Initial Observations of the Effects of Calcium Chloride Infusions in Pediatric Patients with Low Cardiac Output

The Hemodynamic Effects of Bolus Dose Calcium in Patients Undergoing Pulmonary Artery Reconstruction and Unifocalization Surgery: A Pilot Study

OBJECTIVES

To determine if bolus administration of calcium increases pulmonary artery pressures after unifocalization procedures or pulmonary artery reconstruction surgery.

DESIGN

Retrospective cohort study using Stanford University's data warehouse.

SETTING

A large pediatric heart center within an academic quaternary care facility.

PARTICIPANTS

All patients undergoing pulmonary artery reconstruction or unifocalization procedures identifiable in the data warehouse.

INTERVENTIONS

Data were collected from Stanford University's data repository and formatted and analyzed using RStudio (v 2023.06.1+524).

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the change in pulmonary artery systolic pressure (PASP) after a bolus administration of calcium. Secondary endpoints include changes in pulmonary arterial-to-systemic arterial pressure ratio, mean arterial pressure, right-sided filling pressure, and left atrial pressure. The Friedman test was used to assess differences and the Durbin-Conover rank-sum for pairwise comparisons. A difference in PASP after a bolus dose of calcium was found (Friedman X2 = 13.67, p = 0.003), with a higher PASP 5 minutes after calcium administration compared with 2 minutes before administration (35 mmHg v 33 mmHg, p = 0.01), and a higher PASP 10 minutes after calcium administration compared with2 minutes before administration (35 mmHg v 33 mmHg, p = 0.008).

CONCLUSIONS

Calcium bolus administration led to an increase in pulmonary arterial pressure in patients after pulmonary artery reconstruction or unifocalization surgeries. It may be prudent to avoid bolus administration in this patient population immediately after repair or in patients with right ventricular dysfunction.

Biochemical disturbance in damage control resuscitation: mechanisms, management and prognostic utility

PURPOSE OF REVIEW

With advances in resuscitative techniques, trauma patients are surviving increasingly severe injuries and physiological insult. Timely recognition of futility remains important in terms of patient dignity and resource preservation yet is increasingly challenging in the face of these advances. The understanding of biochemical derangement from pathophysiological processes of trauma and iatrogenic effects of resuscitation has expanded recently.

RECENT FINDINGS

Acidosis and hypocalcaemia have been recognized as important contributors to mortality among trauma patients. Although less well recognized and studied, critical injury and high blood product volume resuscitation render patients vulnerable to life-threatening hyperkalaemia. The methods of correcting disruptions to acid-base and electrolyte homeostasis during damage control resuscitation have changed little recently and often rely on evidence from undifferentiated populations. Biochemical disturbances have value as ancillary predictors of futility in trauma resuscitation.

SUMMARY

These findings will contribute to a greater understanding among anaesthesiologists of the causative mechanisms and effects of biochemical derangement after severe injury and aid them in the delivery of well tolerated and effective damage control resuscitation. Gaps in the evidence base are highlighted to encourage future work.

Compatibility of calcium chloride with milrinone, epinephrine, vasopressin, and heparin via in vitro testing and simulated Y-site administration

PURPOSE

The purpose of this study is to evaluate calcium chloride (CaCl) compatibility with commercially available and extemporaneously compounded milrinone, vasopressin, epinephrine, and heparin. This report describes 2 clinical scenarios in which patients experienced intravenous catheter precipitation when receiving multiple continuous infusions, including CaCl, and the results of an in vitro simulation of those scenarios. The hypothesis was that one or a combination of the medications would precipitate with CaCl.

METHODS

CaCl compatibility was tested in 3 stages to simulate clinical situations where line precipitation occurred. Multiple tests were conducted in each stage to determine if precipitation had occurred, including visual assessment, absorbance measurement at 650 nm, and pH measurement. First, milrinone, vasopressin, epinephrine, and heparin were mixed pairwise with CaCl in a test tube. Second, the medications were mixed in different combinations deemed likely to precipitate. Finally, 5 medications were infused via simulated Y-site administration. Incompatibility was defined as observed crystals, haziness, or turbidity upon visual inspection or absorbance of greater than 0.01 absorbance unit (AU). All solutions were tested at time 0 and at 20, 60, 240, and 1,440 minutes.

