Biomedical subjects

H L Frankel

Publications and source records attributed to H L Frankel.

At least 37 records · Page 2Linked to original sources

PubMed1998

Evaluating neurological group homogeneity in assessing the mortality risk for people with spinal cord injuries.

A study of 3178 individuals injured in Britain between 1943 and 1990 and surviving the first year post-injury was conducted to evaluate the homogeneity of mortality risk ratios within groups based on varying degrees of neurological injury level and completeness of the injury. The study shows that it is less than optimal to combine individuals into neurological groupings of C1-C4 ABC, C5-C8 ABC and T1-S5 ABC since the risk ratios are not homogeneous within these groups. Similarly, combining individuals into neurological groupings of tetraplegia complete, tetraplegia incomplete, paraplegia complete and paraplegia incomplete may not be appropriate for the same reasons. The consequence of performing a survival analysis using either of the traditional sets of groups is to dilute the risk ratios for a subset of individuals within a particular group, thereby providing less discrimination between neurological groups. Cox proportional hazards regression was employed to determine a set of neurological groupings with homogeneous risk ratios within a group while providing better differentiation between groups.

Adolescent↗

PubMed1998

Long-term survival in spinal cord injury: a fifty year investigation.

The aims of this study were to examine long-term survival in a population-based sample of spinal cord injury (SCI) survivors in Great Britain, identify risk factors contributing to deaths and explore trends in cause of death over the decades following SCI. Current survival status was successfully identified in 92.3% of the study sample. Standardised mortality ratios (SMRs) were calculated and compared with a similar USA study. Relative risk ratio analysis showed that higher mortality risk was associated with higher neurologic level and completeness of spinal cord injury, older age at injury and earlier year of injury. For the entire fifty year time period, the leading cause of death was related to the respiratory system; urinary deaths ranked second followed by heart disease related deaths, but patterns in causes of death changed over time. In the early decades of injury, urinary deaths ranked first, heart disease deaths second and respiratory deaths third. In the last two decades of injury, respiratory deaths ranked first, heart related deaths were second, injury related deaths ranked third and urinary deaths fourth. This study also raises the question of examining alternative neurological groupings for future mortality risk analysis.

Adolescent↗

PubMed1998

The impact of true partnership between a university Level I trauma center and a community Level II trauma center on patient transfer practices.

OBJECTIVE: To examine the effect of a clinical and administrative partnership with an academic urban Level I trauma center on the patient transfer practices at a suburban/rural Level II center. METHODS: Data for 2 years before affiliation (PRE) abstracted from inpatient charts and the trauma registry were compared with that for 2 years after (POST). The following data were collected: number of, reason for, and destination and demographics of transfers. Chi(2) test and t test analyses were used; p < 0.05 defined significance; data are mean +/- SEM. RESULTS: Transfer rate increased from 4% PRE to 6.9% (p = 0.001) POST with no significant difference in age, Glasgow Coma Scale score, Injury Severity Score, or Revised Trauma Score. Repatriation occurred in 12.8% POST (none PRE). The current Level I facility accepted 1.8% of all transfers PRE and 36.4% POST (p = 0.0001). PRE/POST rates by reason are as follows: pediatric, 14.6%/9.0% (p = 0.04); intensive care unit, 0.4%/1.7% (p = 0.13); complex orthopedic, 100%/0% (p = 0.005); vascular, 50%/0% (p = 0.008); spinal cord injury, 100%/100%; and ophthalmologic, 0%/100% (p = 0.005). CONCLUSIONS: In this experience of Level I/II partnership (1) transfer patterns were altered, (2) select patient cohort transfers decreased (pediatric, complex orthopedic, vascular), whereas others increased (aortic work-up), and (3) repatriation rates were low.

Hospitals, Community↗

PubMed1998

Responses of thenar muscles to transcranial magnetic stimulation of the motor cortex in patients with incomplete spinal cord injury.

