Transformative impact of point-of-care testing in critical care

Abstract

The advent of point-of-care testing (POCT) has revolutionized the approach to patient management, especially for pediatric care. POCT provides rapid, on-the-spot biochemical and microbiological evaluations, bypassing delays typically associated with central laboratory testing, enabling swift clinical decision-making. Additionally, POCT has proven to be a valuable prognostic tool for monitoring electrolyte, lactate, creatinine levels, often a marker of severe illness and poor outcomes. POCT enables its faster identification, allowing for prompt interventions. This capability is essential in managing conditions like sepsis, where timely treatment can significantly impact survival rates. However, the implementation of POCT is not without its challenges. Variability in sample handling, particularly with heparinized syringes, can affect the accuracy of certain measurements, such as potassium levels. The absence of comprehensive follow-up data and cost-effectiveness analyses in some studies indicate the need for continued research to optimize the use of POCT. In conclusion, POCT is a transformative tool in critical care, offering prompt and reliable assessments that significantly enhance patient management. As technology advances, the integration of POCT into emergency departments and intensive critical care units holds great promise for improving the quality of healthcare and patient survival rates.

Key Words: Point-of-care testing; Emergency departments; Intensive care unit; Critical care; Pediatric care; Artificial intelligence

Core Tip: Point-of-care testing has transformed patient management in emergency and intensive care settings by delivering rapid, on-the-spot biochemical and microbiological evaluations. This allows swift clinical decisions which are pivotal for severe medical conditions such as sepsis. Research highlights a strong agreement between point-of-care testing and central lab results for key analytes such as electrolytes and lactate, which is crucial for accurate assessments and timely interventions. Despite the challenges such as sample handling variability, future advancements, including artificial intelligence, hold the potential for faster and more accurate diagnostics, improving overall healthcare quality.

INTRODUCTION

Point-of-care testing (POCT) in critical care has revolutionized the healthcare landscape by providing rapid diagnostics directly at the bedside[1]. The POCT is a medical diagnostic procedure that is performed near or at the site of patient care leading to an immediate improvement in the ongoing treatment and patient outcome[2,3]. Therefore, by mitigating diagnostic delays and enabling prompt, precise interventions in life-threatening situations, POCT enhances efficiency in emergency and intensive care settings, ultimately leading to significant reduction in morbidity and mortality[1]. Initially met with skepticism over analytical performance, increasing evidence now indicates POCT platforms align well with traditional laboratory instruments for many analytes, reinforcing their reliability for direct clinical implementation[4,5].

REAL WORLD SETTINGS: SPEEDING UP PEDIATRIC CARE

POCT diagnostics, using a minimally invasive devices and technology, become particularly imperative in acute care settings, such as pediatric emergency departments, intensive care units, and remote locations, where expeditious patient evaluation and prognostication are pivotal to optimizing clinical outcomes. For instance, some devices that require minimal sample volumes offer an advantage by reducing the blood loss typically associated with phlebotomy. Additionally, the simpler user interface of a POCT makes it more convenient for use for the general public in the community settings and in the absence of trained technical manpower. As POCT platforms advance to offer more testing options, their relevance in pediatric emergency medicine is becoming more widely acknowledged. For example, in pediatric patients with fever, it is crucial to quickly determine the source of infection (such as bacterial or viral) and identify those at high risk for serious bacterial infections[6]. C-reactive protein (CRP) is a useful biomarker for rapidly identifying inflammatory processes. In an earlier study, the use of POCT for CRP resulted in a substantial reduction in consultations and medical interventions in the emergency department, without significantly altering patient outcomes[7].

ADVANTAGES IN CRITICAL CARE PEDIATRIC SETTINGS

Children with chronic illness may have additional challenges in attending healthcare appointments and undergoing diagnostic testing. Most of these children would require more than one diagnostics requirement while presenting ill. The caregiver or the child may refuse to give consent for sampling through venipuncture or procedures like endoscopy. The use of POCT in clinical decision making is likely to be very beneficial and safe in these settings[8]. Additionally, advancements in POCT technology have enabled real-time data integration of POCT devices in remote areas, primary health care and homes, allowing automated, real-time, electronic transmission of POCT results and related information with a referral center to guide management and further action in emergency settings. This integration of POCT devices enhances access to quality diagnostics in underserved regions, prevents adverse events and improves patient outcomes[9].

