Risk factor analysis for low blood pressure and hyponatremia in acutely and subacutely spinal cord injured patients

Mechanisms of hyponatremia and diabetes insipidus after acute spinal cord injury: a critical review

The incidence of hyponatremia after spinal cord injury was reported to be between 25 and 80%. Hyponatremia can lead to a variety of clinical symptoms, from mild to severe and even life-threatening. Hyponatremia is often associated with diabetes insipidus, which refers to insufficient arginine vasopressin (AVP) secretion or defective renal response to AVP, with clinical manifestations of syndromes such as hypoosmolality, polydipsia, and polydipsia. Recent mechanistic studies on hyponatremia and diabetes insipidus after acute spinal cord injury have been performed in isolation, without integrating the above two symptoms into different pathological manifestations that occur in the same injury state and without considering the acute spinal cord injury patient's condition as a whole. The therapeutic principles of CSWS and SIADH are in opposition to one another. It is not easy to identify the mechanism of hyponatremia in clinical practice, which makes selecting the treatment difficult. According to the existing theories, treatments for hyponatremia and diabetes insipidus together are contraindicated, whether the mechanism of hyponatremia is thought to be CSWS or SIADH. In this paper, we review the mechanism of these two pathological manifestations and suggest that our current understanding of the mechanisms of hyponatremia and diabetes insipidus after high acute cervical SCI is insufficient, and it is likely that there are other undetected pathogenetic mechanisms.

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.

A study of predictors for hyponatraemia in patients with cervical spinal cord injury

STUDY DESIGN

A retrospective study.

OBJECTIVES

The objectives of the study were to investigate the predictors for hyponatraemia in patients with cervical spinal cord injuries (CSCIs) and to define the relationship between magnetic resonance imaging (MRI) scans and hyponatraemia.

SETTING

The study was carried out at The First Affiliated Hospital of Anhui Medical University.

METHODS

A total of 292 patients with CSCIs were retrospectively reviewed to determine the predictors of hyponatraemia. Fourteen variables were extracted from the medical records: age, sex, blood pressure (BP), tracheostomy, serum potassium, serum chloride, serum bicarbonate, serum albumin, intravenous fluid intake and urine volume for 24 h, haematocrit, haemoglobin, neurological assessment and four MRI signal patterns. Univariate and multivariate analyses were used to determine the effect of each variable on hyponatraemia.

RESULTS

Eighty-two of the 270 patients (30%) developed hyponatraemia. Univariate analyses indicated that the following variables were significant predictors of hyponatraemia: tracheostomy; the initial American Spinal Injury Association (ASIA) Impairment Scale (AIS) A assessment; and haemorrhage changes on T2-weighted MRI scans, and low BP. Multivariate regression analyses revealed two variables were significant predictors of hyponatraemia: haemorrhage changes on T2-weighted MRI scans and low BP.

CONCLUSIONS

Haemorrhage changes on MRI scans were closely associated with the onset of hyponatremia and could provide objective data for forecasting hyponatraemia in CSCI patients. Low BP was also a reasonable predictor of hyponatremia.

Synergistic impact of acute kidney injury and high level of cervical spinal cord injury on the weaning outcome of patients with acute traumatic cervical spinal cord injury

INTRODUCTION

Respiratory neuromuscular impairment severity is known to predict weaning outcome among patients with cervical spinal cord injury; however, the impact of non-neuromuscular complications remains unexplored. This study was to evaluate possible neuromuscular and non-neuromuscular factors that may negatively impact weaning outcome.

METHODS

From September 2002 to October 2012, acute traumatic cervical spinal cord injury patients who had received mechanical ventilation for >48h were enrolled and divided into successful (n=54) and unsuccessful weaning groups (n=19). Various neuromuscular, non-neuromuscular factors and events during the intensive care unit stay were extracted from medical charts and electronic medical records. Variables presenting with a significant difference (p<0.2) between these two groups were included in the univariate analysis. Following univariate analysis, those significantly different variables (p<0.05) were subjected to multivariate logistic regression to identify independent predictors of unsuccessful weaning.

RESULTS

Compared to successful weaning patients, unsuccessful weaning patients were older; more often had high level of cervical spinal cord injury (C1-3), lower pulse rates, and lower Glasgow Coma Scale score on admission, higher peak blood urea nitrogen, lower trough albumin, and lower trough blood leukocyte counts. Furthermore, unsuccessful weaning patients had a higher incidence of pneumonia, acute respiratory distress syndrome, shock and acute kidney injury during the intensive care unit stay. Multivariate logistic regression analysis revealed acute kidney injury and high level of cervical spinal cord injury were independent risk factors for failure of weaning. Importantly, patients with both risk factors showed a large increase in odds ratio for unsuccessful weaning from mechanical ventilation (p<0.001).

CONCLUSIONS

The presence of acute kidney injury during the intensive care unit stay and high level of cervical spinal injury are two independent risk factors that synergistically work together producing a negative impact on weaning outcome.

Hyponatremia in spinal cord injury patients: new insight into differentiating between the dilution and depletion forms

STUDY DESIGN

This is a retrospective study.

OBJECTIVES

The objectives of this study were to present a new model for differentiating between the dilution and depletion forms of hyponatremia in patients in the postacute phase after spinal cord injury (SCI), and to identify possible etiological factors contributing to hyponatremia in these patients.

SETTING

University Hospital Motol, Prague, Czech Republic.

METHODS

Eighty-seven of 352 patients hospitalized in 2008-2012 in the Spinal Cord Unit were hyponatremic. Seventy-four patients had SNa+=130-135 mmol l(-1) and 13 patients had SNa+ below 130 mmol l(-1). We propose a simple model of an electrolyte solution in which the Na(+) concentration is higher than the Cl(-) concentration, making it possible to compare the effects of dilution and depletion of Na(+) and Cl(-) on the Na(+) concentration. The depletion of Na(+) and Cl(-) leads to a significant increase in the Na(+)/Cl(-) ratio, with the Na(+)-Cl(-) value remaining unchanged. Dilution with water results in a decrease of Na(+)-Cl(-) with the Na(+)/Cl(-) ratio remaining unchanged.

RESULTS

In patients with SNa+ below 130 mmol l(-1), hyponatremia was consistent with the depletion model in 46% and with the dilution model in 32%. In patients with SNa+ ranging between 130 and 135 mmol l(-1), the respective rates were 34 and 12%.

CONCLUSION

Examination of SNa+-SCl- and SNa+/SCl- in patients with SCI could be helpful in considering whether hyponatremia is consistent either with the NaCl dilution model or with the NaCl depletion model. Further studies are needed for more accurate interpretation of the results, particularly with respect to volume and acid-base disorders.