A comparative study of sodium bicarbonate and carbicarb in the treatment of metabolic acidosis induced by Hemorrhagic Shock

“Carbicarb” (CBC; International Medication Systems, South El Monte, CA) is a new alkalinizing agent composed of equimolar NaHCO₃ and NasCO₃, each salt mol/L in concentration. We compared CBC with 1 mol/L NaHCO₃ in the treatment of lactic acidosis in dogs with hemorrhagic shock. Carbon dioxide excretion from the lungs (CO₂ output), along with arterial and mixed venous PCO₂, increased significantly less with CBC than with NaHCO₃ for 30 minutes following therapy. Arterial pH increased more with CBC than with NaHCO₃ for the first five minutes of therapy. Both alkaline solutions produced increases in mean arterial pressure, cardiac output, oxygen delivery, and oxygen consumption. These increases were not significantly different for the two solutions. CBC injection did not result in any damage to RBCs or to the endothelium of peripheral veins.     

Individual differences in psychotic effects of ketamine are predicted by brain function measured under placebo

The symptoms of major psychotic illness are diverse and vary widely across individuals. Furthermore, the prepsychotic phase is indistinct, providing little indication of the precise pattern of symptoms that may subsequently emerge. Likewise, although in some individuals who have affected family members the occurrence of disease may be predicted, the specific symptom profile may not. An important question, therefore, is whether predictive physiological markers of symptom expression can be identified. We conducted a placebo-controlled, within-subjects study in healthy individuals to investigate whether individual variability in baseline physiology, as assessed using functional magnetic resonance imaging, predicted psychosis elicited by the psychotomimetic drug ketamine and whether physiological change under drug reproduced those reported in patients. Here we show that brain responses to cognitive task demands under placebo predict the expression of psychotic phenomena after drug administration. Frontothalamic responses to a working memory task were associated with the tendency of subjects to experience negative symptoms under ketamine. Bilateral frontal responses to an attention task were also predictive of negative symptoms. Frontotemporal activations during language processing tasks were predictive of thought disorder and auditory illusory experiences. A subpsychotic dose of ketamine administered during a second scanning session resulted in increased basal ganglia and thalamic activation during the working memory task, paralleling previous reports in patients with schizophrenia. These results demonstrate precise and predictive brain markers for individual profiles of vulnerability to drug-induced psychosis.     

Cytochrome oxidase deficiency in Alzheimer's disease

We assayed cytochrome oxidase and other electron transport chain activities in platelet mitochondria isolated from patients with Alzheimer's disease (AD). Five of 6 patients had striking reductions of platelet cytochrome oxidase activity (patient mean, 83.72 +/- 82.99 nmol/min/mg; control mean, 167.14 +/- 36.21 nmol/min/mg; n = 8). Other electron transport chain catalytic activities were not significantly different than control values. AD may be a systemic illness, a primary defect in cytochrome oxidase may be pathogenically important in its production, and the mitochondrial genes encoding cytochrome oxidase subunits may be important in producing the defect.     

Neurologic sequelae of chronic solvent vapor abuse

Neurologic abnormalities were seen in 13 of 20 patients with a history of chronic solvent vapor (primarily toluene) abuse for 2 or more years. The patients were evaluated after an abstinence period of at least 4 weeks, to avoid neurologic effects of acute intoxication. Neurologic signs included cognitive (60%), pyramidal (50%), cerebellar (45%), and brainstem/cranial nerve (25%) findings. Eight of nine CTs revealed diffuse atrophy of cerebral hemispheres, cerebellum, and brainstem. BAERs were abnormal in three of four patients, and EEG abnormalities were seen in three of seven patients. Chronic exposure to solvent vapor may cause persistent neurologic impairment.     

Carbicarb: an effective substitute for NaHCO3 for the treatment of acidosis

Carbicarb (Na2CO3 0.33 molar NaHCO3 0.33 molar), a mixture formulated to avoid the objections to sodium bicarbonate therapy, has been compared with 1 mol/L NaHCO3 and 1 mol/L NaCl in the treatment of mixed respiratory and metabolic acidosis (pH 7.17) produced by asphyxia in rats. In clinically appropriate doses, intravenous NaHCO3 raised arterial pH only 0.03 unit, elevated arterial carbon dioxide pressure, and doubled lactate concentration. With Carbicarb, the pH rise was three times as great and the blood lactate level was unchanged. The new drug should be effective in treating the acidosis of cardiopulmonary failure without raising blood carbon dioxide pressure or lactate levels and at lower sodium doses than required for NaHCO3.