IMPROVING EFFICIENCY AND RESOURCE MANAGEMENT

POCT enhances efficiency in healthcare by delivering rapid, on-site diagnostics, in both acute and remote patient care environments. This efficiency boosts patient throughput and minimizes the reliance on central laboratories, which helps cut costs associated with lab tests and specialized staff[10-14]. A study by Crocker et al[11] showed the use of implementation of point-of-care (POC) diagnostic platforms in ambulatory settings resulted in cost reduction and optimizations in clinical operations. Authors reported that subsequent to the deployment of POCT, there was a 21% reduction in the number of tests ordered per patient, accompanied by a marked decline of 89% in follow-up phone calls. Numerous reports have highlighted the clinical and economic advantages of implementing POCT systems, such as shorter turnaround times, reduced length of stay, lower mortality rates, reducing wait times, reduced preanalytical and postanalytical testing errors and shortening hospital stays[12]. An earlier study by Winkelman et al[13], observed that the medical cost was less while using central laboratory testing turn around time of POC blood gas analysis (4.5 minutes) nearly equaled central laboratory testing (6 minutes). Nijman et al[12] found that the bedside CRP reduced the median length of stay in children requiring an laboratory diagnostic CRP test from 178 minutes to 148 minutes, a 30-minute (19%) decrease. In a study among 897 patients, Goldstein et al[10] compared the POC test panel (i-STAT system, complete blood count, electrocardiograms, low dose X-ray) to standard diagnostic methods for cost-effectiveness. Results showed that the standard control investigations cost dollars 9.93 higher than the POCT systems dollars 9.93, if the entire test panel were performed on a patient. While low dose X-ray-based tests saved time, they were more expensive. Higher staffing costs further favored POCT as a more economical option. Studies have reported POCT also streamlines operations by optimizing the use of medical equipment and space, further contributing to cost savings[11].

EXPERIENCES WITH POCT

Traditional POCT devices are available for diagnosing and managing both acute and chronic conditions. These encompass a variety of diagnostic assays including, glucose meters, hemoglobin A1c, and ketone tests; urine creatinine, epidermal growth factor receptor, urinary protein: Creatinine ratio for renal function; troponin and brain natriuretic peptide for diagnosing myocardial infarction; hemoglobin and gastric/fecal occult blood tests for anemia and bleeding; prothrombin, and activated partial thromboplastin time for coagulation profile; urine drug tests, blood gas, electrolytes; CRP and electron spin resonance for inflammation; rapid tests for human immunodeficiency virus, respiratory syncytial virus, influenza, and, more recently, severe acute respiratory syndrome coronavirus 2. Recent advancements in POCT platforms have broadened the range of available assays to include important chemistry and immunoassay markers in various settings[15].

Antimicrobial stewardship

The role of POCT in antimicrobial stewardship has also been found promising. The use of multiplex cards using polymerase chain reaction aids in identifying viruses/parasites to limit the injudicious use of antimicrobials in children presenting with acute undifferentiated febrile illness like influenza[16]. It may also aid in deciding the need for hospitalization that further reduces healthcare costs and risk of hospital acquired infections[17].

Electrolyte

Handheld devices, such as the Nova StatStrip blood gas analyzer provide real-time electrolyte analysis, crucial for monitoring critically ill patients and adjusting treatment plans based on dynamic changes in electrolyte levels[18]. These can process less commonly measured electrolytes like calcium and magnesium in the same volume of blood. The disturbances in levels of these electrolytes aids in decision making and prognosis of sick children[19]. The measurement of these multiple analytes at a single point in time on the same sample also aids in interpretation of plausible biological association. The use of artificial intelligence has improved risk stratification and prognosis algorithms[20].

Microbial testing

Rapid antigen tests, such as the Abbott BinaxNOW^™ and the Quidel Sofia^™ SARS Antigen fractional iron absorption, deliver quick results for detecting severe acute respiratory syndrome coronavirus 2, facilitating timely isolation and management of coronavirus disease 2019 patients. The identification and timely treatment of serious bacterial infection in children is challenging. The use of biomarkers that can be measured using POCT like CRP, neutrophil counts, lactate etc. can aid in better decision making[21].

Hematology testing

Portable hematology analyzers, like the Hemochron Signature Elite, provide immediate results for coagulation profiles, aiding quick treatment decisions in trauma cases or for patients on anticoagulant therapy[22]. Devices such as the i-STAT system offer rapid blood gas and electrolyte testing, crucial for managing premature infants with complex hematological needs[23].

POCT ultrasound in emergency room settings

It is used to quickly assess trauma patients for internal bleeding in the abdomen or chest, guiding immediate surgical or medical intervention. Ultrasound guidance for procedures like central line insertion or paracentesis enhances accuracy and reduces complications, ensuring safety[24,25].

Severe acute respiratory distress syndrome corona virus-2 detection: POCT could radically transform the healthcare system’s capacity to quickly detect and manage coronavirus disease 2019, especially in remote areas where lab-based nucleic acid amplification testing is unfeasible. Unlike traditional lab polymerase chain reaction tests, which take about two days for results, the Abbott ID NOW^™ coronavirus disease 2019 diagnostic assay delivers prompt results - positive results in 6 minutes and negative in 12 - using nucleic acid amplification technology for qualitative severe acute respiratory distress syndrome corona virus-2 detection from nasal and nasopharyngeal swabs[26].

