J W H Watt

Delayed diaphragm recovery in 12 patients after high cervical spinal cord injury. A retrospective review of the diaphragm status of 107 patients ventilated after acute spinal cord injury.

Study Design: The functional outcome of the diaphragm after acute spinal cord injury was reviewed over a 16 year period for 107 patients who had required assisted ventilation in the acute phase. Objectives: To quantify the incidence of recovery of diaphragm function which occurred beyond the period of acute oedema; to produce a time-related profile of this as a guide to clinicians considering phrenic nerve pacing; and to assess the value of phrenic nerve testing in predicting recovery. Setting: The Southport Regional Spinal Injuries Centre, Southport, England. Methods: Bilateral phrenic nerve and diaphragm integrity was assessed clinically, by spirometry, and by fluoroscopy without and with phrenic nerve stimulation. Results: Thirty-one per cent of all the ventilated patients (33 cases), with a level of injury between C1 and C4 (Scale A in ASIA Impairment Scale), had diaphragmatic paralysis at the time of respiratory failure. The subsequent diaphragm recovery which appeared in seven of these patients, between 40 and 393 days (mean 143), permitted weaning from ventilatory support at 93 to 430 days (mean 246) after the acute injury, with a vital capacity of over 15 ml kg−1 at that stage. The diaphragm recovery in a further five patients, whose vital capacity remained below 10 ml kg−1 and who could not be fully weaned, occurred significantly later, between 84 and 569 days (mean 290), P=0.053. Negative phrenic nerve tests were followed by weaning at a later interval in several cases. By contrast, one patient with an early positive phrenic stimulation test and subsequent diaphragm activity could not be weaned from the ventilator. Conclusion: Twenty-one per cent of the patients with initial diaphragm paralysis were ultimately able to breathe independently after 4 and 14 months, whilst a further 15% had some diaphragm recovery. Phrenic nerve testing should be repeated at 3 monthly intervals for the first year after high tetraplegia.

Pathophysiology of autonomic dysreflexia: long-term treatment with terazosin in adult and paediatric spinal cord injury patients manifesting recurrent dysreflexic episodes.

Introduction: Spinal cord injury (SCI) results in disruption of synaptic influences on the sympathetic preganglionic neurones. Remodelling of spinal cord circuits takes place in spinal neurones caudal to cord injury. There is an increased vascular alpha-adrenoceptor responsiveness, and peripheral afferent (bladder) stimulation in SCI subjects induces a marked noradrenaline spillover below the level of spinal lesion. These neurophysiological changes possibly contribute to the development of autonomic dysreflexia, a condition of sympathetic hyper-excitability that develops after cervical, or upper dorsal cord injury with resultant paroxysmal rise in arterial pressure, and provide the scientific basis for the use of terazosin, a once-a-day, selective alpha-one adrenergic blocking drug. Objectives: The use of terazosin, a long-acting, alpha 1-selective blocking agent was investigated in SCI patients who developed recurrent symptoms of autonomic dysreflexia, eg headache, sweating flushing of the face together with an increase in the arterial pressure. Design: An open, prospective study of the efficacy of terazosin in controlling recurrent autonomic dysreflexia in traumatic tetraplegic/paraplegic patients manifesting clinical features of dysreflexia in the absence of an acute precipitating cause such as a blocked catheter. Setting: The initial assessment and treatment were carried out in the Spinal Injuries Centre. Subsequently, the patients were followed-up in the community. They were monitored by telephonic interviews, follow-up visits by the patients to the hospital, and home-visits by the staff of the spinal unit. Subjects: Eighteen adults with tetraplegia (female: 1; male: 17), three children with ventilator-dependent tetraplegia and three adult male patients with paraplegia who exhibited recurrent features of autonomic dysreflexia in the absence of an acute predisposing factor for dysreflexia eg performance of an invasive procedure such as cystoscopy, digital evacuation of bowels, or acute urinary retention, were enrolled in this study.Intervention: After discussion with the patients and their carers, terazosin was prescribed with a starting dose of 1 mg in an adult and 0.5 mg in a child administered nocte. The patients were observed for (1) drug-induced hypotension; (2) clinical symptoms due to side effects of terazosin; and (3) continued occurrence of dysreflexic symptoms. Step-wise increments of the dose of terazosin (1 mg in case of adults, and 0.5 mg in a child) was carried out at intervals of 3–4 days, if a patient continued to develop dysreflexia but did not manifest any serious side effect. Outcome measures: Complete subsidence of dysreflexic symptoms, or development of an adverse event necessitating termination of the terazosin therapy was the clinical end point. Results: The dysreflexic symptoms subsided completely with the terazosin therapy in all the patients. The twenty-one adult patients required a dose varying from 1–10 mg, whereas the paediatric patients required only 1–2 mg of terazosin. The side effects of postural hypotension and drowsiness were transient, and mild. One tetraplegic patient developed persistent dizziness and therefore, the drug therapy was discontinued. Conclusion: In 21 adult and three paediatric spinal cord injury patients manifesting recurrent episodes of autonomic dysreflexia in the absence of an acute predisposing cause, the use of terazosin, a once-a-day, specific alpha-one blocker resulted in complete subsidence of the dysreflexic symptoms. However, one tetraplegic patient required termination of terazosin therapy because of persistent dizziness.

