Safety and Efficacy of Ketamine Without Intubation in the Management of Refractory Seizures: A Case Series

BACKGROUND

Continuous infusion ketamine has demonstrated efficacy in the management of refractory seizures yet does not suppress respiratory drive like other continuous infusion anesthetics (CIAs) used for this indication. The aim of this study is to describe the safety and efficacy of ketamine infusions in patients with refractory seizure without intubation.

METHODS

We analyzed a retrospective cohort of adult patients who were not intubated at the time of initiation of a ketamine infusion for refractory seizures. Seizure onset was determined to be the first clinical seizure or nonconvulsive seizure reported on electroencephalography (EEG) or the start time of EEG for patients with seizures at EEG initiation. Responders were defined as patients with resolution of seizures within 24 h of initiation without the need for intubation or an additional CIA.

RESULTS

A total of 28 patients were analyzed (median age 62 years, 64.3% female, 82.1% African American, 82.1% with structural seizure etiology, and 85.7% focal seizures). Of patients, 78.5% received an initial bolus averaging 0.9 mg/kg, and the majority (89.3%) were initiated on an infusion at 10 μg/kg/minute; median duration was 39.8 h. Maximum infusion rates were 10 μg/kg/minute in 16 patients, 20 μg/kg/minute in seven patients, and 30 μg/kg/minute in five patients. Of patients, 71.4% were assessed to be ketamine responders; six of the eight nonresponders required intubation and an additional CIA. Responders were 80% more likely to have received ketamine 5 or more hours earlier than nonresponders. Hypotension (systolic blood pressure < 90 mmHg) occurred in 31.8% of patients receiving only ketamine, which did not correlate with duration or maximum dose of ketamine; hypertension (systolic blood pressure > 180 mmHg) occurred in 39.3%.

CONCLUSIONS

Ketamine represents a safe and effective treatment option for refractory seizures and has potential to reduce morbidity associated with intubation in a carefully selected patient population. Early initiation may increase the likelihood of success.

Safety of Propofol When Used for Rapid Sequence Intubation in Septic Patients: A Multicenter Cohort Study

Purpose

Septic patients are at risk for hypotension, and this risk may increase during rapid sequence intubation (RSI). Sedatives such as propofol must be used carefully due to its ability to reduce vascular sympathetic tone. Since the safety of propofol for RSI is not well described in sepsis, this was a study evaluating propofol and its effects on hemodynamics when used for RSI in a septic population.

Materials and methods

We conducted a multicenter, retrospective, cohort study of patients with sepsis or severe sepsis requiring sedation for RSI. Patients receiving a propofol bolus for RSI were compared to patients undergoing RSI without a propofol bolus. The safety profile of propofol was evaluated according to the rates of post-intubation hypotension and vasopressor utilization between groups.

Results

A total of 179 patients (79 propofol, 100 non-propofol) were evaluated. There were no differences in hypotension (81% vs 78%; P = .62) or vasopressor utilization between the propofol and non-propofol groups (43% vs 49%; P = .43). Patients in the non-propofol group had increased APACHE II scores and healthcare-associated infections.

Conclusions

In this cohort study, administration of propofol for RSI in patients with sepsis and severe sepsis did not increase incidence of hypotension or vasopressor use, but acute illness may have introduced provider selection bias causing less propofol use in the non-propofol group. Larger prospective studies are needed to better characterize the adverse hemodynamic effects of propofol, before propofol bolus doses for RSI can be considered for safe use in this population.

Levetiracetam pharmacokinetics in critically ill patients undergoing renal replacement therapy

PURPOSE

To determine clearance of levetiracetam in patients requiring continuous renal replacement therapy (CRRT) or sustained low efficiency dialysis (SLED).

MATERIALS AND METHODS

Adult patients with acute kidney injury or end stage renal disease requiring either CRRT or SLED and levetiracetam were eligible for inclusion. Simultaneous arterial, venous, and effluent samples for analysis of levetiracetam concentrations were collected every two hours for up to 6-8 h. Levetiracetam clearance (CL) and half-life (t_1/2) were calculated for each modality.

