Accidental Intravenous Infusion of Air: A Concise Review

Acute Respiratory Distress Syndrome and Shunt Detection With Bubble Studies: A Systematic Review and Meta-Analysis

Acute respiratory distress syndrome (ARDS) is a life-threatening respiratory injury with multiple physiological sequelae. Shunting of deoxygenated blood through intra- and extrapulmonary shunts may complicate ARDS management. Therefore, we conducted a systematic review to determine the prevalence of sonographically detected shunts, and their association with oxygenation and mortality in patients with ARDS.

DATA SOURCES

Medical literature analysis and retrieval system online, Excerpta Medica dataBASE, Cochrane Library, and database of abstracts of reviews of effects databases on March 26, 2021.

STUDY SELECTION

Articles relating to respiratory failure and sonographic shunt detection.

DATA EXTRACTION

Articles were independently screened and extracted in duplicate. Data pertaining to study demographics and shunt detection were compiled for mortality and oxygenation outcomes. Risk of bias was appraised using the Joanna-Briggs Institute and the Newcastle-Ottawa Scale tools with evidence rating certainty using Grading of Recommendations Assessment, Development and Evaluation methodology.

DATA SYNTHESIS

From 4,617 citations, 10 observational studies met eligibility criteria. Sonographic detection of right-to-left shunt was present in 21.8% of patients (range, 14.4-30.0%) among included studies using transthoracic, transesophageal, and transcranial bubble Doppler ultrasonographies. Shunt prevalence may be associated with increased mortality (risk ratio, 1.22; 95% CI, 1.01-1.49; p = 0.04, very low certainty evidence) with no difference in oxygenation as measured by Pao₂:Fio₂ ratio (mean difference, -0.7; 95% CI, -18.6 to 17.2; p = 0.94, very low certainty).

CONCLUSIONS

Intra- and extrapulmonary shunts are detected frequently in ARDS with ultrasound techniques. Shunts may increase mortality among patients with ARDS, but its association with oxygenation is uncertain.

Embolic Events After Computed Tomography Contrast Injection in Patients With Interatrial Shunts: A Cohort Study

BACKGROUND

Patients with interatrial shunts (patient foramen ovale/atrial septal defect) are potentially at increased risk for paradoxical air embolism following computed tomography (CT) scans with intravenous (IV) contrast media injection. IV in-line filters aim to prevent such embolisms but are not compatible with power injection required for diagnostic CT.

PURPOSE

The purpose of this study was to determine whether the incidence of paradoxical embolism to the heart and brain in patients with an interatrial shunt is higher compared with controls within 48 hours following injection of IV contrast media without IV in-line filter.

METHODS

This is a retrospective cohort study conducted at a large tertiary academic center, which included a total of 2929 consecutive patients who underwent 8983 CT scans with IV contrast media injection between July 1, 2000 and April 30, 2018. Diagnosis of an interatrial shunt was confirmed by transthoracic or transesophageal echocardiography. Incidence and risk of cardiac embolic events (new troponin elevation, >0.1 ng/mL) and neurological embolic events (new diagnosis of stroke/transient ischemic attacks) were evaluated.

RESULTS

Among the 2929 patients analyzed (mean±SD age, 61±14 y), 475/2929 (16.2%) patients had an interatrial shunt. After applying the exclusion criteria, new elevated troponin was found in 8/329 (2.4%; 95% confidence interval [CI]: 1.1-4.7) patients with an interatrial shunt compared with 25/1687 (1.5%; 95% CI: 0.9-2.2) patients without an interatrial shunt. New diagnosis of stroke occurred in 2/169 (1%; 95% CI: 0.3-4.2) of patients with an interatrial shunt compared with 7/870 (0.8%; 95% CI: 0.4-1.7) without interatrial shunt.

CONCLUSION

Among patients with echocardiographic evidence of an interatrial shunt, IV CT contrast administration without an in-line filter does not increase the incidence of cardiac or neurological events.

Proactive Air Management in CT Power Injections: A Comprehensive Approach to Reducing Air Embolization

OBJECTIVE

Venous air embolism as a complication of contrast media administration from power injection systems in CT is found to occur in 7%-55% of patients, impacting patient safety, diagnostic image quality, workflow efficiency, and patient and radiographer satisfaction. This study reviews the challenges associated with reactive air management approaches employed on contemporary systems, proposes a novel air management approach using proactive methods, and compares the impact of reactive and proactive approaches on injected air volumes under simulated clinical use.