A retrospective study of hyponatremia in tetraplegic/paraplegic patients with a review of the literature

The aetiology of hyponatremia in tetraplegic patients is multifactorial and includes not only general factors such as the use of diuretics and the intravenous infusion of hypotonic fluids, but also certain mechanisms which operate in the spinal cord injured: decreased renal water excretion due to both intrarenal and arginine vasopressin dependent mechanisms (resetting of the osmostat), coupled with habitually increased fluid intake, and the ingestion of a low salt diet. Between 1984 and 1993 we treated 28 episodes of hyponatremia in 19 patients (males: 10; females: 9). Fourteen were tetraplegic and five paraplegic (thoracic lesion in four and lumbar lesion in one). Six patients were asymptomatic during seven episodes of hyponatremia which were detected during routine blood tests. Seven patients were suffering from an acute chest infection, three had an acute urinary tract infection, one had an infected ischial pressure sore and a 69 year old paraplegic patient had bronchopneumonia as well as sepsis from a gangrenous pressure sore in the supraanal region. The time interval between the onset of paralysis and occurrence of the first episode of hypnoatremia was less than a month in only four of the patients. The lowest plasma sodium level observed was less than 100mmol/l in two, between 100 and 110mmol/l in four, between 111 and 120mmol/l in eight patients, and between 121 and 128mmol/l in 14 cases. Six patients also had hypokalemia (K+ < 3 mmol/l). Only one patient had an elevated plasma creatinine (201umol/l). Treatment of sepsis and fluid restriction were the mainstay of treatment with only two patients receiving hypertonic saline. All patients with underlying sepsis were treated with antibiotics, usually administered intravenously. The outcome was good in 26 of the 28 episodes.Two patients died: a 68 year old tetraplegic patient with consolidation of the left lung, cystadenocarcinoma of both ovaries and squamous cell carcinoma of the forehead who presented with generalised oedema, with a plasma sodium level of 118 mmol/l, and potassium of 2.4 mmol/l and who was treated with 2N saline + postassium + frusemide; she died 1 day later. The only other death was that of a 78 year old female tetraplegic patient who 2 days after sustaining cervical trauma developed hyponatremia because of intravenous infusion of hypotonic fluids given at another hospital, presumably to correct hypotension. She recovered from hyponatremia with fluid restriction, but 3 days later she succumbed to bronchopneumonia and respiratory insufficiency. No patient developed central pontine myelinolysis. No patient with a severe degree of hyponatremia (sodium < 100 mmol/l) had respiratory involvement requiring ventilatory assistance. In conclusion, hyponatremia is seen in tetraplegic patients often in association with sepsis either in the lungs or in the urinary tract, and is best managed by treament of the predisposing factor(s) along with fluid restriction.

