Search PubMed⌕ Search

Biomedical subjects

W S Howland

Publications and source records attributed to W S Howland.

At least 55 records · Page 3Linked to original sources
PubMed1976

Factors influencing the ionization of calcium during major surgical procedures.

The existence of a clinically feasible calcium electrode makes it possible to obtain rapid, accurate levels of ionized calcium. It is now possible to study the actual ionization of calcium under normal and abnormal physiologic conditions. The present investigation was directed at changes in ionized calcium during major surgical procedures. The total series of 125 patients was divided into three groups according to the type of plasma volume expander: group 1, whole blood alone; group 2, whole blood plus exogenous albumin, and group 3, albumin alone. Ionized calcium levels dropped significantly, p less than 0.001, in all three groups. Although albumin alone produced a decrease in ionized calcium, the addition of albumin to whole blood did not result in a greater decline than that experienced with whole blood alone. Chelation with the citrate ion of bank blood preservative was the major factor responsible for the decrease in ionized calcium. There was no statistically significant relationship between the extent of the decrease, the total volume of blood, the volume of blood per kilogram of the rate of transfusion in milliliters per kilogram per minute. Although the ionized calcium level fell initially, it increased while blood administration continued. In view of these facts, it is difficult to estimate the acutal level of ionized calcium at any point during the operation. Twenty patients in the series had ionized calcium levels below 1.25 milliequivalents per liter, range of 0.51 to 1.24 milliequivalents per liter. With the possible exception of one patient, no adverse cardiovascular effects could be attributed to the low levels of ionized calcium. The results in this series confirm our previous conclusion that the administration of exogenous calcium is not necessary during massive transfusion, with the possible exception of bypass open heart procedures and exchange transfusions in children.

Adolescent↗
PubMed1976

Colloid oncotic pressure and levels of albumin and total protein during major surgical procedures.

From the results of this study, it appears that whole blood alone or red blood cells reconstituted with saline solution do not adequately replace the loss of albumin and concomitant decrease in colloid oncotic pressure that occur during extensive intraabdominal and intrathoracic operations. Since colloid oncotic pressure is a major factor in the restitution of intravascular volume from stores of interstitial fluid and since it may also play a role in the development of postoperative pulmonary problems, it is important to maintain a relatively normal colloid oncotic pressure during the operation and in the immediate postoperative period. Although dextran can be used for this purpose, its short half-life of four to six hours and associated coagulation problems militate against its use in large quantities. This leaves purified protein fraction or salt-poor albumin as the main sources of protein for the maintenance of colloid oncotic pressure. Both of these products are expensive and short in supply. The oncometer in present use is a clinically feasible and rapid, one to three minutes, means of determining the colloid oncotic pressure. It permits a rational approach to the use of albumin products, avoiding the pitfalls of under or excess administration in the operative and postoperative periods.

Abdomen↗
PubMed1975

Intraoperative physiologic monitoring and management during hepatic lobectomy using the liver isolation-perfusion technic.

The high operative mortality of major hepatic resection for tumor can be improved by a technic of resection using complete vascular isolation and hypothermic perfusion of the liver. Complete clamping of the portal vein, vena cava, and hepatic artery was necessary and well tolerated. Major physiologic, biochemical, and coagulation changes, however, can occur with this technic that requires close monitoring by the anesthesiologist. With astute observation and prompt corrective measures when indicated, these changes can be minimized to enable a safe and smooth resection to be carried out.

Acid-Base Equilibrium↗
PubMed1974

Major hepatic resection using vascular isolation and hypothermic perfusion.

The technique and results of 29 major hepatic resections using the method of complete vascular isolation and hypothermic perfusion of the liver are reported. The method enables the surgeon to perform otherwise difficult or impossible resections through chilled bloodless hepatic parenchyma. Major intrahepatic vascular structures can thus be recognized and controlled readily under clear vision. Direct neoplastic involvement of, or tumor thrombi in the portal vein, hepatic vein or vena cava, can be successfully dealt with by appropriate surgical measures. The operative mortality was 10.3% for this series which included many tumors previously deemed unresectable. The technical detail and intraoperative physiologic monitoring crucial to success in the use of the method are described. It is hoped that with the widened scope of resectability afforded by this technique, and the use of adjuvant chemotherapy, the currently experienced low cure rates for hepatic cancer can be improved.

Cyclophosphamide↗
PubMed1972

Hemorrhagic shock.

Explore the source record for details and available documents.

Acid-Base Equilibrium↗
PubMed1972

Septic shock.

Explore the source record for details and available documents.

Adenosine Triphosphate↗