Hyponatraemia after acute spinal injury

Incidence of and factors associated with hyponatremia in traumatic cervical spinal cord injury patients

STUDY DESIGN

Retrospective study.

OBJECTIVE

To investigate the incidence of and factors associated with hyponatremia among traumatic cervical spinal cord injury (SCI) patients.

SETTING

Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.

METHODS

This retrospective study included traumatic cervical SCI patients that were admitted to the Siriraj Spinal Unit during January 2002 to May 2013. Patient demographic and clinical data were collected.

RESULTS

One hundred and twenty-three patients (98 males, 25 females) were enrolled. The mean age of patients was 47.2 ± 16.9 years (range: 11-84). There were 38 complete and 85 incomplete cord injuries. Seventy-six patients were treated surgically, and all others received conservative treatment. Hyponatremia developed in 54 patients (43.9%), and 74.1% of all cases of hyponatremia presented within 9 days after SCI. Hyponatremia occurred on the first day in 10 patients (18.5%), on the fifth day in 6 patients (11.1%), and on the eighth day in 5 patients (9.26%). Hyponatremia occurred in 6/10 patients (60.0%) with upper cervical spine injury (C1-2), and in 48/113 patients (42.5%) with lower cervical spine injury (C3-7) (odds ratio [OR]: 2.031, 95% confidence interval [CI]: 0.543-7.596; p = 0.292). The incidence of hyponatremia was 65.8% in complete SCI patients, and 34.1% in incomplete SCI patients. Logistic regression analysis revealed complete SCI to be the only factor significantly associated with hyponatremia (OR: 3.714, 95% CI: 1.658-8.317; p < 0.001).

CONCLUSION

Hyponatremia was found to be common in post-traumatic cervical SCI patients. Complete SCI was identified as the only factor significantly associated with hyponatremia in traumatic cervical SCI patients.

Influence of early extensive posterior decompression on hyponatremia and cardiopulmonary dysfunction after severe traumatic cervical spinal cord injury: A clinical observational study

Retrospective single institution observational study.The aim of the present study was to analyze the influence of early extensive posterior decompression on complications in patients with severe traumatic cervical spinal cord injury (tcSCI).Cervical SCI is associated with a high prevalence of hyponatremia and cardiopulmonary dysfunction. However, very few studies have focused on this exploration to reduce the incidence of SCI early complications.We reviewed the medical records of consecutive patients undergoing extensive posterior decompression within 24 h for severe tcSCI (American Spinal Injury Association Impairment Scale [AIS] A to C) admitted between January 2009 and January 2018. The data collected retrospectively included age, gender, mechanism, and level of SCI, AIS grade, fracture or dislocation, electrolyte, and cardiopulmonary complications.Of the 97 enrolled patients, the baseline AIS grade was AIS A in 14, AIS B in 31, and AIS C in 52. Improvement of at least two AIS grades was found in 26 (26.8%), and improvement of at least one grade was found in 80.4% of patients at discharge. Twenty-nine (29.9%) patients had mild hyponatremia, 8 (8.2%) had moderate hyponatremia, and 3 (3.1%) had severe hyponatremia during hospitalization. The incidences of hyponatremia, hypotension, and tracheotomy were 41.2%, 13.4%, and 6.2%, respectively. The mean forced vital capacity (FVC) on admission and at discharge was 1.34 ± 0.46 L and 2.21 ± 0.41 L (P < .0001), respectively. Five patients developed pneumonia.Our results suggest that early expansive posterior decompression significantly reduces the incidence of hyponatremia, hypotension, and tracheotomy by promoting recovery of spinal cord function after severe tcSCI.

Analysis of risk factors for hyponatremia in patients with acute spinal cord injury: a retrospective single-institution study in Japan

STUDY DESIGN

Retrospective single-institution observational study.

OBJECTIVE

Spinal cord injury (SCI) is associated with a high prevalence of hyponatremia, which can cause various clinical symptoms and increase mortality. We aimed to analyze the risk factors for hyponatremia in patients with acute SCI.

SETTING

Trauma Center, Tohoku University Hospital, Japan METHODS: We reviewed the medical records of patients with SCI admitted between January 2008 and November 2016. Least angle regression analyses was performed to assess the association between hyponatremia and other parameters.

RESULTS

Of the 213 enrolled patients, 85 (40%) had hyponatremia (serum Na < 135 mmol/L) whilst 19 (9%) had severe hyponatremia (serum Na < 130 mmol/L). Least angle regression analyses revealed that hyponatremia was significantly associated with higher American Spinal Injury Association impairment scale, nosocomial pneumonia, deep vein thrombosis, bradycardia, and surgery for SCI before developing hyponatremia. Severe hyponatremia was significantly associated with traumatic brain injury with an abbreviated injury scale score ≥3, higher American Spinal Injury Association impairment scale, bradycardia, vasopressors, and nosocomial pneumonia.

