The prevalence of pulmonary embolism in chronically paralyzed subjects: a review of available evidence.

STUDY DESIGN: Qualitative systematic review. OBJECTIVES: To examine the validity of the prevailing notion that pulmonary embolism (PE) is rare in the chronic spinal cord injury (SCI) population. SETTING: USA. METHODS: Review surveys of adult SCI subjects >2 months after injury in which PE has been looked for and its prevalence estimated. RESULTS: A total of 16 surveys of chronic SCI subjects published between 1956 and 2009 offered data on PE prevalence. Two autopsy surveys, 178 subjects paralyzed >2 months, revealed no PE. Eleven surveys of the cause of death, 3193 subjects paralyzed 1-25 years, revealed PE in 2.1%. Two surveys of survivors of SCI, 5761 subjects paralyzed 1-25 years, revealed PE in 0.4%. Our survey of 112 subjects paralyzed 1-50 years before death, revealed PE in 21 (18.7%), based on autopsy, imaging, clinical and electrocardiographic evidence. In 7 (33%) of the 21 subjects with PE, pulmonary hypertension by transthoracic echocardiography was detected, indicating recurrent and/or unresolved PE. CONCLUSION: PE is not infrequent in the chronic SCI subject; but its presentation may be subclinical; and its apparent recurrence may lead to pulmonary hypertension.

Recurrent, massive pulmonary embolism in chronic myelopathy: a case report.

STUDY DESIGN: Case report. OBJECTIVES: The aim of this report was to describe an example of pulmonary embolism (PE), recently suggested to be highly prevalent in persons with chronic spinal cord lesions. SETTING: Veterans Affairs Hospital, Boston, MA, USA. METHODS: Chart review. RESULTS: A 60-year-old man with paraplegia, T10 motor complete, underwent laminectomy for correction of an arteriovenous malformation. After 41 days, he sustained a massive PE-suggested by right bundle branch block (RBBB) on an electrocardiogram (ECG) and diagnosed by perfusion lung scanning. He was treated with anticoagulants, the lung scan and RBBB resolving within 1 month of initiating treatment. After 5 years, he developed vertebral osteomyelitis at L5-S1 and was treated with antibiotics and bed rest. After 7 days, he was mobilized to a wheelchair, and during a transfer back to bed, he developed anxiety, dyspnea, fluctuating consciousness, low blood pressure and RBBB, absent by ECG 4 days earlier. He expired 20 min after onset of symptoms. The autopsy revealed a fresh thromboembolus occluding both main stem branches of the pulmonary artery. CONCLUSION: Massive PE after surgery in a patient with chronic paraplegia recurred 5 years later in association with severe infection and mobilization after bed rest, which resulted in death.

Anemia and hypoalbuminemia of chronic spinal cord injury: prevalence and prognostic significance.

STUDY DESIGN: The study was a retrospective analysis. OBJECTIVE: The objective of the study was to survey a chronic spinal cord injury (SCI) population for the prevalence and prognostic significance of anemia (AN) and hypoalbuminemia (HA). SETTING: The study was conducted at VA Boston Healthcare System, USA. METHODS: A review of records of 322 SCI subjects (318 males) scheduled for annual examination was carried out for the period from 1998 to 2007. The number of follow-up years with AN (hematocrit <40%) or severe anemia (SAN) (hematocrit <30%) or HA (serum albumin <3 g%) was recorded for all subjects, divided between survivor and deceased subjects. RESULTS: A total of 239 subjects survived to an average age of 60 and 30 years of paralysis and 83 subjects died at an average age of 70 and 27 years of paralysis (P<0.01 and P<0.06, respectively). The level and grade of paralysis were similar in these groups. The average prevalence rates of AN, SAN and HA were 34, 6 and 6% of survey years in the survivor group and 83, 18 and 22% in the deceased group; the respective ratios were 2.4, 3.0 and 3.7 (P<0.001). The fractions of survey years that were positive for SAN and/or HA among causes of death were sepsis, 42%; cancer, 33%; pulmonary failure 30%; cardiovascular disease, 25%; and undetermined causes, 9%. The mortality rate for the 95 subjects with a recurrence of SAN or HA was 40% within 3 years. CONCLUSION: The prevalence of AN, SAN and HA among chronic SCI subjects is high; repeated SAN and HA often precede death, particularly due to sepsis.