OBJECTIVE: To investigate changes in electromyographic (EMG) responses to transcranial magnetic stimulation (TMS) of the motor cortex after incomplete spinal cord injury in humans. METHODS: A group of 10 patients with incomplete spinal cord injury (motor level C3-C8) was compared with a group of 10 healthy control subjects. Surface EMG recordings were made from the thenar muscles. TMS was applied with a 9 cm circular stimulating coil centred over the vertex. The EMG responses to up to 50 magnetic stimuli were rectified and averaged. RESULTS: Thresholds for compound motor evoked potentials (cMEPs) and suppression of voluntary contraction (SVC) elicited by TMS were higher (p < 0.05) in the patient group. Latency of cMEPs was longer (p < 0.05) in the patient group in both relaxed (controls 21.3 (SEM 0.5) ms; patients 27.7 (SEM 1.3) ms) and voluntarily contracted (controls 19.8 (SEM 0.5) ms; patients 27.6 (SEM 1.3) ms) muscles. The latency of SVC was longer (p < 0.05) in the patients (51.8 (SEM 1.8) ms) than in the controls (33.4 (SEM 1.9) ms). The latency difference (SVC-cMEP) was longer in the patients (25.3 (SEM 2.4) ms) than in the controls (13.4 (SEM 1.6) ms). CONCLUSION: The longer latency difference between cMEPs and SVC in the patients may reflect a weak or absent early component of cortical inhibition. Such a change may contribute to the restoration of useful motor function after incomplete spinal cord injury.

Adult↗

PubMed1998

The human motor cortex after incomplete spinal cord injury: an investigation using proton magnetic resonance spectroscopy.

OBJECTIVES: (1) A biochemical investigation of the motor cortex in patients with incomplete spinal cord injury and normal control subjects using proton magnetic resonance spectroscopy (MRS). (2) To relate any altered biochemistry with the physiological changes in corticospinal function seen after spinal cord injury. METHODS: A group of six patients with incomplete spinal cord injury who showed good recovery of motor function were selected. The patients were compared with five healthy control subjects. Electromyographic (EMG) responses of thenar muscles to transcranial magnetic stimulation (TMS) of the motor cortex showed that inhibition of cortical output was weaker in the patients than the controls. Proton MRS data were collected from a plane at the level of the centrum semiovale. Two 4.5 cm3 voxels in the motor cortex and a third voxel in the ipsilateral occipital cortex were examined in the patients and control subjects. RESULTS: The mean level of N-acetylaspartate (NAA), expressed relative to the creatine (Cr) peak (NAA/Cr), was significantly increased in the motor cortex of the patients compared with their ipsilateral occipital cortex or either cortical area in the controls. No differences between patients and controls were seen for any of the other metabolite peaks (choline (Cho), glutamate/glutamine (Glx) or the aspartate component of NAA (AspNAA)) relative to Cr. Choline relative to Cr (Cho/Cr) was higher in the motor cortex of the control subjects than in their ipsilateral occipital cortex. This difference was not present in the patients. CONCLUSIONS: Raised NAA/Cr in the motor cortex of the patients probably results from increased NAA rather than a decrease in the more stable Cr. The possible relevance of a raised NAA/Cr ratio is discussed, particularly with regard to the changed corticospinal physiology and the functional recovery seen in the patients.

Adult↗

PubMed1998

Recidivism in equestrian trauma.

A 3-year chart survey and questionnaire was conducted of equestrian-injured patients at a regional trauma center to determine patterns and consequences of injury and rate of recidivism. Ninety-two patients (95 encounters) were treated; most were young (mean age, 27 +/- 11 years) women (84%) riders sustaining falls (80%). Most injuries were orthopedic (47%); 19 per cent of patients required hospital admission. There was one death. Helmet use was documented in only 34 per cent. Eighty-one per cent of patients responded to a follow-up telephone survey; 36 per cent recounted additional accidents (mean, 1.4 +/- 0.5). Mean time lost from work was 3 weeks, with 19 per cent reporting chronic disability. Mean annual hospital charges for the cohort were $88,925.00. Recidivism is common in equestrian trauma. Hospital charges are significant. Lost time from work is considerable, with one in five patients reporting long-term disability. Given the cost and disability incurred with equestrian trauma, efforts at injury prevention appear warranted.

Accidental Falls↗

PubMed1997

Cardiovascular and hormonal responses to food ingestion in humans with spinal cord transection.

In sympathetic denervation due to primary autonomic failure, ingestion of food causes a fall in blood pressure (BP) and exacerbates postural hypotension. It is not known whether these responses occur in tetraplegics with physiologically complete cervical spinal cord transection, who also have sympathetic dysfunction because of disruption of descending spinal sympathetic pathways. We, therefore, studied the effect of a liquid meal on BP, heart rate (HR) and neurohormonal levels in tetraplegics. Paraplegics with low lesions and without sympathetic dysfunction served as controls. After food ingestion, there was no fall in BP in tetraplegics or in controls. HR did not change in either group. After fund, plasma noradrenaline was unchanged in tetraplegics, but rose in controls, while plasma renin activity (PRA) rose in tetraplegics but not in controls. The fall in BP and rise in HR on head-up tilt after the meal in tetraplegics was similar to that before the meal. There was no change in PRA following pre-prandial tilt in either group; post-prandial tilt raised levels in the tetraplegics, unlike in controls. Thus there is considerable variance in the responses to food between tetraplegics and paraplegic controls, and even greater differences when compared with published data in other autonomic disorders with sympathetic dysfunction; this may relate to the site and the nature of the sympathetic lesion and the ability to activate compensatory mechanisms.