CONCLUSION

Various factors including traumatic brain injury with an abbreviated injury scale score ≥3 and higher American Spinal Injury Association impairment scale may be associated with hyponatremia in patients with acute SCI. These factors can help clinicians identify and monitor SCI patients with a higher hyponatremia risk, and potentially help patients to avoid severe complications.

Effects of exercise training on urinary tract function after spinal cord injury

Spinal cord injury (SCI) causes dramatic changes in the quality of life, including coping with bladder dysfunction which requires repeated daily and nightly catheterizations. Our laboratory has recently demonstrated in a rat SCI model that repetitive sensory information generated through task-specific stepping and/or loading can improve nonlocomotor functions, including bladder function (Ward PJ, Herrity AN, Smith RR, Willhite A, Harrison BJ, Petruska JC, Harkema SJ, Hubscher CH. J Neurotrauma 31: 819-833, 2014). To target potential underlying mechanisms, the current study included a forelimb-only exercise group to ascertain whether improvements may be attributed to general activity effects that impact target organ-neural interactions or to plasticity of the lumbosacral circuitry that receives convergent somatovisceral inputs. Male Wistar rats received a T9 contusion injury and were randomly assigned to three groups 2 wk postinjury: quadrupedal locomotion, forelimb exercise, or a nontrained group. Throughout the study (including preinjury), all animals were placed in metabolic cages once a week for 24 h to monitor water intake and urine output. Following the 10-wk period of daily 1-h treadmill training, awake cystometry data were collected and bladder and kidney tissue harvested for analysis. Metabolic cage frequency-volume measurements of voiding and cystometry reveal an impact of exercise training on multiple SCI-induced impairments related to various aspects of urinary tract function. Improvements in both the quadrupedal and forelimb-trained groups implicate underlying mechanisms beyond repetitive sensory information from the hindlimbs driving spinal network excitability of the lumbosacral urogenital neural circuitry. Furthermore, the impact of exercise training on the upper urinary tract (kidney) underscores the health benefit of activity-based training on the entire urinary system within the SCI population.

Increase in urinary sodium excretion in spinal cord injury patients in the emergency department

OBJECTIVE

Spinal cord injury (SCI) is a pathological condition known to produce hyponatremia. The aim of this study was to elucidate the dynamics of urinary sodium excretion in patients with spinal cord injury.

METHODS

SCI patients undergoing intensive care management were enrolled in this study. These patients were divided into two groups: those with Frankel Grade A spinal cord injury manifesting complete, severe motor disorders (FA group) and those with incomplete spinal cord injury (non-FA group). The occurrence of episode of hyponatremia (serum sodium <135 mmol/L), hypotension, and bradycardia during the first 14 hospital days was counted and fractional excretion of sodium (FENa) was calculated on the 1st, 7th, and 14th hospital days.

RESULTS

Thirty-four patients (FA group, n = 9; non-FA group, n = 25) were included. Eight patients (88.9 %) in the FA group and three patients (12 %) in the non-FA group experienced at least one episode of hyponatremia during the first 14 hospital days. In the FA group, the FENa was significantly increased on the 7th and 14th hospital days compared to the 1st hospital day. FENa on the 14th hospital day was a significant independent predictor of hyponatremic episodes. Hypotension and bradycardia as the symptoms of sympathetic blockade differed significantly as independent predictors of increased FENa on the 14th hospital day.

CONCLUSION

Urinary sodium excretion calculated by FENa increased in patients with severe spinal cord injury. Sympathetic blockade due to SCI may increase urine sodium excretion and lead to hyponatremia.

A case of hyponatremia after cervical spinal cord injury

Hyponatremia is known as a complication of neurosurgical conditions or brain. The prevalence of hyponatremia in acute spinal cord injury has been known to be much higher than in the general medical or surgical patient population. We report here a case of hyponatremia, which occurred 10 days after cervical spinal cord injury. The data on sodium levels were improved under the tapered infusion volume and water intake restriction. Treatment for this case is the same as that for syndrome of inappropriate antidiuretic hormone, which have suggested that reduced extracellular volume is important to improve the hyponatremia after traumatic spinal cord injury. Uncontrolled hyponatremia may lead to lethargy, seizures, coma, cardiac arrhythmia and death. Therefore, the complication of hyponatremia should be paid attention after cervical spinal cord injury. A careful monitoring of sodium levels after the injury is required in the cases of cervical spinal cord injury.

Hyponatremia in the acute stage after traumatic cervical spinal cord injury: clinical and neuroanatomic evidence for autonomic dysfunction

STUDY DESIGN

Retrospective cohort study supplemented by analysis of postmortem spinal cord tissue.

