Randall Cork - Academia.edu (original) (raw)
Papers by Randall Cork
The Internet Journal of Neurology
Voltage-actuated sensory nerve conduction threshold (V-sNCT) is a quantitative test of sensory fu... more Voltage-actuated sensory nerve conduction threshold (V-sNCT) is a quantitative test of sensory function. This study compares the sensitivity, specificity, and predictive value of V-sNCT compared to physical examination for the presence of nerve-root adhesions visible on epidurogram. Predicted abnormal nerve roots by V-sNCT and/or physical examination were compared with abnormal nerve roots documented by abnormal epidurogram in forty-nine patients with L5/S1 radicular back pain. Sensitivity, specificity, and predictive value for V-sNCT predicting nerve root pathology were 94.6%, 70.2%, and 91.0%, respectively, compared to 61.7%, 72.3%, and 87.6%, respectively, for prediction by physical examination alone. In addition, area under ROC Curve and relative risk for V-sNCT were significantly more predictive of nerve-root pathology than physical examination (p<0.05). Prediction of abnormal nerve-root pathology with V-sNCT is superior to prediction from neurological examination.
Anesth Analg, 1981
Covalent binding of fluorinated anesthetic metabolites was measured using intraoperative liver bi... more Covalent binding of fluorinated anesthetic metabolites was measured using intraoperative liver biopsies obtained from 48 morbidly obese patients randomly assigned to receive N2O-O2 combined with either fentanyl, enflurane, or halothane. No difference in binding was found between anesthetic groups. In addition, preoperative and postoperative levels of serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) did not differ among three groups of patients. However, hepatic organic fluoride binding significantly correlated with peak serum ionic fluoride in patients given halothane (p 0.001, r = 0.68). Thus, the fluorinated metabolites binding assay is a reliable index of reductive halothane metabolism. Possible application of this assay to aid in the diagnosis of postoperative liver dysfunction is suggested.
Journal of Clinical Monitoring and Computing, Oct 1, 1991
Accurate hemodynamic monitoring is essential for the clinical management of the recipient of a to... more Accurate hemodynamic monitoring is essential for the clinical management of the recipient of a total artificial heart (TAH). The high incidence of pulmonary congestive disorders in this population complicates this already formidable task. Lack of diagnostic pulmonary artery pressure (PAP) information is recognized as a fundamental source of these problems. Because conventional methods of obtaining hemodynamic information are difficult to implement in TAH recipients, improvement of TAH case management depends on the development of innovative monitoring strategies. Noninvasive monitoring techniques have been developed for three (right atrial pressure, left atrial pressure, and aortic pressure) of the four auxiliary circulatory pressures used to quantify hemodynamic performance. Development of the fourth, for PAP, was the subject of this work. We developed a noninvasive, in vitro method of estimating mean PAP in the Jarvik-7 TAH (Symbion, Inc, Salt Lake City, UT) recipient. This information was obtained by analyzing the relationship between the pneumatic right drive pressure (RDP) and PAP waveforms produced by a Jarvik-7 (70 ml) connected to a Donovan mock circulation and driven by a Utahdrive System IIIe Controller (Symbion, Inc, Salt Lake City, UT). Total artificial heart driver parameters (i.e., heart rate, percent systole, and vacuum) were manipulated to produce a range of ventricular filling volumes (FV), from 40 to 60 ml, for three distinct states of the pulmonary vasculature: hypotensive, normal, and hypertensive. A unique multiple-linear regression equation was derived for each FV from the RDP-PAP relationship exhibited under these conditions. Comparison of computed estimates of PAP with actual measurements showed overall average correlations of greater than 0.92, with a standard error of the estimate of less than 1.9 mm Hg. The mean difference between actual and computed PAP measurements was -0.03 +/- 2.0 Hg. Estimations were accurate within 8.5% of true PAP values. Additional experimentation revealed that while the RDP-PAP relationships are dependent on FV, they are independent of the manner in which FV was obtained. Estimates proved useful over the clinical operating range of the pneumatic heart driver, as well as over the normal physiologic range of PAP in the human. This method is readily applicable to a computer-based monitoring implementation, although its effectiveness needs to be demonstrated in vivo.
Anesthesiology, 1985
Sufentanil and its two primary metabolites, N-(4-[methoxymethyl]-4-piperidinyl)-N-phenyl propanam... more Sufentanil and its two primary metabolites, N-(4-[methoxymethyl]-4-piperidinyl)-N-phenyl propanamide (MPPP), and N-(4[hydroxymethyl]-1-[2-thienylethyl]-4-piperidinyl)-N-phenyl propanamide (desmethyl sufentanil), were detected by capillary gas chromatography with a nitrogen-phosphorous detector. The detection limit for sufentanil and its metabolites is 30-50 pg/ml with minimal interfering substances in the chromatograms. This method allowed for the detection of serum sufentanil in the terminal elimination phase of sufentanil in a patient receiving 1.5 micrograms/kg and will allow for studies to determine the pharmacokinetics and metabolism of sufentanil in a wide variety of patient groups now receiving this agent.
Cork RC, Ferguson D, Echavarria G, Wang H, Ligeti A, Waterman C, Rao A, Holder D, Cassingham S, Z... more Cork RC, Ferguson D, Echavarria G, Wang H, Ligeti A, Waterman C, Rao A, Holder D, Cassingham S, Zavisca F. Comparison between AC-GME review for general surgery and internal medicine in assigment of program cycle length. ... Comparison between ACGME Review ...
