Evaluation of an Intravenous Potassium Dosing Algorithm for Hypokalemic Critically Ill Patients

The effect of potassium supplementation and concomitant medications on potassium homeostasis for hospitalized patients

PURPOSE

Hospitalized patients receive potassium (K+) supplementation for hypokalemia, with clinicians often estimating a rise in serum K+ levels of 0.1 mEq/L per 10 mEq delivered. However, there is limited evidence to support this expectation. Patients also concomitantly take medications that may alter K+ levels, and it is not known to what degree these may impact interventions to correct K+ levels via supplementation. The objective of this study was to identify the impact of oral and/or intravenous K+ supplementation on serum K+ levels, including the influence of selected concomitant medications, in adult hospitalized patients.

METHODS

A single-center, retrospective descriptive study of adult hospitalized patients receiving K+ supplementation at a tertiary hospital between 2021 and 2022 was conducted. Patients were included if they received at least one dose of potassium chloride while admitted to the general medicine ward. The primary outcome was the daily median change in serum K+, normalized per 10 mEq of supplementation administered. The secondary outcome was the impact of selected concomitant medication use on supplement-induced changes in serum K+.

RESULTS

A total of 800 patients and 1,291 daily episodes of K+ supplementation were evaluated. The sample was approximately 53% women, was 78% white, and had a median age of 68 years. The overall daily median change in serum K+ level was 0.05 mEq/L per 10 mEq of supplementation delivered. Patients received a median of 40 mEq of supplementation per day, primarily via the oral route (80.6%). Among the concomitant medications assessed, loop diuretics significantly dampened the impact of K+ supplementation.

CONCLUSION

Supplementation of K+ in non-critically ill hospitalized patients is variable and dependent on concomitant medication use.

An integrative review of potassium replacement protocol use in critical care: Development, use and critical care nurse autonomy

BACKGROUND

Potassium replacement protocols are used to standardise practice, reduce risk, and ensure timely potassium replacement, but there is considerable variability in their development and use, particularly as part of critical care nursing practice.

AIM

To synthesise the research evidence on how potassium replacement protocols are used in adult critical care; and how critical care nurses' role and practice is influenced by a potassium replacement protocol. The research question was 'How are protocols used by intensive care clinicians to guide potassium replacement in adult critical care?'

DESIGN

A structured integrative review was undertaken. A combination of keywords, synonyms, and Medical Subject Headings were used across the Ovid Medline and Embase databases. Records were independently assessed against inclusion and exclusion criteria. All papers were assessed for quality. A narrative synthesis was used to analyse and present the findings.

RESULTS

Ten studies were included in this review from 4076 records identified. Narrative synthesis revealed five categories: (i) protocol design demonstrating variation in protocol mechanisms, (ii) protocol rationale eliciting reasonings for protocol implementation, (iii) protocol use describing how protocols were nurse-driven enabling nursing autonomy (iv) protocol adherence highlighting variability in protocol compliance and (v) critical care nurse acceptability and feasibility coupling greater shared responsibility for patient care and improved clinician satisfaction.

CONCLUSION

Safe, high-quality care, supported by evidence continues to be a priority. Protocolised potassium replacement can improve patient outcomes and promote nurses' autonomy, efficiency, and job satisfaction.

IMPLICATIONS FOR CLINICAL PRACTICE

Recognising and promoting critical care nurses' expert assessment skills and clinical decision-making is essential for optimising efficient, safe, and high-quality patient care. Although protocol deviations are accommodated in protocol development, comprehensive documentation to justify protocol deviations is key to justifying practice. Understanding protocol deviations are crucial to inform future protocol development, improvements, and evaluation to further enhance critical care nursing practice.

Gastric feeding intolerance in critically ill patients during sustained pharmacologic neuromuscular blockade

BACKGROUND

The purpose of this study was to assess gastric feeding intolerance for critically ill patients who received sustained neuromuscular blocker (NMB) pharmacotherapy.

METHODS

Adult patients (>17 years of age) admitted to the trauma intensive care unit who received continuous intravenous NMB pharmacotherapy (rocuronium, cisatracurium, vecuronium, or pancuronium) for ≥48 h during continuous intragastric enteral nutrition (EN) were retrospectively evaluated. Gastric feeding intolerance was defined by initiation of a prokinetic agent (metoclopramide, erythromycin, or both) for an elevated gastric residual volume (GRV) >300 ml and with distention of the abdomen by physical examination, observation of regurgitation or emesis, temporary discontinuation of EN with low intermittent gastric suctioning, or initiation of parenteral nutrition (PN). Patients were evaluated for gastric feeding intolerance for the first 3 days of combined EN and NMB pharmacotherapy. A P value < 0.05 was considered statistically significant.

RESULTS

Ten patients of the 47 patients (21%) were intolerant to EN during NMB pharmacotherapy. No statistically or clinically relevant differences in patient characteristics were found between patients who tolerated EN vs those who experienced gastric feeding intolerance, except for a higher median maximum GRV of 125 ml (28, 200) vs 300 (250, 400) ml, respectively (P < 0.001). Five patients responded to prokinetic therapy and five required PN.

CONCLUSION

Most patients tolerated intragastric EN during sustained NMB pharmacotherapy. Presence of NMB pharmacotherapy is not an absolute contraindication for EN.

Evaluation of Parenteral Potassium Supplementation in Pediatric Patients

OBJECTIVE

The primary objective was to evaluate the effect of parenteral potassium chloride (KCl) supplementation on potassium (K⁺) concentrations in a non-cardiac pediatric population. Secondary outcomes were to identify variables that may influence response to KCl supplementation (i.e., change in K⁺ concentration after KCl administration) and assess the incidence of hyperkalemia.