Silent hydronephrosis/pyonephrosis due to upper urinary tract calculi in spinal cord injury patients.

Study design: A study of four patients with spinal cord injury (SCI) in whom a diagnosis of hydronephrosis or pyonephrosis was delayed since these patients did not manifest the traditional signs and symptoms.Objectives: To learn from these cases as to what steps should be taken to prevent any delay in the diagnosis and treatment of hydronephrosis/pyonephrosis in SCI patients.Setting: Regional Spinal Injuries Centre, Southport, UK.Methods: A retrospective review of cases of hydronephrosis or pyonephrosis due to renal/ureteric calculus in SCI patients between 1994 and 1999, in whom there was a delay in diagnosis.Results: A T-5 paraplegic patient had two episodes of urinary tract infection (UTI) which were successfully treated with antibiotics. When he developed UTI again, an intravenous urography (IVU) was performed. The IVU revealed a non-visualised kidney and a renal pelvic calculus. In a T-6 paraplegic patient, the classical symptom of flank pain was absent, and the symptoms of sweating and increased spasms were attributed to a syrinx. A routine IVU showed non-visualisation of the left kidney with a stone impacted in the pelviureteric junction. In two tetraplegic patients, an obstructed kidney became infected, and there was a delay in the diagnosis of pyonephrosis. The clinicians attention was focused on a co-existent, serious, infective pathology elsewhere. The primary focus of sepsis was chest infection in one patient and a deep pressure sore in the other. The former patient succumbed to chest infection and autopsy revealed pyonephrosis with an abscess between the left kidney and left hemi-diaphragm and xanthogranulomatous inflammation of perinephric fatty tissue. In the latter patient, an abdominal X-ray did not reveal any calculus but computerised axial tomography showed the presence of renal and ureteric calculi.Conclusions: The symptoms of hydronephrosis may be bizarre and non-specific in SCI patients. The symptoms include feeling unwell, abdominal discomfort, increased spasms, and autonomic dysreflexia. Physicians should be aware of the serious import of these symptoms in SCI patients.

Bilateral extracorporeal shock wave lithotripsy in a spinal cord injury patient with a cardiac pacemaker

Objectives: To review the precautions to be observed before and during extracorporeal shock wave lithotripsy (ESWL) in spinal cord injury (SCI) patients with a cardiac pacemaker and the safety of bilateral ESWL performed on the same day.Design: A case report of bilateral ESWL in a SCI patient with a permanent cardiac pacemaker.Setting: The Regional Spinal Injuries Centre, Southport, the Lithotripsy Unit, the Royal Liverpool University Hospitals NHS Trust, Liverpool, and the Department of Cardiology, Manchester Royal Infirmary, Manchester, UK.Subject: A 43-year-old male sustained a T-4 fracture and developed paraplegia with a sensory level at T-2. During the post-injury period, he developed episodes of asystole requiring implantation of a dual chamber (DDD) permanent pacemaker. Twenty-one months later, he developed a right ureteric calculus with hydronephrosis. A radio-opaque shadow was seen in the left kidney with no hydronephrosis. During right ureteric stenting, the ureteric stone was pushed into the renal pelvis. 1,500 shock waves were delivered to this stone on the right side, followed by ESWL to the left intra-renal stone with 1250 shock waves.Results: The patient tolerated ESWL to both kidneys. The pacemaker was reprogrammed to a single chamber ventricular pacing mode at 30 beats per minute with a reduced sensitivity during lithotripsy. There were no untoward cardiac events during or after lithotripsy. The serum creatinine was 45 μmol/l before lithotripsy and 44 μmol/l two weeks after ESWL.Conclusion: SCI patients with a cardiac pacemaker may be able to undergo extracorporeal shock wave lithotripsy following temporary reprogramming of the pacemaker. Bilateral, simultaneous ESWL is safe in the vast majority of patients provided that there is no risk of simultaneous ureteric obstruction by stone fragments. However, it should be remembered that a decrease in renal function could occur following bilateral ESWL of renal calculi.Spinal Cord (2001) 39, 286–289.

