Management of life-threatening autonomic hyper-reflexia using magnesium sulphate in a patient with a high spinal cord injury in the intensive care unit

Main Cations and Cellular Biology of Traumatic Spinal Cord Injury

Traumatic spinal cord injury is a life-changing condition with a significant socio-economic impact on patients, their relatives, their caregivers, and even the community. Despite considerable medical advances, there is still a lack of options for the effective treatment of these patients. The major complexity and significant disabling potential of the pathophysiology that spinal cord trauma triggers are the main factors that have led to incremental scientific research on this topic, including trying to describe the molecular and cellular mechanisms that regulate spinal cord repair and regeneration. Scientists have identified various practical approaches to promote cell growth and survival, remyelination, and neuroplasticity in this part of the central nervous system. This review focuses on specific detailed aspects of the involvement of cations in the cell biology of such pathology and on the possibility of repairing damaged spinal cord tissue. In this context, the cellular biology of sodium, potassium, lithium, calcium, and magnesium is essential for understanding the related pathophysiology and also the possibilities to counteract the harmful effects of traumatic events. Lithium, sodium, potassium—monovalent cations—and calcium and magnesium—bivalent cations—can influence many protein–protein interactions, gene transcription, ion channel functions, cellular energy processes—phosphorylation, oxidation—inflammation, etc. For data systematization and synthesis, we used the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) methodology, trying to make, as far as possible, some order in seeing the “big forest” instead of “trees”. Although we would have expected a large number of articles to address the topic, we were still surprised to find only 51 unique articles after removing duplicates from the 207 articles initially identified. Our article integrates data on many biochemical processes influenced by cations at the molecular level to understand the real possibilities of therapeutic intervention—which must maintain a very narrow balance in cell ion concentrations. Multimolecular, multi-cellular: neuronal cells, glial cells, non-neuronal cells, but also multi-ionic interactions play an important role in the balance between neuro-degenerative pathophysiological processes and the development of effective neuroprotective strategies. This article emphasizes the need for studying cation dynamics as an important future direction.

Machine Learning-based Prediction of Prolonged Intensive Care Unit Stay for Critical Patients with Spinal Cord Injury

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

The objective of the study was to develop machine-learning (ML) classifiers for predicting prolonged intensive care unit (ICU)-stay and prolonged hospital-stay for critical patients with spinal cord injury (SCI).

SUMMARY OF BACKGROUND DATA

Critical patients with SCI in ICU need more attention. SCI patients with prolonged stay in ICU usually occupy vast medical resources and hinder the rehabilitation deployment.

METHODS

A total of 1599 critical patients with SCI were included in the study and labeled with prolonged stay or normal stay. All data were extracted from the eICU Collaborative Research Database and the Medical Information Mart for Intensive Care III-IV Database. The extracted data were randomly divided into training, validation and testing (6:2:2) subdatasets. A total of 91 initial ML classifiers were developed, and the top three initial classifiers with the best performance were further stacked into an ensemble classifier with logistic regressor. The area under the curve (AUC) was the main indicator to assess the prediction performance of all classifiers. The primary predicting outcome was prolonged ICU-stay, while the secondary predicting outcome was prolonged hospital-stay.

RESULTS

In predicting prolonged ICU-stay, the AUC of the ensemble classifier was 0.864 ± 0.021 in the three-time five-fold cross-validation and 0.802 in the independent testing. In predicting prolonged hospital-stay, the AUC of the ensemble classifier was 0.815 ± 0.037 in the three-time five-fold cross-validation and 0.799 in the independent testing. Decision curve analysis showed the merits of the ensemble classifiers, as the curves of the top three initial classifiers varied a lot in either predicting prolonged ICU-stay or discriminating prolonged hospital-stay.

CONCLUSION

The ensemble classifiers successfully predict the prolonged ICU-stay and the prolonged hospital-stay, which showed a high potential of assisting physicians in managing SCI patients in ICU and make full use of medical resources.Level of Evidence: 3.

Assessing the efficacy and safety of magnesium sulfate for management of autonomic nervous system dysregulation in Vietnamese children with severe hand foot and mouth disease

Background

Brainstem encephalitis is a serious complication of hand foot and mouth disease (HFMD) in children. Autonomic nervous system (ANS) dysregulation and hypertension may occur, sometimes progressing to cardiopulmonary failure and death. Vietnamese national guidelines recommend use of milrinone if ANS dysregulation with Stage 2 hypertension develops. We wished to investigate whether magnesium sulfate (MgSO₄) improved outcomes in children with HFMD if used earlier in the evolution of the ANS dysregulation (Stage 1 hypertension).