Adult↗

PubMed1997

Neurological issues.

The case histories of two patients who had had a spinal cord injury (SCI) were selected by the senior author and sent to four experts in the field of SCI. Based on the 1992 American Spinal Injury Association (ASIA) and International Medical Society of Paraplegia (IMSOP) standards, the four participants plus the senior author recorded the motor and sensory scores, the ASIA impairment scale (AIS), the neurological level (NL) and the zone of partial preservation (ZPP). Several minor scoring errors occurred among the participants, especially with motor scores when key muscles could not be tested due to pain, or external immobilization devices. Difficulties with interpretation occurred with the motor levels and the ZPP for the patient with a complete injury. This exercise points to the need for all examiners of SCI patients to thoroughly familiarize themselves with the standards and to use the motor and sensory scores to arrive at a NL and ZPP. They also indicate a need to revise the standards to clarify the determination of sensory levels and how to score muscles whose strength is inhibited by pain.

Adult↗

PubMed1997

Agitation.

Agitation is a frequent clinical problem that adds significant morbidity to the hospital course. Agitation is usually part of an ambiguous constellation of cognitive and psychiatric symptoms, with a fluctuating clinical course. Observation of vastly different symptoms occurring at different times leads to misdiagnosis or underrecognition of serious underlying disorders. The most common causes of agitation include delirium, dementia, and acute psychosis. Risk factors attributable to hospitalization include pain, anxiety, and stressors endemic to intensive care. Agitated states may have multiple causes, and each potential contributor must be pursued and treated independently. Definitive diagnosis is dependent on a comprehensive history, patient observation, physical examination, and selective diagnostic studies.

Adult↗

PubMed1997

Hypothermia.

Hypothermia in the hospitalized adult may be a primary process, as in exposure, or a result of a multitude of disease processes or iatrogenic factors. The condition affects virtually every metabolic process in the body. A thorough understanding of the pathophysiology of hypothermia enables the clinician to differentiate between the hypothermic syndrome and underlying illness and can assist in the detection and management of clinical sequelae. A reliable patient history is the most helpful diagnostic tool, but careful physical examination and laboratory studies are also important for detection of primary or secondary illness.

Adult↗

PubMed1996

Diaspirin cross-linked hemoglobin is efficacious in gut resuscitation as measured by a GI tract optode.

The objective of this study was to compare the efficacy of diaspirin cross-linked hemoglobin (DCLHb) with that of standard resuscitative fluids in restoring intestinal mucosal oxygenation and villous architecture after hemorrhage. Male rats were bled to a base deficit of 5 +/- 2 nmol/l under propofol anesthesia and monitored for 90 minutes postresuscitation with DCLHb, blood, lactated Ringer's solution, albumin, or nothing (DNR) for mucosal oxygen tension (Pmo2) and physiologic and laboratory parameters. Small intestinal histologic specimens were obtained and scored independently by two investigators blinded to therapy on a scale of 0 (normal) to 4 (worst). All treatments restored Pmo2; only DCLHb did so without exceeding baseline values. For untreated rats (DNR), Pmo2 was not restored. Normal mucosal architecture was maintained only in DCLHb-treated rats. As Pmo2 increased, mucosal score improved. In a rat model of controlled hemorrhage, Pmo2 changes measured by an optode correlated with gut histological abnormalities. By these criteria, DCLHb is superior to crystalloid, colloid, and blood in gut resuscitation.

Animals↗

PubMed1995

A prospective study of surgeon-performed ultrasound as the primary adjuvant modality for injured patient assessment.

Ultrasound diagnostic imaging, having been used in Germany in the trauma setting for more than 15 years, has unique qualities that give it distinct advantages over other tests (DPL, CT), and is gradually gaining acceptance by surgeons in the United States. In this prospective study, experienced surgeon sonographers successfully used ultrasound as the primary adjuvant modality to detect hemoperitoneum and pericardial effusion in injured patients. The ultrasound evaluations of 371 patients demonstrated that in 65 patients with significant injuries, ultrasound detected 53, that is, had an 81.5% sensitivity and 99.7% specificity. They conclude that ultrasound should be the primary adjuvant instrument for the evaluation of injured patients because it is rapid, accurate, and is potentially cost-effective.

