Intensive care-acquired hypernatremia after major cardiothoracic surgery is associated with increased mortality

Plasma sodium during the recovery of renal function in critically ill adult patients: Multicenter prospective cohort study

BACKGROUND

Sodium increases during acute kidney injury (AKI) recovery. Both hypernatremia and positive fluid balances are associated with increased mortality. We aimed to evaluate the association between daily fluid balance and daily plasma sodium during the recovery from AKI among critical patients.

METHODS

Adult patients with AKI were enrolled in four ICUs and followed up for four days or until ICU discharge or hemodialysis initiation. Day zero was the peak day of creatinine. The primary outcome was daily plasma sodium; the main exposure was daily fluid balance.

RESULTS

93 patients were included. The median age was 66 years; 68% were male. Plasma sodium increased in 79 patients (85%), and 52% presented hypernatremia. We found no effect of daily fluid balance on plasma sodium (β -0.26, IC95%: -0.63-0.13; p = 0.19). A higher total sodium variation was observed in patients with lower initial plasma sodium (β -0.40, IC95%: -0.53 to -0.27; p < 0.01), higher initial urea (β 0.07, IC95%: 0.04-0.01; p < 0.01), and higher net sodium balance (β 0.002, IC95%: 0.0001-0.01; p = 0.05).

CONCLUSIONS

The increase in plasma sodium is common during AKI recovery and can only partially be attributed to the water and electrolyte balances. The incidence of hypernatremia in this population of patients is higher than in the general critically ill patient population.

Enteral free water vs. parenteral dextrose 5% in water for the treatment of hypernatremia in the intensive care unit: a retrospective cohort study from a mixed ICU

PURPOSE

Effective treatment options for patients with hypernatremia are limited. Free water administration (parenterally or enterally) is the mainstay of treatment but the impact of each strategy on lowering serum sodium (Na) is not known. The purpose of the study was thus to assess the effectiveness of enteral free water vs. parenteral dextrose 5% in water (D5W) in treating ICU-acquired hypernatremia.

METHODS

An electronic medical record-based, retrospective cohort study was conducted in a 30-bed mixed medical-surgical intensive care unit (ICU) in Japan. All adult patients admitted to the ICU from August 2017 to July 2021 were reviewed. After a 2-step exclusion, patients who stayed in the ICU ≥ 24 h and received either or both treatments for ICU-acquired hypernatremia (Na ≥ 145 mEq/L) constituted the study cohort. The primary outcome was a change in serum Na during the 24 h before treatment each day (ΔNa); the secondary outcomes were gastrointestinal complications, serum glucose levels, ICU/hospital mortality, ICU/hospital length of stay, and the duration of mechanical ventilation. Repeated measurements on each patient were addressed using a generalized estimated equation (GEE) for multiple linear regression analysis. Analysis was conducted with R version 4.0.3.

RESULTS

In total, 256/6596 (131: D5W, 125: enteral free water) patients were analyzed. Median treatment lasted 6 days [3-17] for the D5W group vs 7 days [3-14] for the enteral free water group with a total median daily treatment volume of 799 [IQR 299-1221] mL vs. 400 [IQR 262-573] mL. GEE multiple linear regression analysis showed an estimated mean ΔNa per liter of treatment fluid of - 2.25 [95% CI - 2.76 to - 1.74] mEq/L per liter of parenteral D5W vs. - 1.91 mEq decrease [95% CI - 2.75 to - 1.07] per liter of enteral free water. Hydrochlorothiazide was the only medication associated with a statistically significant negative ΔNa by- 0.89 [- 1.57 to - 0.21] mEq/L. There were no significant inter-group differences for secondary outcomes.

CONCLUSIONS

These results suggest that both enteral free water and parenteral D5W are effective for treating ICU-acquired hypernatremia. Parenteral D5W was slightly more effective than enteral free water to lower serum Na levels in patients with ICU-acquired hypernatremia.

TRIAL REGISTRATION

Not applicable.

In Vitro Investigation of Platelet Dysfunction Induced by Osmotic Pressure Variations

BACKGROUND

Severe variations in osmotic pressure are significant contributors to critical patient morbidity and mortality and might also affect platelet volume. We aimed to investigate possible osmotic-induced changes in mean platelet volume (MPV) and their possible effects on platelet aggregation activity (PLAG).

METHODS

We induced experimental variations of serum osmolality in blood samples from healthy volunteers (heparinized whole blood, WB) and isolated platelets (Platelet Rich Plasma, PRP) by adding isotonic, hypertonic, and hypotonic solutions of saline/water (pH = 7.2-7.4). PLAG was tested in WB samples with Impedance Aggregometry (IA) and in PRP samples with Light Transmission Aggregometry (LTA) using three agonists Adenosine Diphosphate (ADP, 10 μΜ), Thrombin Receptor Activating Peptide (TRAP-6, 10 μΜ) and Arachidonic Acid (AA, 500 μΜ). Osmolality was either calculated using a formula or measured directly.

RESULTS

We found almost identical osmolalities in WB and PRP preparations. Osmotic stress did not produce significant changes in MPV. In IA testing the hypotonic challenge of WB preparations produced significant reductions at 50 % (p = 0.056) (95 % CI: 11.2-2.4, in Ohms) of ADP and at 31 % (p = 0.017) (95 % CI: 13.4-8.6, in Ohms) of TRAP-6 -induced PLAG respectively. In PRP we did not observe any variations in PLAG with LTA.

CONCLUSIONS

We conclude that in vitro hypotonic stress of WB samples has an inhibitory effect on the PAR-1 (TRAP-6 induced) pathway and on the P2Y12 (ADP induced) pathway and reflects a distinct in vivo effect of hypo-osmotic stress on WB human platelet preparations.

Catabolism highly influences ICU-acquired hypernatremia in a mainly trauma and surgical cohort

PURPOSE

To further analyse causes and effects of ICU-acquired hypernatremia.

METHODS

This retrospective, single-centre study, analysed 994 patients regarding ICU-acquired hypernatremia. Non-hypernatremic patients (n = 617) were compared to early-hypernatremic (only before ICU-day 4; n = 87), prolonged-hypernatremic (before and after ICU-day 4; n = 169) and late-hypernatremic patients (only after ICU-day 4; n = 121). Trends in glomerular filtration rate (eGFR), urea-to-creatinine ratio (UCR), fraction of urea in total urine osmolality and urine sodium were compared. Risk factors for i) the development of hypernatremia and ii) mortality were determined.

RESULTS

Thirty-eight percent (n = 377) developed ICU-acquired hypernatremia. Specifically in the prolonged- and late-group, decreased eGFRs and urine sodium but increased UCR and fractions of urea in urine osmolality were present. Decreased eGFR was a risk factor for the development of hypernatremia in all groups; disease severity and increased catabolism particularly in the prolonged- and late-hypernatremic group. Increased age, SAPS-III and signs of catabolism but not the development of hypernatremia itself was identified as significant risk factor for mortality.

CONCLUSIONS

Late- and prolonged-hypernatremia is highly related to an increased protein metabolism. Besides excessive catabolism, initial disease severity and a decrease in renal function must be considered when confronted with ICU-acquired hypernatremia.

Post-operative dysnatremia is associated with adverse early outcomes after surgery for congenital heart disease

BACKGROUND

Dysnatremia is a common disorder in critically ill surgical children. The study's aim is to determine the prevalence of dysnatremia and its association with outcomes after surgery for congenital heart disease (CHD).

METHODS

This is a single-center retrospective cohort study of children <18 years of age undergoing surgery for CHD between January 2012 and December 2014. Multivariable logistic regression analysis was used to evaluate the relationship between dysnatremia and outcomes during the perioperative period. A total of 1345 encounters met the inclusion criteria.

RESULTS

The prevalence of pre- and post-operative dysnatremia were 10.2% and 47.1%, respectively. Hyponatremia occurred in 19.1%, hypernatremia in 25.6%. Hypernatremia at 24, 48, and 72 h post-operative was associated with increased hospital mortality (odds ratios (OR) [95% confidence intervals (CI)] 3.08 [1.16-8.17], p = 0.024; 4.35 [1.58-12], p = 0.0045; 4.14 [1.32-12.97], p = 0.0148, respectively. Hypernatremia was associated with adverse neurological events 3.39 [1.12-10.23], p = 0.0302 at 48 h post-operative. Hyponatremia was not associated with any adverse outcome in our secondary analysis.

CONCLUSIONS

Post-operative dysnatremia is a common finding in this heterogeneous cohort of pediatric cardiac-surgical patients. Hypernatremia was more prevalent than hyponatremia and was associated with adverse early post-operative outcomes.

IMPACT

Our study has shown that dysnatremia was highly prevalent in children after congenital heart surgery with hypernatremia associated with adverse outcomes including mortality. It is important to understand fluid and sodium regulation in the post-operative period in children with congenital heart disease to better address fluid overload and associated electrolyte imbalances and acute kidney injury. While clinicians are generally very aware of the importance of hyponatremia in critically ill children, similar attention should be given to hypernatremia in this population.

Nomogram Prediction Model of Hypernatremia on Mortality in Critically Ill Patients

Objective

To investigate the value of hypernatremia in the intensive care unit (ICU) for the risk prediction of mortality in severe patients.