Methods

During a regional epidemic we conducted a randomized, double-blind, placebo-controlled trial of MgSO₄ in children with HFMD, ANS dysregulation and Stage 1 hypertension, at the Hospital for Tropical Diseases in Ho Chi Minh city. Study participants received an infusion of MgSO₄ or matched placebo for 72 h. We also reviewed data from non-trial HFMD patients in whom milrinone failed to control hypertension, some of whom received MgSO₄ as second line therapy. The primary outcome for both analyses was a composite of disease progression within 72 h - addition of milrinone (trial participants only), need for ventilation, shock, or death.

Results

Between June 2014 and September 2016, 14 and 12 participants received MgSO₄ or placebo respectively, before the trial was stopped due to futility. Among 45 non-trial cases with poorly controlled hypertension despite high-dose milrinone, 33 received MgSO₄ while 12 did not. There were no statistically significant differences in the composite outcome between the MgSO₄ and the placebo/control groups in either study (adjusted relative risk (95%CI) of [6/14 (43%) vs. 6/12 (50%)], 0.84 (0.37, 1.92), p = 0.682 in the trial and [1/33 (3%) vs. 2/12 (17%)], 0.16 (0.01, 1.79), p = 0.132 in the observational cohort). The incidence of adverse events was similar between the groups. Potentially toxic magnesium levels occurred very rarely with the infusion regime used.

Conclusion

Although we could not demonstrate efficacy in these studies, there were no safety signals associated with use of 30-50 mg/kg/hr. MgSO₄ in severe HFMD. Intermittent outbreaks of HFMD are likely to continue across the region, and an adequately powered trial is still needed to evaluate use of MgSO₄ in controlling hypertension in severe HFMD, potentially involving a higher dose regimen.

Trial registration

ClinicalTrials.gov Identifier: NCT01940250 (Registered 22 AUG 2013).

Trial sponsor: University of Oxford

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4356-x) contains supplementary material, which is available to authorized users.

[Anesthesiological approach for patients with spinal cord injuries]

Spinal cord injuries (SCI) are serious medical conditions, which are associated with severe and potentially fatal risks and complications depending on the location and extent of injury. Traffic accidents, falls and recreational activities are the leading causes for traumatic SCI (TSCI) worldwide whereas non-traumatic spinal cord injuries (NTSCI) are mostly due to tumors and congenital diseases. As chronification of the injuries progresses other organ systems are affected including anatomical changes, the respiratory and cardiovascular systems and endocrinological pathways. All these effects have to be considered in the anesthesiological management of patients with SCI. Autonomic dysreflexia (AD) is the most dangerous and life-threatening complication in patients with chronic SCI above T6 that results from an overstimulation of sympathetic reflex circuits in the upper thoracic spine and can be fatal. This article summarizes the specific pathophysiology of SCI and how AD can be avoided as well as also providing anesthetists with strategies for perioperative and intensive care management of patients with SCI.

Intravenous magnesium sulfate for the management of severe hand, foot, and mouth disease with autonomic nervous system dysregulation in Vietnamese children: study protocol for a randomized controlled trial

BACKGROUND

Over the last 15 years, hand, foot, and mouth disease (HFMD) has emerged as a major public health burden across the Asia-Pacific region. A small proportion of HFMD patients, typically those infected with enterovirus 71 (EV71), develop brainstem encephalitis with autonomic nervous system (ANS) dysregulation and may progress rapidly to cardiopulmonary failure and death. Although milrinone has been reported to control hypertension and support myocardial function in two small studies, in practice, a number of children still deteriorate despite this treatment. Magnesium sulfate (MgSO4) is a cheap, safe, and readily available medication that is effective in managing tetanus-associated ANS dysregulation and has shown promise when used empirically in EV71-confirmed severe HFMD cases.

