An evaluation of the Rapid Infusion System

When Minutes Matter: Rapid Infusion in Emergency Care

Purpose of Review

This review provides historical context and an update on recent advancements in volume resuscitation for circulatory shock. Emergency department providers who manage critically ill patients with undifferentiated shock will benefit from the insights of early pioneers and an overview of newer techniques which can be used to optimize resuscitation in the first minutes of care.

Recent Findings

Rapid infusion of fluids and blood products can be a life-saving intervention in the management of circulatory and hemorrhagic shock. Recent controversy over the role of fluid resuscitation in sepsis and trauma management has obscured the importance of early and rapid infusion of sufficient volume to restore circulation and improve organ perfusion. Evidence from high-quality studies demonstrates that rapid and early resuscitation improves patient outcomes.

Summary

Current practice standards, guidelines, and available literature support the rapid reversal of shock as a key priority in the treatment of hypotension from traumatic and non-traumatic conditions. An improved understanding of the physiologic rationale of rapid infusion and the timing, volume, and methods of fluid delivery will help clinicians improve care for critically ill patients presenting with shock.

Clinical Case

A 23-year-old male presents to the emergency department (ED) after striking a tree while riding an all-terrain vehicle. On arrival at the scene, first responders found an unconscious patient with an open skull fracture and a Glasgow coma scale score of 3. Bag-valve-mask (BVM) ventilation was initiated, and a semi-rigid cervical collar was placed prior to transport to your ED for stabilization while awaiting air transport to the nearest trauma center. You are the attending emergency medicine physician at a community ED staffed by two attending physicians, two physicians assistants, and six nurses covering 22 beds. On ED arrival, the patient has no spontaneous respiratory effort, and vital signs are as follows: pulse of 140 bpm, blood pressure of 65/30 mmHg, and oxygen saturation 85% while receiving BVM ventilation with 100% oxygen. He is bleeding profusely through a gauze dressing applied to the exposed dura. The prehospital team was unable to establish intravenous access. What are the management priorities for this patient in shock, and how should his hypotension best be addressed?

Factors affecting pediatric isotonic fluid resuscitation efficiency: a randomized controlled trial evaluating the impact of syringe size

BACKGROUND

Goal-directed therapy guidelines for pediatric septic shock resuscitation recommend fluid delivery at speeds in excess of that possible through use of regular fluid infusion pumps. In our experience, syringes are commonly used by health care providers (HCPs) to achieve rapid fluid resuscitation in a pediatric fluid resuscitation scenario. At present, it is unclear which syringe size health care providers should use when performing fluid resuscitation to achieve maximal fluid resuscitation efficiency. The objective of this study was therefore to determine if an optimal syringe size exists for conducting manual pediatric fluid resuscitation.

METHODS

This 48-participant parallel group randomized controlled trial included 4 study arms (10, 20, 30, 60 mL syringe size groups). Eligible participants were HCPs from McMaster Children's Hospital, Hamilton, Canada blinded to the purpose of the trial. Consenting participants were randomized using a third party technique. Following a standardization procedure, participants administered 900 mL (60 mL/kg) of isotonic saline to a simulated 15 kg child using prefilled provided syringes of the allocated size in rapid sequence. Primary outcome was total time to administer the 900 mL and this data was collected through video review by two blinded outcome assessors. Sample size was predetermined based upon a primary outcome analysis using one-way ANOVA.

RESULTS

12 participants were randomized to each group (n=48) and all completed trial protocol to analysis. Analysis was conducted according to intention to treat principles. A significant difference in fluid resuscitation time (in seconds) was found between syringe size group means: 10 mL, 563s [95% CI 521; 606]; 20 mL, 506s [95% CI 64; 548]; 30 mL, 454s [95% CI 412; 596]; 60 mL, 455s [95% CI 413; 497] (p<0.001).

CONCLUSIONS

The syringe size used when performing manual pediatric fluid resuscitation has a significant impact on fluid resuscitation speed, in a setting where fluid filled syringes are continuously available. Greatest efficiency was achieved with 30 or 60 mL syringes.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01494116.

Study protocol for a randomised controlled trial comparing the efficiency of two provider-endorsed manual paediatric fluid resuscitation techniques

INTRODUCTION

Paediatric shock is a life-threatening condition with many possible causes and a global impact. Current resuscitation guidelines require rapid fluid administration as a cornerstone of paediatric shock management. However, little evidence is available to inform clinicians how to most effectively perform rapid fluid administration where this is clinically required, resulting in suboptimal knowledge translation of current resuscitation guidelines into clinical practice.

OBJECTIVES

This study aims to determine which of the two commonly used techniques for paediatric fluid resuscitation (disconnect-reconnect technique and push-pull technique) yields a higher fluid administration rate in a simulated clinical scenario. Secondary objectives include determination of catheter dislodgement rates, subjective and objective measures of provider fatiguability and descriptive information regarding any technical issues encountered with performance of each method under the study.

METHODS AND ANALYSIS

This study will utilise a randomised crossover trial design. Participants will include consenting healthcare providers from McMaster Children's Hospital. Each participant will administer 900 ml (60 ml/kg) of normal saline to a simulated 15 kg infant as quickly as possible on two separate occasions using the manual fluid administration techniques under the study. The primary outcome, rate of fluid administration, will be evaluated using a paired two-tailed Student t test.