OBJECTIVES

This study examines the frequency of hyponatremia in early stage (2 weeks) after cervical spinal cord injury (SCI), and the relationship between integrity of key autonomic pathways and hyponatremia.

SUMMARY OF BACKGROUND DATA

Interruption of key circuits in the spinal cord can induce autonomic dysfunction with disordered metabolic and physiologic homeostasis. Given that hyponatremia may be a common electrolyte disorder during the acute stage post-SCI, we hypothesized that disconnection of descending sympathetic renal spinal cord tracts may be associated with hyponatremia after SCI.

METHODS

Consecutive individuals with cervical spine trauma were included in our cohort of patients, which was divided into a SCI group and a control group (patients with spine trauma without SCI). Also, postmortem spinal cord sections from individuals with cervical, motor complete SCI, and control cases without CNS trauma were evaluated regarding the extent of axonal preservation within the descending vasomotor pathways, the descending renal sympathetic pathways (DRSPs), the corticospinal tracts, and the dorsal columns.

RESULTS

There were 21 SCI individuals (6 women, 15 men; ages, 17-83 years; mean, 57.1) and 12 patients in the control spine trauma group who did not have SCI (4 women, 8 men; ages 18-90 years; mean, 45.9). Patients had either motor complete (7/21) or motor incomplete (14/21) tetraplegia. Hyponatremia occurred in 85.7% after SCI, which was significantly more frequent than the control group. Postmortem analysis included 5 control cases and 6 SCI individuals of whom 3 developed hyponatremia. The number of preserved axons within the DRSPs from normonatremic SCI patients was significantly lower than the number of axons within DRSPs from hyponatremic SCI patients, but development of hyponatremia was not associated with the integrity of the descending vasomotor pathways. Hyponatremic SCI individuals also showed greater evidence of neurogenic hypotension than normonatremic SCI individuals.

CONCLUSION

Hyponatremia is common in the early stage post-SCI. Our results also suggest that hyponatremia is associated with the integrity of descending renal sympathetic circuits which mediate the renin-angiotensin response to neural injury, in the setting of neurogenic hypotension with cardiovascular dysfunction.

Hyponatremia-induced transient visual disturbances in acute spinal cord injury

STUDY DESIGN

Case report and literature review.

OBJECTIVE

To report an unusual case of prolonged hyponatremia in acute cervical spinal cord injury complicated by visual disturbances and to review the literature regarding the issue.

SETTINGS

Spinal Cord Injury Unit in Göteborg, Sweden.

METHODS

Retrospective analysis of clinical charts of an individual with traumatic spinal cord injury.

RESULTS

A previously healthy 28-year-old man sustained a C7 injury in a motor vehicle accident. His injury was managed surgically and he was overhydrated during the acute management and postoperatively. When weaned off the respirator he was confused and anxious and showed a S-Na of 127 mmol/1 and complained of visual disturbances. The hyponatremia was treated by extra sodium and fluid restriction but fell to a lowest value of 121 mmol/l (Day 14 post injury). Visual acuity was 0.2 on right eye and 0.06 on left eye and the eye examination revealed signs of fundus hypertonicus. CT scans and MRI revealed no signs of brain edema. The patient was further treated by mineral corticoids and fluid restriction for 4 months and his vision improved slightly, but on a final examination 125 days post injury he was found to have an afferent pupillary defect on his left eye, and bilateral atrophy of the visual nerves. The hyponatremia resolved and 6 months post injury he showed a normal S-Na.

CONCLUSIONS

SCI individuals are at increased risk of developing hyponatremia. The reported complication of visual disturbances further stresses the importance of prevention of overhydration and of timely management of hyponatremia in this group of patients.

[Hyponatremia in neurologic intensive care: cerebral salt wasting syndrome and inappropriate antidiuretic hormone secretion]

Hyponatraemia is a frequent complication in neurologically injured patients; it is a secondary cerebral injury. Hyponatraemia leads to consciousness problems, convulsions, worsening of the neurological status and thus the neurological evaluation. Hyponatraemia is secondary to free water retention (inappropriate ADH secretion) or to renal salt loss. The cerebral salt wasting syndrome (CSWS) has been described with head injury, subarachnoid haemorrhage and after several sorts of brain insults. It is characterised by an increased natriuresis and diuresis. Diagnosis is based on hyponatraemia, hypernatriuresis, increased diuresis and hypovolaemia. However, inappropriate ADH secretion and CSWS share several diagnostic criteria. The atrial natriuretic factor and the C-type natriuretic factors play a role in the development of the CSWS. The diagnostic approach and monitoring are based on the assessment of sodium and water losses. Therapy is based on correction of the circulating volume and natraemia. Speed of correction is a matter of debate: slow correction presents the risk of further neurological injury whereas rapid correction presents the risk of central pontine myelinosis.