Methods

Clinical data of critically ill patients admitted to the ICU of Beijing Friendship Hospital, were collected for retrospective analysis. Univariate and multivariate logistic regression analyses were employed to analyze the influencing factors. Nomograms predicting the mortality were constructed with R software and validated with repeated sampling.

Results

A total of 442 cases were eligible for this study. Hypernatremia within 48 hours of ICU admission, change in sodium concentration (CNa+) within 48 hours, septic shock, APACHE II score, hyperlactatemia within 48 hours, use of continuous renal replacement therapy (CRRT) within 48 hours, and the use of mechanical ventilation (MV) within 48 hours of ICU admission were all identified as independent risk factors for death within 28 days of ICU admission. These predictors were included in a nomogram of 28-day mortality in severe patients, which was constructed using R software.

Conclusion

The nomogram could predict the individualized risk of 28-day mortality based on the above factors. The model has better discrimination and accuracy and has high clinical application value.

Clinical Outcomes Associated with Degree of Hypernatremia in Neurocritically Ill Patients

OBJECTIVE

Hypernatremia is a common complication encountered during the treatment of neurocritically ill patients. However, it is unclear whether clinical outcomes correlate with the severity of hypernatremia in such patients. Therefore, we investigated the impact of hypernatremia on mortality of these patients, depending on the degree of hypernatremia.

METHODS

Among neurosurgical patients admitted to the intensive care unit (ICU) in a tertiary hospital from January 2013 to December 2019, patients who were hospitalized in the ICU for more than 5 days and whose serum sodium levels were obtained during ICU admission were included. Hypernatremia was defined as the highest serum sodium level exceeding 150 mEq/L observed. We classified the patients into four subgroups according to the severity of hypernatremia and performed propensity score matching analysis.

RESULTS

Among 1146 patients, 353 patients (30.8%) showed hypernatremia. Based on propensity score matching, 290 pairs were included in the analysis. The hypernatremia group had higher rates of in-hospital mortality and 28-day mortality in both overall and matched population (both p<0.001 and p=0.001, respectively). In multivariable analysis of propensity score-matched population, moderate and severe hypernatremia were significantly associated with in-hospital mortality (adjusted odds ratio [OR], 4.58; 95% confidence interval [CI], 2.15-9.75 and adjusted OR, 6.93; 95% CI, 3.46-13.90, respectively) and 28-day mortality (adjusted OR, 3.51; 95% CI, 1.54-7.98 and adjusted OR, 10.60; 95% CI, 5.10-21.90, respectively) compared with the absence of hypernatremia. However, clinical outcomes, including in-hospital mortality and 28-day mortality, were not significantly different between the group without hypernatremia and the group with mild hypernatremia (p=0.720 and p=0.690, respectively). The mortality rates of patients with moderate and severe hypernatremia were significantly higher in both overall and matched population. Interestingly, the mild hypernatremia group of matched population showed the best survival rate.

CONCLUSION

Moderate and severe hypernatremia were associated with poor clinical outcomes in neurocritically ill patients. However, the prognosis of patients with mild hypernatremia was similar with that of patients without hypernatremia. Therefore, mild hypernatremia may be allowed during treatment of intracranial hypertension using hyperosmolar therapy.

Association Between Hypernatremia and Delirium After Cardiac Surgery: A Nested Case-Control Study

Background

The association between hypernatremia and delirium after cardiac surgery has rarely been investigated. This study aimed to determine whether hypernatremia increases the risk of delirium after exposure.

Materials and Methods

From April 2016 to June 2021, 7,831 consecutive patients receiving cardiac surgery were screened for potential enrollment. The primary outcome was postoperative delirium (POD). For the respective case of delirium, 10 controls were matched according to the index date within the nested case-control design. Hypernatremia exposure was defined as serum sodium > 145 mmol/L within 7 days before the index date. A generalized estimation equation was performed to assess excess risks for POD associated with hypernatremia, adjusted for demographics and clinical variables.

Results

About 7,277 patients were included in the final analyses. About 669 (9.2%) patients with POD were assigned to the case group, and 6,690 controls were identified from the whole population. About 66.5% of the cases and 36.3% of the controls had hypernatremia exposure. After being adjusted to certain well-recognized confounding factors, hypernatremia showed a significant correlation with increased risk of delirium after cardiac surgery (adjusted OR, 1.73; 95% CI, 1.41~2.12). An e-value analysis suggested the robustness to unmeasured confounding.

Conclusions

Hypernatremia was associated with an increased risk of delirium after cardiac surgery. This finding could have implications for risk stratification, early detection, and management of delirium in patients receiving cardiac surgery.

Electrolyte and acid-base imbalance in severe COVID-19

Acute systemic diseases, such as severe infections, can lead to electrolyte and acid-base alterations. To study the presence of electrolyte imbalance in severe COVID-19, we investigated the frequency and consequences of changes in electrolyte and acid-base patterns over time. We performed a retrospective cohort study including 406 patients with severe COVID-19. Levels of electrolytes, base excess, pH, serum osmolality, and hematocrit, the first 2 weeks of hospitalization, were collected daily from the laboratory database and clinical data from patients' medical records. We found that hyponatremia was present in 57% of the patients at admission and 2% in hypernatremia. However, within 2 weeks of hospitalization 42% of the patients developed hypernatremia, more frequently in critically ill patients. Lower levels of sodium and potassium during admission were associated with the need for mechanical ventilation. Decreased pH at admission was associated with both death and the need for mechanical ventilation. Hypernatremia in the ICU was combined with rising base excess and a higher pH. In the group without intensive care, potassium levels were significantly lower in the patients with severe hypernatremia. Presence of hypernatremia during the first 2 weeks of hospitalization was associated with 3.942 (95% CI 2.269-6.851) times higher odds of death. In summary, hypernatremia was common and associated with longer hospital stay and a higher risk of death, suggesting that the dynamics of sodium are an important indicator of severity in COVID-19.

Association Between an Increase in Serum Sodium and In-Hospital Mortality in Critically Ill Patients

Supplemental Digital Content is available in the text.

OBJECTIVES:

In critically ill patients, dysnatremia is common, and in these patients, in-hospital mortality is higher. It remains unknown whether changes of serum sodium after ICU admission affect mortality, especially whether normalization of mild hyponatremia improves survival.

DESIGN:

Retrospective cohort study.

SETTING:

Ten Dutch ICUs between January 2011 and April 2017.

Patients:

Adult patients were included if at least one serum sodium measurement within 24 hours of ICU admission and at least one serum sodium measurement 24–48 hours after ICU admission were available.

INTERVENTIONS:

None.

MEASUREMENTS AND MAIN RESULTS:

A logistic regression model adjusted for age, sex, and Acute Physiology and Chronic Health Evaluation-IV–predicted mortality was used to assess the difference between mean of sodium measurements 24–48 hours after ICU admission and first serum sodium measurement at ICU admission (Δ48 hr-[Na]) and in-hospital mortality. In total, 36,660 patients were included for analysis. An increase in serum sodium was independently associated with a higher risk of in-hospital mortality in patients admitted with normonatremia (Δ48 hr-[Na] 5–10 mmol/L odds ratio: 1.61 [1.44–1.79], Δ48 hr-[Na] > 10 mmol/L odds ratio: 4.10 [3.20–5.24]) and hypernatremia (Δ48 hr-[Na] 5–10 mmol/L odds ratio: 1.47 [1.02–2.14], Δ48 hr-[Na] > 10 mmol/L odds ratio: 8.46 [3.31–21.64]). In patients admitted with mild hyponatremia and Δ48 hr-[Na] greater than 5 mmol/L, no significant difference in hospital mortality was found (odds ratio, 1.11 [0.99–1.25]).

CONCLUSIONS:

An increase in serum sodium in the first 48 hours of ICU admission was associated with higher in-hospital mortality in patients admitted with normonatremia and in patients admitted with hypernatremia.

Early ICU-acquired hypernatraemia is associated with injury severity and preceded by reduced renal sodium and chloride excretion in polytrauma patients

PURPOSE

To further elucidate the origin of early ICU-acquired hypernatraemia.

MATERIAL AND METHODS

In this retrospective single-centre study, polytrauma patients requiring ICU treatment were analysed.

RESULTS

Forty-eight (47.5%) of 101 included polytrauma patients developed hypernatraemia within the first 7 days on ICU. They were more severely ill as described by higher SAPS III, ISS, daily SOFA scores and initial norepinephrine requirements as well as longer requirements of mechanical ventilation and ICU treatment in general. The development of hypernatraemia was neither attributable to fluid- or sodium-balances nor renal impairment. Although lower in the hypernatraemic group from day 4 onwards, median creatinine clearances were sufficiently high throughout the observation period. However, in the hypernatraemic group, urine sodium and chloride concentrations prior to the evolvement of hypernatraemia (56 (27-87) mmol/l and 39 (23-77) mmol/l) were significantly decreased when compared to i) the time after developing hypernatraemia (94 (58-134) mmol/l and 78 (36-115) mmol/l; p < 0.001) and ii) the non-hypernatraemic group in general (101 (66-143) mmol/l and 75 (47-109) mmol/l; p < 0.001).

CONCLUSIONS

Early ICU-acquired hypernatraemia is associated with injury severity and preceded by reduced renal sodium and chloride excretion in polytrauma patients.

