Biomedical subjects

F Béïque

Publications and source records attributed to F Béïque.

3 recordsLinked to original sources

PubMed1996

Changes in PCO2 with acute changes in cardiac index.

PURPOSE: A direct relationship between cardiac index (CI) and end-tidal PCO2 (PETCO2) shortly after decreased CI was reported, but arterial PCO2 was not measured. Our purpose was to supply the missing information on the immediate effects of alterations in CI on PaCO2, PETCO2 and thus on Pa-PETCO2. METHODS: We measured CI, Pa and PETCO2 and calculated the difference in 20 patients scheduled for elective heart surgery just before and immediately after the sternotomy. The measurements were made using standard methods: thermodilution for CI, infra-red and blood gas analysis for PET and PaCO2 respectively. The results were analyzed by linear regression. RESULTS: Very significant, direct and immediate changes in PET and PaCO2 with changes in CI were noted. The ratios were 3.8 and 4.2 mmHg L-1 respectively. The calculated values of r were 0.75 (P < 0.001) for PETCO2 and 0.64 (P < 0.005) for PaCO2. The magnitude of individual change in PCO2 varied considerably such that the alterations in Pa-PETCO2 were also variable, without any correlation with the direction or magnitude of change in CI. CONCLUSION: Our results explain the reported wide variations in Pa-PETCO2 that accompany perturbations of cardiac output. Our observations pertain to the unsteady state only. The results suggest that PETCO2 can be used to estimate changes in CI with a reasonable degree of confidence.

Adult↗

PubMed1996

An introduction to transoesophageal echocardiography: I. Basic principles.

PURPOSE: The purpose of this review is to introduce the uninitiated to transoesophageal echocardiography (TEE): how it works, and what it can do. Sufficient detail is provided to serve as a reference guide to anaesthetists already using TEE in clinical practice. SOURCE: A Medline search of English language literature up to and including August 1995 was conducted using the key words echocardiography and TEE. Reference echocardiography textbooks were also utilized in the preparation of this review. PRINCIPLE FINDINGS: All information available from TEE is derived from either cardiac imaging or analysis of blood flow velocity using various Doppler modes. To understand the diagnostic capabilities of TEE we review clinically useful views of the heart as well as modes of cardiac imaging. Sufficient basic physics is presented to allow proper use of adjustment features on the echocardiography machine so that cardiac imaging can be optimized. Available Doppler modes are explained along with an overview of their clinical applications. Figures illustrating clinically useful views obtainable with omniplane TEE are included along with colour prints demonstrating clinical applications of colour flow Doppler. CONCLUSION: TEE is becoming increasingly important in the management of cardiac patients for cardiac and non-cardiac surgery. An understanding of the capabilities of the technology as well as the underlying physics allows the anaesthetist to glean the most information from this valuable technique, both quantitatively and qualitatively.

Blood Flow Velocity↗

PubMed1995

Cardiopulmonary function and laparoscopic cholecystectomy.

This review analyzes the literature dealing with cardiopulmonary function during and pulmonary function following laparoscopic cholecystectomy in order to describe the patterns of changes in these functions and the mechanisms involved as well as to identify areas of concern and lacunae in our knowledge. Information was obtained from a Medline literature search and the annual meeting supplements of Anesthesiology, Anesth Analg, Br J Anaesth, and Can J Anaesth. The principal findings were that changes in cardiovascular function due to the insufflation are characterized by an immediate decrease in cardiac index and an increase in mean arterial blood pressure and systemic vascular resistance. In the next few minutes there is partial restoration of cardiac index and resistance but blood pressure and heart rate do not change. The pattern is the result of the interaction between increased abdominal pressure, neurohumoral responses and absorbed CO2. Pulmonary function changes are characterized by reduced compliance without large alterations in PaO2, but tissue oxygenation can be adversely affected due to reduced O2 delivery. A major difficulty in maintaining normocarbia is due to the abdominal distention reducing pulmonary compliance and to CO2 absorption. End tidal CO2 tension is not a reliable index of PaCO2, particularly in ASA III-IV patients. The pattern of lung function following LC is characterized by a transient reduction in lung volumes and capacities with a restrictive breathing pattern and the loss of the abdominal contribution to breathing. Atelectasis also occurs. These changes are qualitatively similar to but of a lesser magnitude than those following "open" abdominal operations. It is concluded that the changes in cardiopulmonary function during laparoscopic upper abdominal surgery lead us to suggest judicious invasive monitoring and careful interpretation in ASA III-IV patients. Lung function following extensive procedures in sick patients has not been reported.

Blood Pressure↗