RESULTS

Eight CRRT patients and 4 SLED patients completed the study: 67% male, mean age 50 ± 13 years, and 83% had AKI. Seven CRRT patients received continuous venovenous hemodiafiltration (CVVHDF) [median pre-replacement rate 700 mL/h (range 500-1000), post-replacement rate 500 mL/h (range 200-1000), effluent rate 2500 mL/h (range 1700-3650) and delivered CRRT dose 27 mL/kg/h (range 19-54)] and one patient received CVV hemofiltration (CVVH). The mm mean levetiracetam CL during CVVHDF was 31.2 ± 8.5 mL/min, and the and the mean t_1/2 was 10.4 ± 2.2 h. For the patient requiring CVVH, clearance and t_1/2 were 22.5 mL/min and 9.5 h, respectively. Mean levetiracetam CL during SLED performed at a blood flow rate of 250 mL/min and a dialysate flow rate of 100 mL/min was 74.0 ± 25.3 mL/min and t_1/2 was 4.8 ± 2.3 h.

CONCLUSIONS

Levetiracetam clearance was substantial with both modalities under the operating conditions reported. There is the potential for subtherapeutic concentrations with current recommended dosing strategies that account only for kidney function and not these extracorporeal routes of elimination.

Predictors of dysrhythmias with norepinephrine use in septic shock

PURPOSE

Norepinephrine (NE) is recommended first-line for treatment of septic shock, partly due to its intrinsically low effect on heart rate. While dysrhythmias secondary to NE are still reported, factors associated with development of this adverse effect have not been described. Our study sought to investigate factors associated with dysrhythmias in patients receiving NE for septic shock.

MATERIALS AND METHODS

We conducted a retrospective cohort study of adults receiving NE for septic shock if NE was initiated as the first vasopressor and continued for at least 6 h. The primary objective was to determine the rate of dysrhythmias among this patient population. Secondary objectives included determining the effect of dysrhythmia development on patient outcomes and elucidating predictors for dysrhythmia development.

RESULTS

Of the 250 patients included, 34.4% (n = 86) developed a dysrhythmia. These patients had higher mortality (30.5% vs. 63.9%; p < 0.001) with decreased ICU-free days (2 vs. 4; p = 0.04) and ventilator-free days (7 vs. 4; p = 0.048). Duration of NE infusion and maximum NE dose were found to be independently associated with increased rates of dysrhythmia (p < 0.005).

CONCLUSION

Development of dysrhythmia is associated with increased mortality and is independently associated with longer duration of NE infusion and higher NE doses.

Octreotide Added to a Proton Pump Inhibitor Versus a Proton Pump Inhibitor Alone in Nonvariceal Upper-Gastrointestinal Bleeds

Background: Literature indicating clinically relevant benefits of an adjunctive somatostatin analog to standard therapies in nonvariceal upper-gastrointestinal bleeding (NVUGIB) is lacking. Objective: The primary objective of this study was to find the association between outcomes in patients with NVUGIB treated with octreotide and a proton pump inhibitor (PPI; combination group) compared with those treated with a PPI alone. Methods: We conducted a retrospective cohort study of adults admitted within a 5-hospital health care system with a NVUGIB treated with a PPI continuous infusion with or without an octreotide infusion. Notable exclusion criteria included varices, history of cirrhosis without endoscopy, or active gastrointestinal cancer. The primary outcome was association of combination treatment versus PPI alone with hospital length of stay (LOS). Results: A total of 180 patients were included (combination group: n = 90; PPI: n = 90). In univariate analyses, the median hospital and intensive care unit (ICU) LOS in the combination group versus PPI was 6.1 versus 4.9 days (P = 0.25) and 2.3 versus 1.9 days (P = 0.24), and rebleeding and mortality occurred in 9% versus 12% (P = 0.63) and 6.7% versus 5.6% (P = 1.00) of patients. Median units of packed red blood cells in the combination therapy versus PPI group was 3 vs 2 units (P = 0.43). After propensity score adjustment in multivariable analyses, hospital and ICU LOS, rebleeding, and mortality all remained nonsignificant. Conclusion and Relevance: Our study observed no difference in clinical end points. This suggests that octreotide provides no additional major clinical benefit in NVUGIB, and PPI therapy alone may be sufficient.

