Neurologic presentations of acid-base imbalance, electrolyte abnormalities, and endocrine emergencies

Serum bicarbonate levels and gait abnormalities in older adults: a cross-sectional study

Metabolic acidosis is associated with impaired physical function in patients with chronic kidney disease (CKD) and older adults. However, whether acidosis is associated with gait abnormalities has received little attention. In a cohort of 323 community-dwelling adults ≥ 65 years old who underwent quantitative gait analysis, we examined associations of serum bicarbonate with eight individual gait variables. After multivariable adjustment, participants in the lowest bicarbonate tertile (< 25 mEq/L) had 8.6 cm/s slower speed (95% confidence interval [CI] 3.2–13.9), 7.9 cm shorter stride length (95% CI 3.5–12.2), and 0.03 s longer double support time (95% CI 0.002–0.1) compared with those in the middle tertile (25–27 mEq/L). Furthermore, lower bicarbonate levels were associated with more severe gait abnormalities in a graded manner. After further adjustment for possible mediating factors, associations were attenuated but remained significant. Among participants with CKD, associations were of similar or greater magnitude compared with those without CKD. Factor analysis was performed to synthesize the individual gait variables into unifying domains: among the pace, rhythm, and variability domains, lower serum bicarbonate was associated with worse performance in pace. In sum, lower serum bicarbonate was independently associated with worse performance on several quantitative measures of gait among older adults.

Hypophosphataemia is common in patients with aneurysmal subarachnoid haemorrhage

INTRODUCTION

Hypophosphataemia is common in critically ill patients, but neither its prevalence nor its association with outcome have been investigated specifically in patients with aneurysmal subarachnoid haemorrhage (aSAH).

METHODS

Patients with aSAH and at least one phosphate measurement were included from two independent cohorts; an American cohort extracted from two open-access databases (Medical Information Mart for Intensive Care-III and eICU Collaborative Research Database v. 2.0) and a Danish cohort consisting of patients with aSAH admitted to Rigshospitalet, Denmark over a 4-year period. In each cohort, we calculated the prevalence of mild (0.32-0.80 mmol/L) and severe (<0.32 mmol/L) hypophosphataemia and their association with in-hospital mortality before and after propensity-score matching.

RESULTS

Hypophosphataemia occurred in 72.4% (95% CI: 68.1-76.3) of patients in the American cohort (n = 471) and 54.9% (50.0-59.7) in the Danish cohort (n = 419). However, it was not associated with mortality in neither full (American: Mild, Odds ratio (OR) 0.99 (0.91-1.07), Severe OR 1.20 (0.95-1.51); Danish: Mild, OR 1.01 (0.95-1.08), Severe OR 1.20 (0.95-1.51)) nor propensity-score matched cohorts (American (n = 168): Mild, OR 1.06 (0.88-1.28), Severe OR 1.46 (0.96-2.12); Danish (n = 44): Mild, OR 1.16 (0.82-1.65), Severe OR 0.45 (0.13-1.55)).

CONCLUSION

In this retrospective study of patients with aSAH, hypophosphataemia was common.

Intravenous Fluid Selection for Unruptured Intracranial Aneurysm Clipping : Balanced Crystalloid versus Normal Saline

OBJECTIVE

While balanced crystalloid (BC) could be a relevant fluid regimen with buffer system compared with normal saline (NS), there have been no studies on the optimal fluid for surgery of an unruptured intracranial aneurysm (UIA). This study aimed to compare the effects of fluid regimens between NS and BC on the metabolic and clinical outcomes of patients who underwent surgery for UIA.

METHODS

This study was designed as a propensity score matched retrospective comparative study and included adult patients who underwent UIA clipping. Patient groups were categorized as NS and BC groups based on the types of pre-operative fluid and the amount of fluid administered during surgery. The primary outcomes were defined as electrolyte imbalance and acidosis immediately after surgery. The secondary outcomes were the length of stay in the intensive care unit (ICU) and duration from the end of the operation to extubation.

