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Biomedical subjects

J C Maroon

Publications and source records attributed to J C Maroon.

160 records · Page 9Linked to original sources
PubMedDate not supplied

Asanguineous whole body perfusion with a new intracellular acellular solution and ultraprofound hypothermia provides cellular protection during 3.5 hours of cardiac arrest in a canine model.

Temporary cessation of blood flow is a necessary aid for certain complex neurosurgical and cardiovascular procedures, and hypothermia is often used to help protect against the deleterious effects of ischemia and anoxia. In an attempt to protect cellular integrity during ultraprofound hypothermia (< 10 degrees C) and complete blood substitution, two new crystalloid-colloid blood substitutes (Hypothermosol-maintenance [HTS-M] and Hypothermosol-purge [HTS-P]) have been evaluated. Using extracorporeal bypass, 14 dogs were totally exsanguinated during cooling using the HTS-P solution, then perfused (40-85 ml/kg/min; mean arterial blood pressure = 25-40 mmHg) with either TS-M (Group I, n = 11), or with HTS-P as controls (Group II, n = 3) for 3 hr at 7 degrees C. During warming, the dogs were autotransfused and observed neurologically and biochemically during recovery. All dogs in Group I recovered and eight have survived long term (12-80 weeks) without apparent neurologic deficits. In contrast, dogs in Group II were more difficult to revive (cardiac resuscitation); two survived long term with delayed neurologic recovery. Evaluation of biochemical parameters showed only a transient and inconsequential elevation in enzymes (e.g., brain, liver, and heart) in Group I compared with the markedly greater elevations in Group II. The faster neurologic recovery of dogs treated with the "intracellular" maintenance solution supports the biochemical data showing the benefits of this type of blood substitute for extending the safe limits of hypothermic cardiac arrest to beyond 3 hr.

Animals↗
PubMedDate not supplied

Hypothermic blood substitution enables resuscitation after hemorrhagic shock and 2 hours of cardiac arrest.

Uncontrollable hemorrhage accounts for a large proportion of total mortality in both civilian (31%) and military (47%) trauma victims. Hypothermia is a relatively safe method that could provide total body protection during hypovolemic shock and facilitate surgical intervention as a potentially life-saving procedure. This study tested the hypothesis that profound hypothermia and complete blood replacement in an established canine model, would facilitate resuscitative therapy from exsanguinating hypovolemic shock. Adult dogs were prepared for extracorporeal bypass using closed-chest peripheral cannulation under general anesthesia. Controlled hypotensive, hemorrhagic shock (mean arterial blood pressure < 50 mmHg) was induced for 30 min at normal temperature followed by temporary resuscitation using crystalloid infusion for approximately 10 min. Using our established procedure, the dogs were then cooled externally to 27 degrees C before initiating blood substitution with Hypothermosol (Cryomedical Sciences, Inc. Rockville, MD) via the extracorporeal pump. The heart was arrested during further cooling to below 10 degrees C and Hypothermosol was recirculated for 2 hr, with (3 dogs) or without (5 dogs) 1 hr of circulatory arrest. During rewarming the animals were autotransfused, weaned from the pump, and allowed to recover. All dogs (n = 8) survived, all but one with complete neurologic recovery: blood chemistry samples examined immediately after the procedure showed significant differences (p < 0.05) in only a few parameters, including creatine kinase (CK-BB and CK-MB), compared with the previous group of control dogs. The consistent survival of dogs showing apparently normal neurologic, physiologic, and biochemical recovery supports the concept that profound hypothermia using a protective hypothermic blood substitute could provide time for therapeutic resuscitation of currently intractable trauma cases.

Animals↗
PubMedDate not supplied

MR imaging of heterotopic gray matter.

Heterotopic gray matter nodules have long been recognized by pathologists at autopsies. A case of this cerebral congenital abnormality has been studied by CT and magnetic resonance.

Adult↗
PubMedDate not supplied

MR imaging in the diagnosis of spontaneous spinal epidural hematomas.

Three patients with spontaneous (idiopathic) spinal epidural hematomas were diagnosed with magnetic resonance (MR) imaging. Magnetic resonance is an accurate, rapid method of localizing and characterizing the hematomas. We believe that MR (where available) should be the primary method of diagnosis in cases in which spinal epidural hematoma is suspected.

Aged↗
PubMedDate not supplied

Clinical considerations concerning detection of venous air embolism.

Venous air embolism during neurosurgical procedures (detected by Doppler Ultrasound and aspiration via a right atrial catheter) was noted in 100 of 400 patients in the sitting position, 5 of 60 patients in the lateral position, 7 of 48 patients in the supine position, and 1 of 10 individuals monitored in the prone position. We confirmed venous air embolism in many of these cases by using serial technetium-macroaggregated albumin lung scans. Gravitational gradients from the venous portal of entrance to the right side of the heart were as small as 5.0 cm, with aspiration of 200 ml of air occurring. Doppler ultrasonic air bubble detection and aspiration through a previously inserted right atrial catheter are critical factors in the diagnosis and treatment of this condition.

Cardiac Catheterization↗