Correction of orthostatic hypotension by respiratory effort.

STUDY DESIGN: Case report. OBJECTIVE: To describe a role for breathing in maintenance for blood pressure in a tetraplegic man. SETTING: Veterans Administration Hospital, USA. METHODS/RESULTS: A 60-year-old man, tetraplegic for 14 years, was successfully treated for orthostatic hypotension (OH) by raising the head of his bed in the mornings before transfer to his wheelchair. To test the role of breathing in the compensation for OH, we monitored the nasal airflow with a thermistor clipped onto a naris and pulse pressure was measured with a transducer held against a supraorbital artery with an elastic band. On raising the head of the bed to 30 degrees the pulse pressure fell and breathing effort increased. Within 1 min, however, pulse pressure rose to baseline levels whereas increased breathing effort continued. On transfer to his wheelchair OH was avoided and medication was unnecessary. CONCLUSION: For the tetraplegic subject the partial raising of the head of the bed for a period of time to be determined individually will recruit increased breathing effort and venous return to the chest, preventing OH on transfer to an upright position in a wheelchair.

Hypersensitivity to administered adrenaline in tetraplegia.

STUDY DESIGN: Case report. OBJECTIVE: To describe two clinical examples of denervation hypersensitivity, an enhanced response to catecholamines demonstrated experimentally in tetraplegic patients. SETTING: USA. CASE REPORTS: A 63-year-old man with chronic paralysis at C4 ASIA Impairment Scale (AIS) A with partial preservation to T6, and a history of coronary artery and pulmonary disease, developed bradycardia leading to cardiac arrest. He was treated with intravenous atropine 0.4 mg and adrenaline 1 mg. He regained consciousness and blood pressure within 30 s, but developed supraventricular tachycardia leading to ventricular fibrillation and death within minutes. The dose of adrenaline was routine for a cardiac arrest.A 60-year-old man with chronic paralysis at C6, AIS A, presented with fever to 106 degrees F and a renal stone. Thirty minutes after treatment with intravenous fluids, antibiotics, and 1 g aspirin orally, he became afebrile, then suddenly lost consciousness and palpable pulse. He recovered with equal rapidity after an intravenous injection of 0.1 mg adrenaline. The dose of adrenaline was a tenth the usual dose for cardiac arrest. CONCLUSION: Because of denervation hypersensitivity, effective treatment of a cardiac arrest in tetraplegic patients may require a reduced dose of adrenaline.

Thyrotoxic cardiomyopathy and encephalopathy in a paraplegic man.

STUDY DESIGN: Case report. BACKGROUND/OBJECTIVE: Thyrotoxicosis complicating spinal cord injury is more common than generally appreciated. To raise the level of awareness, the following case of fatal thyrotoxicosis is presented. CASE REPORT: A 77-year-old man, paralyzed at the T12 level for 46 years, developed a sudden 42 lb weight loss, dyspnea, interscapular pain, 120/40 mm Hg blood pressure, a nodular thyroid gland, atrial fibrillation, progressive cardiac enlargement, left ventricular ejection fraction diminishing from 30 to 10% and a persistently low level of thyrotropic hormone, 0.05-0.2 microU ml(-1) (normal 0.35-5.5 microU ml(-1)). As coronary artery bypass grafting had been carried out 6 years earlier and other signs of thyrotoxicosis-exophthalmos, lid lag, sweating, tremor and diarrhea-were absent, recurrent arteriosclerotic heart disease was assumed and a trial of thyroid suppression not attempted. He eventually developed depression and memory loss and died in heart failure after a 4-year course of this illness. CONCLUSION: This case probably represented a toxic multinodular goiter in an elderly paraplegic man with potentially treatable cardiovascular and nervous system complications.

A fatal metastasis of Klebsiella pneumoniae to the lungs.

