PubMed Health⌕ Search

Biomedical subjects

P Gomis

Publications and source records attributed to P Gomis.

32 records · Page 2Linked to original sources
PubMed1995

Analysis of high-resolution ECG changes during percutaneous transluminal coronary angioplasty.

The authors have hypothesized that low-level, electrocardiographic changes may accompany transient ischemia induced by percutaneous transluminal coronary angioplasty. Altered repolarization may manifest as subclinical changes in ST-T morphology. Changes in depolarization may manifest as low-amplitude notches and slurs, a phenomenon the authors term abnormal intra-QRS potentials. The initial aim of this study was to characterize changes in high-resolution electrocardiograph signals that might be linked to ischemic involvement of the ventricular myocardium.

Angioplasty, Balloon, Coronary↗
PubMed1994

Adaptive control of drug dosage regimens: basic foundations, relevant issues, and clinical examples.

In this paper we examine several of the fundamental foundations and relevant clinical issues in adaptive control of drug dosage regimens for patients. Truly individualized therapy with drugs having narrow margins of safety first requires a practical pharmacokinetic/dynamic model of the behavior of a drug. Past experience with a drug is stored in the form of a population model. Next, using the information in such a model and its relationship to the incidence of adverse reactions, a specific, explicit therapeutic goal must be selected by the responsible clinician, based on the patient's need for the drug and the risk of adverse reactions felt to be justified by each patient's need, small, moderate, or great. Individualized drug therapy thus begins with the selection of individualized therapeutic goals (low, moderate, or high) for each patient. Using subsequent feedback from the patient's serum drug levels, and using Bayesian fitting, the model is then linked to each patient as a patient-specific model. Control of the model by the dosage regimen increasingly controls the patient, to better obtain the desired explicit therapeutic goals. This process is essentially similar to that of a flight control or missile guidance system.

Bayes Theorem↗
PubMed1994

[Prone position and operative posture in neurosurgery].

The most satisfactory method of prone positioning for the posterior approach to the spine and posterior fossa has been influenced by the necessity of providing good operating condition: prone position without abdominal and thoracic compression with a patient's head in the neutral position. Communication between the cava veins and the vertebral venous plexus explain that induce positioning can produce an excessive venous intraoperative bleeding with decreased surgical visibility. Furthermore venous return to the heart decreased resulting in some degree of impaired cardiac output. Hemodynamic disturbances of cerebral or spinal cord bloods flows can occurred.

Cerebrovascular Circulation↗
PubMed1994

[Right ventricular function and postural changes during surgery of the lumbar spine].

The aim of the study was to assess the effects of the sitting prone position on right ventricular function in a group of patients requiring low back surgery with using of right heart catheterization with a low fast response thermodilution technique. This posture involves moderated hemodynamic effects. A discrete right ventricle impairment characterised by a decreased compliance was observed and may be due to a moderate compression by the sternum and was improved by fluid challenge. Thus, the sitting prone position appears a safe position.

Humans↗
PubMed1994

[Changes in systolic pressure and posture in the surgery of the lumbar spine].

Anesthetized patients for lumbar disk surgery can be placed in prone or knee chest position which may adversely affect circulation. Augmentation of the delta-down component of the systolic blood pressure variation in ventilated patient is a sensitive indicator of intra operative hypovolemia. According to results, cardiac filling pressure is more affected in the knee chest position than in prone position. Preload state variation between the two positions, evaluated with albumin fluid challenge, seems to be more important than 500 ml.

Blood Pressure↗
PubMed1994

[Initial prognostic factors of aneurysmal subarachnoid hemorrhage].

The purpose of this retrospective study is to explain, using a total of 210 consecutive patients with aneurysmal subarachnoid hemorrhage, the survival by several prognostic factors measured at the admission time. A multivariate analysis using the Cox proportional hazards model allowed one to recognize five prognostic factors: secondary arterial hypertension (risk ratio (RR) = 1.8; p = 0.03), the Hunt and Hess grade-3 (RR = 3.3; p = 0.002), the Hunt and Hess grade-4 (RR = 7.3; p = 0.007), and the hunt and Hess grade-5 (RR = 5.8; p = 0.03), the Fisher grade-3 (RR = 2; p = 0.01), and the Fisher grade-4 (RR = 2; p = 0.001). The determination of a prognostic score for each patient (using the coefficients of selected prognostic factors) allowed one to establish 3 prognostic stages with survival probabilities significantly different (p = 0.00005); stage-1; survival rate after 150 days (SR) = 97 %, confidence interval of 95 % (CI) = [0.90; 0.99], stage-2: SR = 66 %, CI = [0.56; 0.74], stage-3; SR = 34 %, CI = [0.17; 0.54]. The relative death risk for the stage-2 was 14 times higher than that for stage-1 (p = 0.00005), and the relative death risk for the stage-3 was 36 times higher than that for stage-1 (p = 0.00005). The age, the essential arterial hypertension, the sex and the angiographic classification of George have no prognostic value. The rebleeding incidence was correlated with prognostic stages (respectively from stage-1 to the stage-3: 8 %, 14 %, 34 %).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Intraoperative posture in the surgery of lumbar disk hernia].

