The Responsiveness of Cerebral Blood Flow to Changes in Arterial Carbon Dioxide Is Maintained during Propofol–Nitrous Oxide Anesthesia in Humans

Fox, James R.; Gelb, Adrian W.; Enns, Justine P; Murkin, John M.; Farrar, J. K.; Manninen, Pirjo

doi:10.1097/00000542-199209000-00008

Cited by 87 publications

(50 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…10,23,24 Matta et al 23 examined cerebral CO 2 reactivity using TCD during propofol-induced electrical silence of the electroencephalogram in 10 patients undergoing anesthesia for nonneurosurgical procedures (mean age, 37 years) and found that cerebral CO 2 reactivity remained intact during propofol anesthesia. Fox et al 24 reported in 7 patients undergoing elective gynecologic or orthopedic surgery (mean age, 40.5Ϯ7 years) that the slope of the CBF-CO 2 response measured by the 133 Xe-inhalation method was similar to that found in awake individuals and during propofol-nitrous oxide anesthesia. Myburgh et al 22 reported in sheep (nϭ6) that the mean slopes of the CO 2 reactivity curves in the sagittal sinus measured by a Doppler probe did not differ between awake conditions and propofol anesthesia.…”

Section: Study Limitationsmentioning

confidence: 99%

Diabetic Patients Have an Impaired Cerebral Vasodilatory Response to Hypercapnia Under Propofol Anesthesia

Kikuchi

Hara

Kunimoto

et al. 2003

Stroke

View full text Add to dashboard Cite

Background and Purpose-The purpose of this study was to examine the effects of diabetes mellitus and its severity on the cerebral vasodilatory response to hypercapnia. Methods-Thirty diabetic patients consecutively scheduled for elective major surgery were studied. After induction of anesthesia, a 2.5-MHz pulsed transcranial Doppler probe was attached to the patient's head at the right temporal window, and mean blood flow velocity of the middle cerebral artery (Vmca) was measured continuously. After the baseline Vmca, arterial blood gases, and cardiovascular hemodynamic values were measured, end-tidal CO 2 was increased by reducing ventilatory frequency by 2 to 5 breaths per minute. Measurements were repeated when end-tidal CO 2 increased and remained stable for 5 to 10 minutes. Results-Significant differences were observed in absolute and relative CO 2 reactivity between the diabetes and control groups (absolute CO 2 reactivity: control, 2.8Ϯ0.7; diabetes mellitus, 2.1Ϯ1.3; PϽ0.01; relative CO 2 reactivity: control, 6.3Ϯ1.4; diabetes mellitus, 4.5Ϯ2.7; PϽ0.01, Mann-Whitney U test). Significant differences were also found between diabetic patients with retinopathy and those without retinopathy in absolute (Pϭ0.002) and relative (Pϭ0.002) CO 2 reactivity, glycosylated hemoglobin (Pϭ0.0034), and fasting blood sugar (Pϭ0.01) (Scheffé's test, Mann-Whitney U test). There was an inverse correlation between absolute CO 2 reactivity and glycosylated hemoglobin (rϭ0.69, PϽ0.001). Conclusions-Insulin-dependent diabetic patients have an impaired vasodilatory response to hypercapnia compared with that of the control group, and the present findings suggest that their degree of impairment is related to the severity of diabetes mellitus.

show abstract

Section: Study Limitationsmentioning

confidence: 99%

Diabetic Patients Have an Impaired Cerebral Vasodilatory Response to Hypercapnia Under Propofol Anesthesia

Kikuchi

Hara

Kunimoto

et al. 2003

Stroke

View full text Add to dashboard Cite

show abstract

“…The narrow limits were selected to allow calculated values to be interpolated rather than extrapolated, and because normal individuals show a CO 2 response curve that is linear within these limits. 17 All results described are median values and interquartile ranges. Comparisons were made using the Mann-Whitney U test for nonparametric data, with P Յ .05 considered significant.…”

Section: The Reactivity Of the Cerebral Vasculature To Changes In Artmentioning

confidence: 99%

Cerebral blood flow and metabolism in patients with chronic liver disease undergoing orthotopic liver transplantation