BACKGROUND/OBJECTIVE: To describe the relationship between a seemingly innocuous colonization in one organ and a fatal infection in another organ in a tetraplegic man. DESIGN: Case report. SOURCE: Veterans Administration Hospital, USA. METHODS/RESULTS: A 61-year-old man, paralyzed at C7, American Spinal Injury Association Impairment Scale A for 31 years, presented with cough and negative sputum but urine positive for Klebsiella pneumoniae. After 2 days, he presented with sepsis and hypotension, received fluids and multiple antibiotics (blood and urine cultures taken after antibiotics were negative), and developed pulmonary failure 2 weeks after admission. Bronchial secretions obtained by bronchoscopy for mucous plugging revealed K. pneumoniae. The spectrum of antibiotic sensitivities for the organism from the initial urine and the later bronchial secretions was identical except for resistance to antibiotics administered between cultures. The subject developed an encephalopathy in association with respiratory acidosis, hyponatremia, hypoalbuminemia and renal failure and expired 36 days after presentation. CONCLUSION: The urinary and respiratory tracts were infected with the same organism, leading to fatal sepsis in a chronically paralyzed tetraplegic man, suggesting migration between the two sites.

Mutual control of breathing and blood pressure: case report.

STUDY DESIGN: Trial outcome. OBJECTIVES: To demonstrate the relationship between circulation and breathing with orthostasis in a tetraplegic man. SETTING: A long-term care unit at a Veterans Administration Hospital, USA. METHOD: A tetraplegic patient with a history of orthostatic hypotension was monitored for blood flow at the level of the supraorbital artery, for breathing by nasal air flow, and for pulse oxymetry on a tilt table at 0, 45 and 0 degrees of head elevation. RESULTS: Tilting up caused a coincidental reduction in blood flow and enhanced breathing. These effects were coincidentally reversed by tilting down. Oxyhemoglobin concentration and pulse rates increased with orthostasis and returned to baseline on tilting down. CONCLUSION: A reciprocal relationship between breathing and circulation has been demonstrated in a tetraplegic patient challenged by orthostasis.

Salt wasting, hypotension, polydipsia, and hyponatremia and the level of spinal cord injury.

STUDY DESIGN: Case control. OBJECTIVE: To test the reported correlation of hypotension, polydipsia, and hyponatremia with higher levels of spinal cord injury (SCI). SETTING: A Veterans Administration Hospital, USA. METHODS: The records of men who were paralyzed owing to trauma at any spinal cord level with motor complete lesions (ASIA A or B) and who received an annual physical and laboratory examination were reviewed for age, duration of paralysis, level of paralysis, blood pressure (BP), serum sodium, and 24 h urinary volume, creatinine, and sodium. Creatinine clearance and fractional excretion of sodium (FcNa) were calculated. Spearman rank-order correlations (r (s)) were carried out. RESULTS: Patients were aged 25 to 88 years, median 56 years, paralyzed 2-61 years, median 26 years, with levels of paralysis ranging from C2 to L4, median T4, n=111. From lower to higher levels of paralysis FcNa increased (0.4-7.3%), mean BP diminished (132-66 mmHg), urine volume increased (600-5400 ml), and serum sodium was reduced (148-129 mEq/l) - r (s)=0.29, 0.49, -0.22, and 0.23, respectively. Increasing 24 h urinary volumes correlated with lower serum sodium concentrations but higher creatinine clearance, r (s)=-0.28, 0.24. Increasing 24 h urinary sodium improved creatinine clearance, r (s)=0.37. P-values ranged from <0.05 to <0.001. CONCLUSION: Higher levels of SCI correlate with reduced sodium conservation, hypotension, polydipsia, and hyponatremia. Greater water intake raises creatinine clearance but lowers serum sodium. Greater salt intake increases creatinine clearance.

Unstable baseline blood pressure in chronic tetraplegia.

