoxicillin use decreased. Since the introduction of cephalosporins, increases in the antibiotic resistance of gram-negative organisms have been largely confined to an outbreak of gentamicin- and ceftazidime-resistant organisms caused by contaminated arterial pressure monitors during 1992 and 1993 and a two-fold increase in ceftazidime resistance of the Pseudomonas species. Gentamicin resistance of gram-negative aerobes remained unchanged (excluding the arterial pressure monitor outbreak), despite gentamicin being one of the most frequently prescribed antibiotics throughout the 25-yr period. Between 1986 and 1995, two thirds of all bacteremic organisms were cultured from intravascular catheters, which were designated as the focus of infection, 7% were secondary to gastrointestinal pathology, but only approximately 3% were secondary to wound, respiratory tract, or urinary tract infections. CONCLUSIONS: Bacteremias have become more frequent in the ICU, probably because of the increased use of intravascular catheters, which are the most frequent foci for bacteremic infection. The spectrum of organisms has changed, and this can be temporally related to the changes in the antibiotics prescribed. Gentamicin resistance of gram-negative organisms has not increased during a 25-yr period, despite being one of the most frequently prescribed antibiotics in the ICU.

Adult↗
PubMed1999

The metabolic consequences of critical illness: acute effects on glutamine and protein metabolism.

Net protein loss and large decreases in plasma glutamine concentration are characteristics of critical illness. We have used [2-15N]glutamine and [1-13C]leucine to investigate whole body glutamine and leucine kinetics in a group of critically ill patients and matched healthy controls. Glutamine appearance rate (Ra,Gln) was similar in both groups. However, in the patients, the proportion of Ra,Gln arising from protein breakdown was higher than in the control group (43 +/- 3 vs. 32 +/- 2%, P < 0.05). Glutamine metabolic clearance rate (MCR) was 92 +/- 8% higher (P < 0.001), whereas plasma glutamine concentration was 38 +/- 5% lower (P < 0.001) than in the control group. Leucine appearance rate (whole body proteolysis) and nonoxidative leucine disposal (whole body protein synthesis) were 59 +/- 14 and 49 +/- 15% higher in the patients (P < 0.001). Leucine oxidation and MCR were increased in the patients by 104 +/- 37 and 129 +/- 39%, respectively (P < 0.05). These results demonstrate that critical illness is associated with a major increase in protein turnover. The acute decrease in plasma glutamine concentration and the unaltered plasma Ra,Gln suggest that the increase in proteolysis is insufficient to meet increased demand for glutamine in this severe catabolic state.

Adult↗
PubMed1998

Relationship between TISS and ICU cost.

OBJECTIVE: To determine whether the therapeutic intervention scoring system (TISS) reliably reflects the cost of the overall intensive care unit (ICU) population, subgroups of that population and individual ICU patients. DESIGN: Prospective analysis of individual patient costs and comparison with TISS. SETTING: Adult, 12 bedded general medical and surgical ICU in a university teaching hospital. SUBJECTS: Two hundred fifty-seven consecutive patients including 52 coronary care (CCU), 99 cardiac surgery (CS) and 106 general ICU (GIC) cases admitted to the ICU during a 12-week period in 1994. A total of 916 TISS-scored patient days were analysed MAIN OUTCOME MEASURES: A variable cost (VC) that included consumables and service usage (nursing, physiotherapy, radiology and pathology staff costs) for individual patients was measured daily. Nursing costs were calculated in proportion to a daily nursing dependency score. A fixed cost (FC) was calculated for each patient to include medical, technical and clerical salary costs, capital equipment depreciation, equipment and central hospital costs. The correlation between cost and TISS was analysed using regression analysis. RESULTS: For the whole group (n = 257) the average daily FC was pound sterling 255 and daily VC was pound sterling 541 (SEM 10); range pound sterling 23-pound sterling 2,806. In the patient subgroups average daily cost (FC + VC) for CCU was pound sterling 476 (SEM 17.5), for CS pound sterling 766 (SEM 13.8) and for GIC pound sterling 873 (SEM 13.6). In the group as a whole, a strong correlation was demonstrated between VC and the TISS for each patient day (r = 0.87, p < 0.001) and this improved further when the total TISS score was compared with the total VC of the entire patient episode (r = 0.93, p < 0.001). This correlation was maintained in CCU, CS and GIC patient cohorts with only a small median difference between actual and predicted cost (2.2 % for GIC patients). However, in the individual patient, the range of error was up to +/- 65 % of the true variable cost. For the whole group the variable cost per TISS point was pound sterling 25. CONCLUSION: These results demonstrate that TISS reliably measures overall ICU population costs as well as those of the subgroups CCU, CS and GIC. However, the relationship between TISS and cost is less reliable for the individual patient.

