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Biomedical subjects

R Orlando

Publications and source records attributed to R Orlando.

At least 145 records · Page 8Linked to original sources

Continuous mixed venous oximetry in critically ill surgical patients. 'High-tech' cost-effectiveness.

Mixed venous oxygen saturation (Svo2) provides a measure of cardiorespiratory ability to meet the body's needs for oxygen. The Svo2 was measured continuously in 20 critically ill surgical patients using a pulmonary-artery oximetry system. The accuracy of the technique was validated by comparing initial continuous Svo2 to the laboratory determination of Svo2. Oximetry was used to guide therapeutic decisions regarding fluid, inotropic agents, vasodilators and ventilator setting and was useful in ten cases. Sepsis developed in nine patients; this severely limited the usefulness of the technique. With clinical decision making based on oximetry, there was a savings per catheter of 2.65 cardiac output determinations and 5.9 venous blood gas determinations, resulting in a net savings per catheter of +75.

Blood Gas Analysis↗

The effect of drugs on bile flow and composition. An overview.

Many drugs are eliminated via the hepatobiliary route, after biotransformation in the liver. Some of them may affect bile flow and/or the hepatic secretion of biliary lipids such as bile acids, cholesterol and phospholipids. Bile acids are the most potent agents which increase bile flow, especially unconjugated bile acids. Other drugs which increase bile flow include phenobarbitone (phenobarbital), theophylline, glucagon and insulin. In contrast, ethacrynic acid, amiloride, ouabain, oestrogens and chlorpromazine are among those agents which decrease bile flow. Biliary bile acid secretion is altered by a variety of drugs, including cheno- and ursodeoxycholic acids (CDCA and UCDA), the bile acid sequestrants cholestyramine and colestipol, and ethinyloestradiol. The composition of bile can also be altered by drug therapy. Thus, clofibrate increases biliary cholesterol secretion, and reduces bile acid concentrations, without altering biliary phospholipid concentrations. However, other clofibrate derivatives may produce changes of a different pattern, suggesting that the risk of developing gallstones may differ for each derivative. Nicotinic acid and d-thyroxine also increase biliary cholesterol saturation, while CDCA and UDCA reduce biliary cholesterol concentration. The potential consequences of drug-induced changes in bile flow and composition extend to the liver, the gallbladder and the intestine. If adverse effects are to be avoided, further study in this often overlooked area is required.

Animals↗

Hepatitis B immunisation with a reduced number of doses in newborn babies and children.

74 healthy babies born to mothers positive for hepatitis B surface antigen (HBsAg) were randomly divided at birth to receive either HB immunoglobulin and 2 doses of HB vaccine 2 months apart, or HB immunoglobulin and 3 doses of HB vaccine 1 month apart. 80 healthy babies born to HBsAg, anti-HBs, and anti-HB core (c) negative mothers were randomly divided at birth to receive either 2 doses of vaccine 2 months apart or 3 doses 1 month apart. The seroconversion rates and the geometric means of anti-HBs titres were lower in both groups of babies given 2 doses of vaccine than in the groups given 3 doses. 60 pairs of children at risk, aged 1 to 12 years and HBsAg, anti-HBs, and anti-HBc negative, were randomly divided to receive either the 2-dose regimen or the 3-dose regimen. The seroconversion rates and the geometric means of anti-HBs titres were satisfactory in both groups.

Child↗

Pharmacokinetics of Josamycin in patients with liver cirrhosis and Gilbert's syndrome after repeated doses.

The pharmacokinetics of Josamycin was studied in 31 subjects (10 normals, 9 Gilbert's syndrome and 12 compensated liver cirrhosis) after the administration of Josamycin (1 g orally) and in 13 subjects (4 normals, 4 Gilbert's syndrome and 5 compensated liver cirrhosis) after 3-day Josamycin treatment (1 g orally every 12 hours). Josamycin pharmacokinetics was impaired in liver cirrhosis and, to a lesser extent, in Gilbert's syndrome. Moreover, in the three groups of individuals studied the drug accumulated after multiple dosing. These results suggest that a dosage adjustment of Josamycin is recommended when dealing with these patients.

Adult↗

Oral and intravenous pharmacokinetics of ranitidine in patients with liver cirrhosis.

The kinetics of p. o. (150 mg) and i.v. (50 mg) ranitidine was studied in nine healthy controls and in nine patients with compensated liver cirrhosis. Plasma concentrations and urinary recovery of unchanged drug were determined by high performance liquid chromatography. The pharmacokinetic data observed in the cirrhotic patients did not differ from those of controls after p.o. or i.v. administration. Moreover, oral bioavailability was similar in controls and cirrhotics. In conclusion, the pharmacokinetics of ranitidine is not altered in patients with compensated liver cirrhosis.

Administration, Oral↗

The pharmacokinetics of H2 receptor blocking agents in compensated liver cirrhosis.

The bioavailability of oral and intravenous cimetidine and ranitidine was studied in patients with compensated liver cirrhosis. Single doses of 200 and 400 mg cimetidine were used for both administration routes, while ranitidine was administered in doses of 150 mg orally or 50 mg i.v. Plasma concentrations and urinary recovery were determined by the HPLC method. The pharmacokinetics of both of these drugs in the cirrhotic patients did not differ from those found in normal subjects. The two doses of cimetidine given i.v. gave rise to the same plasma concentrations, while after oral administration, 400 mg produced higher plasma concentrations than 200 mg. As to the pharmacokinetic parameters, neither cimetidine nor ranitidine administered i.v. offered any further advantages compared to the oral route. The urinary recovery of both cimetidine and ranitidine was higher after intravenous than after oral administration. It is concluded therefore that the pharmacokinetics of cimetidine and ranitidine is not altered in compensated liver cirrhosis.