STUDY DESIGN: Case-control. OBJECTIVE: Tetraplegic patients are subject to episodes of autonomic dysreflexia and postural hypotension. It is suggested that these patients sustain, in addition, unstable baseline blood pressure (BP) that is independent of symptoms and body position. METHODS: BP monitoring was conducted in 10 tetraplegic patients, motor and sensory complete (American Spinal Injury Association (ASIA) A) (Group A), and five paraplegic at T8-T10 levels, ASIA A (Group B). A SpaceLabs automatically inflating pneumatic cuff recorded arm pressures at 10-30 min intervals in the daytime, sitting position and at 30 min intervals in the night-time, recumbent position. Group mean arterial pressure (MAP) and MAP standard deviation (MAP variation) for sitting and recumbent positions were compared. RESULTS: Sitting the MAP for Group A was less than that of Group B; 87+/-9 versus 108+/-7 mmHg, P<0.01. However, MAP variability for Group A was greater than for Group B; 17+/-4 (20% of MAP) versus 13+/-2 mmHg (12% of MAP), P=0.04. In the recumbent position, the MAP for Group A was similar to that for Group B; 87+/-13 versus 97+/-7 mmHg, P=0.16. However, MAP variability for Group A remained higher than for Group B; 13+/-3 (20% of MAP) versus 8+/-2 mmHg (8% of MAP), P=0.02. CONCLUSION: Tetraplegic patients demonstrate unstable BP in either the sitting or recumbent position compared with low thoracic paraplegic patients.

Prostate atrophy and spinal cord lesions.

STUDY DESIGN: A single blinded, quantifiable survey of prostate size in spinal cord injury (SCI) patients. OBJECTIVE: A small prostate gland is sometimes found on routine digital rectal examination (DRE) in SCI patients. Interruption of neurohormonal supply to the prostate gland might lead to atrophy. To test this interpretation, transrectal ultrasonic (TRUS) examinations have been carried out in SCI patients stratified by severity of paralysis. SUBJECTS: Nine severely paralyzed spinal cord-injured men (levels at T10 or above and ASIA A, B, or C) were compared with 12 less severely paralyzed men (levels lower than T10 at any grade or ASIA D at any level). The groups were age matched. METHODS: All patients were examined with a 90 degrees sector TRUS probe that measured the prostate gland in three dimensions and calculated the prostate volume and weight. Prostate-specific antigen (PSA) levels were also measured. RESULTS: By TRUS the prostate size was smaller in the severely paralyzed (range 8-16 g, mean 13 g) than in the less severely paralyzed (range 10-70 g, mean 28 g), P=0.02. The PSA level of the severely paralyzed group tended to be lower (0.5-2.1, mean 0.7 ng/ml versus 0.5-10.4, mean 2.2 ng/ml), P=0.08. CONCLUSION: The prostate gland of severely paralyzed SCI patients is small. Interruption of neurohormonal pathways due to extensive cord damage may be a factor.

An animal model for venous thrombosis and spontaneous pulmonary embolism.

STUDY DESIGN: An animal model. OBJECTIVE: To test the natural sequence of venous thrombosis and pulmonary thromboembolism experimentally. SETTING: Veterans Administration Hospital, USA. METHOD: In dogs, a venous thrombosis was induced in a isolated segment of the internal jugular vein by a 5 min exposure to sodium morrhuate and then re-establishing venous patency. A tracer, (125)I human fibrinogen, was administered through another vein 1 h prior to the end of each experiment when a blood sample, the venous thrombus, and the lungs were removed. Thrombi were described by age, weight, histology, and fibrin uptake (thrombus to blood radioactivity ratio, g/g). Pulmonary emboli (PE) were identified by autoradiography of lung slices or by microscopic examination of lung sections. RESULTS: Venous thrombosis developed in all experiments, duration 1-64, median 5 h (n=12). Histologically, younger thrombi were characterized by platelet aggregates surrounded by polymorphonuclear leukocytes (PMN), and uniform fibrin deposit; the older thrombi by platelet ghost cells, fewer PMN leukocytes, and broken fibrin strands and loops (n=6). Pulmonary thromboemboli were imaged as 'hot spots' in six of six experiments in which lung slices were autoradiographed and were identified microscopically in six of six experiments in which lung sections were taken. The number of PE diagnosed microscopically did not correlate with the age of the corresponding thrombus but was directly related to fibrin uptake (n=5, r=0.99, P<0.01). CONCLUSION: An animal model for venous thrombosis that generates pulmonary thromboembolism has been described.

