Automated Seizure Detection in Patients with Cardiac Arrest: A Retrospective Review of Ceribell™ Rapid-EEG Recordings

BACKGROUND

In patients with cardiac arrest who remain comatose after return of spontaneous circulation, seizures and other abnormalities on electroencephalogram (EEG) are common. Thus, guidelines recommend urgent initiation of EEG for the evaluation of seizures in this population. Point-of-care EEG systems, such as Ceribell™ Rapid Response EEG (Rapid-EEG), allow for prompt initiation of EEG monitoring, albeit through a reduced-channel montage. Rapid-EEG incorporates an automated seizure detection software (Clarity™) to measure seizure burden in real time and alert clinicians at the bedside when a high seizure burden, consistent with possible status epilepticus, is identified. External validation of Clarity is still needed. Our goal was to evaluate the real-world performance of Clarity for the detection of seizures and status epilepticus in a sample of patients with cardiac arrest.

METHODS

This study was a retrospective review of Rapid-EEG recordings from all the patients who were admitted to the medical intensive care unit at Kent Hospital (Warwick, RI) between 6/1/2021 and 3/18/2022 for management after cardiac arrest and who underwent Rapid-EEG monitoring as part of their routine clinical care (n = 21). Board-certified epileptologists identified events that met criteria for seizures or status epilepticus, as per the 2021 American Clinical Neurophysiology Society's Standardized Critical Care EEG Terminology, and evaluated any seizure burden detections generated by Clarity.

RESULTS

In this study, 4 of 21 patients with cardiac arrest (19.0%) who underwent Rapid-EEG monitoring had multiple electrographic seizures, and 2 of those patients (9.5%) had electrographic status epilepticus within the first 24 h of the study. None of these ictal abnormalities were detected by the Clarity seizure detection system. Clarity showed 0% seizure burden throughout the entirety of all four Rapid-EEG recordings, including the EEG pages that showed definite seizures or status epilepticus.

CONCLUSIONS

The presence of frequent electrographic seizures and/or status epilepticus can go undetected by Clarity. Timely and careful review of all raw Rapid-EEG recordings by a qualified human EEG reader is necessary to guide clinical care, regardless of Clarity seizure burden measurements.

Ten Influential Point-of-Care Ultrasound Papers: 2022 in Review

Keeping up with the latest developments in the point-of-care ultrasound (POCUS) literature is challenging, as with any area of medicine. Our group of POCUS experts has selected 10 influential papers from the past 12 months and provided a short summary of each. We hope to provide emergency physicians, intensivists, and other acute care providers with a succinct update concerning some key areas of ultrasound interest.

Ten Influential Point-of-Care Ultrasound Papers: 2021 in Review

The ongoing rapid expansion of point-of-care ultrasound (POCUS) and its corresponding supporting literature leaves the frontline clinician in a difficult position when trying to keep abreast of the latest developments. Our group of POCUS experts has selected ten influential POCUS-related papers from the past twelve months and provided a short summary of each. Our aim is to give to emergency physicians, intensivists, and other acute care providers key information, helping them to keep up to date on rapidly evolving POCUS literature.

The Utility of Point-of-Care Ultrasound in the Pediatric Intensive Care Unit

Objectives: Point of care ultrasound (POCUS) in adult critical care environments has become the standard of care in many hospitals. A robust literature shows its benefits for both diagnosis and delivery of care. The utility of POCUS in the pediatric intensive care unit (PICU), however, is understudied. This study describes in a series of PICU patients the clinical indications, protocols, findings and impact of pediatric POCUS on clinical management. Design: Retrospective analysis of 200 consecutive POCUS scans performed by a PICU physician. Patients: Pediatric critical care patients who required POCUS scans over a 15-month period. Setting: The pediatric and cardiac ICUs at a tertiary pediatric care center. Interventions: Performance of a POCUS scan by a pediatric critical care attending with advanced training in ultrasonography. Measurement and Main Results: A total of 200 POCUS scans comprised of one or more protocols (lung and pleura, cardiac, abdominal, or vascular diagnostic protocols) were performed on 155 patients over a 15-month period. The protocols used for each scan reflected the clinical question to be answered. These 200 scans included 133 thoracic protocols, 110 cardiac protocols, 77 abdominal protocols, and 4 vascular protocols. In this series, 42% of scans identified pathology that required a change in therapy, 26% confirmed pathology consistent with the ongoing plans for new therapy, and 32% identified pathology that did not result in initiation of a new therapy. Conclusions: POCUS performed by a trained pediatric intensivist provided useful clinical information to guide patient management.