RESULTS

A total of 586 patients were enrolled in this study, with each of 293 patients assigned to the NS and BC groups, respectively. Immediately after surgery, serum chloride levels were significantly higher in the NS group. Compared to the NS group, the BC group had lower incidence rates of acidemia (6.5% vs. 11.6%, p=0.043) and metabolic acidosis (0.7% vs. 4.4%, p=0.007). As compared to NS group, BC group had significantly shorter duration from the end of the operation to extubation (250±824 vs. 122±372 minutes, p=0.016) and length of stay in ICU (1.37±1.11 vs. 1.12±0.61 days, p=0.001). Throughout multivariable analysis, use of BC was found to be significant factor for favorable post-operative results.

CONCLUSION

This study showed that the patients who received BC during UIA clipping had lower incidence of metabolic acidosis, earlier extubation and shorter ICU stay compared to those who received NS. Therefore, using BC as a peri-operative fluid can be recommended for patients who undergo surgery for UIA.

Electrolyte Disorders and the Nervous System

PURPOSE OF REVIEW

This article provides an overview of the major electrolyte disorders and discusses in detail the homeostasis, etiologies, neurologic manifestations, and treatment of these disorders.

RECENT FINDINGS

The diagnosis and management of hyponatremia continue to evolve. Diagnostic accuracy is improved by assessing serum and urine osmolality as well as urinary sodium. Avoiding overcorrection of hyponatremia is crucial to avoid osmotic demyelination syndrome, although even careful correction can cause osmotic demyelination syndrome in patients who have other risk factors. The clinical presentation of osmotic demyelination syndrome has expanded, with many patients presenting with extrapontine myelinolysis in addition to central pontine myelinolysis.

SUMMARY

Electrolyte disorders often present with neurologic manifestations. Whereas disorders of some electrolytes, such as sodium, preferentially affect the central nervous system, disorders of others, such as potassium and calcium, have significant neuromuscular manifestations. An understanding of the pathophysiology of these disorders and recognition of these manifestations are crucial for the practicing neurologist as the symptoms are reversible with correct management.

Neurologic Complications in the Intensive Care Unit

Complications involving the central and peripheral nervous system are frequently encountered in critically ill patients. All components of the neuraxis can be involved including the brain, spinal cord, peripheral nerves, neuromuscular junction, and muscles. Neurologic complications adversely impact outcome and length of stay. These complications can be related to underlying critical illness, pre-existing comorbid conditions, and commonly used and life-saving procedures and medications. Familiarity with the myriad neurologic complications that occur in the intensive care unit can facilitate their timely recognition and treatment. Additionally, awareness of treatment-related neurologic complications may inform decision-making, mitigate risk, and improve outcomes.

Advanced age, altered level of consciousness and a new diagnosis of diabetes are independently associated with hypernatreamia in hyperglycaemic crisis

BACKGROUND

There is limited literature on hypernatreamia in the setting of hyperglycaemic crisis. This is despite the fact that the presence of hypernatreamia may impact on the classification of hyperglycaemic crisis and its management particularly with regards to the nature of fluid therapy. We determined the prevalence of hypernatreamia and its associated factors at presentation for hyperglycaemic crisis.

METHODS

This was a retrospective review of data for hyperglycaemic crisis admissions in Nelson Mandela Academic Hospital, Mthatha, South Africa. The prevalence of hypernatreamia (uncorrected Serum Sodium at presentation >145 mmol/L) was determined. Hyperosmolality was defined by calculated effective osmolality >320 mosmols/Kg. Multivariate logistic regression was undertaken using variables that were statistically significant in univariate analysis to ascertain those that were independently associated (Odds Ratio (OR) with 95% Confidence Interval (CI)) with hypernatreamia.

RESULTS

The prevalence of hypernatreamia in our admissions for hyperglycaemic crisis was 11.7% (n = 32/273 including 171 females and 102 males). All admissions with hypernatreamia met the criteria for hyperosmolality. Age ≥ 60 years (OR = 3.9 95% CI 1.3-12.3; P = 0.018), Altered level of consciousness (OR = 8.8 95% CI 2.3-32.8; P < 0.001) and a new diagnosis of diabetes (OR = 3.7 95%CI 1.2-11.5; P = 0.025) were independently associated with hypernatreamia.

CONCLUSION

The prevalence rate of hypernatreamia in hyperglycaemic admissions was high with all hypernatreamic admissions meeting the criteria for hyperosmolality. Advanced age, altered conscious level and a new diagnosis of diabetes were independently associated with hypernatreamia.