Disagreement in Estimates of Kidney Function for Drug Dosing in Obese Inpatients

BACKGROUND:

The Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations are used to estimate kidney function. However, utility has been questioned in the obese population.

OBJECTIVE:

To evaluate differences in estimates of kidney function in obese patients and implications for drug dosing.

METHODS:

This was a retrospective study of adult inpatients with a body mass index ≥30 kg/m² and stable kidney function. Patients were categorized based on creatinine clearance (CrCl): group 1-CrCl ≥ 60 mL/min and group 2-CrCl 15 to 59 mL/min. Mean estimates of kidney function and recommended doses of 8 renally eliminated medications were compared.

RESULTS:

For the 166 patients included, mean estimates using CG, MDRD, and CKD-EPI for group 1 were 87 (23) mL/min, 91 (21) mL/min, and 96 (23) mL/min, respectively. Group 2 estimates were 42 (13) mL/min, 51 (15) mL/min, and 51 (16) mL/min, respectively. MDRD and CKD-EPI estimates were significantly higher than CG in 125 (75%) and 140 (84%) patients, respectively. Dose discrepancies were most often due to higher dose recommendations using MDRD or CKD-EPI compared to CG.

CONCLUSION:

Careful consideration of the method used to estimate kidney function, the method used for developing dosing recommendations, and the risk-benefit profile is warranted when designing drug regimens in obese individuals.

Effects of propofol on vasopressor use in patients with sepsis and severe sepsis: A pilot study

PURPOSE

Propofol is one of the most commonly used sedatives in the intensive care unit (ICU) despite its undesirable hypotensive effects. The purpose of this study was to determine the effects of continuous intravenous (CIV) propofol on vasopressor requirements in mechanically ventilated patients with sepsis.

MATERIALS AND METHODS

A multicenter, retrospective, propensity-matched pilot study was conducted comparing patients with sepsis or severe sepsis who received CIV propofol for sedation to those who did not. The primary outcome was incidence of vasopressor support. Secondary outcomes included change in mean arterial pressure, mortality, and length of stay.

RESULTS

A total of 279 patients (149 CIV propofol, 130 non-CIV propofol) were evaluated, with 174 patients matched 1:1 based on propensity score. There was no difference in vasopressor support requirements (49.4% vs 54%; P= .65) or in those experiencing a greater than 20% decrease in mean arterial pressure from baseline (58.6% vs 63.2%; P= .53) in the CIV propofol and non-CIV propofol groups. Furthermore, there were no differences in any secondary outcomes including hospital mortality (32.2% vs 33.3%; P= .87).

CONCLUSIONS

Continuous intravenous propofol for sedation did not increase vasopressor requirements in this septic population. Furthermore, CIV propofol was not associated with significant differences in the use of multiple vasopressors, change in mean arterial pressure, length of stay, or mortality.

Predictors of severe hypotension in neurocritical care patients sedated with propofol

INTRODUCTION

Propofol is used extensively in neurocritical care (NCC) due to its pharmacologic properties allowing for facilitation of serial neurologic examinations. Despite widespread use, few studies have identified risk factors for hypotension in these patients. We aimed to determine predictors of hypotension in NCC patients sedated with propofol.