CHALLENGES: GOVERNANCE AND SAFETY AUDIT REQUIREMENTS

A survey across the United Kingdom and Ireland on use of POCT for managing paediatric patients showed most of the POCT were being performed by the nursing staff. The action on these reports was taken by the doctor or the consultant in the majority except for the gas analysis. The issue identified was that most POCT reports could not be entered into the electronic system and had to be recorded manually[27,28]. Though POCT is likely to be advantageous in primary care settings, there may be additional challenges in these settings related to accountability of conducting the test, work distribution in primary care settings, standardization of protocol on management of a child based on the POCT report, patient safety and funding[29].

Therefore, improving awareness and training on the use of POCT as a triaging tool becomes important. A few areas that need improvement with the use of POCT are mentioned below: (1) Simpler home-monitoring of children with chronic illness for emergencies like ketoacidosis (in children with diabetes), dyselectrolytemia (malabsorption, diabetes insipidus, tubulopathy). Therefore, all metabolic emergencies cannot be monitored or detected at home[30]; (2) Ensuring quality and validity of POCT - this requires a periodic calibration of POCT devices to ensure the device meets manufacturer specifications, enhancing test reliability and reducing the risk of false results. A few devices are claimed to have zero-maintenance and repair costs. However, calibration is not inbuilt as a regular protocol. The end-user may fail to recognize the error in reporting that may make results invalid till a replacement of the device can be arranged[31-33]; (3) Ensuring diagnostic accuracy and modifying treatment - the use of POCT is beneficial if it can address a diagnostic uncertainty that arises at the end of clinical examination, and can be resolved for instituting specific clinical management. For example, the use of POCT nasal swab polymerase chain reaction to detect influenza can avoid overuse of antibiotics. However, this may not be true for a few POCT where the sensitivity is high but specificity is low[34]; (4) Most of the experience on use of POCT is derived from use in adult settings that were tested later in pediatric settings. However, the applicability, clinical utility and cost-effectiveness will vary in children. For example, the most common cause of hyperglycemia with metabolic acidosis in a sick child could be systemic inflammatory response syndrome instead of acute complication of diabetes which is more common in adults. Therefore, the test algorithms for action based on POCT will be different from adults[35]; and (5) Additionally, in infants and children, pediatric reference interval studies for POCT systems are lacking, undermining the accuracy and standard of test result interpretation of test results. The interpretation of the normal range of the analytes needs to be as per the age of the child. For example, the normal serum bicarbonate level in a newborn is lower (16-24 meq/L) than a child (18-26 meq/L)[35]. Further investigations are imperative to delineate age-specific reference ranges and critical thresholds as novel POCT systems are progressively integrated into clinical practice.

Future directions

Future directions for POCT include the development of more sophisticated and user-friendly devices, integration with digital health systems for seamless data management, and expanding testing capabilities to cover a broader range of conditions. Innovations such as advanced biosensors, lab-on-a-chip technologies, and artificial intelligence-driven analytics will further enhance accuracy and efficiency[19,36]. For lateral immunoassays, Yan et al[37] used magnetic nanoparticles conjugated with antibodies to detect analytes like human chorionic gonadotropin, cardiac troponin I, creatine phosphokinase and myoglobin, measuring magnetic signals with an immunoassay reader. They employed a novel data-processing method using a support vector machine classifier and custom waveform reconstruction to enhance sensitivity and accuracy for weak signals. Human chorionic gonadotropin was quantitatively detected with a detection limit of 0.014 mIU/mL, well below the typical < 5 mIU/mL cut-off of laboratory instruments. Microfluidic “lab-on-a-chip” technology boasts a high surface-area-to-volume ratio, facilitating fast analysis time and enabling POCT. It holds significant potential to perform intricate diagnostic assays, such as nucleic acid short tandem repeat fingerprinting, by integrating all requisite functional modules within a single chip[38]. These developments promise significant transformation in the clinical practice paradigm of emergency and critical care.

CONCLUSION

In conclusion, with ongoing technological advancements, the integration of POCT into emergency departments and intensive care units holds immense potential for enhancing healthcare quality and increasing patient survival rates. Implementation of existing POCT systems in emergency and critical care brings the laboratory directly to the patient, streamlining the testing process and reducing the time to clinical intervention, thereby significantly enhancing patient management. Current evidence highlights several key benefits for patient care, including shorter length of stay, rapid diagnosis, better outcomes for acute conditions, and lower hospitalization costs. Studies have reported additional administrative and economic benefits with adequate education and training such as enhanced staff satisfaction and optimized workflow efficiency. However, before clinical deployment of POCT, careful attention to their analytical requirements is essential. Not all POCT systems are homogeneous, and discrepancies between POCT devices and central laboratory analyzers continue to be documented, often necessitating device-specific test interpretation. Nonetheless, despite these challenges, the development of innovations, like lab-on-a-chip platforms and AI-driven analytical frameworks, will greatly enhance the operational efficiency of POCT devices in critical care settings.