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Biomedical subjects

R L Applegate

Publications and source records attributed to R L Applegate.

6 recordsLinked to original sources
PubMed1996

Effect of oncotic pressure of diaspirin cross-linked hemoglobin (DCLHb) on brain injury after temporary focal cerebral ischemia in rats.

Previous studies have shown that diaspirin cross-linked hemoglobin (DCLHb, 10 g/dL) decreases cerebral ischemia and the resultant injury in a dose-dependent manner, requiring large volumes of DCLHb for maximum efficacy. We assessed the effect of a more concentrated (20 g/dL) and more hyperoncotic preparation of DCLHb on cerebral infarction volume. Immediately after middle cerebral artery occlusion, rats were randomized to one of the following groups: Control, hematocrit not manipulated; 10/Hb, hematocrit decreased to 30% with 10% DCLHb (oncotic pressure 43 mm Hg); 7.5/Alb, hematocrit decreased to 30% with 7.5% albumin (oncotic pressure 43 mm Hg); 20/Hb, the same dose of DCLHb (20%, oncotic pressure 129 mm Hg) as the 10/HB group (half the volume); or 15/Alb, the same dose of albumin (15%, oncotic pressure 130 mm Hg) as the 7.5/Alb group half the volume). After 90 min of ischemia, 72 h of reperfusion was allowed. Infarction volume (mm3, mean +/- sd) was less in the DCLHb groups (10/Hb = 79 +/- 17; 20/HB = 51 +/- 14) than the oncotically matched albumin groups (7.5/Alb = 124 +/- 21; 15/Alb = 85 +/- 18) and the Control group (135 +/- 17) (P < 0.05). These data indicate that in this model of cerebral ischemia, DCLHb decreases ischemic brain injury more effectively than albumin, and that a hyperoncotic preparation of DCLHb is preferable.

Animals↗
PubMed1996

Salt, starch, and water on the brain.

Isotonic fluids have been thoroughly studied and for the vast majority of neurosurgical patients are both safe and effective. Conversely, HS may have some transient beneficial effects on cerebral physiology in animal models of brain injury. However, further studies are needed to measure the functional outcome rather than early parameters of CNS function with HS resuscitation. In addition, HS has a defined risk. Until the risk-benefit ratio of HS is better defined in humans, physicians should exercise caution and adhere to the Hippocratic oath. However, if this risk-benefit ratio is defined, HS may hold promise for the clinical conditions cited herein as well as other novel uses (cardiopulmonary bypass, spinal trauma [55,56]).

Body Water↗
PubMed1991

Persistent sacral nerve root deficits after continuous spinal anaesthesia.

Neurological deficits following spinal anaesthesia are rare. We report two cases of persistent sacral nerve root deficits after continuous spinal anaesthesia (CSA) performed with hyperbaric lidocaine through a lumbar microcatheter. In both cases the dose of 5% lidocaine (5.7 and 4.3 ml) was greater than usual. In the immediate postoperative period the constellation of neurological deficits included perianal hypaesthesia, lower extremity paresis, urinary retention, and difficult defaecation. Both patients have residual perianal hypaesthesia and difficult defaecation. In these cases, the high-dose requirements of local anaesthetic via microcatheter CSA with focal sensory block suggests nonuniform distribution of the hyperbaric lidocaine. Microcatheter CSA may convey a unique risk of maldistribution of the local anaesthetic solution and local neurotoxicity.

Aged↗
PubMed1990

Factor analysis of the substance abuse attitude survey with college undergraduates.

Few standardized instruments measure attitudes and beliefs towards substance abuse. The Substance Abuse Attitude Survey, developed for measuring drug attitudes in medical education, was administered to 598 college undergraduates, and a factor analysis was performed. Three coherent and stable factors were identified, e.g., Stereotypes and Moralism, Treatment, and Permissiveness. Internal consistency and 6-wk. test-retest measures indicated moderate to high reliability factor structure. Results are discussed in terms of sample differences between this effort and a previous validation.

Adult↗
PubMedDate not supplied

The use of transesophageal echocardiography to guide sternal division for cardiac operations via mini-sternotomy.

Cardiac surgery utilizing the mini-sternotomy technique offers many advantages, including lessened pain and hospitalization. Mid-line upper sternotomy (or mini-sternotomy) can provide adequate exposure of the ascending aorta, the aortic root, the right atrial appendage and the dome of the left atrium. Inherent in providing adequate exposure is the level at which the sternum is "T'd" off. The lower aspect of the sternotomy is "T'd" off at the second, third, or fourth intercostal space depending on the patient's anatomy. We describe a technique that uses transesophageal echocardiography to determine the precise location for "T'ing" off the sternotomy, rather than approximating the sternotomy site by physical exam and chest radiograph. This technique will reliably delineate the sternotomy site, irrespective of a patient's body size and habitus.

Cardiac Surgical Procedures↗