Adolescent↗

PubMed1994

Increased hypoxic ventilatory sensitivity during exercise in man: are neural afferents necessary?

1. The acute ventilatory response to 3 min periods of hypoxia (AHR) was examined in nine patients with clinically complete spinal cord transection (T4-T7) during (a) rest and (b) electrically induced leg exercise (EEL). 2. EEL was produced by surface electrode stimulation of the quadriceps muscles so as to cause the legs to extend at the knee against gravity. End-tidal PCO2 was held constant 1-2 mmHg above resting values throughout both protocols. 3. On exercise, the average increase in metabolic CO2 production (VCO2 +/- S.E.M.) was 41 +/- 5 ml min-1. Venous lactate levels did not rise with exercise. 4. Baseline euoxic ventilation did not increase significantly with EEL, but there was a consistent and highly significant increase in the ventilatory response to hypoxia during EEL (mean delta AHR +/- S.E.M. of 1.6 +/- 0.21 min-1). 5. We conclude that an increase in hypoxic sensitivity during exercise can occur in the absence of volitional control of exercise and in the absence of afferent neural input from the limbs.

Adult↗

PubMed1994

Indications for obtaining surveillance thoracic and lumbar spine radiographs.

The purpose of this study was to identify risk factors for thoracic/lumbar spine fractures in patients with blunt injuries and subsequently establish indications for obtaining surveillance thoracolumbar radiographs. Retrospective review of all patients with blunt injuries (n = 1485) admitted in 1992 to a level I trauma center with a discharge diagnosis of thoracolumbar spine fracture established entrance criteria for a 4-month prospective study. Relative risk of fracture (RR) was calculated. Retrospective. Seventy-six percent (176 of 233) had radiographs; 21% had fractures; one diagnosed late. Prospective. One hundred percent (167 of 167) had radiographs; 9% (15 of 167) had fractures; none diagnosed late or missed. Forty percent (26 of 65) of patients with fractures had no pain or tenderness; 35% (9) required surgical spinal fixation. Our data define these indications for obtaining thoracolumbar radiographs in patients with blunt injuries: back pain (RR1), fall > or = 10 feet, ejection from motorcycle/motor vehicle crash > or = 50 mph, GCS score < or = 8, (all RR2), and neurologic deficit (RR10). The sensitivity of our surveillance radiography protocol has increased to 100%. The absence of back pain does not exclude significant thoracolumbar trauma.

Adult↗

PubMed1994

Minimizing admission laboratory testing in trauma patients: use of a microanalyzer.

OBJECTIVE: Routine admission laboratory test protocols in injured patients are costly and involve excessive phlebotomy and turnaround time. The purpose of this prospective study was to evaluate the utility of (1) a microanalyzer, NOVA-SP5 (which provides rapid results on minimal blood volume), and (2) each component of our standard laboratory test battery. METHODS: Laboratory test results for 200 consecutive injured patients admitted to a level I trauma center were evaluated by paired sample analysis. Our standard battery [60 mL: ($348): type and screen, complete blood count, PT/PTT, electrolytes, BUN, creatinine, glucose, calcium, amylase, ethanol level, and arterial blood gas] run "stat" in the central laboratory was compared to the microanalyzer profile [< 1 mL: ($182): hemoglobin, hematocrit, electrolytes, glucose, Ca2+, and arterial blood gas] run by the trauma team in the resuscitation area. Patient data and laboratory turnaround time (from time of admission to time results obtained) were recorded. Data were analyzed by linear regression. RESULTS: Components of the paired samples correlated well (r2 0.78 to 0.99). Turnaround times were 64 (+/- 3) and 6 (+/- 1) minutes for standard analysis and microanalysis, respectively. Only two of the 26 patients requiring emergent surgical procedures had standard results available preoperatively. These patients had twice as many laboratory abnormalities as the remainder. Minimal diagnosis or intervention resulted from those values exclusive to standard analysis (white blood count, amylase, ethanol level, BUN, creatinine, platelet count, PT, and PTT). Six of ten abnormal BUN or creatinine results normalized, including two values in patients who received contrast for portable intravenous pyelography, and in all patients without a history of hypertension or diabetes. Platelet count and PT/PTT were normal in 85% of non-head-injured patients, compared with 58% of those with GCS score < or = 8. CONCLUSIONS: Microanalysis is accurate, expedient, conserves blood, and is sufficient for evaluation of most trauma patients. Those with hypertension, diabetes, or severe head trauma may require additional testing. Routine use of this technique could reduce cost substantially ($16,000/100 patients). The role of microanalysis in follow-up laboratory evaluation of injured patients remains to be elucidated.