Dyskalemias in patients with acute kidney injury presenting to the emergency department are common and independent predictors of adverse outcome

BACKGROUND

No data concerning the prevalence and risk factors of dyskalemia in acute kidney injury (AKI) exist. We investigated (a) prevalence rates, (b) risk factors and (c) outcome of hypo- and hyperkalemia in emergency patients.

METHODS

In this cross-sectional analysis, all patients admitted to the emergency department of a large public hospital in Switzerland between January 1st 2017 and December 31st 2018 with measurements of creatinine and potassium were included. Baseline characteristics, medication and laboratory data were extracted. Chart reviews were performed to identify patients with a diagnosis of chronic kidney disease (CKD) and to extract their baseline creatinine. For all other patients, the ADQI backformula was used in order to calculate baseline creatinine. AKI was graduated using creatinine criteria of the acute kidney injury network. Binary logistic regression analysis was used to identify risk factors for appearance of hyperkalemia and outcome.

RESULTS

AKI was found in 8% of patients. Hyperkalemia was present in 13% and hypokalemia in 11% of patients with AKI. AKI stage, potassium-sparing diuretics, ACE inhibitors and underlying CKD were the strongest risk factors for hyperkalemia. Hyperkalemia as well as profound hypokalemia were independently associated with prolonged length of stay and in-hospital mortality. The study is limited by its dependency on chart review data in order to identify patients with chronic kidney disease and by limitations of the ADQI backformula to calculate baseline creatinine.

CONCLUSIONS

Dyskalemias are common in emergency patients with AKI and are independent risk factors for adverse outcomes. Potassium-sparing diuretics, ACE-inhibitors, AKIN stage and CKD are predictors of hyperkalemia in AKI.

Hyperosmolarity Deserves More Attention in Critically Ill COVID-19 Patients with Diabetes: A Cohort-Based Study

PURPOSE

Recently, a cluster of pneumonia caused by SARS-CoV-2 were identified in Wuhan and spread throughout the world. More information about risk factors for mortality of critically ill patients infected with SARS-CoV-2 remain to be evaluated.

METHODS

We included adult patients confirmed with SARS-CoV-2 infection who were critically ill and admitted to the intensive care unit (ICU) of Tongji Hospital in Wuhan from Feb 4, 2020 to Feb 20, 2020. Data were collected and compared between patients who died and improved. Logistic regression was used to explore the risk factors for death of SARS-CoV-2-infected critically ill patients.

RESULTS

A total of 160 critically ill patients with SARS-CoV-2 infection were included, of which 146 patients with appeared outcomes were included into the final analysis. The random blood glucose, serum sodium and effective plasma osmolarity were higher in deceased patients, especially in patients with diabetes. There were 7 patients with diabetes with hyperosmolar status and all of them were deceased. Multivariable regression revealed that older age (odds ratio 4.28, 95% CI 1.01-18.20; p = 0.049), higher C-reactive protein (odds ratio 1.01, 1.00-1.03; p = 0.024), higher interleukin-6 (odds ratio 1.01, 1.00-1.03; p = 0.0323), and d-dimer greater than 1 μg/mL (odds ratio 1.10, 1.01-1.20; p = 0.032) at admission were associated with increased odds of death.

CONCLUSION

In conclusion, hyperosmolarity needs more attention and may contribute to mortality in critically ill patients with COVID-19, especially in those with diabetes. Older age, inflammatory response, and thrombosis may be risk factors for death of critically ill patients with SARS-CoV-2 infection.

Association Between ICU-Acquired Hypernatremia and In-Hospital Mortality: Data From the Medical Information Mart for Intensive Care III and the Electronic ICU Collaborative Research Database

Objectives

Describe the relationship between ICU-acquired hypernatremia and in-hospital mortality and investigate the optimal hypernatremia correction rate.

Design Setting Participants and Measurements

Observational study including two individual ICU cohorts. We used the Medical Information Mart for Intensive Care III v. 1.4 database consists of all ICU patients admitted to the Beth Israel Deaconess Medical Center in Boston from 2001 to 2012 (n = 46,476). The electronic ICU v. 2.0 database consists of all ICU patients admitted to 208 distinct hospitals across the United States from 2014 to 2015 (n = 200,859). We included all adult patients admitted to an ICU with two consecutive sodium samples within normal range (135-145 mmol/L) and without two consecutive hyponatremic samples (< 135 mmol/L) during the ICU stay.

Results

Of 23,445 patients identified in Medical Information Mart for Intensive Care III, 9% (n = 2,172) developed hypernatremia during their ICU stay. In electronic ICU, 88,160 patients were identified and 7% (n = 5,790) developed hypernatremia. In both cohorts, patients with hypernatremia had a higher mortality (Medical Information Mart for Intensive Care III: 20% vs 42%; p < 0.01 and electronic ICU: 6% vs 22%; p < 0.01), with hypernatremia increasing the risk of in-hospital mortality (Medical Information Mart for Intensive Care III: odds ratio, 1.15; 95% CI, 1.13-1.17 and electronic ICU: odds ratio, 1.11; 95% CI, 1.10-1.12) and over time using a Cox regression. Rapid sodium correction rate (> 0.5 mmol/L/hr) was associated with an increased in-hospital mortality in both cohorts (Medical Information Mart for Intensive Care III: odds ratio, 1.08; 95% CI, 1.03-1.13 and electronic ICU: odds ratio, 1.10; 95% CI, 1.06-1.13). In the electronic ICU cohort, rapid correction rates were associated with a significant difference in in-hospital mortality, but there was no statistically significant association in the Medical Information Mart for Intensive Care III cohort.

Conclusions

ICU-acquired hypernatremia is associated with increased in-hospital mortality. Furthermore, a rapid sodium correction rates may be harmful. This suggests it is important to both prevent ICU-acquired hypernatremia and to avoid rapid correction rates if a patient becomes hypernatremic.

ICU-Acquired Hypernatremia Is Associated with Persistent Inflammation, Immunosuppression and Catabolism Syndrome

Developing hypernatremia while on intensive care unit (ICU) is a common problem with various undesirable effects. A link to persistent inflammation, immunosuppression and catabolism syndrome (PICS) can be established in two ways. On the one hand, hypernatremia can lead to inflammation and catabolism via hyperosmolar cell stress, and on the other, profound catabolism can lead to hypernatremia via urea-induced osmotic diuresis. In this retrospective single-center study, we examined 115 patients with prolonged ICU stays (≥14 days) and sufficient renal function. Depending on their serum sodium concentrations between ICU day 7 and 21, allocation to a hypernatremic (high) and a nonhypernatremic group (low) took place. Distinct signs of PICS were detectable within the complete cohort. Thirty-three of them (28.7%) suffered from ICU-acquired hypernatremia, which was associated with explicitly higher signs of inflammation and ongoing catabolism as well as a prolonged ICU length of stay. Catabolism was discriminated better by the urea generation rate and the urea-to-creatinine ratio than by serum albumin concentration. An assignable cause for hypernatremia was the urea-induced osmotic diuresis. When dealing with ICU patients requiring prolonged treatment, hypernatremia should at least trigger thoughts on PICS as a contributing factor. In this regard, the urea-to-creatinine ratio is an easily accessible biomarker for catabolism.

Prevalence and Prognostic Impact of Hypernatremia in Sepsis and Septic Shock Patients in the Intensive Care Unit: A Single Centre Experience

Introduction

Hypernatremia is a commonly associated electrolyte disturbance in sepsis and septic shock patients in the ICU. The objective of this study was to identify the prognostic value of hypernatremia in sepsis and septic shock

Material and Methods

A prospective study conducted on sepsis and septic shock patients diagnosed prior to admission in the ICU in King Hamad University Hospital, Bahrain from January 1st 2017 to February 28th 2019. Data including age, sex, comorbidities, source of sepsis, sodium levels on days one, three, and seven. Data was correlated with the outcome (survival/death and the length of ICU stay).

Results

Patients included were 168, 110 survived, and 58 died. Hypernatraemia at day seven was associated with significantly higher mortality (P= 0.03). Hypernatraemia at Day1was associated with a significantly prolonged stay in the ICU (p= 0.039).Multivariate analysis to identify the independent predictors of mortality revealed that immunosuppression and hypernatraemia at Day7 proved to be independent predictors of mortality (P= 0.026 and 0.039 respectively).

Conclusion

Hypernatremia can be an independent predictor of poor outcome in septic and septic shock patients in the ICU.

Perioperative care of geriatric patients

The older population is expected to nearly double across the globe by 2050, and the baby boom cohort is expected to represent at least 20% of the US population by 2030. Geriatric patients will increasingly utilize the health-care system, and therefore surgical and perioperative care must be tailored to this sensitive group given the increased risk for perioperative complications. The literature was reviewed to highlight fundamental components of the preoperative evaluation as well as cardiac, pulmonary, and renal complications. Frailty is a multidimensional process that can lead to the physiologic effects of aging and estimates the risk of perioperative morbidity and mortality better than chronologic age alone. Health-care providers should assess a geriatric patient's cognitive status, decision-making capacity, frailty, advance care planning, medications, and anesthetic approach in a multidisciplinary fashion to ensure optimal care. The risks of postoperative cardiac, pulmonary, and renal complications should be evaluated and optimized preoperatively to reduce the potential for adverse outcomes.