Reversal of Severe Multiorgan Failure Associated With Sickle Cell Crisis Using Plasma Exchange: A Case Series

OBJECTIVE

Red blood cell exchange (RBCE) is the standard of care for patients with sickle cell disease (SCD) who present with severe vaso-occlusive crisis (VOC). However, subsets of these critically ill patients have progressive multiorgan failure (MOF) despite RBCE therapy. The purpose of this case series is to describe the use of plasma exchange (PLEX) for the treatment of SCD-related MOF that is refractory to RBCE.

METHODS

A retrospective case review of patients with severe MOF from sickle cell crisis unresponsive to RBCE who underwent PLEX in a 14-bed adult medical intensive care unit (ICU) at a tertiary care university hospital over a 4-year time period. Key laboratory data including complete blood count, indices of hemolysis, and markers of organ failure were recorded before and after both RBCE and PLEX.

RESULTS

Our primary objective is to evaluate the effectiveness of PLEX, in addition to RBCE, on organ dysfunction, laboratory indices, and mortality. Of the 7 patients, 6 survived. Of the patients who survived, all remained hemodynamically stable during PLEX sessions and showed both clinical and laboratory evidences of improvement in hemolysis and organ function. Average time from completion of first PLEX treatment to initial laboratory signs of organ failure reversal for patients who survived was 15.6 hours, the average length of stay in the ICU was 5.6 days, and the average total length of stay in the hospital was 14 days.

CONCLUSIONS

Plasma exchange, in addition to RBCE, may be a novel synergistic treatment option to decrease risk of mortality in patients with refractory VOC and MOF.

Assessment of Diaphragm Function and Pleural Pressures During Thoracentesis

BACKGROUND

This prospective observational study reports on diaphragm excursion, velocity of diaphragm contraction, and changes in pleural pressure that occur with thoracentesis.

METHODS

Twenty-eight patients with pleural effusion underwent therapeutic thoracentesis. Diaphragm excursion and velocity of diaphragm contraction were measured with M-mode ultrasonography of the affected hemidiaphragm. Pleural pressure was measured at each aliquot of 250 mL of fluid removal. Fluid removal was continued until no more fluid could be withdrawn, unless there was evidence of nonexpandable lung defined as a pleural elastance greater > 14.5 cm H₂O/L and/or ipsilateral anterior chest discomfort.

RESULTS

Twenty-three patients had expandable lung, and five patients had nonexpandable lung. Velocity of diaphragm contraction (mean ± SD) increased from 1.5 ± 0.4 cm/s to 2.8 ± 0.4 cm/s pre-thoracentesis and post-thoracentesis, respectively (CI, 0.93-1.61; P < .001) in subjects with expandable lung. Velocity of diaphragm contraction (mean ± SD) increased from 2.0 ± 0.4 cm/s to 2.3 ± 0.4 cm/s pre-thoracentesis and post-thoracentesis (P = .45) in subjects with nonexpandable lung. Diaphragm excursion was significantly increased in subjects with expandable lung at the end of thoracentesis; diaphragm excursion did not increase to a significant extent in patients with nonexpandable lung.

CONCLUSIONS

The velocity of diaphragm contraction and diaphragm excursion increased in association with fluid removal with thoracentesis in patients with expandable lung, whereas it did not significantly change in patients with nonexpandable lung. This may derive from improvement in loading conditions of the diaphragm in patients with expandable lung related to its preload and length-tension characteristics.