Administration, Oral↗

Acute acalculous cholecystitis in the critically ill patient.

Nine cases of acute acalculous cholecystitis were diagnosed in the surgical intensive care unit at Hartford Hospital during a 2 year period after abdominal, cardiovascular, and traumatic surgery. A tender mass in the right upper quadrant was suggestive but not diagnostic of the condition. Hyperamylasemia was seen in all patients. Ultrasonography is the most useful diagnostic tool; serial studies reveal progressive gallbladder dilatation and edema. Tube cholecystostomy was used in five patients and cholecystectomy in four. Cholecystostomy led to resolution of the inflammatory process in all five patients. Cholecystectomy should be reserved for those patients with extensive gallbladder necrosis. Six of the nine patients in the series died, all from multiple systems failure with concomitant sepsis. Hypotension is probably central to the development of acute acalculous cholecystitis. In the face of elevated intraluminal gallbladder pressure caused by ampullary edema and increased bile viscosity, hypotension may result in mucosal ischemia and necrosis with subsequent bacterial colonization. Acute acalculous cholecystitis represents another organ failure in critically ill patients who are experiencing progressive failure of multiple organ systems. An aggressive approach to the manifestations of organ failure, including acalculous cholecystitis, must be employed.

Acute Disease↗

Effect of Silybin on biliary lipid composition in rats.

The authors studied the influence of Silybin in rats, administered i.p. for 7 days (daily dose of 100 mg/kg/b.w.) on the biliary lipid composition and on the maximal excretory rate of bile salts. Following this treatment, biliary cholesterol excretion was reduced, while the other lipids and bile flow were not significantly modified. After sodium cholate infusion (1.6 mumol/min/100 g b.w. i.v. for 80 minutes), the Tm of bile salts and bile flow remained unchanged in Silybin pretreated rats. The mechanism by which Silybin treatment reduces cholesterol excretion, is discussed.

Animals↗

Intra-aortic balloon counterpulsation in blunt cardiac injury.

Intra-aortic balloon counterpulsation (IABC) is a widely used form of mechanical circulatory assistance. We have successfully employed IABC in three patients with refractory cardiogenic shock secondary to cardiac contusion. All patients had multiple blunt injuries with cardiac contusion documented electrocardiographically, by CPK isoenzyme determinations, and clinically. IABC was instituted for hypotension refractory to vasoactive drugs and optimization of intravascular volume status. Cardiac output and blood pressure rose in all cases and fewer ventricular arrhythmias were noted. Discontinuation of IABC was possible within 48 hours in all cases with adequate cardiac performance. We conclude that IABC is a useful approach in the treatment of refractory cardiogenic shock associated with cardiac contusion.

Accidents↗

Gastric lymphoma: a clinicopathologic reappraisal.

Histologic material from 42 cases diagnosed as gastric lymphoma at Hartford Hospital was reviewed, confirming the diagnosis in 37. Three cases of pseudolymphoma were found. The incidence of gastric lymphoma has increased steadily over the past 50 years: 35 percent of cases occurred during the past decade. Most patients with gastric lymphoma are in the seventh or eighth decade of life. Resection offered the best chance for long-term survival, either alone or with radiation therapy. Nodal status was correlated with length of survival of survival; 60 percent of patients with negative nodes survived 5 years or more. Cases were classified according to the Rappaport classification and the Working Formulation of Non-Hodgkin's Lymphomas. The formulation was more useful than the Rappaport classification in assessing prognosis in various types of lymphoma and better reflects our current understanding of neoplasms of the lymphoid system.

Adult↗

Parathyroid cysts.

Fourteen new cases of parathyroid cyst are presented. Two distinct groups were identified: functioning and nonfunctioning. Patients with functioning cysts presented with hypercalcemia, tended to be men and were older. Patients with nonfunctioning cysts were all women, had normocalcemia and all presented with neck masses. Ultrasonography proved useful while radionuclide thyroid scans were often misleading. In the functioning group removal of parathyroid cysts resulted in postoperative normocalcemia in all cases. In the nonfunctioning cysts thyroid lobectomy was performed in five of six instances. Parathyroid cysts usually contain clear or serous fluid and are surrounded by a well-delineated plane of dissection. We believe that preoperative aspiration of cystic neck masses and consideration of the diagnosis of parathyroid cysts may avoid needless thyroid lobectomy.

Adenoma↗

Pharmacokinetic studies of cefuroxime in patients with liver cirrhosis.

Blood levels and urinary excretion of 6R,7R-3-carbamoyloxy-methyl-7-(2Z)-2-methoxyimino-(fur-2-yl)-acetamido-ceph-3-em-4-carboxylate sodium salt (cefuroxime) were determined in cirrhotic patients without ascites and in healthy volunteers after an i.m. injection of 750 mg and an i.v. injection of 1 g. An average peak serum level of 23.9 micrograms/ml in the case of cirrhotic patients and 22.5 micrograms/ml in the case of volunteers was reached 0.5 h after the i.m. dose, followed by a gradual decrease. An average serum level of 78.8 micrograms/ml in the case of cirrhotic patients was obtained 5 min after i.v. injection. During the first 6 h after administration of the 750 mg i.m. dose and the first 4 h after the administration of the 1 g i.v. dose, 90% of the administered dose were excreted in the urine, in the case of both cirrhotic patients and volunteers. These results show that the pharmacokinetic features of cefuroxime are not affected in cirrhotic patients without ascites; therefore the antibiotic is particularly suitable for acute infections in hospital, and also for cirrhotic patients without ascites without any difference in the dosage.

Adult↗