ETHICS AND DISSEMINATION

This protocol has been approved by the Hamilton Health Sciences Research Ethics Board.

RESULTS

These will be published in a peer-reviewed scientific journal and presented at one or more scientific conferences.

PROTOCOL REGISTRATION

Protocol Registered on ClinicalTrials.gov NCT01774214.

The effect of IV cannula length on the rate of infusion

According to the Hagen-Poiseuille's law, rate of laminar flow through a tubular structure varies directly with fourth power of its radius and inversely with its length. Although it is well recognised that faster infusion rates can be achieved with wider-bore IV cannulae, the effect of length on flow rates is less well known. In the current in vitro study, we assessed the effect of length of an IV cannula on the rate of flow of infusion. Mathematical calculations performed using Hagen-Poiseuille's law predicted an increase of 40% in flow rates when the IV cannulae were shortened by 13mm. However, when the flow rates of the shortened cannulae were measured in vitro an increase of only 4-18% was observed. Although the increase in flow rates was statistically significant, it may not be sufficient to be significant in clinical practice. Turbulence resulting from design characteristics of the infusion system is responsible for the measured flow rates to be lower than that predicted by mathematical calculations.

Intraoperative pediatric blood transfusion therapy: a review of common issues. Part I: hematologic and physiologic differences from adults; metabolic and infectious risks

Pediatric intraoperative transfusion therapy, particularly the approach to massive blood transfusion (blood loss > or =one blood volume) can be quite complex because of the unique relationship between the patient's blood volume and the volume of the individual blood product transfused. This paper is divided into two parts: part 1 presents an overview of the physiologic and hematologic differences between children and adults as well as an overview of the metabolic consequences of blood transfusions, risks of disease transmission, and blood compatibility issues.

The effect of the InterLink cannula on fluid flow rates and haemolysis

OBJECTIVE

To examine the effect of the InterLink cannula system (Becton Dickinson, New Jersey, NY, USA) on intravenous fluid flow rates and red blood cell haemolysis.

METHODS

An in vitro study was performed with crystalloid and packed red blood cells run through intravenous catheters of various sizes, with and without the InterLink cannula. Data recorded and analysed included fluid flow rates and plasma free haemoglobin concentration.

RESULTS

The InterLink cannula significantly reduced flow of crystalloid through a 14G catheter (reduction of median flow rate by 0.72 L/h, 12.3%, P < 0.001). There was a reduction of flow of packed red blood cells through a 14G catheter (0.11 L/h) but this was not statistically significant. There was no significant reduction of flow through smaller catheters and no significant effect on red blood cell haemolysis.

CONCLUSIONS

The InterLink cannula reduced flow rates through large diameter intravenous catheters. Because of other factors affecting fluid infusion in vivo this is of minor clinical significance. No increased haemolysis of red blood cells occurred with the InterLink cannula.

The effect of devices used to reduce the risk of blood spillage or needlestick injury on the flow of intravenous infusion systems

We evaluated the effect of two devices used to reduce needlestick injury and blood spillage on the flow of saline, polygeline and blood through intravenous infusion equipment and their effects on methods of increasing flow. The devices studied all reduced flow compared with control. The reductions were less for the reflux valve (< or = 9%) and greater for the anaesthesia extension set (< or = 59%), with little further reduction in flow when both were used in series (< or = 60%). Reductions in flow increased with increasing viscosity of the fluid infused, being greatest with blood. The flow reduction produced by the reflux valve was more than compensated by increasing pressure or increasing to the next larger cannula size. The flow reduction produced by the anaesthesia extension was compensated by increasing pressure but not by increasing cannula size.

Excess mortality associated with the use of a rapid infusion system at a level 1 trauma center

The Rapid Infusion System (RIS) is a device which can deliver warm fluid and blood products rapidly and at precise rates. It has been in use since 1990 for the management of victims of major trauma at the R Adams Cowley Shock Trauma Center (STC) in Baltimore. Although the RIS is unquestionably a convenience to the anesthesiologist, no study to date has addressed its effect on patient outcome. We have therefore undertaken a retrospective review of all uses of the RIS on trauma patients during the years in which it has been available at the Shock Trauma Center, comparing actual patient mortality both to expected mortality derived from the STC Trauma Registry, and to matched historical controls who did not receive fluids via the RIS. A total of 527 patients were included in the study. The mean volume infused via the RIS was 9724 ml, and the total volumes ranged from 24-117 585 ml. Overall survival was significantly less than expected (52.9% vs. 61.8%, P < 0.001). Survival in penetrating trauma was similar to expected, but in blunt trauma it was considerably less (48.8% vs. 63.0%, P < 0.001). Patients whose probability was between 0.1% and 0.9% also survived significantly less frequently than expected (44.3% vs. 57%, n = 105, P < 0.008). In those patients who received less than 6000 ml via the RIS, the actual and expected survival rates were almost identical. In those receiving more than 6000 ml (180 patients), the difference between actual and expected survival was striking (37.2% vs. 57.2%, P < 0.0001). As compared to matched control patients injured to the same extent during the same time period, patients who received fluids via the RIS had a 4.8 times greater chance of dying (95% confidence interval 2.4-7.1). These data call into question current protocols for rapid volume infusion in trauma management and point to the need for further prospective trials.