Push-Dose Pressors During Peri-intubation Hypotension in the Emergency Department: A Case Series

Introduction Emergency physicians frequently encounter critically ill patients in circulatory shock requiring definitive airway procedures. Performing rapid sequence intubation in these patients without blood pressure correction has lethal complications. Questioning the efficacy and fearing side effects of push-dose pressors (PDP) has created an obstacle for their use in the emergency department (ED) setting. In this case series we describe the efficacy and side effects of PDP use during peri-intubation hypotension in the ED. Case series We included 11 patients receiving PDPs in this case series. The mean increase in systolic blood pressure was 41.3%, in diastolic blood pressure 44.3%, and in mean arterial pressure 35.1%. No adverse events were documented in this case series. Conclusion The use of push-dose pressors during peri-intubation hypotension may potentially improve hemodynamic status when used carefully in the ED.


INTRODUCTION
Rapid sequence intubation (RSI) is the cornerstone of emergency airway management. Nonetheless, if not executed carefully the complications can be deadly. 1 In one study, patients with systolic hypotension (<90 millimeters of mercury [mmHg]) during RSI were more likely to sustain postintubation cardiac arrest. The multivariate analysis showed that systolic hypotension was independently associated with post-intubation cardiac arrest (3.7 [95% confidence interval (CI), 1.6-8.6]; P = 0.01). 2,3 For many years, push-dose pressors (PDP) have been used in the operating room for rapid blood pressure correction. 4,5 This practice, however, has yet to be translated into standard emergency medicine practice. 6 The emergency department (ED) environment poses unique challenges in ensuring seamless and safe administration; treatment of unfamiliar patients, crowding, reliance on verbal orders, dispensing and administering The King Abdulaziz University, Department of Emergency Medicine, Jeddah, Saudi Arabia The King Abdulaziz University, Faculty of Medicine, Jeddah, Saudi Arabia * † medications without verification by a pharmacist, and understaffing. 7 A major reason for discouraging the use of such medications is that they add additional patient safety risks in addition to the complex, multistep process of using bolus-dose pressors. 7,8 Risks include the need for dose calculation, drug dilution, and incremental push-dose administration. These are all areas in which errors are common and potentially fatal. 9,10 In this case series we assessed the effect of PDP on blood pressure during RSI (defined as blood pressure change of at least 20%). We additionally assessed for any side effects including tachyarrhythmias, local tissue injury, and errors.

CASE SERIES
The use of PDP during peri-intubation hypotension was part of a quality improvement program within the ED. We implemented a RSI bundle; this included instructions for PDP mixing (Supplementary). These instructions were What makes this presentation of disease reportable?
Understanding the effects of PDPs during peri-intubation hypotension will aid emergency physicians in clinical practice.
What is the major learning point?

Consider careful use of PDP for peri-intubation hypotension in the ED.
How might this improve emergency medicine practice? Rapid correction of hemodynamic parameters prior to rapid sequence intubation, is crucial to lower deadly complications such as periintubation cardiac arrest.
permanently attached to each intubation cart in the department, allowing immediate access. Additionally, an endotracheal intubation procedure note was completed for every patient requiring intubation by the emergency physician. We collected data retrospectively from intubation procedure notes. The notes included the following: patient information; diagnosis; indication for intubation; pre-and post-intubation vital signs; pre-and post-intubation drugs (with dose and time); number of intubation attempts; device used; operator level; and complications. Push-dose pressors are prepared (following mixing instructions) and administered via large bore (14-18 gauge) peripheral intravenous (IV) access over one minute by the primary nurse. Vital signs were documented in the note at five minutes before and after the procedure. Adverse effects including extravasation and dysrhythmias were monitored for 30 minutes of PDP administration; standard procedure for nursing staff is to monitor for these adverse effects and document in the electronic health record if they do occur. Study investigators raised awareness of the new RSI bundle and PDP mixing instructions via departmental educational activities, bedside clinical demonstration, didactic lectures, and procedure note review. The bundle was approved by the department's chair and clinical practice committee.
We included patients undergoing the following: 1) RSI in the ED; or 2) receiving PDPs for a systolic blood pressure less than or equal to 100 mm Hg and/or diastolic blood pressure less than or equal to 60 mm Hg. During the one-year study period (January 2019-January 2020), a total of 86 patients underwent RSI by emergency physicians. Of those, only 11 patients received PDP for hypotension (defined as blood pressure less than or equal to 100/60 mm Hg within five minutes prior to the procedure). Table 1 describes the general characteristics of these patients. Table 2 describes the change in hemodynamic parameters in relation to PDP.

Efficacy
We assessed the efficacy based on pre-and post-PDP vital signs in 11 patients (Table 3). The overall mean change in systolic blood pressure was 33.5 mm Hg (41.3% increase from baseline), the change in diastolic blood pressure was 21.4 mm Hg (44.3%
increase from baseline), and in mean arterial pressure the change was 21.5 mm Hg (35.1% increase from baseline).

Safety
It is standard procedure to document any side effects from medication administration given intravenously. This is especially true for high-risk medications such as peripheral vasopressors. No events of extravasation or local tissue injury were documented in patients receiving PDP via peripheral IV route. Additionally, no documented cardiac dysrhythmias were found.

DISCUSSION
Significant data exist on the utilization and benefit of phenylephrine for hypotension induced by spinal anesthesia and neurologic emergencies. 11,12 However, only scant scientific evidence examines the use of PDP for peri-intubation hypotension in the ED. 6 This case series describes a one-year cohort of patients receiving PDP for peri-intubation hypotension. We found a mean increase from baseline in all hemodynamic parameters with the use of PDP: systolic blood pressure increased by 41.3%; diastolic blood pressure increased by 44.3%; and mean arterial pressure increased by 35.1%. Rotando et al 13 evaluated PDP practice patterns and sought to determine the efficacy in hospitalized hypotensive patients outside of the operating room. Results show a mean increase in systolic blood pressure of 32.5% and a mean increase in diastolic blood pressure of 27.2%. Our series shows a larger mean increase in hemodynamic parameters. This is explained by the different agents used in both studies. The most frequently used PDP in this series is epinephrine (10 out of 11 patients). Previous reports, including those by Rotando et al, mostly used phenylephrine and ephedrine. 6,13

LIMITATIONS
First, this is a small sample size without comparison and therefore results are not generalizable. Second, the most commonly used PDP was epinephrine in 10 patients, while phenylephrine was only used in 1 patient. Third, this case series lacks data on patients requiring continuous vasopressor infusion after PDP. Fourth, dysrhythmias and extravasation was only monitored for 30-minutes post administration. While these PDPs are short-acting it is unclear if side effects may develop after the 3-minute time point.

CONCLUSION
Based on this small case series we conclude that the use of push-dose pressors causes a significant increase in systolic, diastolic, and mean arterial blood pressure (defined as >20% change). Therefore, if implemented with strict monitoring guidelines and appropriate education, we do not anticipate significant adverse events.