Could sodium imbalances predispose to postoperative venous thromboembolism? An analysis of the NSQIP database

Background

Hyponatremia is common among patients with pulmonary embolism, while hypernatremia increases the risk of venous thromboembolism (VTE). Our objective was to evaluate the association between sodium imbalances and the incidence of VTE and other selected perioperative outcomes.

Methods

We conducted a retrospective cohort study using the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) and identified 1,108,704 patients undergoing major surgery from 2008 to 2012. We evaluated 30-day perioperative outcomes, including mortality and cardiac, respiratory, neurological, urinary, wound, and VTE outcomes. Multivariate logistic regressions were used to estimate the odds of 30-day perioperative outcomes.

Results

Compared with the normal sodium group, in which VTE occurred in 1.0% of patients, 1.8% of patients in the hyponatremia group (unadjusted odds ratio (OR) 1.84) and 2.4% of patients in the hypernatremia group (unadjusted OR 2.49) experienced VTE. Crude mortality was 1.3% in the normal sodium group, 4.9% in the hyponatremia group (unadjusted OR 3.93) and 8.4% in the hypernatremia group (unadjusted OR 7.01). Crude composite morbidity was 7.1% for the normal sodium group, 16.7% for the hyponatremia group (unadjusted OR 2.63) and 20.6% for the hypernatremia group (unadjusted OR 3.43). After adjusting for potential confounders, hyponatremia and hypernatremia remained significantly and independently associated with an increased risk of VTE (adjusted OR 1.43 and 1.56, respectively), mortality (adjusted OR 1.39 and 1.39, respectively) and composite morbidity (adjusted OR 2.15 and 3.34, respectively).

Conclusions

Pre-operative hyponatremia and hypernatremia are potential prognostic markers for perioperative 30-day morbidity, mortality and VTE.

Recommendations for active correction of hypernatremia in volume-resuscitated shock or sepsis patients should be taken with a grain of salt: A systematic review

Background:

Healthcare-acquired hypernatremia (serum sodium >145 mEq/dL) is common among critically ill and other hospitalized patients and is usually treated with hypotonic fluid and/or diuretics to correct a “free water deficit.” However, many hypernatremic patients are eu- or hypervolemic, and an evolving body of literature emphasizes the importance of rapidly returning critically ill patients to a neutral fluid balance after resuscitation.

Objective:

We searched for any randomized- or observational-controlled studies evaluating the impact of active interventions intended to correct hypernatremia to eunatremia on any outcome in volume-resuscitated patients with shock and/or sepsis.

Data sources:

We performed a systematic literature search with studies identified by searching MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, ClinicalTrials.gov, Index-Catalogue of the Library of the Surgeon General’s Office, DARE (Database of Reviews of Effects), and CINAHL and scanning reference lists of relevant articles with abstracts published in English.

Data synthesis:

We found no randomized- or observational-controlled trials measuring the impact of active correction of hypernatremia on any outcome in resuscitated patients.

Conclusion:

Recommendations for active correction of hypernatremia in resuscitated patients with sepsis or shock are unsupported by clinical research acceptable by modern evidence standards.

Hospital-Associated Hypernatremia Spectrum and Clinical Outcomes in an Unselected Cohort

BACKGROUND

Although hypernatremia is associated with adverse outcomes, most studies examined selected populations.

METHODS

Discharge data of 19,072 unselected hospitalized adults were analyzed. The crude relationship between serum sodium [Na⁺] and mortality defined hypernatremia as serum [Na⁺] >142 mEq/L. Patients with community-acquired hypernatremia or hospital-acquired hypernatremia were compared with normonatremic patients (admission [Na⁺] 138-142 mEq/L) regarding in-hospital mortality, length of stay, and discharge disposition. Patients with community-acquired hypernatremia whose hypernatremia worsened during hospitalization were compared with those without aggravation.

RESULTS

Community-acquired hypernatremia occurred in 21% of hospitalized patients and was associated with an adjusted odds ratio (OR) of 1.67 (95% confidence interval [CI], 1.38-2.01) for in-hospital mortality and 1.44 (95% CI, 1.32-1.56) for discharge to a short-/long-term care facility and an adjusted 10% (95% CI, 7-13) increase in length of stay. Hospital-acquired hypernatremia developed in 25.9% of hospitalized patients and was associated with an adjusted OR of 3.17 (95% CI, 2.45-4.09) for in-hospital mortality and 1.45 (95% CI, 1.32-1.59) for discharge to a facility, and an adjusted 49% (95% CI, 44-53) increase in length of stay. Hospital-aggravated hypernatremia developed in 11.7% of patients with community-acquired hypernatremia and was associated with greater risk of in-hospital mortality (adjusted OR, 1.84; 95% CI, 1.32-2.56) and discharge to a facility (adjusted OR, 2.14; 95% CI, 1.71-2.69), and an adjusted 16% (95% CI, 7-27) increase in length of stay.

CONCLUSIONS

The hypernatremia spectrum in unselected hospitalized patients is independently associated with increased in-hospital mortality and heightened resource consumption.

Morbidity and mortality associated with hypernatremia in patients with severe traumatic brain injury

OBJECTIVE

Hypernatremia is independently associated with increased mortality in critically ill patients. Few studies have evaluated the impact of hypernatremia on early mortality in patients with severe traumatic brain injury (TBI) treated in a neurocritical care unit.

METHODS

A retrospective review of patients with severe TBI (admission Glasgow Coma Scale score ≤ 8) treated in a single neurocritical care unit between 1986 and 2012 was performed. Patients with at least 3 serum sodium values were selected for the study. Patients with diabetes insipidus and those with hypernatremia on admission were excluded. The highest serum sodium level during the hospital stay was recorded, and hypernatremia was classified as none (≤ 150 mEq/L), mild (151–155 mEq/L), moderate (156–160 mEq/L), and severe (> 160 mEq/L). Multivariate Cox regression analysis was performed to determine independent predictors of early mortality.

RESULTS

A total of 588 patients with severe TBI were studied. The median number of serum sodium measurements for patients in this study was 17 (range 3–190). No hypernatremia was seen in 371 patients (63.1%), mild hypernatremia in 77 patients (13.1%), moderate hypernatremia in 50 patients (8.5%), and severe hypernatremia in 90 patients (15.3%). Hypernatremia was detected within the 1st week of admission in 79.3% of patients (n = 172), with the majority of patients (46%) being diagnosed within 72 hours after admission. Acute kidney injury, defined as a rise in creatinine of ≥ 0.3 mg/dl, was observed in 162 patients (27.6%) and was significantly associated with the degree of hypernatremia (p < 0.001). At discharge, 148 patients (25.2%) had died. Hypernatremia was a significant independent predictor of mortality (hazard ratios for mild: 3.4, moderate: 4.4, and severe: 8.4; p < 0.001). Survival analysis showed significantly lower survival rates for patients with greater degrees of hypernatremia (log-rank test, p < 0.001).

CONCLUSIONS

Hypernatremia after admission in patients with severe TBI was independently associated with greater risk of early mortality. In addition to severe hypernatremia, mild and moderate hypernatremia were significantly associated with increased early mortality in patients with severe TBI.

Sodium bicarbonate use and the risk of hypernatremia in thoracic aortic surgical patients with metabolic acidosis following deep hypothermic circulatory arrest

Objective:

Metabolic acidosis after deep hypothermic circulatory arrest (DHCA) for thoracic aortic operations is commonly managed with sodium bicarbonate (NaHCO₃). The purpose of this study was to determine the relationships between total NaHCO₃ dose and the severity of metabolic acidosis, duration of mechanical ventilation, duration of vasoactive infusions, and Intensive Care Unit (ICU) or hospital length of stay (LOS).

Methods:

In a single center, retrospective study, 87 consecutive elective thoracic aortic operations utilizing DHCA, were studied. Linear regression analysis was used to test for the relationships between the total NaHCO₃ dose administered through postoperative day 2, clinical variables, arterial blood gas values, and short-term clinical outcomes.

Results:

Seventy-five patients (86%) received NaHCO₃. Total NaHCO₃ dose averaged 136 ± 112 mEq (range: 0.0–535 mEq) per patient. Total NaHCO₃ dose correlated with minimum pH (r = 0.41, P < 0.0001), minimum serum bicarbonate (r = −0.40, P < 0.001), maximum serum lactate (r = 0.46, P = 0.007), duration of metabolic acidosis (r = 0.33, P = 0.002), and maximum serum sodium concentrations (r = 0.29, P = 0.007). Postoperative hypernatremia was present in 67% of patients and peaked at 12 h following DHCA. Eight percent of patients had a serum sodium ≥ 150 mEq/L. Total NaHCO₃ dose did not correlate with anion gap, serum chloride, not the duration of mechanical ventilator support, vasoactive infusions, ICU or hospital LOS.

Conclusion:

Routine administration of NaHCO₃ was common for the management of metabolic acidosis after DHCA. Total dose of NaHCO₃ was a function of the severity and duration of metabolic acidosis. NaHCO₃ administration contributed to postoperative hypernatremia that was often severe. The total NaHCO₃ dose administered was unrelated to short-term clinical outcomes.

Could dysnatremias play a role as independent factors to predict mortality in surgical critically ill patients?