RESULTS

Across all tests, only a commercially available formulation of heparin 2 units/mL in 0.9% sodium chloride injection precipitated with CaCl, alone or in combination with other medications. Upon further review, it was found that this specific formulation of heparin contained a monohydrate and dibasic sodium phosphate buffer.

CONCLUSION

CaCl only precipitated with a commercially available heparin formulation that contained a phosphate buffer. CaCl was deemed to be compatible with all other medications and formulations tested.

Use of Aminophylline to Reverse Acute Kidney Injury in Pediatric Critical Care Patients

OBJECTIVE

Acute kidney injury (AKI) is a complication encountered in 18% to 51% of pediatric critical care patients admitted for treatment of other primary diagnoses and is an independent risk factor for increased morbidity and mortality. Aminophylline has shown promise as a medication to treat AKI, but published studies have shown conflicting results. Our study seeks to assess the reversal of AKI following the administration of aminophylline in critically ill pediatric patients.

METHODS

We performed a single-institution retrospective chart review of pediatric inpatients who were diagnosed with AKI and subsequently treated with non-continuous dose aminophylline between January 2016 and December 2018. Data were collected beginning 2 days prior to the initial dose of aminophylline through completion of the 5-day aminophylline course.

RESULTS

Nineteen therapies among 17 patients were included in analysis. Twelve of the therapies resulted in resolution of AKI during the study period. We observed urine output increase of 19% (p = 0.0063) on the day following initiation of aminophylline therapy in the subset of patients whose AKI resolved. Trends toward decreased serum creatinine and lower inotropic support were also noted.

CONCLUSIONS

Based on these findings, aminophylline could be considered a potentially effective medication for use as rescue therapy in critically ill children with AKI. Limitations include small study population and retrospective nature. Further research in this area with a larger study population and a randomized control trial would allow for better characterization of the efficacy of aminophylline in reversal of AKI.

Calcium Responsive Pediatric Septic Shock Refractory to Isotonic Crystalloids and Inotropic Agents

Pediatric septic shock is a life-threatening condition with significant rates of morbidity and mortality. Standard management includes fluid resuscitation, timely antimicrobial administration, and epinephrine or norepinephrine if unresolved with initial management. Additional therapies are not well defined and include vasopressin, hydrocortisone, phenylephrine, levosimendan, dopamine, and others. Many of these agents modify cellular effects of calcium in the smooth muscle. The use of a calcium infusion may improve vasoactivity in the smooth muscle without the use of signaling pathways. Children are more susceptible to the effects of calcium, which may predispose them to enhanced vasoconstriction with the administration of intravenous calcium. We present a case in which a patient on chronic calcium channel blocker therapy presented with septic shock. She continued to remain hypotensive after fluid resuscitation, antibiotics, epinephrine, and norepinephrine. Her blood pressure improved with the initiation of a continuous calcium chloride infusion. Norepinephrine and epinephrine doses were decreased after the initiation of the calcium infusion.

Hemodynamic Response to Calcium Chloride Boluses in Single-Ventricle Patients with Parallel Circulation

The purpose of this study is to assess the effect of calcium bolus in response to a hypotensive episode by assessing high-fidelity hemodynamic data obtained from children with single-ventricle physiology with parallel circulation. Single-center, retrospective analysis of hemodynamic data after calcium bolus administrations within the first 2 weeks post-surgery. Time intervals were the baseline (- 60 to - 10 min); the hypotensive episode (- 10 to 0 min); time point zero at the bolus administration; and the response (0 to 60 min). The main responses assessed were the peak increase in mean blood pressure (mBP), duration of the response after the bolus, and markers of oximetric effects. These analyses included 128 boluses in 63 patients. Of the total boluses analyzed, 80% increased the mBP by 5 mmHg or higher with the effect lasting at least 10 min, whereas 10% of the boluses analyzed increased the mBP by 20 mmHg or higher with the effect lasting at least 50 min. The boluses induced a significant increase in arterial oxygen saturation and an upward trend in pulmonary-to-systemic flow ratio, without increasing renal or cerebral oxygen extraction ratios. Calcium chloride boluses are an effective rescue medication for hypotensive episodes in children with parallel circulation. They lead to an improvement in mBP, as well as an increase in pulmonary-to-systemic blood flow ratio. More importantly, these boluses do not compromise systemic oxygen delivery.