Ultrasound Billing for Intensivists

Point-of-care ultrasonography is a key skill for the critical care clinician and is gaining widespread acceptance by clinicians in all areas of medicine. In addition to mastery of image acquisition, image interpretation, and clinical application, intensivists need to be adept with billing for their scanning activity. This article summarizes the requirements for documentation and image storage that must be met to obtain reimbursement for point-of-care ultrasonography services.

Safety of peripheral intravenous administration of vasoactive medication

BACKGROUND

Central venous access is commonly performed to administer vasoactive medication. The administration of vasoactive medication via peripheral intravenous access is a potential method of reducing the need for central venous access. The aim of this study was to evaluate the safety of vasoactive medication administered through peripheral intravenous access.

METHODS

Over a 20-month period starting in September 2012, we monitored the use of vasoactive medication via peripheral intravenous access in an 18-bed medical intensive care unit. Norepinephrine, dopamine, and phenylephrine were all approved for use through peripheral intravenous access.

RESULTS

A total of 734 patients (age 72 ± 15 years, male/female 398/336, SAPS II score 75 ± 15) received vasoactive medication via peripheral intravenous access 783 times. Vasoactive medication used was norepinephrine (n = 506), dopamine (n = 101), and phenylephrine (n = 176). The duration of vasoactive medication via peripheral intravenous access was 49 ± 22 hours. Extravasation of the peripheral intravenous access during administration of vasoactive medication occurred in 19 patients (2%) without any tissue injury following treatment, with local phentolamine injection and application of local nitroglycerin paste. There were 95 patients (13%) receiving vasoactive medication through peripheral intravenous access who eventually required central intravenous access.

CONCLUSIONS

Administration of norepinephrine, dopamine, or phenylephrine by peripheral intravenous access was feasible and safe in this single-center medical intensive care unit. Extravasation from the peripheral intravenous line was uncommon, and phentolamine with nitroglycerin paste were effective in preventing local ischemic injury. Clinicians should not regard the use of vasoactive medication is an automatic indication for central venous access.

Respiratory failure with hilar mass: Role of endobronchial ultrasound-guided transbronchial needle aspiration in the medical intensive care unit

We report the case of a 58-year-old man on chronic steroid therapy, who developed a rapidly progressive right upper lobe infiltrate/mass that extended into the right hilum. Respiratory failure necessitated endotracheal intubation. Broad spectrum antibiotics were initiated without clinical improvement and because of his immunosuppressive therapy opportunistic pathogens were considered. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) was performed in the Medical Intensive Care Unit (MICU) with rapid onsite evaluation. Specimens obtained from the right hilar mass revealed organisms suspicious for cryptococcal infection, subsequently confirmed via a culture. No complications occurred during the EBUS procedure despite the patient requiring vasopressor support and 100% inspired oxygen. Little data exists regarding the use of EBUS in patients admitted to the MICU with respiratory failure of unknown etiology and mediastinal/hilar lymphadenopathy. This case illustrates the potential safe use of EBUS-TBNA in patients presenting with respiratory failure, with a mediastinal or hilar mass and suspected infectious etiology.

Advanced echocardiography for the critical care physician: part 2

This article is the second part of a series that describes practical techniques in advanced critical care echocardiography and their use in the management of hemodynamic instability. Measurement of left ventricular function and segmental wall motion abnormalities, evaluation of left ventricular filling pressures, assessment of right-sided heart function, and determination of preload sensitivity, including passive leg raising, are discussed. Video examples help to demonstrate techniques described in the text.

Safety of Propofol as an Induction Agent for Urgent Endotracheal Intubation in the Medical Intensive Care Unit

Purpose:

Propofol is known to provide excellent intubation conditions without the use of neuromuscular blocking agents. However, propofol has adverse effects that may limit its use in the critically ill patients, particularly in the hemodynamically unstable patient. We report on the safety and efficacy of propofol for use as an agent for urgent endotracheal intubation (UEI) in the critically ill patients.