Several studies have demonstrated the impact of dysnatremias on mortality of intensive care unit (ICU) patients. The objective of this study was to assess whether dysnatremia is an independent factor to predict mortality in surgical critically ill patients admitted to ICU in postoperative phase.One thousand five hundred and ninety-nine surgical patients (58.8% males; mean age of 60.6 ± 14.4 years) admitted to the ICU in the postoperative period were retrospectively studied. The patients were classified according to their serum sodium levels (mmol/L) at admission as normonatremia (135-145), hyponatremia (<135), and hypernatremia (>145). APACHE II, SAPS III, and SOFA were recorded. The capability of each index to predict mortality of ICU and hospital mortality of patients was analyzed by multiple logistic regression.Hyponatremia did not have an influence on mortality in the ICU with a relative risk (RR) = 0.95 (0.43-2.05) and hospital mortality of RR = 1.40 (0.75-2.59). However, this association was greater in patients with hypernatremia mortality in the ICU (RR = 3.33 [95% confidence interval, CI 1.58-7.0]) and also in hospital mortality (RR = 2.9 [ 95% CI = 1.51-5.55). The pairwise comparison of ROC curves among the different prognostic indexes (APACHE II, SAPS III, SOFA) did not show statistical significance. The comparison of these indexes with serum sodium levels for general population, hyponatremia, and normonatremia was statistically significant (P < .001). For hypernatremia, the AUC and 95% CI for APACHE II, SAPS III, SOFA, and serum sodium level were 0.815 (0.713-0.892), 0.805 (0.702-0.885), 0.885 (0.794-0.945), and 0.663 (0.549-0.764), respectively. The comparison among the prognostic indexes was not statistically significant. Only SOFA score had a statistic difference compared with hypernatremia (P < .02).The serum sodium levels at admission, especially hypernatremia, may be used as an independent predictor of outcome in the surgical critically ill patients.

The association between sodium fluctuations and mortality in surgical patients requiring intensive care

PURPOSE

Serum sodium derangement is the most common electrolyte disturbance among patients admitted to intensive care. This study aims to validate the association between dysnatremia and serum sodium fluctuation with mortality in surgical intensive care patients.

METHOD

We performed a retrospective analysis of the Medical Information Mart for Intensive Care II database. Dysnatremia was defined as a sodium concentration outside physiologic range (135-145mmol/L) and subjects were categorized by severity of dysnatremia and sodium fluctuation. Univariate and multivariable logistic regressions were used to test for associations between sodium fluctuations and mortality.

RESULTS

We identified 8600 subjects, 39% of whom were female, with a median age of 66years for analysis. Subjects with dysnatremia were more likely to be dead at 28 days (17% vs 7%; P<.001). There was a significant association between sodium fluctuation and mortality at 28 days (adjusted odds ratio per 1mmol/L change, 1.10 [95% confidence interval, 1.08-1.12; P<.001]), even in patients who remained normotremic during their intensive care unit stay (1.12 [95% confidence interval, 1.09-1.16; P<.001]) CONCLUSIONS: This observational study validates previous findings of an association between serum sodium fluctuations and mortality in surgical intensive care patients. This association was also present in subjects who remained normonatremic throughout their intensive care unit admission.

Hydrochlorothiazide in intensive care unit-acquired hypernatremia: A randomized controlled trial

PURPOSE

Thiazides are suggested as a treatment for intensive care unit (ICU)-acquired hypernatremia (IAH). The primary aim of the study was reducing serum sodium concentration (sNa) in patients with IAH with hydrochlorothiazide (HCT) in comparison to placebo. Secondary end points were a difference in urine sodium concentration (uNa) and duration of severe IAH.

MATERIALS

A monocentric, double-blind, placebo-controlled trial was conducted in 50 patients with IAH and urine potassium + uNa less than sNa in a spot urine sample. Patients were randomized to HCT 25 mg or placebo 1 qd for maximal 7 days. Patients on renal replacement therapy, on medication inducing diabetes insipidus, or with recent use of diuretics were excluded. IAH was defined as sNa of at least 143 mmol/L.

RESULTS

At baseline, sNa and uNa were comparable between groups. During the study period, sNa decreased significantly with median 4 mmol/L in both groups, with no significant difference between groups (P=.32). Median uNa increased significantly in both groups (46 [16-86] mmol/L in the HCT-group; 20 [10-66]mmol/L in the placebo group), with no difference between groups (P=.34). Median duration of sNa of at least 145 mmol/L was 3 days in both groups (P=.91).

CONCLUSION

HCT 25 mg 1 qd did not significantly affect sNa or uNa in patients with IAH.

Differences between prolonged weaning patients from medical and surgical intensive care units

BACKGROUND

It is not clear whether patients entering a specialized, interdisciplinary weaning unit from surgical or medical intensive care units (ICU) distinguish substantially. The purpose of the present study was to assess differences in patients with prolonged weaning being referred from surgical and medical ICU.

METHODS

Data collected from April 2013 to April 2014 was conducted for retrospective analysis. Mortality rates, demographic data, clinical, and microbial differences in 150 patients with prolonged weaning were assessed (80 surgical and 70 medical).

RESULTS

Surgical ICU referrals tended to be older (70.7 ± 11.3 vs. 67.3 ± 12.3, P = 0.051) and had fewer underlying pulmonary diseases (45% vs. 60%, P = 0.067). Sodium values at the time of referral to the weaning unit were significantly higher in surgical (147.1 ± 9.6) vs. medical (141.3 ± 6.7 mmol/l) patients (P < 0.001). Each 10-unit increase in sodium at the time of referral to the weaning unit was associated with a 2.5-day (95% CI -0.4, 5.4; P = 0.09) prolongation of stay in the weaning unit. Although significant differences in microbiological agents from tracheal aspiration were seen, the infection rate on the weaning unit was similar in both groups. There was no difference in weaning unit mortality between surgical and medical ICU patients (18% vs. 23%; P = 0.41).

CONCLUSION

Few differences were found between patients being referred to a specialized weaning unit from surgical vs. medical ICUs. Besides differences in microbiological characteristics of tracheal secretions, there were also differences in sodium levels, which appear to influence on treatment duration.

The Reduction Rate of Serum Sodium and Mortality in Patients Undergoing Continuous Venovenous Hemofiltration for Acute Severe Hypernatremia

BACKGROUND

The excessive correction of acute hypernatremia is not known to be harmful. This study aimed to evaluate whether a reduction rate of serum sodium (RRSeNa) > 1mEq/L/hour in acute severe hypernatremia is an independent risk factor for mortality in critically ill patients undergoing continuous venovenous hemofiltration (CVVH) treatment.

MATERIALS AND METHODS

For this retrospective study, we reviewed records of 75 critically ill patients undergoing CVVH treatment for acute severe hypernatremia between March 2011 and March 2015.

RESULTS

The 28-day mortality rate of all patients was 61.3%. In multivariate Cox regression analyses, a reduction rate of serum sodium (RRSeNa) > 1mEq/L/hour (hazard ratio = 1.89; 95% CI: 1.03-3.47; P = 0.04), Acute Physiology and Chronic Health Evaluation II score and vasopressor dependency (yes or no) had a statistically significantly effect on mortality. Once we excluded patients with an RRSeNa ≤ 0.5mEq/L/hour, only RRSeNa > 1mEq/L/hour (hazard ratio = 2.611; 95% CI: 1.228-5.550; P = 0.013) and vasopressor dependency had a statistically significant influence on mortality in multivariate regression.

CONCLUSIONS

In addition to the Acute Physiology and Chronic Health Evaluation II score and vasopressor dependency, the excessive correction of acute severe hypernatremia was possibly associated with mortality in critically ill patients undergoing CVVH treatment. The optimal reduction rate of acute hypernatremia should be extensively studied in critically ill patients.

Incidence, severity and prognosis associated with hypernatremia in dogs and cats

Background

Hypernatremia has been associated with substantial morbidity and death in human patients. The incidence and importance of hypernatremia in dogs and cats has not been determined.

Hypothesis/Objectives

To describe the incidence of and prognosis associated with hypernatremia in dogs and cats at a university teaching hospital.

Animals

A total of 16,691 dogs and 4,211 cats with measured blood or serum sodium concentration.

Methods

Retrospective study. Medical records of animals with a blood or serum sodium concentration measured during a 60‐month period were reviewed to determine the severity of hypernatremia and its associated case fatality rate. Cases with moderate (11–15 mmol/L above the reference range) or severe hypernatremia (≥16 mmol/L above the reference range) were further reviewed.

Results

A total of 957 dogs (5.7%) and 338 cats (8.0%) were diagnosed with hypernatremia. Case fatality rates of dogs and cats with hypernatremia was 20.6 and 28.1%, respectively compared to 4.4 and 4.5% with a normal blood or serum sodium concentration (P < .0001). The magnitude of hypernatremia was linearly associated with a higher case fatality rate (P < .0001). Hypernatremia was associated with a higher case fatality rate than hyponatremia. Among the animals with moderate or severe hypernatremia, 50% of dogs and 38.5% of cats presented with community‐acquired hypernatremia, and 50% of dogs and 61.5% of cats developed hospital‐acquired hypernatremia.

Conclusions and clinical importance

Hypernatremia was found infrequently in this population but was associated with increased case fatality rates in dogs and cats. Presence and severity of hypernatremia might be useful as a prognostic indicator.

