Biomedical subjects

B Bazmi

Publications and source records attributed to B Bazmi.

6 recordsLinked to original sources

PubMed1994

Change in spinal curvature following release of tethered spinal cord associated with spina bifida.

Changes in spinal curvature, scoliosis, kyphosis and lordosis are associated with the growth of patients with myelomeningocele. Previous investigators have stated that progressive developmental scoliosis is related to tethered spinal cord. In order to investigate the relationship of tethered spinal cord release to progression of spinal curvature, we surveyed the medical records of 262 patients with a history of one or more tethered spinal cord release. For 216 of these patients, a total of 2,369 serial spine x-rays, obtained over a 20-year period, were reviewed by the standard Cobb method for progression of scoliosis, thoracic kyphosis and lordosis. In addition, the serial spine x-rays of 74 patients without clinical findings of tethered spinal cord were collected and reviewed for comparison of progressive scoliosis and kyphosis. One hundred and sixty normal lumbar x-rays were evaluated to compare the progression of the lordotic curve in patients with tethered cord release with a normal population. Progression of scoliosis plateaued or declined following release of tethered cord in patients with lumbar and sacral level lesions, however, tether release did not halt the progression of scoliosis in the thoracic level group. Tethered cord release altered the course of lordosis in L1 through L3 level lesions, but had little affect on the normal progression of lordosis in patients with L4, L5 or sacral level lesions. Finally, tethered spinal cord release appears to be associated with a decrease in the incidence and magnitude of kyphosis.

Adolescent↗

PubMed1993

Rewarming, ultraprofound hypothermia and cardiopulmonary bypass.

Rewarming, a key event in resuscitation from accidental, experimental and clinical hypothermia, is sometimes followed by neurologic, cardiac, and respiratory sequelae and may lead to death. The rate of rewarming has been implicated but not quantified as etiologic in these sequelae. Under anesthesia fifteen dogs were cannulated and connected to an extracorporeal circuit for oxygenation, core cooling and rewarming. They were subjected to ultra-profound hypothermia with a core (esophageal) temperature as low as 1.3 degrees C, cardiac arrest, blood substitution, and continuous low flow perfusion. After 2-3 hours of cardiac arrest, rewarming began. Mechanical activity of the heart was seen between 10 degrees and 28 degrees C and respiration resumed at 29 degrees C. The rewarming rates of the 15 dogs were retrospectively studied. They were placed into three categories (G) based on the outcome. G-I (N=2):no neurological complications, G-II (N=8):transient neurological problems, and G-III (N=5):death, mainly from cardiovascular and respiratory complications confirmed at death by autopsy. Heat gain by each animal was recorded as a function of time for all experiments. The time it took each dog to reach 35 degrees C was determined and a mean was calculated (rewarming rate). Normal body temperature for a dog is 37.8 degrees C. Statistical analysis (ANOVA) was performed ex post facto to determine the relationship between rewarming rate and outcome. Our data contradicts the notion that slow core rewarming from nadir to normal temperature offers better outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗

PubMed1992

Comparison of the effects of total blood substitution during two different levels of hypothermic cardiac arrest.

The effect of total blood replacement with a solution containing neither hemoglobin nor fluorocarbon was studied under two different levels of hypothermia. Ten dogs were anesthetized and esophageal temperature lowered to about 24 degrees at which time exsanguination began. Upon cardiac arrest and the completion of exsanguination, continuous whole body closed chest extracorporeal circulation of an oxygenated blood substitute was begun. Hematocrit was 1% while core temperature remained less than 10 degrees C for 3 hours of perfusion during which nadirs of 1.3 degrees C (Group I, N = 5) and 7.3 degrees (Group II, N = 5) were achieved. Replacement of the perfusate with whole blood began once the dog was rewarmed to approximately 10 degrees C. All dogs survived the procedure. Two dogs from each group died by the fourth post-operative day but the others survived long term. Group II showed a faster return to normal based on motor behavioral, biochemical and hematological changes. Thus the combination of profound hypothermia and complete blood substitution with a solution lacking any special oxygen carrying molecule, can be tolerated for 3 hours using both levels of hypothermia, however, the warmer one appears to be associated with faster recovery.

