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Biomedical subjects

G Christodoulou

Publications and source records attributed to G Christodoulou.

13 recordsLinked to original sources
PubMed2001

Modelling hospital and social care bed occupancy and use by elderly people in an English health district.

The paper confirms that exponential equations can be used to model the total system and sub-systems of institutional health and social care for elderly people using bed occupancy census data for 6,068 elderly aged 65 and over. Two streams of flow were present in NHS acute hospitals, Local Authority residential homes and independent sector nursing homes. Three streams of flow were present in the overall data set and in the NHS geriatric hospital beds, NHS psychiatry beds and independent sector residential care homes. In total 22% of patients/residents stayed an average of 24 days (short stay), 69% for 825 days (medium stay) and 9% for 3,384 days (long stay). In both sexes, the older a patient/resident, the longer the time they occupied short stay beds and the shorter the time they occupied long stay beds.

Aged↗
PubMed2001

Using a continuous time hidden Markov process, with covariates, to model bed occupancy of people aged over 65 years.

Previously, the application of a continuous time hidden Markov model with discrete states was used to model geriatric inpatient behaviour. This was itself built on research using a discrete deterministic model to represent the flow of geriatric patients around departments of geriatric medicine. This paper uses the continuous time hidden Markov models and includes the effect of covariates, age and sex, in the model. Fitting the models we can visually see that the two compartment models provides estimates that are much closer to those observed in the data. The addition of covariates provides us with evidence of a difference in length of stay between men and women. However, even significant alterations to the mean age of patients in the model does not effect the length of stay.

Age Factors↗
PubMed2000

Prolactin secretion in response to haloperidol challenge in delusional (psychotic) and non-delusional depression.

Certain studies on measures related to central neurotransmitter activity have demonstrated that in delusional (psychotic) depression there is a dopaminergic dysregulation which distinguishes it from non-psychotic depression. A neuroendocrinologic method to check the degree of DA receptor responsivity is by measuring the prolactin responses to acute intramuscular administration of haloperidol. We studied this possibility by applying the haloperidol test in seven delusional and ten non-delusional depressed patients. All patients met DSM-IV criteria for a major depressive episode, single or recurrent, with or without psychotic features. After a three-week washout period, 5 mg of haloperidol were injected i.m. and blood samples were taken at 0, 30, 60, 90 and 120 minutes. In both trials, significant time effects were observed (elevated prolactin levels, F = 11.36, P = 0.000). However, the prolactin responses to haloperidol did not differ significantly between the two patient groups (F = 0.12, P = 0.97). These data do not show a difference in D(2) receptor responsivity, at least at the hypothalamus-pituitary level, between psychotic and non-psychotic depression.

Adolescent↗
PubMed2000

Psychophysiological evaluation of short-term neurotoxicity after prophylactic brain irradiation in patients with small cell lung cancer: a study of event related potentials.

BACKGROUND: The aim of this study was to show, whether a certain prophylacting applicable radiation affects the cognition, particularly, the specific cognitive components P50, N100, P300 and N400 of auditory event related potentials (ERPs) during a short memory test. METHODS AND MATERIALS: Eleven patients with small cell lung cancer (SCLC), who had presented complete response of disease after chemotherapy and radical radiotherapy in the lung, were prescribed to receive a prophylacting cranial irradiation (PCI) with a 6 MeV linear accelerator. The dose schedule was consisting of a total dose up to 30 Gy in 10 fractions, within 12 days (5 days a week). The psychophysiological approach before and after PCI was assessed by measurements of the auditory ERPs during a short memory performance using the digit-span Wechsler test. Components of ERP were recorded from 15 scalp electrodes. Additionally, symptomatology of depression and anxiety were assessed using Zung Self-Rating Depression Scale and Spielberger Anxiety Inventory, respectively, for pre- and post-PCI. RESULTS: No significant difference was noticed pre- and post-radiotherapy of all particular level of psychophysiological analysis concerning both the latencies and the amplitudes of ERPs auditory components P50, N100, P300 and N400 (P > 0.05, Wilcoxon signed test). Additionally, no changes were found with regard to behavioral performance (memory recall), depression symptomatology and state anxiety, according to pre- and post-radiation measurements. However, the self-reported depression symptomatology showed that the patients presented moderate depression. CONCLUSION: No short-term psychophysiological neurotoxicity was detected with this PCI schedule using these instruments, lending additional support to evidence suggesting the benefit of this certain PCI schedule for patients with SCLC.

Aged↗
PubMed2000

Measuring and modelling surgical bed usage.

Surgical departments treat two groups of inpatients--the simple and the complex--consequently a single average fails to describe the use being made of the occupied beds. Using decision support techniques, we show why indicators such as the average length, the average occupancy and the average admissions mislead. Furthermore, by analysing the fluctuating pattern of weekly admissions we show how weekends and the Christmas holiday periods impact on bed usage. Next, we demonstrate that flow process models can be used to describe how the in-patient workload concerns two groups of patients. On an average day, 71.4% of the beds contained patients who will have an average (exponential) stay of 4.8 days, and the other beds, 28.6%, contain patients who will have an average (exponential) stay of 22.8 days. The article concludes by demonstrating the short and long-term impact on daily admissions of a 10% change in four different parameters of the model. The data used come from a surgical department in Adelaide, as UK data sets report finished consultant episodes rather than completed in-patient spells.

Bed Occupancy↗
PubMed1995

The use of sonography for evaluation of the integrity and healing process of the tibiofibular interosseous membrane in ankle fractures.

