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Biomedical subjects

P Spiers

Publications and source records attributed to P Spiers.

At least 19 recordsLinked to original sources
PubMed2006

Collagen type-I degradation is related to arterial stiffness in hypertensive and normotensive subjects.

Although arterial stiffness is an independent cardiovascular risk factor associated with both aging and hypertension, relatively little is known regarding the structural changes in the vessel wall that occur with vessel stiffening. We determined if collagen type-I metabolism is related to arterial stiffening in both hypertensive and normotensive subjects. Arterial stiffness was assessed by aortic pulse wave velocity (PWV) and augmentation index (AIx) in 46 subjects (48.7 +/- 2 years, 32 hypertensives) and related to circulating markers of collagen type-I turnover. Collagen synthesis was assessed by the measurement of carboxy-terminal peptide of procollagen type-I (PIP) and collagen degradation by the measurement of carboxy-terminal telopeptide of collagen type-I (ICTP), by quantitative immunoassay. Matrix metalloproteinase-1 (MMP-1) and the tissue inhibitor of metalloproteinase-1 (TIMP-1) were also quantified by immunoassay. The ratio of collagen type-I synthesis to degradation was negatively correlated with both PWV (P<0.05) and AIx (P<0.05), whereas plasma MMP-1 levels displayed a positive correlation with both PWV (P<0.01) and AIx (P<0.01), after adjustment for age and mean arterial pressure. The relationship between collagen type-I turnover and arterial stiffness was similar in both the normotensive and hypertensive subjects. Although circulating markers of collagen synthesis were increased in the hypertensive subjects, this was not related to arterial stiffness. Collagen type-I degradation is increased in relation to collagen type-I synthesis in subjects with stiffer arteries. Matrix metalloproteinase-1, the enzyme responsible for collagen type-I degradation, is positively related to both large elastic and muscular artery stiffness in normotensive and hypertensive subjects.

Adult↗
PubMed2004

The Surgical Acute Care Unit (SACU): effects on surgical workload and mortality.

BACKGROUND: A surgical acute care unit (SACU) is designed to provide level 1 care for surgical patients. The aim of the present study was to audit the effects of the introduction of a SACU in a teaching hospital surgical department. METHODS: A retrospective case-note audit of all admissions to the newly established SACU over the first 6 months was performed. Expected mortality and morbidity was calculated using POSSUM (physiological and operative severity score for the enumeration of mortality and morbidity) scores. Critical care data for the same period and the 6 months prior to the SACU opening was examined to determine any effect on critical care workload. RESULTS: The SACU admitted 131 patients during the audit period. There was no significant difference between predicted and observed mortality or morbidity. There was no effect on critical care length of stay after the SACU opened. Many patients who would have needed critical care beds before the SACU opened were admitted directly to the SACU after it opened. CONCLUSIONS: This audit demonstrates that the provision of a surgical acute care unit allows many patients who would normally need to be admitted to the critical care unit for postoperative care to be safely admitted to level 1 care beds.

Adult↗
PubMed2004

Evaluation of the role of a specialist tracheostomy service. From critical care to outreach and beyond.

The impact that a new specialist tracheostomy service, designed specifically for the care of patients with tracheostomies, was assessed in terms of type of tracheostomy tube used, time to first tube change, time to decannulation, and incidence of tracheostomy related complications in a teaching hospital with no on-site ear, nose, and throat facility. A total of 170 patients were studied. After service implementation, fewer patients (17.6%, n = 21) were discharged from the intensive treatment unit to the wards with tracheostomy tubes compared with the first group (39%, n = 20) (p = 0.006), and the number of tracheostomy related complications on the wards were significantly reduced (p = 0.031).

Case-Control Studies↗
PubMed2000

Positive effect of bumetanide on contractile activity of ventricular cardiomyocytes.

Although the beneficial effects of loop-diuretics in relieving congestive heart failure and essential hypertension are well established, there has been limited investigation into the direct cardiac effect of these drugs. The aim of the present study was to investigate mechanical and electrophysiological effects of three loop-diuretics, namely, frusemide, bumetanide and torasemide, in ventricular cardiomyocytes isolated from rabbit myocardium. Contractile performance was assessed using a video edge detection method and effects on L-type Ca(2+) currents were determined using a 'perforated' patch-clamp technique. Unlike frusemide and torasemide, bumetanide produced concentration-dependent (3x10(-8) to 10(-5) M) increases in cell shortening and velocity of cell shortening. Neither frusemide, bumetanide nor torasemide exerted any action on peak Ca(2+) current amplitudes. In summary, the present investigation provides evidence for a direct contractile effect of the loop diuretic, bumetanide, in contrast to absence of effects by frusemide and torasemide, in ventricular cardiomyocytes isolated from rabbit myocardium.

Animals↗
PubMed1999

The immediate impact of opening an adult high dependency unit on intensive care unit occupancy.

We assessed the hourly occupancy of our intensive care and high dependency units over an 8-week period commencing on the day our high dependency unit opened. Using criteria established by the working group on 'Guidelines on Admission to and Discharge from Intensive Care and High Dependency Units' published by the National Health Service Executive, we defined each patient daily as intensive care or high dependency status. Compared with hourly occupancy figures obtained before the high dependency unit opened, occupancy of the intensive care unit by high dependency patients has been shown to decrease significantly from 21.6% to 11.2%. Use of intensive care beds became more appropriate, their occupancy increasing significantly from 63.7% to 73.4%. A significant decrease in readmissions occurred, supporting the hypothesis that having high dependency beds reduces the number of patients discharged prematurely to the wards.

APACHE↗
PubMed1998

Occupancy of a teaching hospital adult intensive care unit by high dependency patients.

