Hypocalcemia is associated with hypotension during CRRT: A secondary analysis of the Acute Renal Failure Trial Network Study

Recurrent Intradialytic Hypotension, Associated Risk Factors, and Outcomes in Northern Tanzania: A Retrospective Cohort Study

Background and Aims

Intradialytic hypotension (IDH) is a common phenomenon during hemodialysis (HD), with profound complications and all-cause mortality. Data on IHD is scarce in Sub-Saharan Africa. The study aimed to evaluate the incidence, risk factors, and outcome associated with recurrent IDH among patients on maintenance HD.

Methods

This was a retrospective cohort study conducted at the Kilimanjaro Christian Medical Centre HD unit between August 1, 2021 and July 31, 2022. In the study, 39 met the inclusion criteria, and a total of 4706 HD sessions were analyzed. The predictor was the occurrence of recurrent IDH. The outcomes were mortality from IDH, hospital admission due to IDH, and termination of the respective HD session. Descriptive statistics for categorical and continuous variables. A χ 2 test was used to identify associations, and the receiver operating characteristics curve was used to determine the cutoff threshold for different parameters in determining risk factors for recurrent IDH.

Results

The incidence of IDH was 4.35%; 46.3% of these IDH episodes were recurrent. Risk of IDH was higher in patients with pre-dialytic serum inorganic phosphate levels > 1.8 mmol/L (RR: 2.33, 95% CI: 1.02-5.35, p < 0.001) with a predicted threshold of 1.27 mmol/L by ROC curve (AUC 0.618, CI: 0.541-0.694, sensitivity 60%, specificity 40%), among males (aRR: 9.65, CI: 2.27-40.85, p = 0.002). A systolic blood pressure of < 140 mmHg had a significant protective effect (aRR: 0.34, CI: 0.17-0.69, p = 0.003).

Conclusion

Recurrent IDH is more common in males, among patients with hyperphosphatemia, and shows seasonal variations. Systolic blood pressure of < 140 mmHg confers a protective effect against recurrent IDH.

Association of Hypocalcemia and Mean Arterial Pressure With Patient Outcome in ICU

OBJECTIVES

We aimed to verify the relationship between hypocalcemia in the first 24 hours of ICU admission and mortality, we also hypothesized that blood pressure and blood pressure reactivity are associated with ionized calcium (iCa) and might have mediation effects in the iCa-mortality association.

DESIGN

Retrospective, observational study.

SETTING

ICUs in a general hospital.

PATIENTS

Nonhypercalcemia adult patients were divided into two groups based on mean iCa within the first 24 hours after ICU admission using a cutoff of 1.1 mmol/L.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 4947 patients from Peking Union Medical College Hospital between January 2013 and December 2022 were included in the study, with 2160 (43.7%) suffering from hypocalcemia. Overall, the median (interquartile range) age was 61 years (49-71 yr), with 2824 (57.1%) being female. Time-weighted average mean arterial pressure (TWA-MAP) above 0 and 65 mm Hg, respectively, during the first 24 hours were used to analyze the MAP of each patient and TWA-MAP/norepinephrine (TWA-MAP/NE) dose was calculated to examine blood pressure reactivity. Among 4091 patients eligible for multivariate analysis, iCa was independently associated with ICU mortality (odds ratio, 0.17; 95% CI, 0.04-0.79; p < 0.05). Both the blood pressure parameter (TWA-MAP above 0 mm Hg [TWA-MAP-0]) and pressure reactivity parameter (TWA-MAP-0/weight-adjusted dose of norepinephrine infusion in the first 24 hr after ICU admission [TWA-MAP-0/NE]) mediated the outcome of ICU mortality with a proportion of 4.55% (95% CI, 0.16-17%; p < 0.05) and 2.6% (95% CI, 0.02-11%; p < 0.05), respectively. TWA-MAP-0 correlated positively with iCa (Spearman rank test, ρ = 0.17; p < 0.01) while no significant association was found between iCa and TWA-MAP-0/NE (Spearman rank test, ρ = -0.07; p < 0.01).

CONCLUSIONS

In this retrospective study on nonhypercalcemia patients, iCa of the first 24 hours after admission was independently associated with ICU mortality, which was potentially mediated by TWA-MAP and blood pressure reactivity (TWA-MAP/NE). iCa was also positively associated with TWA-MAP, while no general relationship was found between iCa and TWA-MAP/NE.