METHODS

This single-center, retrospective study evaluated infants and children who received parenteral KCl supplementation of 0.5 or 1 mEq/kg between January 2017 and December 2019.

RESULTS

The study included 102 patients with a median age of 1 year (IQR, 0.4-3.9) and weight of 9.1 kg (IQR, 4.9-14.2) who received 288 parenteral KCl administrations. One hundred seventy-three administrations were in the 1 mEq/kg group, and 115 administrations were in the 0.5 mEq/kg group. The median changes in K⁺ were 0.8 and 0.5 mEq/L in the 1 mEq/kg and 0.5 mEq/kg groups, respectively. Patients who had a repeat K⁺ concentration within 4 hours of the end of a 1 to 2-hour infusion had a higher median change in K⁺ compared with those who had a concentration drawn after this time frame (0.8 vs 0.6 mEq/L; p < 0.01).

CONCLUSIONS

There is a paucity of data on the correlation between parenteral KCl supplementation and change in K⁺ concentrations in pediatric patients. Our study demonstrated an association between KCl supplementation doses of 1 and 0.5 mEq/kg and changes in K⁺ of 0.8 and 0.5 mEq/L, respectively, in non-cardiac pediatric patients, with low observed incidence of hyperkalemia.

Augmented Renal Clearance Following Traumatic Injury in Critically Ill Patients Requiring Nutrition Therapy

The intent of this study was to ascertain the prevalence of augmented renal clearance (ARC) in patients with traumatic injuries who require nutrition therapy and identify factors associated with ARC. Adult patients admitted to the trauma intensive care unit from January 2015 to September 2016 who received enteral or parenteral nutrition therapy and had a 24 h urine collection within 4 to 14 days after injury were retrospectively evaluated. Patients with a serum creatinine concentration > 1.5 mg/dL, required dialysis, or had an incomplete urine collection were excluded. ARC was defined as a measured creatinine clearance > 149 mL/min/1.73 m². Two hundred and three patients were evaluated. One hundred and two (50%) exhibited ARC. A greater proportion of patients with ARC were male (86% vs. 67%; p = 0.004), had traumatic brain injury (33% vs. 9%; p = 0.001), a higher injury severity score (30 ± 11 vs. 26 ± 12; p = 0.015), were younger (36 ± 15 vs. 54 ± 17 years; p = 0.001), had a lower serum creatinine concentration (0.7 ± 2 vs. 0.9 ± 0.2 mg/dL; p = 0.001) and were more catabolic (nitrogen balance of −10.8 ± 13.0 vs. −6.2 ± 9.2 g/d; p = 0.004). The multivariate analysis revealed African American race and protein intake were also associated with ARC. Half of critically ill patients with traumatic injuries experience ARC. Patients with multiple risk factors for ARC should be closely evaluated for dosing of renally-eliminated electrolytes, nutrients, and medications.

Analysis of hypo- and hypermagnesemia in an intensive care unit cohort

INTRODUCTION

The aim of this study was to evaluate if magnesium deviations correlate with higher 180 day overall mortality or increased morbidity, compared to controls.

METHODS

We conducted a retrospective study on 5369 patients with 22,003 magnesium values treated at the Adult Intensive Care Unit at Skåne University Hospital, Lund, Sweden during 2006-2014. The patients were retrospectively divided into a control group with only normal magnesium values 0.7-1.0 mmol/l, and three study groups; hypomagnesemic; Mg²⁺ < 0.7 mmol/l, hypermagnesemic; Mg²⁺ > 1.0 mmol/l and an unstable mixed group showing both hypo/hypermagnesemia. Gender, age, disease severity represented by maximum organ system SOFA score, renal SOFA score, lowest potassium value and diagnoses classes were included in a Cox hazard model in order to adjust for confounding factors, with time to death in the first 180 days from the ICU admission as outcome.

RESULTS

The hypermagnesemic study group and the mixed group showed increased hazard ratios for mortality; 1.4 (CI 98.3% 1.2, 1.6, P < 0.0001) and 2.1 (CI 98.3% 1.2, 2.8, P < 0.0001) respectively, compared to controls, while the hypomagnesemic group did not reach significance. In addition, patients in the hypermagnesemic and the mixed groups are older, more ill with significantly higher EMR and SOFA scores and show significantly longer ventilator times and ICU stays, compared to controls.

CONCLUSIONS

Patients with magnesium deviations are more ill compared to patients with explicitly normal magnesium values throughout the ICU stay. Cox analysis suggests that the magnesium deviation itself might have an impact on mortality.

Hypokalaemia: Addressing human factors and improving education around prescription and administration of Intravenous(IV) Potassium infusion in Trauma and Orthopaedics

A high incidence of hypokalaemia was noted in Trauma and Orthopaedics of Ninewells Hospital. We sought to establish the reason behind this and implemented three PDSA cycles via questionnaires to 30 ward staff, both doctors and nurses over a 1 week period in December, February and July 2016. Key baseline measures include availability of IV fluids with 40mmol potassium on the wards, confidence prescribing or administering IV fluids with 40mmol potassium, necessity for cardiac monitoring during slow IV potassium replacement and recognition of confusion and learning need in this area. Interventions made include awareness and education session, departmental guideline, improving stock of IV fluids and hypokalaemia management pathway for mild, moderate and severe hypokalaemia. Post-intervention results showed 70% from 33% who said 40mmol IV potassium was available, 87% from 67% were confident prescribing or administering IV potassium and 70% from 27% were aware that cardiac monitoring was not necessary.