METHODS/DESIGN

We describe the protocol for a randomized, placebo-controlled, double-blind trial of intravenous MgSO4 in Vietnamese children diagnosed clinically with HFMD plus ANS dysregulation with systemic hypertension. A loading dose of MgSO4 or identical placebo is given over 20 min followed by a maintenance infusion for 72 h according to response, aiming for Mg levels two to three times the normal level in the treatment arm. The primary endpoint is a composite of disease progression within 72 h defined as follows: development of pre-specified blood pressure criteria necessitating the addition of milrinone, the need for ventilation, shock, or death. Secondary endpoints comprise these parameters singly, plus other clinical endpoints including the following: requirement for other inotropic agents; duration of hospitalization; presence of neurological sequelae at discharge in survivors; and neurodevelopmental status assessed 6 months after discharge. The number and severity of adverse events observed in the two treatment arms will also be compared. Based on preliminary data from a case series, and allowing for some losses, 190 patients (95 in each arm) will allow detection of a 50 % reduction in disease progression with 90 % power at a two-sided 5 % significance level.

DISCUSSION

Given the large numbers of HFMD cases currently being seen in hospitals in Asia, if MgSO4 is shown to be effective in controlling ANS dysregulation and preventing severe HFMD complications, this finding would be important to pediatric care throughout the region.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01940250 (Registered 22 August 2013).

Mg supplementation protects against ritonavir-mediated endothelial oxidative stress and hepatic eNOS downregulation

Ritonavir (RTV), a prototypical protease inhibitor currently used as a key component of anti-HIV therapy, is known for its endothelial and hepatic toxicity. The effects of RTV and magnesium supplementation on cultured bovine endothelial cell (EC) and rat hepatic endothelial nitric oxide synthase (eNOS) status were investigated. RTV dose-dependently (5-30 µM) decreased EC viability after 48 h; high Mg (2mM) significantly attenuated the lost viability. ECs incubated with 15 µM RTV for 6 to 24h resulted in two- to fourfold elevation of oxidized glutathione and a 25% loss of total glutathione. At 24h, EC superoxide production due to RTV was detected by dihydroethidium staining and increased 41% when quantified by flow cytometry; altered glutathione status and superoxide levels were both substantially reversed by 2mM Mg. RTV reduced eNOS mRNA (-25% at 24 h) and led to decreased eNOS dimer/monomer ratios; nitric oxide-derived products decreased 40%; both changes were attenuated by Mg supplementation. In male Lewis-Brown Norway rats, RTV administration (75 mg/kg/day, 5 weeks) resulted in an 85% increase in plasma 8-isoprostane and a 23% decrease in hepatic eNOS mRNA; concomitantly, eNOS protein decreased 75%, whereas plasma nitrite level was reduced 48%. Dietary Mg supplementation (sixfold higher than control) prevented the eNOS mRNA decrease along with lowering 8-isoprostane and restored the eNOS protein and plasma nitrite levels comparable to controls. In conclusion, Mg attenuates RTV-mediated EC oxidative eNOS dysfunction and downregulation of hepatic eNOS expression; we suggest that Mg can serve as a beneficial adjunct therapeutic against RTV-mediated eNOS toxicity.

Effect of continuous magnesium sulfate infusion on spinal block characteristics: A prospective study

Background:

Spinal anesthesia is an established mode of anesthesia for lower limb orthopedic surgeries. The limitations of the technique are short duration of action and limited post-operative analgesia. Concomitant use of intravenous infusion of magnesium sulfate may have an effect on the block characteristics and duration of action of intrathecal bupivacaine.

Methods:

A total of 80 American Society of Anesthesiologists I and II patients, either sex, 20-60 years of age scheduled for elective orthopedic fixation of fracture of long bones of lower limbs under spinal anesthesia were included. Spinal anesthesia administered with 2.5 ml heavy bupivacaine mixed with 10 mcg fentanyl. The groups were then divided to receive an infusion of injection magnesium sulfate 50 mg/kg/h over 15 min followed by 15 mg/kg/h until the end of the surgery (Group M) and 15 ml of Normal Saline over 15 min followed by 100 ml/h until the end of surgery (Group S). Onset, duration of sensory and motor block and amount of post-operative analgesic were noted.