The role of intravenous glutamine administration in critical care patients with acute kidney injury: a narrative review

The kidneys are complex organs responsible for waste removal and various regulatory functions. Critically ill patients often experience acute kidney injury (AKI). Although renal replacement therapy is used to manage AKI, nutritional therapy is crucial. Glutamine, an amino acid involved in cellular functions, has potential benefits when administered intravenously to critically ill patients. This administration is associated with reduced mortality rates, infectious complications, and hospitalization duration. However, its use in patients with AKI remains controversial. Glutamine is used by various organs, including the kidneys, and its metabolism affects several important pathways. Intravenous glutamine supplementation at specific doses can improve blood marker levels and restore plasma glutamine concentrations. Moreover, this supplementation reduces infections, enhances immune responses, decreases disease severity scores, and reduces complications in critically ill patients. However, caution is advised in patients with multiple organ failure, particularly AKI, as high doses of glutamine may increase mortality rates. Hyperglutaminemia can have adverse effects. Monitoring and appropriate dosing can help to mitigate these risks. Kidneys rely on glutamine for various essential functions. Thus, the use of intravenous glutamine in critically ill patients with AKI remains controversial. Despite its potential benefits in terms of infection reduction, immunomodulation, and improved outcomes, careful consideration of the patient’s condition, dosage, and treatment duration is necessary. Further research is needed to establish optimal guidelines for glutamine administration in this patient population.

Risk Factors Asscociated with Hypokalemia during Postanesthesia Recovery and Its Impact on Outcomes in Gynecological Patients: A Propensity Score Matching Study

OBJECTIVE

This study aimed to explore the risk factors and outcomes of hypokalemia during the recovery period from anesthesia in the gynecological population.

METHODS

This retrospective cohort study included 208 patients who underwent gynecological surgery at our institution between January 2021 and March 2022. Data were collected for each patient, including demographics, disease status, surgical data, and clinical information. Preoperative bowel preparation, postoperative gastrointestinal function, and electrolyte levels were compared between the two groups using propensity score matching (PSM).

RESULTS

The incidence of hypokalemia (serum potassium level <3.5 mmol/L) during the recovery period from anesthesia was approximately 43.75%. After PSM, oral laxative use (96.4% vs. 82.4%, P=0.005), the number of general enemas (P=0.014), and the rate of ≥2 general enemas (92.9% vs. 77.8%, P=0.004) were identified as risk factors for hypokalemia, which was accompanied by decreased PaCO2 and hypocalcemia. There were no significant differences in postoperative gastrointestinal outcomes, such as the time to first flatus or feces, the I-FEED score (a scoring system was created to evaluate impaired postoperative gastrointestinal function), or postoperative recovery outcomes, between the hypokalemia group and the normal serum potassium group.

CONCLUSION

Hypokalemia during postanesthesia recovery period occurred in 43.75% of gynecological patients, which resulted from preoperative mechanical bowel preparation; however, it did not directly affect clinical outcomes, including postoperative gastrointestinal function, postoperative complications, and length of hospital stay.

Ultrafiltration Tolerance: A Phenotype That We Need to Recognize

BACKGROUND

The evaluation and management of fluid balance are key challenges in critical care patients who require renal replacement therapies because cumulative fluid balance is an independent factor that increases morbidity and mortality in different clinical scenarios.

SUMMARY

One of the strategies when fluid overload is refractory to diuretics is extracorporeal fluid removal (i.e., net ultrafiltration [UFNET] during kidney replacement therapy). However, problems with UFNET without individualized assessment are cardiovascular events and intradialytic hypotension, events that contribute to decreasing organ perfusion and sympathetic stress. Therefore, we must consider and try to predict the best timing for the start of ultrafiltration and find the point where the patient is most tolerant to ultrafiltration, making a simile to the concept of fluid tolerance.

KEY MESSAGES

UFNET is a continuous and dynamic process, going through moments of tolerance and intolerance to ultrafiltration; as nephrologists, we must take the necessary measures to move through this period.

Risk factors for hypotension in patients with hemodialysis-associated superior vena cava syndrome

OBJECTIVE

We analyzed the risk factors for hypotension in patients with hemodialysis-associated superior vena cava syndrome (SVCS) and effectiveness of endovascular intervention in hypotension related to SVCS.

METHODS

This was a retrospective cohort study. A total of 194 maintenance hemodialysis patients diagnosed with SVCS who were admitted to the Department of Nephrology, West China Hospital of Sichuan University from January 2019 to December 2021 were selected and divided into a hypotension group and a nonhypotension group. Demographic and clinical data were compared. Hypotension simply refers to blood pressure levels of <90/60 mm Hg on a nondialysis day. All patients received endovascular intervention.