METHODS

This retrospective, multicenter study evaluated 237 patients at two academic medical centers, both with dedicated NCC teams led by board-certified neurointensivists. Univariate analyses were performed to determine risk factors associated with severe hypotension during sedation with propofol. Multivariable analysis was performed to determine variables independently associated with hypotension, defined as a mean arterial pressure (MAP) less than 60 mmHg.

RESULTS

There was an average maximum reduction in MAP of 28.8 % after propofol initiation in the entire cohort. Severe hypotension developed in 62 (26.2 %) patients to a median nadir MAP of 56 mmHg. Those who developed severe hypotension had a longer median duration of mechanical ventilation (5.0 vs. 3.6 days; p = 0.01) and an increased in-hospital mortality (38.7 vs. 24.0 %; p = 0.03). Multivariable logistic regression analysis identified increasing number of changes to the propofol infusion rate, baseline MAP 60-70 mmHg, and need for renal replacement therapy (RRT) as factors independently associated with hypotension.

CONCLUSIONS

Multiple factors predicted hypotension in NCC patients receiving propofol. Clinicians should use propofol cautiously in patients with a lower baseline MAP or receiving RRT. Development of protocols related to the frequency of dose titrations is also recommended to prevent this avoidable complication.

Dabigatran Use in the Real World

Dabigatran etexilate, an oral direct thrombin inhibitor, was approved by the Food and Drug Administration to reduce the risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation based on the outcomes of the Randomized Evaluation of Long-term anticoagulant therapY (RE-LY) study. Although this study provides robust data on the efficacy and safety of dabigatran, there may be differences in the drug use and outcomes in routine clinical practice following drug approval. In this retrospective chart review study, we describe the use of dabigatran in 160 patients in 4 adult hospitals (1 academic and 3 community), including appropriate prescribing for indication, starting dose, concomitant anticoagulant and antiplatelet use, and clinical outcomes such as bleeding, myocardial infarction, and stroke. The study revealed appropriate indication of nonvalvular atrial fibrillation in 145 (91%) of the 160 patients. The dose of dabigatran was appropriate in 90% of the patients, with the most common cause of inappropriate dosing due to perceived bleeding risk. Over a follow-up period of 6 months, bleeding complications were noted in 6 patients still taking dabigatran, 5 of which were gastrointestinal bleeding. Our study underscores the importance of prescriber education regarding the appropriate indication, dosage, and safety of dabigatran with active participation of pharmacists in this process.

Predictors of severe hypotension in neurocritical care patients sedated with propofol

INTRODUCTION

Propofol is used extensively in neurocritical care (NCC) due to its pharmacologic properties allowing for facilitation of serial neurologic examinations. Despite widespread use, few studies have identified risk factors for hypotension in these patients. We aimed to determine predictors of hypotension in NCC patients sedated with propofol.

METHODS

This retrospective, multicenter study evaluated 237 patients at two academic medical centers, both with dedicated NCC teams led by board-certified neurointensivists. Univariate analyses were performed to determine risk factors associated with severe hypotension during sedation with propofol. Multivariable analysis was performed to determine variables independently associated with hypotension, defined as a mean arterial pressure (MAP) less than 60 mmHg.

RESULTS

There was an average maximum reduction in MAP of 28.8 % after propofol initiation in the entire cohort. Severe hypotension developed in 62 (26.2 %) patients to a median nadir MAP of 56 mmHg. Those who developed severe hypotension had a longer median duration of mechanical ventilation (5.0 vs. 3.6 days; p = 0.01) and an increased in-hospital mortality (38.7 vs. 24.0 %; p = 0.03). Multivariable logistic regression analysis identified increasing number of changes to the propofol infusion rate, baseline MAP 60-70 mmHg, and need for renal replacement therapy (RRT) as factors independently associated with hypotension.

CONCLUSIONS

Multiple factors predicted hypotension in NCC patients receiving propofol. Clinicians should use propofol cautiously in patients with a lower baseline MAP or receiving RRT. Development of protocols related to the frequency of dose titrations is also recommended to prevent this avoidable complication.