Adolescent↗
PubMed1998

Melatonin administration and pituitary hormone secretion.

OBJECTIVE: The relationship between the pineal gland and pituitary function remains controversial, while the role of melatonin in the adaptation of the organism to the light-dark cycle of the environment is becoming increasingly recognized. The aim of this study was to investigate the effect of a manipulation of the melatonin rhythm on pituitary hormone secretion in man. DESIGN: Double-blind controlled clinical study. SUBJECTS: Ten adult healthy male volunteers, aged 21-33 years, were studied on two occasions: once after the administration of melatonin 5 mg orally for 4 days at 1700 hours and once after the administration of placebo, at similar times. On the day of each study the subjects undertook their normal duties but refrained from taking heavy exercise, from smoking and drinking alcohol. MEASUREMENTS: Serum cortisol, growth hormone, prolactin and plasma vasopressin, oxytocin, melatonin, sodium, potassium, osmolality and packed cell volume were measured over the following 24 hours. RESULTS: The cortisol peak was advanced and prolactin release increased after melatonin administration, while growth hormone was not affected. Vasopressin and oxytocin levels were found to increase during the night in the control study, but the period of the nocturnal increase in vasopressin concentrations was reduced after the administration of melatonin and the nocturnal increase of oxytocin was absent. CONCLUSION: Altering the melatonin rhythm may affect neuroendocrine function, influencing the nocturnal pattern of neurohypophysial hormone secretion, augmenting prolactin release and advancing the peak of cortisol release.

Administration, Oral↗
PubMed1998

Bright light exposure and pituitary hormone secretion.

OBJECTIVE: Exposure to bright light inhibits melatonin secretion in man. As the relationship between melatonin and pituitary function remains controversial, we investigated the effect of altering the melatonin rhythm by bright light during the early hours of darkness on pituitary hormone secretion in man. DESIGN: The investigation took the form of a randomized controlled clinical trial. SUBJECTS: Ten adult healthy male volunteers, who were non-smokers and aged 21-33 years, were studied on two occasions: once during exposure to bright light from 2000 h to 0200 h and once during exposure to normal room lighting over the same period. On each day of the study, the subjects were allowed to sleep after lights were switched off at 0200 h. Observations were also performed when subjects were exposed to normal room lighting from 2000 h to 2400 h, thereafter being allowed to sleep. On each study day the subjects undertook their normal duties but refrained from taking heavy exercise and drinking alcohol. MEASUREMENTS: Serum cortisol, GH and PRL, plasma vasopressin, oxytocin, melatonin, sodium, potassium and osmolality and packed cell volume were measured over 24 hours. RESULTS: Bright light delayed the nocturnal melatonin peak by 2 hours and resulted in a decrease in cortisol concentrations. Growth hormone levels decreased but subsequently there was a significantly greater nocturnal increase. The PRL peak was delayed and nocturnal vasopressin concentrations were lower in both the studies where subjects were exposed to a modified sleep schedule. CONCLUSION: Exposure to bright light during the early hours of darkness delays the nocturnal melatonin peak and alters cortisol, GH, PRL and nocturnal vasopressin secretion, while modification of the sleep pattern decreases vasopressin concentrations and alters its nocturnal peak.

Adult↗
PubMed1998

Neurohypophysial hormone and melatonin secretion over the natural and suppressed menstrual cycle in premenopausal women.