RESULTS

Hypotension was found in 85 of the 194 patients. The following factors were significantly different between the hypotension and nonhypotension groups: body mass index, history of hypertension, tunneled-cuffed catheter as the means of dialysis access, azygos ectasis, SVC stenosis of >70% or occlusion, occlusion at the cavitary junction, serum calcium, diastolic left ventricular (LV) posterior wall thickness, LV end-diastolic volume, stroke output, and LV ejection fraction. Multivariate logistic regression analysis showed that hypertension history (OR, 0.314; P = .027), tunneled-cuffed catheter as vascular access (OR, 3.997; P < .001), SVC stenosis of >70% or occlusion (OR, 5.243; P < .001), LV posterior wall thickness (OR, 0.772; P = .044), and serum calcium (OR, 0.146; P = .005) were independent risk factors for hypotension. The mean values of systolic and diastolic blood pressure after intravascular treatment were significantly elevated from those before intervention (P < .001). The primary patency rates of SVC were 66.8%, 58.7%, and 50.0% at 3, 6, and 12 months after the procedure.

CONCLUSIONS

The incidence of hypotension in patients with hemodialysis-associated SVCS is high. The identification of risk factors of hemodialysis-related hypotension provides insight into potential treatment strategies. Endovascular treatment is expected to improve hypotension related to SVCS in hemodialysis patients.

Timing of kidney replacement therapy initiation for acute kidney injury

BACKGROUND

Acute kidney injury (AKI) is a common condition among patients in intensive care units (ICUs) and is associated with high numbers of deaths. Kidney replacement therapy (KRT) is a blood purification technique used to treat the most severe forms of AKI. The optimal time to initiate KRT so as to improve clinical outcomes remains uncertain. This is an update of a review first published in 2018. This review complements another Cochrane review by the same authors: Intensity of continuous renal replacement therapy for acute kidney injury.

OBJECTIVES

To assess the effects of different timing (early and standard) of KRT initiation on death and recovery of kidney function in critically ill patients with AKI.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant's Specialised Register to 4 August 2022 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Register, ClinicalTrials and LILACS to 1 August 2022.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs). We included all patients with AKI in the ICU regardless of age, comparing early versus standard KRT initiation. For safety and cost outcomes, we planned to include cohort studies and non-RCTs.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two authors. The random-effects model was used, and results were reported as risk ratios(RR) for dichotomous outcomes and mean difference(MD) for continuous outcomes, with 95% confidence intervals (CI).

MAIN RESULTS

We included 12 studies enrolling 4880 participants. Overall, most domains were assessed as being at low or unclear risk of bias. Compared to standard treatment, early KRT initiation may have little to no difference on the risk of death at day 30 (12 studies, 4826 participants: RR 0.97,95% CI 0.87 to 1.09; I²= 29%; low certainty evidence), and death after 30 days (7 studies, 4534 participants: RR 0.99, 95% CI 0.92 to 1.07; I² = 6%; moderate certainty evidence). Early KRT initiation may make little or no difference to the risk of death or non-recovery of kidney function at 90 days (6 studies, 4011 participants: RR 0.91, 95% CI 0.74 to 1.11; I² = 66%; low certainty evidence); CIs included both benefits and harms. Low certainty evidence showed early KRT initiation may make little or no difference to the number of patients who were free from KRT (10 studies, 4717 participants: RR 1.07, 95% CI 0.94 to1.22; I² = 55%) and recovery of kidney function among survivors who were free from KRT after day 30 (10 studies, 2510 participants: RR 1.02, 95% CI 0.97 to 1.07; I² = 69%) compared to standard treatment. High certainty evidence showed early KRT initiation increased the risk of hypophosphataemia (1 study, 2927 participants: RR 1.80, 95% CI 1.33 to 2.44), hypotension (5 studies, 3864 participants: RR 1.54, 95% CI 1.29 to 1.85; I² = 0%), cardiac-rhythm disorder (6 studies, 4483 participants: RR 1.35, 95% CI 1.04 to 1.75; I² = 16%), and infection (5 studies, 4252 participants: RR 1.33, 95% CI 1.00 to 1.77; I² = 0%); however, it is uncertain whether early KRT initiation increases or reduces the number of patients who experienced any adverse events (5 studies, 3983 participants: RR 1.23, 95% CI 0.90 to 1.68; I² = 91%; very low certainty evidence). Moderate certainty evidence showed early KRT initiation probably reduces the number of days in hospital (7 studies, 4589 participants: MD-2.45 days, 95% CI -4.75 to -0.14; I² = 10%) and length of stay in ICU (5 studies, 4240 participants: MD -1.01 days, 95% CI -1.60 to -0.42; I² = 0%).

AUTHORS' CONCLUSIONS

Based on mainly low to moderate certainty of the evidence, early KRT has no beneficial effect on death and may increase the recovery of kidney function. Earlier KRT probably reduces the length of ICU and hospital stay but increases the risk of adverse events. Further adequate-powered RCTs using robust and validated tools that complement clinical judgement are needed to define the optimal time of KRT in critical patients with AKI in order to improve their outcomes. The surgical AKI population should be considered in future research.