Results:

A total of 6 patients (Group M) and seven patients (Group S) had inadequate block and excluded from the study. Mean block height was T6. Time required to achieve block height was 8.82 min versus 7.42 min in Groups M and S respectively (P = 0.04). Mean duration of motor block was longer in group M (160.63 ± 17.76 min) compared with Group S (130.12 ± 20.70 min) (P = 0.000). Time for regression of sensory block to T12/L1was 206.88 ± 20.96 min (Group M) and 163.88 ± 15.46 min (Group S) (P = 0.000). Hemodynamic parameters were similar and statistically not significant. Need for first analgesic requirement was after 262.88 ± 21.11 min in group M and 193.25 ± 17.74 min in the group S (P = 0.000). Mean dosage of tramadol needed in first 24 h was less in group M (190 ± 30.38 mg vs. 265 ± 48.30 mg, P = 0.000).

Conclusion:

Use of intravenous magnesium with spinal anesthesia reduces post-operative pain and analgesic consumption.

A systematic review of the management of autonomic dysreflexia after spinal cord injury

OBJECTIVE

To review systematically the clinical evidence on strategies to prevent and manage autonomic dysreflexia (AD).

DATA SOURCES

A key word search of several databases (Medline, CINAHL, EMBASE, and PsycINFO), in addition to manual searches of retrieved articles, was undertaken to identify all English-language literature evaluating the efficacy of interventions for AD.

STUDY SELECTION

Studies selected for review included randomized controlled trials (RCTs), prospective cohort studies, and cross-sectional studies. Treatments reviewed included pharmacologic and nonpharmacologic interventions for the management of AD in subjects with spinal cord injury. Studies that failed to assess AD outcomes (eg, blood pressure) or symptoms (eg, headaches, sweating) were excluded.

DATA EXTRACTION

Studies were critically reviewed and assessed for their methodologic quality by 2 independent reviewers.

DATA SYNTHESIS

Thirty-one studies were assessed, including 6 RCTs. Preventative strategies to reduce the episodes of AD caused by common triggers (eg, urogenital system, surgery) primarily were supported by level 4 (pre-post studies) and level 5 (observational studies) evidence. The initial acute nonpharmacologic management of an episode of AD (ie, positioning the patient upright, loosening tight clothing, eliminating any precipitating stimulus) is supported by clinical consensus and physiologic data (level 5 evidence). The use of antihypertensive drugs in the presence of sustained elevated blood pressure is supported by level 1 (prazosin) and level 2 evidence (nifedipine and prostaglandin E(2)).

CONCLUSIONS

A variety of options are available to prevent AD (eg, surgical, pharmacologic) and manage the acute episode (elimination of triggers, pharmacologic); however, these options are predominantly supported by evidence from noncontrolled trials, and more rigorous trials are required.

Recognition and effective management of autonomic dysreflexia in spinal cord injuries

Autonomic dysreflexia is a potentially life-threatening hypertensive medical emergency that occurs most often in spinal cord-injured individuals with spinal lesions at or above the mid-thoracic spinal cord level. It is a condition that remains poorly recognised outside of spinal cord injury centres, which may result in adverse outcomes including mortality from potentially delayed diagnosis and treatment. Acute autonomic dysreflexia is characterised by severe paroxysmal hypertension associated with throbbing headaches, profuse sweating, nasal stuffiness, flushing of the skin above the level of the lesion, bradycardia, apprehension and anxiety, which is sometimes accompanied by cognitive impairment. The key to effective management is prevention of the condition, by recognition and avoidance of factors that initiate the condition. When it occurs, immediate recognition and reversal of trigger factors along with prompt administration of pharmacological treatment is of paramount importance in order to prevent complications, which include intracranial and retinal haemorrhage, convulsions, cardiac irregularities and death. Promising data from recent animal studies may hold the key to future treatment options.

Obstetric Management of the Patient With Spinal Cord Injury

Pregnancies in spinal cord-injured patients present unique clinical challenges to obstetric providers. Spinal cord injury (SCI) alters the function of multiple organ systems, and chronic medical conditions are extremely common in this patient population. Autonomic dysreflexia (ADR) is a potentially life-threatening complication of SCI, usually involving patients with spinal cord lesions at or above the T6 level. Intrapartum care of women with SCI is particularly complicated, and labor is the period during which ADR is most likely to arise. A multidisciplinary team in a unit capable of invasive hemodynamic monitoring should deliver these patients. Epidural anesthesia should be administered early in labor to prevent ADR. If proper precautions are taken, most patients with SCI will have successful vaginal deliveries at term.