Recurrent pulmonary embolism and pulmonary hypertension in chronic tetraplegia.

STUDY DESIGN: Case report. OBJECTIVE: To describe an unusual case of progressive pulmonary hypertension due to recurrent pulmonary embolism in a chronically paralyzed spinal cord injury patient. SETTING: Veterans Administration Hospital, West Roxbury, MA, USA. SUBJECT: A 57-year-old man, tetraplegic, sensory incomplete and motor complete for 30 years due to a diving accident, complained of lightheadedness and shortness of breath intermittently for 7 years. Examination during the latest episode revealed anxiety, confusion, respirations 28 per min, blood pressure 80/60 mmHg, and arterial pH 7.41, P(CO2) 28 mmHg, P(O2) 95 mmHg on 2 l of oxygen. A chest film 2 weeks earlier had revealed a right-sided cutoff of pulmonary vasculature; the current film showed right-sided pleural effusion. Review of EKGs showed a trend of increasing right axis deviation with recovery and recurrences during the previous 9 years and a current incomplete right bundle branch block with clockwise rotation and inverted T waves in V1-4. Computerized tomography with contrast material revealed small pulmonary emboli, but only in retrospect. The patient died shortly after scanning. AUTOPSY: The pulmonary arteries were free of thromboemboli on gross examination but medium and small-sized arteries were constricted or obliterated with thrombotic material microscopically. The estimated ages of the thromboemboli ranged from days to years. The right ventricle was hypertrophied; the coronary arteries were patent. CONCLUSION: Recurrent pulmonary emboli resulted in chronic pulmonary hypertension and eventual death in a patient with chronic tetraplegia.

Breathing and the support of blood pressure after spinal cord injury.

STUDY DESIGN: Literature review. OBJECTIVES: The recognized effect of breathing on venous return and cardiac output has not been assessed in the spinal cord injury (SCI) patient. To test this effect indirectly, the breathing capacity and blood pressure have been compared at various levels of SCI. SETTING: SCI service, Massachusetts, USA. METHODS: Spinal cord-injured subjects with complete motor paralysis were studied. The forced vital capacity (FVC) (one study, 455 subjects, 91% male) was compared with the mean blood pressure (MBP) (one study, 461 subjects, 100% male) of subjects by level of paralysis. RESULTS: For lumbar to cervical levels of paralysis, FVC and MBP each diminish progressively. To compare FVC directly with MBP by level of paralysis, r=0.85, P<0.001. CONCLUSION: Breathing capacity is correlated with blood pressure in SCI patients.

Cheyne-Stokes respiration, periodic circulation, and pulsus alternans in spinal cord injury patients.

STUDY DESIGN: Case reports. OBJECTIVES: To describe Cheyne-Stokes respiration (CSR) and associated circulatory abnormalities in three patients with spinal cord lesions. SETTING: Veterans Administration Hospital, USA. SUBJECTS: One paraplegic patient with coronary artery disease in congestive heart failure, one tetraplegic patient with alcoholic cardiomyopathy and postural hypotension, and one tetraplegic complete patient with cardiomegaly, severe aortic atherosclerosis, and postural hypotension. METHODS: Breathing activity was measured with a nasal thermistor or abdominal stretch transducer. Cardiac activity was estimated with a photoelectric sensor for cutaneous blood flow placed on the forehead or a piezoelectric transducer for pressure positioned over an artery or the cardiac apex. Tracings were drawn on a strip chart recorder. The subjects were at rest in semireclining positions. RESULTS: Survey times were 17-21 min, and cycling periods were 41-72 s. Periodic changes in the depth of breathing were accompanied by periodic changes in amplitude of forehead cutaneous pulse, blood pressure, or apical cardiac impulse in all patients. Peak circulation occurred at or following peak respiration. In addition, cyclical pulsus alternans occurred in two patients. CONCLUSION: Three spinal cord injury patients sustained CSR and circulatory periodicity associated with cardiac disease and postural hypotension.