This study evaluates the value of sonography in the diagnosis of the rupture and healing process of the interosseous membrane in Weber type B and C ankle fractures. In 90 such fractures a rupture of the interosseous membrane was intraoperatively observed in 35 cases (38.8%). All Weber type C fractures showed a rupture of the interosseous membrane, whereas only 23% of the Weber type B fractures were associated with a rupture of the interosseous membrane (p < 0.001). In the vast majority of the cases (77%), particularly in all Weber type B fractures (p < 0.01), the rupture of the interosseous membrane extended above the proximal fracture line of the fibula. By means of sonography, in the acute posttrauma period a rupture of the interosseous membrane was found in 37.4% of the cases. Thus, in our series the results of sonography and the operative findings coincided in 88.6% of the cases concerning location, type, and extent. Sonography was performed by three unbiased observers, and the results were compared with the intraoperative findings. Thus, the sensitivity of the sonography in the diagnosis of the rupture of the interosseous membrane was 88.8%, the diagnostic value of the method 92.2%, and specificity 94.5%. The sonographic findings of the healing process of the interosseous membrane were in absolute (100%) agreement with the intraoperative observations at the time of removal of the osteosynthesis material. Complete healing occurred within 3-5 months after trauma in 70% of the cases of ruptured interosseous membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Acetabular roof reinforcement rings.

A series of 30 total hip arthroplasties was performed in 29 patients with the use of the Mueller roof reinforcement ring (RRR). The mean follow-up observation time was 30 months (standard deviation [SD] = 7.6). The clinical and radiologic results were evaluated according to the Mayo Clinic scoring system. The overall preoperative clinical score of 21.963 (SD = 18.776) points improved to a follow-up examination score of 69.533 (SD = 11.599), a correction of 68.41%. The authors' goal in this series was to implant the ring together with the polyethylene socket as close to the anatomic position of the acetabulum as possible. There was no loosening of the RRR or the polyethylene sockets, nor was there material failure in the last evaluation of the hips. No statistically significant difference was found when the differences between the follow-up scores of the primary versus the revisionary procedures were compared. The roof replacement ring has been helpful for primary and revision arthroplasties of acetabular deficiencies occurring within five years after operation.

Acetabulum↗
PubMed1992

Open tibial shaft fractures: a comparative analysis of different methods of fixation in southwestern Greece.

A change in the method of managing open-grade-III tibial shaft fractures provided a new opportunity for a comparative study. One series of patients was treated exclusively by internal fixation and compared with another series treated with external fixation solely as well as with a series treated initially by external skeletal fixation and later by "Sarmiento walking plaster." The latter method was found to be a successful treatment and a good alternative to internal fixation for open grade-II and grade-III tibial shaft fractures when soft-tissue healing was completed. The supplementary use of the Sarmiento walking plaster had dramatically decreased the duration of hospital stay, saving the patient from an additional operation. There were no nonunions in this series. In open grade-I-II tibial shaft fractures, the deep infection rate in the cases in which internal fixation was used was significantly higher (5.4%), than that observed in the cases treated with external fixation, in which there was no deep infection. The nonunion rate was higher (22%) in the external fixation group compared with the internal fixation group (9%). The functional impairment of the ankle joint of the affected limb was less (15%) by using internal fixation than that of either the external fixation group (20%) or the group where the external fixation was changed to a Sarmiento walking plaster (35%).

Adolescent↗
PubMed1991

Influence of psychological and clinical factors on postoperative pain and narcotic consumption.

Demographic, psychological and clinical factors influencing postoperative pain and narcotic analgesic requirements in 162 patients undergoing elective operations under general anesthesia were studied. Eysencks Personality Questionnaire, Foulds Hostility Questionnaire, Zung's Anxiety-Depression (self-rating) Scales and the 43 Item Life Events Inventory by Holmes and Rahe were used. Clinical correlates such as surgical department, outcome of the operation, patient's knowledge of the diagnosis, were studied. Using multiple regression analysis the following results were obtained: postoperative pain levels increase with higher score of extroverted hostility (p = 0.038), abdominal surgery (p = 0.004), longer stay at hospital postoperatively (p = 0.15) and higher educational status (p = 0.13). Postoperative narcotic requirements increase with increased postoperative pain levels (p = 0.039) and preoccupation with pain postoperatively (p = 0.025), preoperative analgesic drug use (p = 0.017), abdominal surgery (p = 0.009) and longer stay at hospital preoperatively (p = 0.016). Also the department in which the patients were hospitalized influenced narcotic consumption.

Abdomen↗
PubMed1990

Anterior dislocation of the hip associated with fracture of the ipsilateral greater trochanter. A case report.

A 22-year-old male motorcyclist fell from a height and sustained an obturator hip dislocation with concomitant fracture of the ipsilateral greater trochanter. The immediate reduction of the dislocation associated with open reduction of the fracture of the greater trochanter showed excellent results at the short-term and long-term follow-up examinations. This extremely rare hip injury seems not to have been previously reported in the literature.

Adult↗
PubMed1976

Observations on the evolution of the hysterical symptomatology.

A retrospective study of the records of 17,571 psychiatric patients who attended the out-patients department of Eginition Hospital in Athens during three two-year periods (1948-50, 1958-60 and 1969-71) revealed a statistically significant decrease in the frequency of patients diagnosed as suffering from hysteria, a statistically significant decrease in the relative frequency of patients with hysterical fits and with mental conversion symptoms, and a statistically significant increase in the relative frequency of patients with mixed conversion symptoms. The findings confirm the notion that hysteria is still a 'woman's disease', although a statistically significant increase in male participation was noted. The significance of the above findings for the understanding of certain aspects of hysteria is discussed.

Adult↗