For surgery of the lumbar disc, with a posterior route, the patient is placed either in a prone, or a knee-chest, or a lateral position. They aim at facilitating the surgical access in decreasing local bleeding and collapsing the dural sheath. This benefit, as a result of the maintenance of the pressure in the epidural venous system at a low level, is obtained through the absence of any abdominal compression as well as the posture. In the prone position, the abdominal compression and the increase of the physiologic lordosis impair the systemic venous return and carry the risk of cardiac arrest. In addition to these adverse effects, the conventional knee-chest position increases the haemodynamic repercussions in modifying the distribution of blood volume and increasing the potential risk of mediastinal compression and air embolism. The lateral position generates only minor haemodynamic modifications, except in the obese. However it is difficult to stabilize the patients' position and to maintain the alignment of the spine. Therefore it is used the less one. The postural risks of all three positions are numerous and include mainly the compression of nerves, vessels and skin. Finally the selection of the position depends basically on morphological criteria and the adaptative capacities of the patient. The optimal position is the one offering a low pressure level in the spinal venous system, while maintaining the venous return.

Anesthesia, General↗
PubMed1993

Individualizing drug dosage regimens: roles of population pharmacokinetic and dynamic models, Bayesian fitting, and adaptive control.

The role of population pharmacokinetic modeling is to store experience with drug behavior. The behavior of the model is then correlated with the clinical behavior of the patients studied, permitting selection of a specific serum level therapeutic goal that is based on each individual patient's need for the drug and on the risk of adverse reactions, both of which must be considered. A dosage regimen is then computed to achieve that goal with maximum precision. The patient should not run a greater risk of toxicity than is justified, and should obtain the maximum possible benefit within the acceptable risk. The regimen is given and the patient monitored.

Bayes Theorem↗
PubMed1993

[Comparison of 2 consecutive series of aneurysmal subarachnoid hemorrhage with or without nimodipine and study of the temperature curve].

A total of 210 consecutive patients with aneurysmal subarachnoid hemorrhage (S.A.H.) of any clinical grade admitted from January 1985 through May 1990 were retrospectively studied to determine the effect of intravenous Nimodipine on survival and functional results and to analyse temperature curve as a prognosis factor. The 106 patients admitted from January 1985 through November 1987 constituted the reference series termed G1. The 104 patients admitted from December 1987 through May 1990 and treated with intravenous Nimodipine constituted the series termed G2. Of the 210 patients, 172 (82%) could be operated on with a similar mean operative delay in both series (G1 = 9.5 days, G2 = 9.8 days). Of the 210 patients, 153 (73%) survived with an average follow-up of 111 weeks for G1 and of 64 weeks for G2. Nimodipine treatment was associated with a significant increase of survival (11.8%, P = 0.05) which was not the result of improved operative technique but of a lower incidence of deaths caused by postoperative vasospasm (G1 = 5 deaths, G2 = 0 deaths, P = 0.05) and by rebleeding (G1 = 15 deaths, G2 = 5 deaths, P = 0.03). No significant difference between the two series G1 and G2 was observed regarding functional results in the 153 survivors, frequency and seriousness of clinical signs of vasospasm during the waiting phase for surgery, radiologic signs of vasospasm on initial and second angiography, cerebral infarctus on second C.T.-Scan. Analysis of temperature curves of the 210 patients revealed that a delayed fever with a plateau pattern was associated with a higher incidence of vasospasm, rebleeding, and deaths.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[Stability of theophylline in mono- and multi-layer parenteral nutrition bags].

The addition of drugs to parenteral nutrition (PN) presents a high risk of physical and chemical incompatibilities. In certain patients with water restriction or limited vein access, however, it may be necessary to add medicines to PN. Although there are numerous studies into the stability of aminophylline in PN, all of them refer to periods of less than 2 days. The purpose of the present study is to determine the stability of anhydrous theophylline over 24 hours at room temperature in 24 hours parenteral nutrition and over five days (four days stored in refrigerator and 24 hours at room temperature). In addition, to assess whether its degradation is affected by the use of single-layer or multi-layer bags. The composition of PN corresponds to a standard 1,800 Kcal diet at our hospital with a concentration of 0.164 mg/ml of anhydrous theophylline. No statistically significant differences were obtained in any of the cases studied, thus demonstrating the stability of theophylline under our study conditions both after 24 hours at room temperature and after four days of storage in the refrigerator followed by 24 hours at room temperature. Nor were differences found between storing the drug in single-layer and multi-layer bags.

Drug Packaging↗
PubMedDate not supplied

["All in one" parenteral nutrition: is it that safe?].

The use of "all in one" admixtures is supported by an extensive number of studies and by many years of experience. However, we detected stability problems in some mixtures whose stability was previously reported. We made modifications in one of these mixtures [composed of 1.000 ml Freamine 8.5%, 100 ml 10% dextrose, 500 ml water, 500 ml Intralipid 20%, 75 ml electrolyte solution (Na 75 mEq, K 60 mEq, Ca 15 mEg, Mg 15 mEq, Cl 90 mEq, acetate 75 mEq)] in order to see how the different components affect the emulsion stability. All the admixtures were visually inspected after storage during 24 hour at room temperature. It was observed that admixtures with low glucose concentration, high electrolyte levels and high volume were less stable than admixtures containing high glucose, low electrolyte and low volume. Amino acid concentration did not increased the stability as expected. MCT/LCT emulsions were more stable than LCT emulsions. More studies are needed to explain the stability problems of these TPN solutions.

Amino Acids↗