Methods:

We reviewed the outcomes of 472 consecutive UEIs performed by a medical intensive care unit (ICU) team at a tertiary care hospital from November 2008 through November 2012. Outcome data were collected prospectively as part of an ongoing quality improvement project.

Results:

Propofol was used as the sole sedative agent in 409 (87%) of the 472 patients. In 18 (4%) of the 472 patients, other agents (midazolam, lorazepam, or etomidate) were used in addition to propofol. Of the 472, 10 (2%) intubations were performed with a sedative agent other than propofol, and 35 (7%) of the 472 intubations were performed without any sedating agent. Endotracheal tube insertion was successful in all 472 patients. Complications of UEI in those patients who received propofol were as follows: desaturation (Sao2 < 80%) 30 (7%) of the 427, hypotension (systolic blood pressure < 70 mm Hg) 19 (4%) of the 427, difficult intubation (>2 attempts) 44 (10%) of the 427, esophageal intubation 24 (6%) of the 427, aspiration 6 (1%) of the 427, and oropharyngeal injury 4 (1%) of the 427. There were no deaths. Average dose of propofol was 99 mg (standard deviation 7.39) per person.

Conclusions:

Our results compare favorably with the complication rate of UEI reported in the critical care and anesthesiology literature and indicate that propofol is a useful agent for airway management in the ICU.

Video laryngoscopy is associated with increased first pass success and decreased rate of esophageal intubations during urgent endotracheal intubation in a medical intensive care unit when compared to direct laryngoscopy

BACKGROUND

To compare the complication rates of urgent endotracheal intubation (UEI) performed by pulmonary critical care medicine (PCCM) fellows and attending intensivists using a direct laryngoscope (DL) versus a video laryngoscope (VL) in a medical intensive care unit (MICU).

METHODS

We studied all UEIs performed from November 2008 through July 2012 in an 18-bed MICU in a university-affiliated hospital. All UEIs were performed by 15 PCCM fellows or attending intensivists using only the DL from November 2008 through February 2010 and the VL from March 2010 to July 2012. Throughout the entire study period, the UEI team leader recorded complications of the procedure using a standard data collection form immediately following the completion of the procedure. This permitted a comparison of complication rates between the DL and the VL.

RESULTS

A total of 140 UEIs were performed using the DL and 252 using the VL. Using the DL, the esophageal intubation rate was 19% and the difficult intubation rate was 22%; using the VL, the esophageal intubation rate was 0.4% and the difficult intubation rate was 7%. There was no significant difference in the rate of severe hypotension, severe desaturation, aspiration, dental injury, airway injury, or death between the 2 groups.

CONCLUSION

The use of the VL for UEI performed by PCCM fellows is associated with a reduction in the rate of esophageal intubation and difficult endotracheal intubation when compared to the use of the DL.

Potential role of endogenous adenosine in ticagrelor-induced dyspnea

Ticagrelor, a recently approved platelet antagonist indicated for the reduction of thrombotic cardiovascular events in patients with acute coronary syndrome (ACS), has been reported to cause dyspnea in more than 13% of patients. Dyspnea is not a clinically relevant adverse event with other medications indicated for ACS. One suggested mechanism of ticagrelor-induced dyspnea involves an increase in systemic adenosine concentrations through adenosine deaminase inhibition. Dyspnea, a subjective finding resulting from physiologic and sensory mechanisms, may be a consequence of increased systemic adenosine concentrations, leading to amplified and prolonged receptor activity. Current literature suggests, however, that pulmonary status is not compromised, with no reduction of efficacy seen in patients with ticagrelor-induced dyspnea, thus allowing clinicians to continue therapy without reservation. Still, patients with a history of asthma and chronic obstructive pulmonary disease may be more susceptible to ticagrelor-induced dyspnea, potentially leading to nonadherence and exacerbations of morbidity. Therefore, it is paramount that health care providers continually monitor these patients with the aims of maintaining medication therapy adherence and providing relevant options if dyspnea becomes intolerable.