Acquired hypernatremia in a general surgical Intensive Care Unit: Incidence and prognosis

Purpose:

Intensive Care Unit (ICU)-acquired hypernatremia (IAH) is a serious electrolyte disturbance that recently was shown to present an independent risk factor for mortality in critically ill patients. IAH has not been widely investigated in Surgical ICU (SICU) patients. No study has specifically investigated IAH epidemiology in the Kingdome of Saudi Arabia (KSA) in general SICU. The objectives of this study are to assess the epidemiological characteristics and prognostic impact of IAH on SICU mortality and outcome in KSA and compare it with international figures.

Materials and Methods:

A retrospective observational study on a prospectively collected data of patients (14 years of age or older) admitted to SICU over 2 years, with normal serum sodium on admission and who developed IAH (serum sodium above 145 mmol/L) from day two of admission. Traumatic brain injury patients with therapeutic target sodium level above 145 mmol/L were excluded.

Results:

Over 2 years study period, 864 patients were admitted to SICU. A total of 50 (5.8%) developed IAH and were included in the study. Twenty-eight (56%) patients were male. The median age was 47 (14-84) years. The mean (± standard deviation) Acute Physiology and Chronic Health Evaluation II score was 17 ± 6.5. The incident density (the rate of occurrence of IAH per 100 days care for SICU admission for the first episode) was 0.71. Risk factors include mechanical ventilation, male sex, age ≥50 years, postgastrointestinal surgeries, weekend and night admission. SICU mortality was 40%. The SICU and hospital median (range) length of stay was 8.3 (2-53) and 28.8 (3-95), respectively.

Conclusions:

IAH is not uncommon in SICU patients and is associated with increased risk of SICU as well as hospital mortality.

The German Validation Study of the Surgical Intensive Care Unit Optimal Mobility Score

PURPOSE

Immobilization of critically ill patients leads to muscle weakness, which translates to increased costs of care and long-term functional disability. We tested the validity of a German Surgical Intensive Care Unit (ICU) Optimal Mobilization Score (SOMS) in 2 different cohorts (neurocritical and nonneurocritical care patients).

MATERIALS AND METHODS

Physical therapists estimated the patients' mobilization capacity by using the German version of the SOMS the morning after admission. We tested the prognostic value of the prediction for ICU and hospital length of stay (LOS) as well as for mortality, and built a model to account for other known predictors of these outcomes in the 2 cohorts.

RESULTS

A total of 128 patients were included in the analysis, 48 of these were neurocritical care patients. The SOMS predicted mortality and ICU and hospital LOS. Neurocritical care patients stayed significantly longer in the ICU (median 12 vs 4 days, P < .001) and in the hospital (25 vs 17 days, P = .02). The SOMS predicted ICU and hospital LOS. It predicted mortality only in nonneurocritical patients.

CONCLUSIONS

The German SOMS assessed by physical therapists on the day after ICU admission predicts ICU and hospital LOS, and mortality. Our data suggest that the association between early mobilization and mortality is more complex in neurocritical care patients.

Are the Dysnatremias a Permanent Threat to the Critically Ill Patients?

Backgroud

The dysnatremias (hyponatremia and hypernatremia) are relatively common findings on admission of intensive care unit (ICU) patients and may represent a major risk. The aim of the study was to assess the ability of serum sodium levels and the Acute Physiology and Chronic Health Evaluation II (APACHE II) to predict mortality of surgical critically ill patients.

Methods

One hundred and ninety-five surgical patients (62% males and 38% females; mean age of 51.8 ± 17.3 years) admitted to the ICU in the postoperative phase were retrospectively studied. The patients were divided into survivors (n = 152) and non-survivors (n = 43). APACHE II, and serum sodium levels at admission, 48 h and discharge were analyzed by generation of receiver operating characteristic (ROC) curves.

Results

The mean APACHE II was 16.3 ± 8.3 (13.6 ± 6.1 for survivors and 25.5 ± 8.5 for non-survivors). The area under the ROC curve for APACHE II was 0.841 (0.782 - 0.889) and 0.721 (0.653 - 0.783), 0.754 (0.653 - 0.783) and 0.720 (0.687 - 0.812) for serum sodium level at admission, 48 h and discharge, respectively.

Conclusion

Even though APACHE II scoring system was the most effective index to predict mortality in the surgical critically ill patients, the serum sodium levels on admission may also be used as an independent predictor of outcome.

Acute serum sodium concentration changes in pediatric patients undergoing cardiopulmonary bypass and the association with postoperative outcomes

The objective of this study is to investigate the degree of serum sodium changes and its association with patient outcomes in pediatrics undergoing heart surgery with cardiopulmonary bypass (CPB). We reviewed the medical records of 275 pediatric patients who underwent heart surgery with CPB. Prior to CPB, hyponatremia (≤135 mmol/L) was observed in 21 of 275 patients. After initiation of CPB, serum sodium decreased significantly and severe hyponatermia (≤130 mmol/L) subsequently developed in 32 patients. At the end of CPB, however, hypernatremia (≥145 mmol/L) developed in 86 patients. The degree of acute serum sodium change during CPB was not associated with patient outcomes. However, the patients with preoperative hyponatremia and those with hypernatremia at the conclusion of CPB had longer hospital stays and higher postoperative complication rates. Lower serum sodium prior to CPB and higher serum sodium at the end of CPB, along with age and duration of the operation, were independently associated with worse in-hospital outcomes. Acute and transient hyponatremia occurred frequently after initiation of CPB, and then serum sodium immediately increased above preoperative levels at the end of CPB. Caution is required to avoid serum sodium overcorrection on the conclusion of CPB.

Incidence and mortality prognosis of dysnatremias in neurologic critically ill patients

BACKGROUND

Dysnatremia, which is associated with increased mortality in general intensive care units (ICU), has not been thoroughly studied in neurologic ICU (NICU).

METHODS

Prevalence of dysnatremia was retrospectively assessed. The multivariable binary logistic regression model was used to determine the influence of dysnatremia on mortality.

RESULTS

Of 519 patients, 106 (20.4%) were admitted with hyponatremia and 177 (34.10%) with hypernatremia. Hypernatremia was detected in 69 (13.29%) patients on admission to NICU and in 108 patients (20.81%) during the ICU stay. However, the incidence of dysnatremia did not differ across the neurological categories (p = 0.4690). ICU stay in patients with acquired hypernatremia (22.3 ± 25.35 days) was longer than those with admission hypernatremia (13.5 ± 12.8 days) or with consistent normonatremia (16.16 ± 20.06 days). The other indicators such as Acute Physiology and Chronic Health Evaluation II, Glasgow Coma Scale score, urinary catheterization, and incidence of pneumonia were also associated with the serum sodium concentrations. Hypernatremia both on admission and acquired in NICU could significantly differentiate between survivors and nonsurvivors (p = 0.002 and <0.0001). However, only NICU-acquired hypernatremia was the independent risk factor for mortality with high sensitivity (p = 0.000).

CONCLUSIONS

Dysnatremia is more common in NICU, whereas only acquired-hypernatremia was independently associated with outcome.

Early intensive care unit-acquired hypernatremia in severe sepsis patients receiving 0.9% saline fluid resuscitation

BACKGROUND

Intensive care unit (ICU)-acquired hypernatremia is associated with increased mortality and ascribed to excessive sodium/insufficient free water intakes. We aimed to determine whether the volume of intravenous 0.9% saline fluid resuscitation was associated with hypernatremia in severe sepsis.

METHODS

We retrospectively reviewed the charts of patients admitted to our medical ICU over 1 year with severe sepsis, and recorded all fluid intakes and plasma sodium levels (Nap ) for 5 days along with clinical data. ΔNap was defined as the difference between maximal Nap reached and initial Nap . Hypernatremia was defined as Nap  > 145 mmoles/l.

RESULTS

Among 95 patients with severe sepsis, 29 developed hypernatremia within 5 days (31%), reaching a maximum Nap of 149.1 ± 2.5 mmoles/l on average 3.8 ± 1.5 days after admission. For every 50-ml/kg increase in 0.9% saline intake for the first 48 h, the odds of hypernatremia were 1.61 times larger [confidence interval (CI): 0.98-2.62; P = 0.06] and the mean of ΔNap increased by 1.86 mmoles/l (CI: 0.86-2.86; P < 0.001). Compared with non-hypernatremic patients, hypernatremic patients received more 0.9% saline within the first 48 h (111 ± 50 ml/kg vs. 92 ± 42 ml/kg, P < 0.05) and more other fluids from 48 to 96 h (64 ± 38 ml/kg vs. 42 ± 24 ml/kg, P < 0.05). Patients developing hypernatremia had increased length of mechanical ventilation (12.0 ± 12.6 vs. 9.1 ± 7.2 days, P < 0.05) and ICU mortality (38.5% vs. 13%, P < 0.01).

CONCLUSIONS

Early acquired hypernatremia is a frequent complication in severe sepsis patients and is associated with the volume of 0.9% saline received during the first 48 h of admission.

Association of serum sodium with morbidity and mortality in hospitalized patients undergoing major orthopedic surgery

BACKGROUND

Dysnatremia may predispose to falls and fractures, and serum sodium may influence bone health. Little is known of the association of perioperative dysnatremia and clinical outcomes in those undergoing major orthopedic surgery.

OBJECTIVE

We examined the association of serum sodium (corrected for glucose) with morbidity and mortality in a sample of hospitalized patients undergoing major orthopedic procedures at 2 large academic medical centers.