et al. 1998

View full text Add to dashboard Cite

Changes in cerebral hemodynamics and metabolism associated with anesthesia and liver transplantation may present particular hazards for patients with cirrhosis. Fifteen patients undergoing liver transplantation were studied, 7 of whom had encephalopathy. Cerebral blood flow (CBF) was measured at the start of surgery, during venovenous bypass and post reperfusion, using a method based on the Kety-Schmidt method. Cerebral metabolism was assessed by measuring the cerebral metabolic rate for oxygen (CMRO 2 ) and the lactate oxygen index (LOI). The cerebral vascular reactivity to carbon dioxide (CO 2 ) was studied during the preanhepatic and post reperfusion phases. During the preanhepatic period, the median CBF was 44 mL/100 g/min at an arterial carbon dioxide tension (PaCO 2 ) of 3.8 kPa. After reperfusion the CBF increased (P F .02) to 102 mL/100 g/min, the arterial hydrogen ion concentration increased from 39 nmol/L to 53 nmol/L (P F .02) and the jugular venous oxygen saturation from 74% to 89% (P F .02). CBF was similar in patients with and without encephalopathy. The cerebral vascular reactivity to CO 2 remained intact, although after reperfusion, the CBF for a given PaCO 2 was greater, and the slope of the CBF/CO 2 response curve diminished. The CMRO 2 was normal in patients without encephalopathy. In the encephalopathic patients, the CMRO 2 was low during all stages of transplantation (0.54, 0.86, 1.24 mL/100 g/min, respectively). Patients with encephalopathy may be at increased risk of hypoxemic brain injury during transplantation. To minimize this possibility, more detailed neurological monitoring may be useful. (HEPATOLOGY 1998;27:369-376.)

show abstract

“…Under N 2 O anesthesia, rCBF responses to pCO 2 changes or behavioral or pharmacological stimuli remain intact (Fox et al, 1992;Yaster et al, 1994). N 2 O was chosen because other anesthetics affect metabolic or flow responses to dopaminergics McCulloch, 1981, 1983).…”

Section: Discussionmentioning

confidence: 99%

PET Measurement of Dopamine D₂Receptor-Mediated Changes in Striatopallidal Function

1997

View full text Add to dashboard Cite

This study was designed to validate an in vivo measurement of the functional sensitivity of basal ganglia neuronal circuits containing dopamine D 2 receptors. We hypothesized that a D 2 agonist would decrease striatopallidal neuronal activity, and hence regional cerebral blood flow (rCBF) over the axon terminals in the globus pallidus. Quantitative pallidal blood flow was measured using positron emission tomography (PET) with bolus injections of H 2 15 O and arterial sampling in six baboons before and after intravenous administration of the selective D 2 agonist U91356a. We also tested whether the response to U91356a was modified by previous acute administration of various antagonists. Another baboon had serial measurements of blood flow under identical conditions, but received no dopaminergic drugs. In all animals that received U91356a, pallidal flow decreased in a dose-related manner. Global CBF had a similar response, but the decline in pallidal flow was greater in magnitude and remained significant after accounting for the global effect. A D 2 antagonist, but not antagonists of D 1 , serotonin-2, or peripheral D 2 receptors, prevented this decrease. This work demonstrates and validates an in vivo measure of the sensitivity of D 2 -mediated basal ganglia pathways. It also supports the hypothesis that activation of the indirect striatopallidal pathway, previously demonstrated using nonselective D 2 -like agonists, can be mediated specifically by D 2 receptors. We speculate that the U91356a-PET technique may prove useful in detecting functional abnormalities of D 2 -mediated dopaminergic function in diseases such as parkinsonism, dystonia, Tourette syndrome, or schizophrenia.

show abstract

The Responsiveness of Cerebral Blood Flow to Changes in Arterial Carbon Dioxide Is Maintained during Propofol–Nitrous Oxide Anesthesia in Humans

Cited by 87 publications

References 0 publications

Diabetic Patients Have an Impaired Cerebral Vasodilatory Response to Hypercapnia Under Propofol Anesthesia

Diabetic Patients Have an Impaired Cerebral Vasodilatory Response to Hypercapnia Under Propofol Anesthesia

Cerebral blood flow and metabolism in patients with chronic liver disease undergoing orthotopic liver transplantation

PET Measurement of Dopamine D₂Receptor-Mediated Changes in Striatopallidal Function

Contact Info

Product

Resources

About

The Responsiveness of Cerebral Blood Flow to Changes in Arterial Carbon Dioxide Is Maintained during Propofol–Nitrous Oxide Anesthesia in Humans

Cited by 87 publications

References 0 publications

Diabetic Patients Have an Impaired Cerebral Vasodilatory Response to Hypercapnia Under Propofol Anesthesia

Diabetic Patients Have an Impaired Cerebral Vasodilatory Response to Hypercapnia Under Propofol Anesthesia

Cerebral blood flow and metabolism in patients with chronic liver disease undergoing orthotopic liver transplantation

PET Measurement of Dopamine D2Receptor-Mediated Changes in Striatopallidal Function

Contact Info

Product

Resources

About

PET Measurement of Dopamine D₂Receptor-Mediated Changes in Striatopallidal Function