METHODS

Injected air volumes from three power injection systems were measured under simulated clinical use via custom air trap fixture. Two of the systems employed reactive air management approaches, while a new system implemented the proposed proactive air management approach.

RESULTS

The proactive system injected significantly less air (average of 0.005 mL ± 0.006 mL with a maximum of 0.017 mL) when compared to two systems with reactive approaches (averages of 0.130 mL ± 0.082 mL and 0.106 mL ± 0.094 mL with maximums of 0.259 mL and 0.311 mL, respectively) (p < 0.05). CT images were taken of static and dynamic 0.1 mL air bubbles inside of a vascular phantom, both of which were clearly visible. Additionally, the dynamic bubble was shown to introduce image artifacts similar to those observed clinically.

CONCLUSION

Comparison of the injected air volumes show that a system with a proactive air management approach injected significantly less air compared to tested systems employing reactive approaches.

SIGNIFICANCE

The results indicate that the use of a proactive approach could significantly reduce the prevalence of observable, and potentially artifact-inducing, venous air embolism in contrast-enhanced CT procedures.

Understanding Infusion Pumps

Infusion systems are complicated electromechanical systems that are used to deliver anesthetic drugs with moderate precision. Four types of systems are described-gravity feed, in-line piston, peristaltic, and syringe. These systems are subject to a number of failure modes-occlusion, disconnection, siphoning, infiltration, and air bubbles. The relative advantages of the various systems and some of the monitoring capabilities are discussed. A brief example of the use of an infusion system during anesthetic induction is presented. With understanding of the functioning of these systems, users may develop greater comfort.

A prospective case series evaluating use of an in-line air detection and purging system to reduce air burden during major surgery

Background

Intravascular air embolism (AE) is a preventable but potentially catastrophic complication caused by intravenous tubing, trauma, and diagnostic and surgical procedures. The potentially fatal risks of arterial AE are well-known, and emerging evidence demonstrates impact of venous AEs on inflammatory response and coagulation factors. A novel FDA-approved in-line air detection and purging system was used to detect and remove air caused by administering a rapid fluid bolus during surgery.

Methods

A prospective, randomized, case series was conducted. Subjects were observed using standard monitors, including transesophageal echocardiography (TEE) in the operating room. After general anesthesia was induced, an introducer and pulmonary artery catheter was inserted in the right internal jugular to administer fluids and monitor cardiac pressures. Six patients undergoing cardiac surgery were studied. Each patient received four randomized fluid boluses: two with the in-line air purging device, two without. For each bolus, a bulb infuser was squeezed three times (10–15 mL) over 5 s. The TEE was positioned in the mid-esophageal right atrium (RA) to quantify peak air clearance, and images were video recorded throughout each bolus. Air was quantified using optical densitometry (OD) from images demonstrating maximal air in the RA.

Results

All subjects demonstrated significantly lower air burden when the air reduction device was used (p = 0.004), and the average time to clear 90% of air was also lower, 3.7 ± 1.2 s vs. 5.3 ± 1.3 s (p < 0.001).

Conclusion

An air purging system reduced air burden from bolus administration and could consequently reduce the risk of harmful or fatal AEs during surgery.

Complications of Peripheral Venous Access Devices: Prevention, Detection, and Recovery Strategies

Most hospitalized patients have placement of a peripheral venous access device, either a short peripheral catheter or a peripherally inserted central catheter. Compared with central venous catheters that are not peripherally inserted, the other 2 types are generally perceived by health care providers as safer and less complicated to manage, and less emphasis is placed on the prevention and management of complications. Expertise of nurses in inserting, managing, and removing these devices may reduce the likelihood of complications, and increased recognition of complications associated with use of the devices is important to ensure continued improvements in the safety, quality, and efficiency of health care. Complications associated with short peripheral catheters and peripherally inserted central catheters include tourniquet retention, tubing and catheter misconnections, phlebitis, air embolism, device fragment embolization, and inadvertent discharge with a retained peripheral venous access device. Integration of prevention, detection, and recovery strategies into personal nursing practice promotes the quality and safety of health care delivery.