OBJECTIVE: Vasopressin, oxytocin and melatonin have been reported to be influenced by ovarian steroids. The neurohypophysial hormones have also been shown to display a diurnal pattern of secretion in men. We therefore studied the diurnal pattern of neurohypophysial hormone and melatonin secretion in premenopausal women and in women on oral contraceptives. DESIGN: Healthy normally cycling premenopausal women were studied over 24 hours during the midfollicular and midluteal phases of the menstrual cycle. Healthy premenopausal women on oral contraceptives were studied over 24 hours at similar times. SUBJECTS: Eight healthy normally cycling women and 7 healthy premenopausal women on oral contraceptives. MEASUREMENTS: Plasma vasopressin, oxytocin and melatonin were measured by radioimmunoassay. RESULTS: Vasopressin concentrations and its nocturnal peak were highest in the follicular phase of the natural menstrual cycle and attenuated in the women on oral contraceptives. Oxytocin concentrations did not vary between the two phases of the menstrual cycle, but increased on oestrogen administration. Overall melatonin secretion was augmented in the women on oral contraceptives. CONCLUSIONS: Vasopressin release and its nocturnal peak were greatest in the follicular phase of the menstrual cycle, while melatonin secretion was augmented in the women on oral contraception.

Adult↗
PubMed1998

Bicarbonate-based haemofiltration in the management of acute renal failure with lactic acidosis.

Continuous haemofiltration with lactate-based replacement fluid is widely used for the treatment of acute renal failure (ARF). In the presence of lactic acidosis, such treatment exacerbates rather than improves the clinical state. Continuous haemofiltration using a locally-prepared bicarbonate-based replacement fluid was performed in 200 patients over 7 years. All the patients had ARF with concomitant lactic acidosis, or demonstrated lactate intolerance after starting haemofiltration with lactate-based replacement fluids. In every case it was possible to correct the acidosis without inducing either extracellular volume expansion or hypernatraemia. In 89 patients (45%), the lactic acidosis resolved while being treated with bicarbonate-based haemofiltration. Fifty-seven patients (28.5%) survived. Significant differences at presentation in the group who survived, compared with those who died, were seen in age (50.8 vs. 57.1), mean arterial pressure (68.5 vs. 60.0 mmHg) and APACHE II score (32.1 vs. 38.9). Neither the severity of the presenting acidosis nor the arterial blood lactate appeared to predict outcome. Patients who developed ARF and lactic acidosis after cardiac surgery had a low survival rate. The combination of ARF and lactic acidosis that cannot safely be treated by haemofiltration using lactate-based replacement fluids can be managed with bicarbonate-based haemofiltration.

Acidosis, Lactic↗
PubMed1998

Daily patterns of secretion of neurohypophysial hormones in man: effect of age.

The neurohypophysial hormone vasopressin contributes to control of urine output and, while urine flow shows a clear daily rhythm, there has been debate as to whether this is true of neurohypophysial hormones. A study was performed on fifteen adult males, with a mean age of 25 years, over a 24 h period, nine blood samples being taken at regular intervals for the determination of neurohypophysial hormones and indices of fluid balance. Samples were taken via an indwelling cannula so that sleep was undisturbed. A daily variation in the plasma concentrations of oxytocin and vasopressin was demonstrated with concentrations reaching a nadir in the late afternoon. Concentrations of both hormones peaked at 02.00 h. Vasopressin concentrations were inversely correlated with packed cell volume, indicating that the altered hormone release was affecting fluid retention. Consistent with this was the observation that the relationship of plasma osmolality to vasopressin depended on the time of day. To determine the effect of ageing, a similar study was performed on nine healthy elderly subjects with a mean age of 70 years. The nocturnal peak of vasopressin was markedly attenuated, while oxytocin release was similar to that in the younger group. These observations confirm the existence of a daily rhythm in the plasma concentrations of neurohypophysial hormones and indicate that the amplitude of the vasopressin change decreases with age.

Adult↗
PubMed1998

A novel leucocyte-depleting filter for use in continuous venovenous haemofiltration: preliminary in vitro studies.

Multiple organ failure (MOF) secondary to circulatory shock, sepsis, or trauma was first described over 20 years ago. Despite much research effort and clinical trials of biological response modifiers, MOF continues to be the leading cause of death in both medical and surgical intensive care units (ICU). MOF is associated with widespread cellular and humoral systemic inflammatory responses which, in turn, are linked with inadequate tissue perfusion to vital organs and the inappropriate accumulation of activated neutrophils, resulting in microcirculatory injury. Much evidence suggests that such activated neutrophils cause vascular damage by adhering to the endothelium and releasing a variety of highly reactive and toxic moieties; these may subsequently produce endothelial injury and compromised organ function. We reasoned that a clinical device designed to remove such cells in a controlled fashion from the circulation of patients with MOF by means of using a continuous venovenous circuit might be beneficial. We report the leucocyte depletion performance of a novel filter medium as a first step towards the production of a clinical device, and show specific depletion of phagocytes relative to other formed elements in the blood.