DESIGN

Retrospective observational study.

SETTING AND PARTICIPANTS

Adult patients admitted to major academic teaching hospitals for a major orthopedic procedure from January 2006 to January 2011.

METHODS

The association of serum sodium with log-transformed hospital length of stay was assessed by fitting linear regression models. The association with 30-day mortality was assessed by fitting Cox proportional hazards models.

RESULTS

There were 16,206 unique admissions, of which 44.8% were male, with a mean age of 62.5 years. Mean corrected serum sodium was 138.5 ± 2.9 mmol/L; 1.2% had moderate/severe hyponatremia, 6.4% had mild hyponatremia, and 2.5% were hypernatremic. In adjusted models, compared with normonatremia, moderate/severe hyponatremia, mild hyponatremia, and hypernatremia were associated with a 1.6-, 1.4-, and 1.4-day-longer hospital stay, respectively, and greater risk of 30-day mortality (hazard ratio [HR]: 2.47, 95% confidence interval [CI]: 1.33-4.59 for moderate/severe hyponatremia; HR: 1.80, 95% CI: 1.21-2.66 for mild hyponatremia; and HR: 2.99, 95% CI: 1.79-4.98 for hypernatremia).

CONCLUSION AND RELEVANCE

Dysnatremia is relatively common in the hospitalized orthopedic population and associated with greater length of stay and 30-day mortality. Future studies should address potential mechanisms underlying these associations and whether correction of perioperative dysnatremia may improve patient outcomes.

Normal saline to dilute parenteral drugs and to keep catheters open is a major and preventable source of hypernatremia acquired in the intensive care unit

PURPOSE

We wanted to identify modifiable risk factors for intensive care unit (ICU)-acquired hypernatremia.

MATERIALS AND METHODS

We retrospectively studied sodium and fluid loads and balances up to 7 days prior to the development of hypernatremia (first serum sodium concentration, [Na+], >150 mmol/L; H) vs control (maximum [Na+] ≤150 mmol/L; N), in consecutive patients admitted into the ICU with a normal serum sodium (<145 mmol/L) and without cerebral disease, within a period of 8 months.

RESULTS

There were 57 H and 150 N patients. Severity of disease and organ failure was greater, and length of stay and mechanical ventilation in the ICU were longer in H (P<.001), with a mortality rate of 28% vs 16% in N (P=.002). Sodium input was higher in H than in N, particularly from 0.9% saline to dissolve drugs for infusion and to keep catheters open during the week prior to the first day of hypernatremia (P<.001). Fluid balances were positive and did not differ from N on most days in the presence of slightly higher plasma creatinine and more frequent administration of furosemide, at higher doses, in H than in N.

CONCLUSIONS

High sodium input by 0.9% saline used to dilute drugs and keep catheters open is a modifiable risk factor for ICU-acquired H. Dissolving drugs in dextrose 5% may partially prevent potentially harmful sodium overloading and H.

Preoperative hypernatremia predicts increased perioperative morbidity and mortality

BACKGROUND

The prognostic implications of preoperative hypernatremia are unknown. We sought to determine whether preoperative hypernatremia is a predictor of 30-day perioperative morbidity and mortality.

METHODS

We conducted a cohort study using the American College of Surgeons-National Surgical Quality Improvement Program and identified 908,869 adult patients undergoing major surgery from approximately 300 hospitals from the years 2005 to 2010. We followed the patients for 30-day perioperative outcomes, which included death, major coronary events, wound infections, pneumonia, and venous thromboembolism. Multivariable logistic regression was used to estimate the odds of 30-day perioperative outcomes.

RESULTS

The 20,029 patients (2.2%) with preoperative hypernatremia (>144 mmol/L) were compared with the 888,840 patients with a normal baseline sodium (135-144 mmol/L). Hypernatremia was associated with a higher odds for 30-day mortality (5.2% vs 1.3%; adjusted odds ratio [aOR], 1.44; 95% confidence interval [CI], 1.33-1.56), and this finding was consistent in all subgroups. The odds increased according to the severity of hypernatremia (P < .001 for pairwise comparison for mild [145-148 mmol/L] vs severe [>148 mmol/L] categories). Furthermore, hypernatremia was associated with a greater odds for perioperative major coronary events (1.6% vs 0.7%; aOR, 1.16; 95% CI, 1.03-1.32), pneumonia (3.4% vs 1.5%; aOR, 1.23; 95% CI, 1.13-1.34), and venous thromboembolism (1.8% vs 0.9%; OR, 1.28; 95% CI, 1.14-1.42).

CONCLUSION

Preoperative hypernatremia is associated with increased perioperative 30-day morbidity and mortality.

Hypernatremia severity and the risk of death after traumatic brain injury

PURPOSE

To investigate the relationship between severity of hypernatremia and the risk of death for patients with traumatic brain injury (TBI) who have been admitted to the neurosurgical intensive care unit (NICU).

METHODS

A total of 1044 patients with TBI were admitted to our NICU from January 2005 to January 2010. Of these patients, 881 were included in this study. Based on blood serum sodium level in the NICU the 881 patients were divided into four groups: 614 had normal serum sodium (Na<150mmol/L), 34 had mild hypernatremia (Na 150-<155mmol/L), 66 had moderate hypernatremia (Na 155-160mmol/L) and 167 had severe hypernatremia (Na≥160mmol/L).

RESULTS

The mortality rates for the mild, moderate, and severe hypernatremia groups were 20.6%, 42.4%, and 86.8%, respectively; the mortality rate for the normal group was 2.0%. In multivariable analysis, mild, moderate, and severe hypernatremia were independent risk factors for mortality; compared with the normal group the odds ratios of mild, moderate, and severe hypernatremia were 9.50, 4.34, and 29.35, respectively.

CONCLUSIONS

Severe hypernatremia is an independent risk factor with extremely high odds ratio for death in patients with TBI who are admitted to the NICU.

Body salt and water balances in cardiothoracic surgery patients with intensive care unit-acquired hyponatremia

PURPOSE

Hyponatremia is frequently observed in intensive care unit (ICU) patients, but there is still lack information on the physiological mechanisms of development.

MATERIALS AND METHODS

In this retrospective analysis we performed tonicity balances in 54 patients with ICU acquired hyponatremia. We calculated fluid and solute in and outputs during 24 hours in 106 patient days with decreasing serum-sodium levels.

RESULTS

We could observe a positive fluid balance as a single reason for hyponatremia in 25% of patients and a negative solute balance in 57%. In 18% both factors contributed to the decrease in serum-sodium. Hyponatremic patients had renal water retention, measured by electrolyte free water clearance calculation in 79% and positive input of free water in 67% as reasons for decline of serum-sodium. The theoretical change of serum sodium during 24 hours according to the calculations of measured balances correlated well with the real change of serum sodium (r = 0.78, P < .01).

CONCLUSIONS

Balance studies showed that renal water retention together with renal sodium loss and high electrolyte free water input are the major contributors to the development of hyponatremia. Control of renal water and sodium handling by urine analysis may contribute to a better fluid management in the ICU population.

Safety and efficacy of intravenous hypotonic 0.225% sodium chloride infusion for the treatment of hypernatremia in critically ill patients

BACKGROUND

The purpose of this study was to evaluate the safety and efficacy of central venous administration of a hypotonic 0.225% sodium chloride (one-quarter normal saline [¼ NS]) infusion for critically ill patients with hypernatremia.

METHODS

Critically ill, adult patients with traumatic injuries and hypernatremia (serum sodium [Na] >150 mEq/L) who were given ¼ NS were retrospectively studied. Serum sodium, fluid balance, free water intake, sodium intake, and plasma free hemoglobin concentration (fHgb) were assessed.

RESULTS

Twenty patients (age, 50 ± 18 years; Injury Severity Score, 29 ± 12) were evaluated. The ¼ NS infusion was given at 1.5 ± 1.0 L/d for 4.6 ± 1.6 days. Serum sodium concentration decreased from 156 ± 4 to 143 ± 6 mEq/L (P < .001) over 3-7 days. Total sodium intake was decreased from 210 ± 153 to 156 ± 112 mEq/d (P < .05). Daily net fluid balance was not significantly increased. Plasma fHgb increased from 4.9 ± 5.4 mg/dL preinfusion to 8.9 ± 7.4 mg/dL after 2.6 ± 1.3 days of continuous intravenous (IV) ¼ NS in 10 patients (P = .055). An additional 10 patients had a plasma fHgb of 10.2 ± 9.0 mg/dL during the infusion. Hematocrit and hemoglobin decreased (26% ± 3% to 24% ± 2%, P < .001 and 9.1 ± 1.1 to 8.2 ± 0.8 g/dL, P < .001, respectively).

CONCLUSIONS

Although IV ¼ NS was effective for decreasing serum sodium concentration, evidence for minor hemolysis warrants further research to establish its safety before its routine use can be recommended.

Impact of diuretic therapy-associated electrolyte disorders present on admission to the emergency department: a cross-sectional analysis

BACKGROUND

Diuretics are among the most commonly prescribed medications and, due to their mechanisms of action, electrolyte disorders are common side effects of their use. In the present work we investigated the associations between diuretics being taken and the prevalence of electrolyte disorders on admission as well as the impact of electrolyte disorders on patient outcome.