Vascular air embolism: A silent hazard to patient safety

PURPOSE

To narratively review published information on prevention, detection, pathophysiology, and appropriate treatment of vascular air embolism (VAE).

MATERIALS AND METHODS

MEDLINE, SCOPUS, Cochrane Central Register and Google Scholar databases were searched for data published through October 2016. The Manufacturer and User Facility Device Experience (MAUDE) database was queried for "air embolism" reports (years 2011-2016).

RESULTS

VAE may be introduced through disruption in the integrity of the venous circulation that occurs during insertion, maintenance, or removal of intravenous or central venous catheters. VAE impacts pulmonary circulation, respiratory and cardiac function, systemic inflammation and coagulation, often with serious or fatal consequences. When VAE enters arterial circulation, air emboli affect cerebral blood flow and the central nervous system. New medical devices remove air from intravenous infusions. Early recognition and treatment reduce the clinical sequelae of VAE. An organized team approach to treatment including clinical simulation can facilitate preparedness for VAE. The MAUDE database included 416 injuries and 95 fatalities from VAE. Data from the American Society of Anesthesiologists Closed Claims Project showed 100% of claims for VAE resulted in a median payment of $325,000.

CONCLUSIONS

VAE is an important and underappreciated complication of surgery, anesthesia and medical procedures.

Perioperative Blood Pressure Control and Management

Blood pressure monitoring and management is a vital part of the perianesthetic period. Disturbances in blood pressure, especially hypotension, can have significant impacts on the well-being of small animal patients. There are a variety of mechanisms present to control blood pressure, including ultra-short-, short-, and long-term mechanisms. Several conditions can contribute to decreased blood pressure, including anesthetics, tension pneumothorax, intermittent positive pressure ventilation, hypoxemia, hypercapnia, surgical positioning, and abdominal distension. If hypotension is encountered, the initial response is to provide appropriate fluid therapy. If this is inadequate, other interventions can be used to increase blood pressure and thereby increase perfusion.

Normal cranial postmortem CT findings in children

INTRODUCTION

Postmortem imaging (both CT and MRI) has become a widely used tool the last few years, both for adults and children. If it would be known which findings are normal postmortem changes, interpretation of abnormal findings becomes less ambiguous. Our aim was to describe postmortem intracranial radiological findings on postmortem CT (PMCT) in children, which did not have a relationship with the cause of death, and to determine whether these findings have a relationship with the postmortem interval or with medical interventions.

MATERIALS AND METHODS

We selected all consecutive pediatric autopsies that were performed at the Netherlands Forensic Institute in the period 1-1-2008 to 31-12-2011, whereby the subject underwent total body PMCT. We collected data on age at death, gender, cause of death determined by forensic autopsy and time between death and PMCT. Normal findings that were scored were: gray-white differentiation of the brain, collapse of the ventricles, air in the orbit, fluid accumulation in the frontal and maxillary sinuses, and air in vessels of head and neck.

RESULTS

One-hundred-fifty-nine forensic pediatric autopsies were performed in the 4 year study period at the NFI; 77 underwent a total body PMCT, of which 68 were included in the analyses. Fluid accumulation in the sinuses was present 30-40% of the cases in which the sinuses were developed. In 22% of all children intravascular intracranial air, either arterial or venous, was detected. We did not find a relationship between the duration of the postmortem interval and the appearance of any of the findings. Intravenous infusion is not significantly associated with the presence of intravascular air, except for air in the left and right common carotid artery (B=2.9, P=0.05).

CONCLUSIONS

By demonstrating the intracranial abnormalities that appear postmortem, we have tried to provide more insight in the range of findings that can be seen with pediatric PMCT. As these findings resemble antemortem pathology, it is important that the radiologist who interprets PMCT has knowledge of these normal postmortem findings.

Recognising air embolism as a complication of vascular access

The insertion and maintenance of advanced vascular access devices is increasingly becoming the remit of advanced nurses. Understanding the potential for air embolism as a complication of this procedure, recognising and managing the signs and symptoms, and being able to apply preventative measures, are imperative to enhance patient safety. A range of outcomes can present from air embolism depending on the rate and volume of air entrained, from sub-clinical to death, so the application of expert knowledge and vigilance is essential to minimise risk. According the the available literature, supplemental oxygen administration appears to be the most effective treatment.