Hemofiltration↗
PubMed1997

Comparison of jet and ultrasonic nebulizer pulmonary aerosol deposition during mechanical ventilation.

Increased delivery of aerosol to a model lung (attached to a mechanical ventilator) has been demonstrated with an ultrasonic nebulizer as compared to a jet nebulizer. This study examined whether the increased aerosol deposition with an ultrasonic nebulizer could also be demonstrated in vivo. Seven patients (6 male and 1 female) were studied during mechanical ventilalion (Siemens Servo 900C, Middlesex, UK) after open heart surgery. Two studies were performed in each patient. In the first study, aerosol was delivered via a Siemens Servo 945 nebulizer system (high setting) driving a System 22 Acorn jet nebulizer (Medic-Aid, Sussex, UK) containing 3 mL (99m)technetium-labelled human serum albumin (99mTc-HSA) (50 microg; activity 74 MBq). In the second study, a DP100 ultrasonic nebulizer (DP Medical, Meylan, France) containing 12 mL 99mTc-HSA (50 microg; activity 185 MBq) was used. Pulmonary deposition was quantified using a gamma camera. The humidification of the circuit and the ventilator settings were kept constant according to the patient's clinical requirements. The total lung aerosol deposition (mean+/-SD), as a percentage of initial nebulizer activity, was greater using the ultrasonic nebulizer than using the jet nebulizer (53+/-1.4 vs 2.3+/-0.9%; p<0.002). The ultrasonic nebulizer was also associated with a reduction in the time required to complete nebulization (9 vs 21 min, respectively) (p<0.0001). Use of the DP100 ultrasonic nebulizer more than doubled lung deposition compared with the System 22 jet nebulizers in mechanically-ventilated patients. Their efficiency, speed of drug delivery, and compatibility with mechanical ventilator circuits make ultrasonic nebulizers potentially attractive for use during mechanical ventilation.

Administration, Inhalation↗
PubMed1996

Gastrointestinal permeability and absorptive capacity in sepsis.

OBJECTIVE: To assess gastrointestinal permeability and functional absorptive capacity in patients with sepsis. DESIGN: Case control study to analyze gastrointestinal permeability and functional absorptive capacity of septic patients by differential saccharide absorption (from an oral test solution) and excretion. SETTING: The intensive Therapy Unit of St. Thomas' Hospital, London, UK. PATIENTS: Twenty patients with a mean Acute Physiology and Chronic Health Evaluation (APACHE) II score of 18.4 who were admitted to the intensive care unit with a diagnosis of sepsis. All patients were on enteral feeding. Patients with abdominal pathology were excluded. INTERVENTIONS: An oral test solution containing 5 g of lactulose, 1 g of L-rhamnose, 0.5 g of D-xylose, and 0.2 g of 3-O-methyl-D-glucose dissolved in water to a final volume of 100 mL was administered to patients and controls. Urine was collected for 5 hrs starting immediately after administration of the test solution and the saccharide content of the urine was estimated and expressed as a percentage recovery of the oral test solution. MEASUREMENTS AND MAIN RESULTS: Septic patients had increased lactulose/L-rhamnose urine excretion ratios (0.23 +/- 0.19) compared with control subjects (0.03 +/- 0.01, p < .001), consistent with increased gastrointestinal permeability in sepsis. Septic patients had decreased L-rhamnose/3-O-methyl-D-glucose urine excretion ratios (0.14 +/- 0.07) compared with normal controls (0.28 +/- 0.08, p < .001), consistent with decreased gastrointestinal functional absorptive capacity in sepsis. CONCLUSIONS: Patients with acute sepsis exhibit increased gastrointestinal permeability and decreased gastrointestinal functional absorptive capacity in comparison with healthy control subjects. These abnormalities may contribute to the pathophysiology of sepsis.

3-O-Methylglucose↗