Calcium Chloride Infusions are Not Associated with Improved Outcomes in Neonates Undergoing Cardiac Operations

Neonatal cardiac performance is dependent on calcium delivery to the myocardium. Little is known about the use and impact of calcium chloride infusions in neonates who undergo cardiac surgery. We hypothesized that the use of calcium chloride infusions would decrease the doses required of traditional inotropic and vasoactive medications by supporting cardiac output in this patient population. We performed a single-institution, retrospective, cohort study. All neonates (≤ 30 days old) undergoing cardiac surgery from 06/01/2015 through 12/31/2018 were included. Patients were divided into two groups: those who received postoperative calcium chloride infusions (calcium group) and those who did not (control group). The primary outcome was the occurrence of a maximum Vasoactive Inotropic Score (VIS) > 15 in the first 24 h following surgery. One hundred and thirty-five patients met inclusion criteria. Sixty-six patients received postoperative calcium infusions and 69 patients did not. Gestational age, weight at surgery, age at surgery, surgical complexity and cardiopulmonary bypass times were similar between groups. Forty-two (70%) patients receiving calcium had a postoperative maximum VIS > 15 compared with 38 (55%) patients not on a calcium infusion (p = 0.08). There were no differences in postoperative length of ventilation, time to enteral feeding, hospital LOS, or operative mortality between groups. Calcium chloride infusions in neonates who underwent cardiac surgery did not decrease exposure to other inotropic and vasoactive agents in the first 24 post-operative hours or improve patient outcomes.

Impact of Medical Interventions and Comorbidities on Norwood Admission for Patients with Hypoplastic Left Heart Syndrome

The purpose of these analyses was to determine how specific comorbidities and medical interventions impact risk of inpatient mortality in those with hypoplastic left heart syndrome undergoing Norwood procedure. The secondary aims were to determine the impact of these on billed charges, postoperative length of stay, and risk of cardiac arrest. Admissions from 2004 to 2015 in the Pediatric Health Information System database with hypoplastic left heart syndrome and Norwood procedure were identified. Admission characteristics, patient interventions, and the presence of comorbidities were captured. A total of 5,138 admissions were identified meeting inclusion criteria. Of these 829 (16.1%) experienced inpatient mortality, and 352 (6.7%) experienced cardiac arrest. The frequency of inpatient mortality did not significantly change over the course of the study era. The frequency of cardiac arrest significantly decreased from 7.4% in 2004 to 4.3% in 2015 (p = 0.04). The frequency of pharmacologic therapies, particularly vasoactive use, decreased as the study period progressed. Regression analyses demonstrated a significant association between cardiac arrest and inpatient mortality with arrhythmias, acute kidney injury, and pulmonary hypertension. Similarly, regression analyses demonstrated a significant association between increase in billed charges and length of stay with year of surgery, presence of heart failure, syndromes, and acute kidney injury. For patients with hypoplastic left heart syndrome undergoing the Norwood procedure, the frequency of pharmacologic therapies and cardiac arrest has decreased over time. There are significant associations between acute kidney injury, arrythmias, and pulmonary hypertension with cardiac arrest and mortality.

Cardiac critical care of the post-operative congenital heart disease patient

Cardiac critical care has become an increasingly complex subspecialty, involving multiple subspecialists to support patients with congenital heart disease. This requires understanding of their physiology and the impact of medical interventions. The purpose of this article is to provide a concise review of the current strategies utilized by cardiac intensivists to optimize outcomes for this vulnerable patient population, with the goal of broadening the knowledge of other members of the multi-disciplinary team.

Impact of protein-losing enteropathy in children who underwent the Fontan operation