Bladder stones - red herring for resurgence of spasticity in a spinal cord injury patient with implantation of Medtronic Synchromed pump for intrathecal delivery of baclofen - a case report.

BackgroundIncreased spasms in spinal cord injury (SCI) patients, whose spasticity was previously well controlled with intrathecal baclofen therapy, are due to (in order of frequency) drug tolerance, increased stimulus, low reservoir volume, catheter malfunction, disease progression, human error, and pump mechanical failure. We present a SCI patient, in whom bladder calculi acted as red herring for increased spasticity whereas the real cause was spontaneous extrusion of catheter from intrathecal space.Case PresentationA 44-year-old male sustained a fracture of C5/6 and incomplete tetraplegia at C-8 level. Medtronic Synchromed pump for intrathecal baclofen therapy was implanted 13 months later to control severe spasticity. The tip of catheter was placed at T-10 level. The initial dose of baclofen was 300 micrograms/day of baclofen, administered by a simple continuous infusion. During a nine-month period, he required increasing doses of baclofen (875 micrograms/day) to control spasticity. X-ray of abdomen showed multiple radio opaque shadows in the region of urinary bladder. No malfunction of the pump was detected. Therefore, increased spasticity was attributed to bladder stones. Electrohydraulic lithotripsy of bladder stones was carried out successfully. Even after removal of bladder stones, this patient required further increases in the dose of intrathecal baclofen (950, 1050, 1200 and then 1300 micrograms/day). Careful evaluation of pump-catheter system revealed that the catheter had extruded spontaneously and was lying in the paraspinal space at L-4, where the catheter had been anchored before it entered the subarachnoid space. A new catheter was passed into the subarachnoid space and the tip of catheter was located at T-8 level. The dose of intrathecal baclofen was decreased to 300 micrograms/day.ConclusionVesical calculi acted as red herring for resurgence of spasticity. The real cause for increased spasms was spontaneous extrusion of whole length of catheter from subarachnoid space. Repeated bending forwards and straightening of torso for pressure relief and during transfers from wheel chair probably contributed to spontaneous extrusion of catheter from spinal canal in this patient.

Dosage of once-daily gentamicin in spinal cord injury patients

Introduction: In patients with spinal cord injury (SCI), serum creatinine does not accurately reflect the level of renal function. Therefore, in SCI patients, the dose of potentially nephrotoxic drugs should be adjusted on an individual basis from the estimated creatinine clearance. Case Report: A 41-year-old male with tetraplegia due to cervical spinal cord injury underwent extended pyelolithotomy for staghorn calculus in the right kidney. The blood urea level was 9.9 mmol/l; creatinine was 112 umol/l (reference range: 0–135). We were conscious of this patients renal disease, and therefore, administered only 3 mg/kg of gentamicin (240 mg) instead of the standard dose of 5 mg/kg body weight. Despite taking this precaution, the gentamicin level measured 22.5 h after the initial dose, was in the potentially toxic range–3.3 mg/l. Conclusion: We recommend that even the first dose of gentamicin in the once-daily regimen, which is 5 mg/kg, should be individualised in SCI patients based on age, sex, weight, height, level of spinal cord injury, and renal function. Spinal Cord (2000) 38, 197–198.