Baillière's Clinical Anaesthesiology, 1995
Encyclopedia of Medical Devices and Instrumentation, 2006
The Journal of the Louisiana State Medical Society : official organ of the Louisiana State Medical Society
The Internet Journal of Neurology
Voltage-actuated sensory nerve conduction threshold (V-sNCT) is a quantitative test of sensory fu... more Voltage-actuated sensory nerve conduction threshold (V-sNCT) is a quantitative test of sensory function. This study compares the sensitivity, specificity, and predictive value of V-sNCT compared to physical examination for the presence of nerve-root adhesions visible on epidurogram. Predicted abnormal nerve roots by V-sNCT and/or physical examination were compared with abnormal nerve roots documented by abnormal epidurogram in forty-nine patients with L5/S1 radicular back pain. Sensitivity, specificity, and predictive value for V-sNCT predicting nerve root pathology were 94.6%, 70.2%, and 91.0%, respectively, compared to 61.7%, 72.3%, and 87.6%, respectively, for prediction by physical examination alone. In addition, area under ROC Curve and relative risk for V-sNCT were significantly more predictive of nerve-root pathology than physical examination (p<0.05). Prediction of abnormal nerve-root pathology with V-sNCT is superior to prediction from neurological examination.
Anesth Analg, 1981
Covalent binding of fluorinated anesthetic metabolites was measured using intraoperative liver bi... more Covalent binding of fluorinated anesthetic metabolites was measured using intraoperative liver biopsies obtained from 48 morbidly obese patients randomly assigned to receive N2O-O2 combined with either fentanyl, enflurane, or halothane. No difference in binding was found between anesthetic groups. In addition, preoperative and postoperative levels of serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) did not differ among three groups of patients. However, hepatic organic fluoride binding significantly correlated with peak serum ionic fluoride in patients given halothane (p 0.001, r = 0.68). Thus, the fluorinated metabolites binding assay is a reliable index of reductive halothane metabolism. Possible application of this assay to aid in the diagnosis of postoperative liver dysfunction is suggested.
Journal of Clinical Monitoring and Computing, Oct 1, 1991
Accurate hemodynamic monitoring is essential for the clinical management of the recipient of a to... more Accurate hemodynamic monitoring is essential for the clinical management of the recipient of a total artificial heart (TAH). The high incidence of pulmonary congestive disorders in this population complicates this already formidable task. Lack of diagnostic pulmonary artery pressure (PAP) information is recognized as a fundamental source of these problems. Because conventional methods of obtaining hemodynamic information are difficult to implement in TAH recipients, improvement of TAH case management depends on the development of innovative monitoring strategies. Noninvasive monitoring techniques have been developed for three (right atrial pressure, left atrial pressure, and aortic pressure) of the four auxiliary circulatory pressures used to quantify hemodynamic performance. Development of the fourth, for PAP, was the subject of this work. We developed a noninvasive, in vitro method of estimating mean PAP in the Jarvik-7 TAH (Symbion, Inc, Salt Lake City, UT) recipient. This information was obtained by analyzing the relationship between the pneumatic right drive pressure (RDP) and PAP waveforms produced by a Jarvik-7 (70 ml) connected to a Donovan mock circulation and driven by a Utahdrive System IIIe Controller (Symbion, Inc, Salt Lake City, UT). Total artificial heart driver parameters (i.e., heart rate, percent systole, and vacuum) were manipulated to produce a range of ventricular filling volumes (FV), from 40 to 60 ml, for three distinct states of the pulmonary vasculature: hypotensive, normal, and hypertensive. A unique multiple-linear regression equation was derived for each FV from the RDP-PAP relationship exhibited under these conditions. Comparison of computed estimates of PAP with actual measurements showed overall average correlations of greater than 0.92, with a standard error of the estimate of less than 1.9 mm Hg. The mean difference between actual and computed PAP measurements was -0.03 +/- 2.0 Hg. Estimations were accurate within 8.5% of true PAP values. Additional experimentation revealed that while the RDP-PAP relationships are dependent on FV, they are independent of the manner in which FV was obtained. Estimates proved useful over the clinical operating range of the pneumatic heart driver, as well as over the normal physiologic range of PAP in the human. This method is readily applicable to a computer-based monitoring implementation, although its effectiveness needs to be demonstrated in vivo.
Anesthesiology, 1985
Sufentanil and its two primary metabolites, N-(4-[methoxymethyl]-4-piperidinyl)-N-phenyl propanam... more Sufentanil and its two primary metabolites, N-(4-[methoxymethyl]-4-piperidinyl)-N-phenyl propanamide (MPPP), and N-(4[hydroxymethyl]-1-[2-thienylethyl]-4-piperidinyl)-N-phenyl propanamide (desmethyl sufentanil), were detected by capillary gas chromatography with a nitrogen-phosphorous detector. The detection limit for sufentanil and its metabolites is 30-50 pg/ml with minimal interfering substances in the chromatograms. This method allowed for the detection of serum sufentanil in the terminal elimination phase of sufentanil in a patient receiving 1.5 micrograms/kg and will allow for studies to determine the pharmacokinetics and metabolism of sufentanil in a wide variety of patient groups now receiving this agent.
Cork RC, Ferguson D, Echavarria G, Wang H, Ligeti A, Waterman C, Rao A, Holder D, Cassingham S, Z... more Cork RC, Ferguson D, Echavarria G, Wang H, Ligeti A, Waterman C, Rao A, Holder D, Cassingham S, Zavisca F. Comparison between AC-GME review for general surgery and internal medicine in assigment of program cycle length. ... Comparison between ACGME Review ...
Baillière's Clinical Anaesthesiology, 1995
Encyclopedia of Medical Devices and Instrumentation, 2006
The Journal of the Louisiana State Medical Society : official organ of the Louisiana State Medical Society