METHODS

In this cross sectional analysis, all patients presenting between 1 January 2010 and 31 December 2011 to the emergency room (ER) of the Inselspital, University Hospital Bern, Switzerland were included. Data on diuretic medication, baseline characteristics and laboratory data including electrolytes and renal function parameters were obtained from all patients. A multivariable logistic regression model was performed to assess the impact of factors on electrolyte disorders and patient outcome.

RESULTS

A total of 8.5% of patients presenting to the ER used one diuretic, 2.5% two, and 0.4% three or four. In all, 4% had hyponatremia on admission and 12% hypernatremia. Hypokalemia was present in 11% and hyperkalemia in 4%. All forms of dysnatremia and dyskalemia were more common in patients taking diuretics. Loop diuretics were an independent risk factor for hypernatremia and hypokalemia, while thiazide diuretics were associated with the presence of hyponatremia and hypokalemia. In the Cox regression model, all forms of dysnatremia and dyskalemia were independent risk factors for in hospital mortality.

CONCLUSIONS

Existing diuretic treatment on admission to the ER was associated with an increased prevalence of electrolyte disorders. Diuretic therapy itself and disorders of serum sodium and potassium were risk factors for an adverse outcome.

Hypernatremia is associated with increased risk of mortality in pediatric severe traumatic brain injury

Acquired hypernatremia in hospitalized patients is often associated with poorer outcomes. Our aim was to evaluate the relationship between acquired hypernatremia and outcome in children with severe traumatic brain injury (sTBI). We performed a retrospective cohort study of all severely injured trauma patients (Injury Severity Score ≥12) with sTBI (Glasgow Coma Scale [GCS] ≤8 and Maximum Abbreviated Injury Scale [MAIS] ≥4) admitted to a Pediatric Critical Care Unit ([PCCU]; 2000-2009). In a cohort of 165 patients, 76% had normonatremia (135-150 mmol/L), 18% had hypernatremia (151-160 mmol/L), and 6% had severe hypernatremia (>160 mmol/L). The groups were similar except for lower GCS (p=0.002) and increased incidence of fixed pupil(s) on admission in both hypernatremia groups (p<0.001). Mortality rate was four-fold and six-fold greater with hypernatremia and severe hypernatremia, respectively (p<0.001), and mortality rates were unchanged when patients with fixed pupils or those with central diabetes insipidus were excluded (p<0.001). Hypernatremic patients had fewer ventilator-free days (p<0.001). Survivors with hypernatremia had greater PCCU (p=0.001) and hospital (p=0.031) lengths of stays and were less frequently discharged home (p=0.008). Logistic regression analyses of patient characteristics and sTBI interventions demonstrated that hypernatremia was independently associated with the presence of fixed pupil(s) on admission (odds ratio [OR] 5.38; p=0.003); administration of thiopental (OR 8.64; p=0.014), and development of central diabetes insipidus (OR 5.66; p=0.005). Additional logistic regression analyses demonstrated a significant association between hypernatremia and mortality (OR 6.660; p=0.034). In summary, acquired hypernatremia appears to signal higher risk of mortality in pediatric sTBI and is associated with a higher discharge level of care in sTBI survivors.

Intensive care unit-acquired hypernatremia is an independent predictor of increased mortality and length of stay

PURPOSE

The purpose of this study is to examine the impact of hypernatremia acquired after intensive care unit (ICU) admission on mortality and length of stay (LOS).

MATERIALS AND METHODS

Data for this observational study were collected from patients admitted between January 1, 2008, and September 30, 2010 to 344 ICUs in the eICU Research Institute.

RESULTS

Of the 207702 eligible patients, 8896 (4.3%) developed hypernatremia (serum Na >149 mEq/L). Hospital mortality was 32% for patients with hypernatremia and 11% for patients without hypernatremia (P < .0001). Intensive care unit LOS was 13.7 ± 9.7 days for patients with hypernatremia and 5.1 ± 4.6 for patients without hypernatremia (P < .0001). Multivariate analysis showed that hypernatremia was an independent risk factor for hospital mortality with a relative risk (RR) of 1.40 (95% confidence interval, 1.34-1.45) and ICU LOS with a rate ratio (RtR) of 1.28 (1.26-1.30). The RR for mortality and RtR for ICU LOS increased with increasing severity strata of hypernatremia, but the duration of hypernatremia was not associated with mortality.

CONCLUSIONS

Hypernatremia developed following ICU admission in 4.3% of patients. Hypernatremia was independently associated with a 40% increase in risk for hospital mortality and a 28% increase in ICU LOS. Severity, but not duration of ICU-acquired hypernatremia was associated with hospital mortality.

Prognostic consequences of borderline dysnatremia: pay attention to minimal serum sodium change

Introduction

To assess the prevalence of dysnatremia, including borderline changes in serum sodium concentration, and to estimate the impact of these dysnatremia on mortality after adjustment for confounders.

Methods

Observational study on a prospective database fed by 13 intensive care units (ICUs). Unselected patients with ICU stay longer than 48 h were enrolled over a 14-year period were included in this study. Mild to severe hyponatremia were defined as serum sodium concentration < 135, < 130, and < 125 mmol/L respectively. Mild to severe hypernatremia were defined as serum sodium concentration > 145, > 150, and > 155 mmol/L respectively. Borderline hyponatremia and hypernatremia were defined as serum sodium concentration between 135 and 137 mmol/L or 143 and 145 respectively.

Results

A total of 11,125 patients were included in this study. Among these patients, 3,047 (27.4%) had mild to severe hyponatremia at ICU admission, 2,258 (20.3%) had borderline hyponatremia at ICU admission, 1,078 (9.7%) had borderline hypernatremia and 877 (7.9%) had mild to severe hypernatremia. After adjustment for confounder, both moderate and severe hyponatremia (subdistribution hazard ratio (sHR) 1.82, 95% CI 1.002 to 1.395 and 1.27, 95% CI 1.01 to 1.60 respectively) were associated with day-30 mortality. Similarly, mild, moderate and severe hypernatremia (sHR 1.34, 95% CI 1.14 to 1.57; 1.51, 95% CI 1.15 to 1.99; and 2.64, 95% CI 2.00 to 3.81 respectively) were independently associated with day-30 mortality.

Conclusions

One-third of critically ill patients had a mild to moderate dysnatremia at ICU admission. Dysnatremia, including mild changes in serum sodium concentration, is an independent risk factor for hospital mortality and should not be neglected.

Dysnatremias and survival in adult burn patients: a retrospective analysis

BACKGROUND/AIMS

Dysnatremias have been evaluated in many populations and have been found to be significantly associated with mortality. However, this relationship has not been well described in the burn population.

METHODS

Admissions to the burn center at our institution from January 2003 to December 2008 were examined. Independent variables included gender, age, percentage total body surface area burned (%TBSA), percentage of third-degree burn, inhalation injury, injury severity score (ISS), Acute Kidney Injury Network (AKIN) stage, hypernatremia, and hyponatremia. They were examined via Cox proportional hazard regression models against death. Moderate to severe hypo- and hypernatremia were defined as serum sodium <130 and >150 mmol/l, respectively.

RESULTS

In 1,969 subjects with a mean age of 36.3 ± 16.4 years, a median %TBSA of 9 (interquartile range 4-20) and a median ISS of 5 (interquartile range 1-16) hypernatremia occurred in 9.9% (n = 194), while hyponatremia occurred in 6.8% (n = 134) with mortality rates of 33.5 and 13.8%, respectively. Patients without a dysnatremia had a mortality rate of 4.3%. On Cox proportional hazard regression age, %TBSA, ISS, and AKIN stage were found to be significant predictors of mortality. Hypernatremia (HR 2.00, 95% CI 1.212-3.31; p = 0.0066), but not hyponatremia (HR 1.72, 95% CI 0.89-3.34; p = 0.1068) was associated with mortality.

CONCLUSIONS

In the burn population, hypernatremia, but not hyponatremia, is an independent predictor of mortality.

Rising serum sodium levels are associated with a concurrent development of metabolic alkalosis in critically ill patients

PURPOSE

Changes in electrolyte homeostasis are important causes of acid-base disorders. While the effects of chloride are well studied, only little is known of the potential contributions of sodium to metabolic acid-base state. Thus, we investigated the effects of intensive care unit (ICU)-acquired hypernatremia on acid-base state.

METHODS

We included critically ill patients who developed hypernatremia, defined as a serum sodium concentration exceeding 149 mmol/L, after ICU admission in this retrospective study. Data on electrolyte and acid-base state in all included patients were gathered in order to analyze the effects of hypernatremia on metabolic acid-base state by use of the physical-chemical approach.

RESULTS

A total of 51 patients were included in the study. The time of rising serum sodium and hypernatremia was accompanied by metabolic alkalosis. A transient increase in total base excess (standard base excess from 0.1 to 5.5 mmol/L) paralleled by a transient increase in the base excess due to sodium (base excess sodium from 0.7 to 4.1 mmol/L) could be observed. The other determinants of metabolic acid-base state remained stable. The increase in base excess was accompanied by a slight increase in overall pH (from 7.392 to 7.429, standard base excess from 0.1 to 5.5 mmol/L).

CONCLUSIONS

Hypernatremia is accompanied by metabolic alkalosis and an increase in pH. Given the high prevalence of hypernatremia, especially in critically ill patients, hypernatremic alkalosis should be part of the differential diagnosis of metabolic acid-base disorders.