Previous reports have identified risk factors associated with development of post-Fontan protein-losing enteropathy. Less is known about the economic impact and resource utilisation required for post-Fontan protein-losing enteropathy in the current era. We conducted a single-centre retrospective study to assess the impact of post-Fontan protein-losing enteropathy on transplant-free survival. We also described resource utilisation and treatment variations among post-Fontan protein-losing enteropathy patients. Children who received care at our centre between 2009 and 2017 after the Fontan surgery were eligible. Initial admissions for the Fontan operative procedure were excluded. Demographics, hospital admissions, resource utilisation, medications and charges were reviewed. Patients were divided into two groups based on the presence of post-Fontan protein-losing enteropathy. Of the 343 patients screened, 147 met the eligibility criteria. Of these, 28 (19%) developed protein-losing enteropathy. After adjusting for follow-up duration, the protein-losing enteropathy group had higher number of encounters (2.15 ± 2.16 versus 1.47 ± 2.56, p 0.002), hospital length of stay (days) (25 ± 51.3 versus 11.4 ± 41.7, p < 0.0001) and total charges (2018US$) (388,489 ± 759,859 versus 202,725 ± 1,076,625, p < 0.0001). Encounters for patients with protein-losing enteropathy utilised more therapies. Among those with protein-losing enteropathy, use of digoxin was associated with slightly decreased odds for mortality and/or transplant (0.95, confidence interval 0.90-0.99, p 0.021). The 10-year transplant-free survival for patients with/without protein-losing enteropathy was 65.7/97.3% (p 0.002), respectively. Post-Fontan protein-losing enteropathy is associated with reduced 10-year transplant-free survival, higher resource utilisation, charges and medication use compared with the non-protein-losing enteropathy group. Practice variation among post-Fontan protein-losing-enteropathy patients is common. Further larger studies are needed to assess the impact of standardisation on the well-being of children with post-Fontan protein-losing enteropathy.

Concurrent Use of Calcium Chloride and Arginine Vasopressin Infusions in Pediatric Patients with Acute Cardiocirculatory Failure

Acute heart failure (AHF) can cause low cardiac output and poor end-organ perfusion. Inotropic agents along with vasodilators can improve organ perfusion. Arginine vasopressin (AVP) and calcium chloride (CaCl) infusions are increasingly being used in low cardiac output states in pediatric AHF. We retrospectively reviewed 77 patients (0-18 years) with AHF admitted between January 2014 and May 2017 who received concurrent AVP and CaCl infusions. Surrogates of cardiac output and organ perfusion included hemodynamic vital signs, laboratory parameters, and urine output (UO). Organ dysfunction and vasopressor inotropic scores were also calculated. Median (IQR) age was 0.88 years (0, 3.75), and median weight was 6.62 kg (3.5, 13.7). Congenital heart disease was present in 70% (46/77) patients. Univentricular physiology was present in 25% (25/77) patients. None of the patients were in the immediate postoperative period. Median durations of AVP and CaCl were 2 days (1, 3) and 3 days (2, 6), respectively. Using Wilcoxon-signed rank test and Bonferroni correction, post hoc comparison showed that at 8 h post infusion, all systolic blood pressure (SBP) and diastolic blood pressure (DBP) results, and UO were greater than those 1 h prior to infusion. Median SBP increased from 79 mm Hg (71, 92) 1 h prior to 97 mm Hg (84, 107) 8 h post. Median DBP increased from 44 mm Hg (35, 52) 1 h prior to 54 mm Hg (44, 62) 8 h post. Heart rate showed a decrease between measurements 1 h prior to infusion and 8 h post, with median scores 146 (127, 162) and 136 (114, 150) beats per minute, respectively. Within first 8 h, median UO continuously increased from 6 mL/h. (0, 25) at 1 h post infusion to 20 mL/h. (2, 62) at 8 h post infusion. Median pediatric logarithmic organ dysfunction scores on days 4 through 7 post infusion were lower compared to day 1; median vasopressor inotropic scores on day 2 through 7 post infusion were lower compared to day 1. Serum lactate level, arterial pH, and base excess all showed favorable trend. Concurrent use of AVP and CaCl infusions may improve surrogates of cardiac output, and intensive care outcomes, and prevent organ dysfunction in children with AHF.

Pediatric cardiac transplantation

Heart transplantation in pediatric patients generally arises as a treatment option of last resort, that is, the indication is for patients with heart failure of various etiologies, with potential or actual end-organ dysfunction, in whom there are no reasonable, long-term options for life-prolonging therapy. The concept of heart failure is complex in a pediatric population, particularly those with congenital heart disease. While heart failure may refer simply to systolic dysfunction leading to low cardiac output, it can also encompass: diastolic dysfunction in restrictive cardiomyopathy; single ventricle physiology without an option for stable palliation. A good candidate should have a predicted life expectancy less than the median lifetime of a transplanted heart. Significant improvement in survival has been observed over time with 1- and 5-year survival approximately 90% and 80% in the contemporary era.