Anesthesia and analgesia
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Anesthesia and analgesia · Apr 1993
ReviewCerebral blood flow and metabolism during cardiopulmonary bypass.
Although much has been learned about cerebral physiology during CPB in the past decade, the role of alterations in CBF and CMRO2 during CPB and the unfortunately common occurrence of neuropsychologic injury still is understood incompletely. It is apparent that during CPB temperature, anesthetic depth, CMRO2, and PaCO2 are the major factors that effect CBF. The systemic pressure, pump flow, and flow character (pulsatile versus nonpulsatile) have little influence on CBF within the bounds of usual clinical practice. ⋯ It must be emphasized that not the absolute level of CBF, but the appropriateness of oxygen delivery to demand is paramount. However, the assumption that the control of cerebral oxygen and nutrient supply and demand will prevent neurologic injury during CPB is simplistic. A better understanding of CBF, CMRO2, autoregulation and mechanism(s) of cerebral injury during CPB has lead to a scientific basis for many of the decisions made regarding extracorporeal perfusion.
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Anesthesia and analgesia · Apr 1993
Randomized Controlled Trial Comparative Study Clinical TrialDirect or modified Seldinger guide wire-directed technique for arterial catheter insertion.
Percutaneous radial artery cannulation is widely used for direct continuous arterial blood pressure measurement and sampling of arterial blood. We compared the success rate of arterial catheter placement in patients undergoing aortocoronary bypass operations using the direct and the modified Seldinger techniques. The effects of gender and quality of the pulse were also investigated. ⋯ We conclude that the success rate for cannulation is high in male patients, and patients with a bounding pulse regardless of the use of the direct or guide-wire techniques. The guide wire is recommended as the initial technique for cannulating the radial artery of female patients. In patients with a thready pulse, no significant advantage could be obtained by using a guide wire, but in salvaging an arterial line the guide wire is efficacious.
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Anesthesia and analgesia · Apr 1993
Randomized Controlled Trial Comparative Study Clinical TrialEvaluation of STAT-CRIT hematocrit determination in comparison to Coulter and centrifuge: the effects of isotonic hemodilution and albumin administration.
The accuracy of the STAT-CRIT hematocrit (hct) was compared to Coulter and centrifuge methods in this study of the interrelationship between non-red cell blood constituents and accuracy of conductivity-based hct measurements. In the first part of the study, blood samples from 31 patients undergoing elective cardiac procedures were analyzed at three times: before induction of anesthesia (Time 1), during the rewarming period of cardiopulmonary bypass (CPB) (Time 2), and after transfusion of all cell-saver blood available after termination of CPB (Time 3). Laboratory evaluation included hct using the Stat-Crit, Coulter, and centrifuge methods, and sodium (Na), potassium (K), chloride (Cl), white blood cell count, total protein (TP), and albumin. ⋯ Blood variables having the most significant effect on the Coulter-Stat-Crit difference (bias) were protein, Cl, and Na. Single regression analysis indicated that a 1-g/dL decrease in TP resulted in an absolute decrease in the hct reading by 1 hct% units. A 10-mmol/L change in either Cl or Na concentration resulted in a change in Stat-Crit accuracy of 3.5% and 2.5%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)