We assessed the hourly occupancy of our intensive care unit by high dependency patients over an 8-week period using the criteria established by the Working Group on Guidelines on Admission to and Discharge from Intensive Care and High Dependency Units published by the National Health Service Executive. High dependency patients accounted for 1914 bed hours (21.6%) out of a potential available total of 8880 hours. Measurement of Therapeutic Intervention Scoring System points and Acute Physiology and Chronic Health Evaluation II scores confirmed that categorising patients according to the new guidelines produced significantly different populations of patients. Mean (standard deviation) Therapeutic Intervention Scoring System points for intensive care status patients were 38.57 (10.40) compared to 21.65 (5.98) points for high dependency status patients (p < 0.001). Median (range) Acute Physiology and Chronic Health Evaluation II score for intensive care status patients was 16 (1-45) compared to 11 (1-27) for high dependency status patients (p < 0.0001). Calculating bed occupancy with different definitions for the whole of our intensive care unit population during the 8 weeks revealed a range of occupancies between 85.3% and 107.3%. We recommend the intensive care unit bed occupancy should be calculated in a standard manner nationally to allow comparison between units. We suggest that hourly occupancy be adopted as the universal method.

APACHE↗
PubMed1997

Accuracy of pulse oximetry in patients with low systemic vascular resistance.

In order to assess the accuracy of pulse oximeters in patients with septic shock, we compared 80 paired readings of oxygen saturations taken from pulse oximeters and oxygen saturations obtained from co-oximetry in patients receiving intensive therapy with indwelling pulmonary artery flotation catheters. Comparison between groups with low or normal systemic vascular resistance indices showed a small (1.4%) but significant (p < 0.001) underreading of the saturation from the pulse oximeter in the presence of a low systemic vascular resistance. With normal or high systemic vascular resistance pulse oximeter readings correlated well with co-oximetry. We hypothesise that the main cause of this underreading is because the pulse oximeter is sensing pulsatile venous flow due to the opening of arteriovenous channels in the skin in septic states.

Adult↗
PubMed1996

Dual effects of endothelin-1 on the L-type Ca2+ current in ventricular cardiomyocytes.

The effects of endothelin-1 on the L-type Ca2+ current were studied in rabbit ventricular cardiomyocytes, using both the 'perforated' and the conventional 'ruptured' whole-cell patch-clamp techniques. Endothelin-1 exerts a dual effect on ventricular cardiomyocytes using experimental conditions which minimize intracellular dialysis; endothelin-1 produced both an increase (10(-9) M) and a decrease (10(-8) M) in the L-type Ca2+ current using the perforated patch-clamp technique. However, using the ruptured patch-clamp technique, endothelin-1 produced a similar decrease in L-type Ca2+ current at 10(-8) M, but no effect was observed at a concentration of 10(-9) M. These effects suggest multiplicity in the receptor-effector coupling mechanism.

Animals↗
PubMed1996

Hemodynamic effects of intravenous elgodipine in coronary artery disease during rest and exercise, and basic pharmacokinetic parameters.

Using an echo-Doppler method (Quantascope), the hemodynamic profile of the calcium channel antagonist elgodipine (64 micrograms/kg, i.v.) was investigated in 22 patients with angina pectoris at rest and during exercise. A placebo control was used. At rest, elgodipine significantly decreased systemic vascular resistance as well as systolic and diastolic blood pressure, while increasing cardiac output and stroke volume. During supine bicycle exercise the constant workload, elgodipine significantly increased cardiac output and stroke volume, and decrease the rate-pressure-product (double product); the exercise systolic blood pressure was decreased without change in the diastolic component. Elgodipine significantly reduced the incidence and severity (self-rated pain score) of exercise-induced anginal systems. Heart rate was not affected by elgodipine, either at rest or during exercise. In particular, no negative inotropy could be inferred from the echo-Doppler data. In the elgodipine plasma concentration profile (HPLC), three phases of elimination with half-life times of less than 1 hour, between 3 and 7 hours, and between 10 and 24 hours may be distinguished, indicating a "shallow" and a "deep" compartment. The hemodynamic data indicate an intermediate pharmacodynamic profile of elgodipine, lying between that of other dihydropyridines and that od compounds such as verapamil or diltiazem.

Adult↗
PubMed1995

The effect of a carbohydrate-rich beverage on mood, appetite, and cognitive function in women with premenstrual syndrome.

OBJECTIVE: To test the efficacy of a specially-formulated, carbohydrate-rich beverage (one known to increase the serum ratio of tryptophan to other large neutral amino acids) on the mood, cognitive, and appetitive disturbances of premenstrual syndrome (PMS). METHODS: Twenty-four women with confirmed PMS were enrolled in a double-blind, crossover study to test the efficacy of the specially-formulated beverage compared with two other isocaloric products on PMS symptoms. The study was conducted over three menstrual cycles preceded by a 1-month placebo run-in. Patients were tested at home or work using an interactive computer-telephone system. Standardized measurements of mood, cognitive performance, and food cravings were made before and 30, 90, and 180 minutes after consumption of active and placebo beverages during the late luteal phase of the menstrual cycle. RESULTS: The experimental carbohydrate intervention significantly decreased self-reported depression, anger, confusion, and carbohydrate craving 90-180 minutes after intake. Memory word recognition was also improved significantly compared with scores obtained during the placebo run-in month (P < .05). The isocaloric placebo interventions had no significant effect on any of these measures. CONCLUSION: The results suggest that the psychological and appetitive symptoms of PMS can be relieved after consuming a specially-formulated, carbohydrate-rich beverage known to increase serum tryptophan levels.

Adult↗