Community-care waiting list for persons with spinal cord injury

Objectives: To disseminate the concept of community care waiting lists for spinal cord injury (SCI) patients with particular reference to carer support for management of neuropathic bladder by a regime of intermittent catheterisation.Methodology: The surgical waiting list focuses only on operative procedures, and ignores the wider requirements for ensuring satisfactory rehabilitation of people with spinal cord injury in the community. A community-care waiting list for individuals with spinal cord injury should include the following aspects of community care: (1) Home adaptation; (2) Provision of appropriate mobility needs (including wheelchair and cushion); (3) Equipment for comfortable living (including provision of hoist, pressure relieving mattress); (4) Psychological support for spinal cord injury patients and their partners; (5) Nursing home or residential care placement where appropriate; (6) Carer support for global management of complex needs associated with spinal cord injury (eg neuropathic bladder and bowel).Results: Whereas full physical adaptation of the home can wait for some time after discharge, carer support for intermittent catheterisation is required from the first day after discharge from a spinal unit. Lack of such support means that some SCI patients are discharged with long-term indwelling urinary catheters, even though clean intermittent catheterisation is known to be the safest regime for managing the neuropathic bladder. Therefore, the absence of a community care waiting list means that best practice cannot be achieved for some tetraplegic subjects.Conclusion: We believe that a community care waiting list for bladder management will help to provide optimum care for neuropathic bladder and, hopefully, reduce the complications related to long-term indwelling catheters in spinal cord injury patients.Spinal Cord (2001) 39, 584–588.

Intravenous salbutamol treatment for penile erection arising during cystoscopy of cervical spinal cord injury patients

Two patients with long-standing tetraplegia after spinal cord injury developed reflex penile erection in the operation theatre. One had not received any anaesthesia, and penile erection occurred after introduction of the cystoscope into the urethra, and also autonomic dysreflexia. Intravenous salbutamol, in a dose of 10 micrograms, produced immediate and persistent penile detumescence and salbutamol-induced fall in blood pressure was of therapeutic value. In the second patient, penile erection occurred during general anaesthesia prior to cystoscopy. Immediate and persistent penile detumescence was achieved with intravenous salbutamol 20 micrograms. There was transient fall of blood pressure which responded to intravenous infusion of 0.9% sodium chloride. Salbutamol-induced fall in blood pressure is of therapeutic value in those spinal cord injury patients who develop, in addition to penile erection, autonomie dysreflexia precipitated by urethral instrumentation, or bladder distension with the irrigating fluid. Intravenous salbutamol is preferable to intra-cavernosal phenylephrine, noradrenaline, metaraminol, and epinephrine, or intravenous ephedrine which are contra-indicated in patients with hypertension.

Calculus anuria in a spina bifida patient, who had solitary functioning kidney and recurrent renal calculi.

Study design: Clinical case report with comments by colleagues from Austria, Belgium, Germany, Japan, and Poland.Objectives: To discuss challenges in the management of spinal bifida patients, who have marked kyphoscoliosis and no vascular access.Setting: Regional Spinal Injuries Centre, Southport, UK.Methods: A female patient, who was born with spina bifida, paraplegia and solitary right kidney, had undergone ileal loop urinary diversion. Renal calculi were noted in 1986. Percutaneous nephrostolithotomy was performed in 1989 and there was no residual stone fragment. However, she developed recurrence of calculi in the lower pole of the right kidney in 1991. Intravenous urography, performed in 1995, revealed right staghorn calculus and hydronephrosis. Chest X-ray showed markedly restricted lung volume due to severe kyphoscoliosis. In 2000, she was declared unsuitable for anaesthesia due to a lack of venous access and a high likelihood of difficulty in weaning off the ventilator in the postoperative period. In June 2002, she developed anuria (urine output=18 ml/24 h) due to ball-valve-type obstruction by a renal stone at the ureteropelvic junction. Urea: 14.4 mmol/l; creatinine: 236 μl/l. Ultrasound showed right hydronephrosis. Percutaneous nephrostomy was performed.Results: Following relief of urinary tract obstruction, there was postobstructive diuresis (3765 ml/24 h). However, the patient expired 19 days later due to progressive respiratory failure.Conclusion: In this spina bifida patient, who had reached the age of 35 years, severe kyphoscoliosis and lack of vascular access presented insurmountable challenges to implement the desired surgical procedure for removal of stones from a solitary kidney.