Bladder Scan Tools are essential non-invasive devices utilized in healthcare settings to assess urinary bladder volume, diagnose urinary dysfunction, and guide treatment decisions. These portable ultrasound instruments provide a quick and painless method to measure urine volume within the bladder, significantly aiding in patient care and management of urinary issues. This guide aims to provide a comprehensive understanding of bladder scan tools, their proper usage, and the benefits they offer in modern medical practice.
Understanding Bladder Scan Tools: Definition and Purpose
A bladder scan tool, also known as a bladder scanner, employs ultrasonic technology to differentiate the urinary bladder from surrounding tissues within the body. This non-invasive procedure offers a significant advantage in diagnosing and managing urinary outflow dysfunction without the need for invasive catheterization in many instances. The primary function of a bladder scan tool is to accurately measure post-void residual (PVR) urine volume and bladder capacity.
The benefits of using bladder scan tools are multifaceted:
- Determining the Necessity for Catheterization: Bladder scans help clinicians objectively assess urinary retention, guiding decisions on whether catheterization is truly needed.
- Reducing Unnecessary Urinary Catheter Placement: By providing accurate bladder volume measurements, these tools can prevent the insertion of urinary catheters when not clinically indicated, thus minimizing the risk of catheter-associated urinary tract infections (CAUTIs).
- Quick Measurement of Postvoid Residual (PVR) and Bladder Capacity: Bladder scans offer rapid and reliable measurements of PVR and bladder capacity, crucial for diagnosing and managing various urinary dysfunctions efficiently.
Policy and Guidelines for Bladder Scan Tool Usage
To ensure effective and safe utilization, specific policies and guidelines should be followed when using a bladder scan tool.
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Indications for Use: A bladder scan should be considered for patients presenting with acute or chronic urinary dysfunction. This includes conditions such as urinary retention, incontinence, and other lower urinary tract symptoms.
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Contraindications: While generally safe, bladder scans should not be used under certain conditions:
- Open Skin or Wounds: Avoid use if the patient has open skin or a wound in the suprapubic region to prevent potential infection and discomfort.
- Pregnancy: Bladder scans are not indicated for pregnant patients.
- Flammable Anesthetics: Do not use bladder scan tools in the presence of flammable anesthetics due to potential safety hazards.
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Postvoid Residual (PVR) Assessment Guidelines: When using a bladder scan to assess PVR:
- Document Voided Volume: Always record the amount of urine voided by the patient prior to performing the bladder scan.
- PVR Thresholds: If the PVR volume measured by the bladder scan exceeds 300-500 cc, consider straight catheterization (per physician order) as an initial intervention. Aim to avoid indwelling urinary catheter (Foley) placement if possible to reduce infection risks.
- Post-Scan Catheterization: If straight catheterization is performed following the bladder scan, meticulously document the volume of urine obtained via catheterization for accurate patient record-keeping.
Step-by-Step Procedure for Bladder Scanning
Proper technique is crucial for obtaining accurate readings from a bladder scan tool. Follow these steps for effective bladder scanning:
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Preparation: Don clean, non-sterile gloves to maintain hygiene.
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Scanner Head Cleaning: Prior to and after each patient use, diligently clean the scanner head with a hospital-approved disinfectant, adhering to the manufacturer’s instructions to prevent cross-contamination.
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Equipment Check: Ensure the bladder scanner is in optimal working condition. Verify that the battery is correctly placed and the probe is securely plugged in.
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Patient Positioning: The bladder scan can be performed with the patient in either a sitting or supine position, whichever is more comfortable and feasible for the patient and clinical setting.
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Abdominal Exposure: Adjust or remove the patient’s clothing to adequately expose the abdominal area, specifically the suprapubic region, where the bladder is located.
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Powering On and Initialization: Turn on the bladder scanner. Observe the self-testing sequence displayed on the panel, which also helps identify the function of different buttons and controls.
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Gender and Patient Specific Settings: Press the “scan” button and accurately input the patient’s gender.
- Hysterectomy Considerations: For female patients who have undergone a hysterectomy, select the “male” gender setting on the scanner for accurate readings.
- Body Habitus Adjustments: For patients who are very thin or obese, use a generous amount of ultrasound gel to ensure good acoustic contact and image quality.
- Excessive Abdominal Hair: In patients with significant lower abdominal hair, apply the ultrasound gel directly to the skin to ensure proper probe contact. Inform the patient that the gel will feel cool upon application.