Animals↗

PubMed1992

Complete blood substitution during profound hypothermic cardiac arrest in dogs.

This study compared the effects of 3 hours of cardiac arrest performed at 2 different levels of profound hypothermia in totally exsanguinated, blood substituted dogs. Dogs (N = 10) were anesthetized and esophageal temperature was lowered to 24 degrees at which time exsanguination began. Once exsanguination was complete and the heart had arrested, continuous whole body perfusion of an oxygenated blood substitute solution was performed for 3 hours. Core temperature during this period remained below 10 degrees C and reached nadirs of 1.3 degrees C in Group 1 (N = 5) versus 7.3 degrees C in Group II (N = 5). Once the dog was allowed to rewarm to 10 degrees C replacement of the perfusate with blood was begun. All dogs survived the procedure but 2 dogs from each group died by 4 days following the experiment. The remaining 6 dogs were observed for between 10 and 85 days. The group perfused with blood substitute at the warmer nadir had a faster recovery of motor behavior and showed smaller changes from normal in several biochemical and hematological parameters. These findings indicate that profound hypothermia and total blood substitution can be successfully achieved at either temperature nadir, but the warmer level appears to be associated with a faster recovery.

Animals↗

PubMed1992

Blood substitution: an experimental study.

Priming fluids for cardiopulmonary bypass have been extremely varied, with resultant hemodilution. Furthermore, major surgeries utilizing cardiopulmonary bypass require multiple postoperative transfusions of blood and blood products. The appeal of having a readily available blood substitute for major cardiovascular and neurosurgical operations could prove to be a life saver, while also eliminating the risk of diseases transmitted by transfusion. Blood substitutes could also lessen the reported complications resulting from blood damage due to prolonged circulation of the blood by the extracorporeal pump. A technique was examined in 15 dogs using hypothermia for maximum metabolic suppression, incorporating an aqueous blood substitute (Cryomedical Sciences, Inc., Rockville, MD). The anesthetized animals were cannulated for extracorporeal pump oxygenation. As temperature was lowered the dogs were exsanguinated and volume replaced with blood substitute to lower the hematocrit to less than 1%. After 3 hours of cardiac arrest and continuous perfusion at a core temperature less than 10 degrees C, rewarming began. When temperature reached greater than or equal to 10 degrees C, the blood substitute was drained and the animals were autotransfused. The heart was started at 15 degrees C and spontaneous respiration resumed at 29 degrees C. Using the first generation blood substitute the survival rate was maximal (100%) at 2.5 hrs under 10 degrees C and 3 hours of cardiac arrest. Research is underway on a new blood substitute, which is to serve as a universal hypothermic preservation solution (in situ organ preservation).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMedDate not supplied

A pilot investigation of poloxamer 407 for the prevention of leptomeningeal adhesions in the rabbit.

Leptomeningeal adhesion formation frequently complicates operations and diseases of the central nervous system. Chronic adhesive arachnoiditis may follow intraspinal surgery for disc, tumor, and closure of myelomeningocele, eventually producing pain and declining neurological status of the patient. Reoperation for scar removal is seldom successful as the arachnoidal adhesions reform. Poloxamer 407 (P407) has been shown to reduce postoperative peritoneal adhesion formation in rats and golden hamsters. In a rabbit model, we investigated the potential of P407 to prevent the production of arachnoidal adhesions and nerve root scarring following laminectomy and surgical meningeal injury. The lumbar spinal roots of 8 New Zealand white rabbits were surgically isolated under magnification. One root sleeve axilla was opened and immediately closed with 10-0 suture (control site) and a second root sleeve axilla was opened, P407 injected, and closed with 10-0 suture (treatment site). Five of 7 rabbits treated with P407 and followed for 7-42 days showed no arachnoidal adhesions at the level of the nerve root. Four New Zealand white rabbits had the lamina removed, and the dura over the spinal cord was opened at two sites separated by one to two lumbar segments. At one site P407 was inserted beneath the dura following durotomy, and the other site was opened in a similar fashion and immediately closed without the insertion of P407. There was a 50% reduction in leptomeningeal adhesion formation with the use of P407. P407 may be useful in neurosurgery for the prevention of arachnoidal adhesions.

Animals↗