Adult↗

PubMed1992

Mortality, morbidity, and psychosocial outcomes of persons spinal cord injured more than 20 years ago.

Mortality, morbidity, health, functional, and psychosocial outcomes were examined in 834 individuals with long term spinal cord injuries. All were treated at one of two British spinal injury centres: the National Spinal Injuries Centre at Stoke Mandeville Hospital or the Regional Spinal Injuries Centre in Southport; all were 20 or more years post injury. Using life table techniques, median survival time was determined for the overall sample (32 years), and for various subgroups based on level and completeness of injury and age at injury. With the number of renal deaths decreasing over time, the cause of death patterns in the study group as it aged began to approximate those of the general population. Morbidity patterns were found to be associated with age, years post injury, or a combination of these factors, depending upon the particular medical complication examined. A current medical examination of 282 of the survivors revealed significant declines in functional abilities associated with the aging process. Declines with age also were found in measures of handicap and life satisfaction, but three quarters of those interviewed reported generally good health and rated their current quality of life as either good or excellent.

Adaptation, Psychological↗

PubMed1991

Hemodynamic and neurohormonal effects of clonidine in patients with preganglionic and postganglionic sympathetic lesions. Evidence for a central sympatholytic action.

BACKGROUND: Clonidine, a partial presynaptic and postsynaptic alpha-adrenoceptor agonist, has been shown to lower blood pressure in normal subjects but not in tetraplegics; however, the mechanisms of this action have not been elucidated. METHODS AND RESULTS: The hemodynamic and hormonal basis of the hypotensive action of clonidine was investigated in tetraplegics with complete cervical spinal cord transection and preganglionic sympathetic denervation, in patients with unilateral brachial plexus injury and postganglionic sympathetic denervation, and in normal subjects. In normal subjects, the fall in blood pressure after clonidine infusion was accompanied by a reduction in cardiac output that was predominantly due to a fall in stroke volume and in heart rate. The lack of fall in blood pressure, cardiac output, and stroke volume in tetraplegics indicates that these effects are exerted at a supraspinal level and require intact descending sympathetic pathways. After clonidine infusion, digital skin vasodilatation occurred in normal subjects, in the innervated but not the denervated limb of patients with unilateral brachial plexus injury, and in tetraplegics, indicating that this response is due to the central sympatholytic effect of clonidine. Plasma norepinephrine was much lower in tetraplegics compared with normal subjects, and after clonidine infusion, it fell substantially in normal subjects alone. Plasma renin activity did not change. Bladder stimulation in tetraplegics resulted in a rise in blood pressure and vasoconstriction in digital skin vessels. The inability of clonidine to significantly reduce or abolish the pressor and digital vasoconstrictor responses after bladder stimulation in tetraplegics indicates that clonidine does not exert a major effect on spinal preganglionic neurons or peripheral presynaptic alpha 2-adrenoceptors. CONCLUSIONS: Therefore, clonidine is a suitable drug for use in analyzing the central supraspinal levels of control in varying circulatory disorders, such as hypertension and postural hypotension.

Adolescent↗

PubMed1990

Wound healing and T-lymphocytes.

T-cell depletion leads to impaired wound healing. We studied the effect of combined T-helper and T-suppressor lymphocyte depletion on wound healing and compared it with the effect of all T-cell depletion. Groups of 10 male balb/c mice, 8 weeks old, underwent a 2.5-cm skin incision and subcutaneous implantation of polyvinyl alcohol sponges. Twenty-four hours prior to wounding one group was treated with 3OH12, a rat anti-mouse monoclonal antibody against the Thy-1.2 antigen present on all T-cells (1 mg); another group received 1 mg each of GK1.5 (anti-L3T4, CD4; anti-helper/effector subset) and 2.43 (anti-Lyt 2.1, CD8; anti-suppressor/cytotoxic subset). All monoclonal antibodies are cytotoxic in vivo. Controls received 1 mg of nonspecific rat IgG. Treatments were repeated weekly. Animals were sacrificed at 2 and 4 weeks postwounding. Equal depletion of all T- and Th- and Ts-subsets in peripheral blood and spleens was noted in the two experimental groups at sacrifice. Depleting Thy-1.2 cells (all T-cells) impaired wound healing as assessed by wound breaking strength and collagen synthesis. Combined anti-T-helper/effector and T-suppressor/cytotoxic depletion resulted in improved wound-healing parameters. This suggests that there is a Thy-1.2+, L3T4-, Lyt2- subpopulation of T lymphocytes which normally stimulates wound healing.

Animals↗