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Gel Application: Apply a sufficient amount of ultrasound transmission gel to the scanner head. Take care to eliminate any air bubbles within the gel, as air bubbles can interfere with ultrasound transmission and image quality.
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Probe Placement: Position the scanner head approximately one inch above the symphysis pubis. Angle the probe slightly downwards, aiming towards the expected location of the urinary bladder within the pelvis. Ensure that the head of the icon on the scan head is oriented towards the patient’s head to maintain correct anatomical alignment.
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Scanning and Measurement: Press the “scan” button and hold the scanner head steady and motionless throughout the scan process. Continue holding until you hear an audible beep from the device, indicating the scan completion. The bladder scanner will then display the measured urine volume and a visual aiming display with crosshairs. If the crosshairs are not centered on the bladder image displayed on the screen, adjust the probe position slightly and rescan until the crosshairs are properly centered for an accurate measurement.
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Result Confirmation: Once you are confident that the displayed results are accurate and the crosshairs are correctly positioned, press the “done” button to finalize the measurement. The bladder scan tool will then display the largest measured volume for both the longitudinal and horizontal planes of the bladder.
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Printing Results (if needed): If documentation in hard copy is required, press the “print” button to generate a printed report of the bladder volume measurement.
Safety Tips and Best Practices for Accurate Bladder Scans
To maximize the safety and accuracy of bladder scan measurements, adhere to the following helpful tips and best practices:
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Not for Fetal Heart Tones: Emphasize that bladder scan tools are specifically designed for urinary bladder volume measurement and should never be used for fetal heart tone monitoring.
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Caution with Surgical Patients: Exercise particular caution when using bladder scans on patients who have undergone suprapubic or pelvic surgery. Scar tissue, surgical incisions, sutures, or staples in the surgical area can potentially affect the accuracy of the scan readings due to altered tissue density and ultrasound wave reflection.
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“Greater Than” Symbol Interpretation: If the bladder volume measurement displayed on the screen is accompanied by a “greater than” symbol (>), it indicates that the entire bladder volume was not fully within the scan head’s range. This suggests that the patient’s true bladder volume is actually greater than the volume displayed. To obtain a more accurate measurement, reposition the scan head and repeat the scan. An exception to this rule is when the displayed volume exceeds a very high threshold (e.g., 999 cc). In such cases, the bladder is likely within the instrument’s full range, and the displayed reading is considered accurate, even if it’s a high volume. It’s important to note that in situations of extreme bladder distention, repositioning might not significantly improve accuracy, but even an underestimated reading can still provide clinically useful information.
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Motionless Scan Head: The bladder scan tool calculates bladder volume based on multiple cross-sectional images. It is critical to hold the scan head completely motionless throughout the entire scan process to prevent image distortion and ensure measurement accuracy.
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Optimal Patient Position: The most accurate bladder volume measurements are generally obtained when the patient is resting quietly in the supine position. This position helps stabilize the bladder and surrounding tissues, leading to clearer images and more reliable results.
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User Proficiency: The accuracy of bladder scan results is highly dependent on the user’s skill in obtaining an optimal and reportable image. Proper training and practice are essential for healthcare providers to become proficient in using bladder scan tools and interpreting the results correctly.
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Absence of Urinary Catheter: Ensure that the patient does not have a urinary catheter in situ during the bladder scan. The presence of a catheter within the bladder can introduce microbubbles, which can interfere with ultrasound waves and negatively impact the accuracy of the bladder volume measurement.
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Power Saving Feature: To conserve battery power, bladder scan tools are designed to automatically power off when not in use for a certain period. This feature helps extend battery life and ensures the device is ready for use when needed.
By adhering to these guidelines and procedures, healthcare professionals can effectively utilize bladder scan tools to enhance patient care, reduce unnecessary catheterizations, and improve the management of urinary dysfunction.
References
- ANA CAUTI Prevention Tool: https://www.nursingworld.org/practice-policy/work-environment/health-safety/infection-prevention/ana-cauti-prevention-tool/
- Gupta SS, Irukulla PK, Shenoy MA, Nyemba V, Yacoub D, Kupfer Y. Successful strategy to decrease indwelling catheter utilization rates in an academic medical intensive care unit. Am J Infect Control 2017;45(12):1349-1355.
- Purvis S, Gion T, Kennedy G, et al. Catheter-associated urinary tract infection: a successful prevention effort employing a multipronged initiative at an academic medical center. J Nurs Care Qual 2014;29(2):141-148.
- Portable bladder ultrasound: an evidence-based analysis. Ont Health Technol Assess Ser 2006;6(11):1-51. PMID: 23074481.
