Pain assessment is a fundamental aspect of healthcare. It not only allows us to better understand the suffering of patients, but also to manage it effectively. The use of pain scales is a systematic and validated method for quantifying and qualifying this experience, which remains profoundly subjective.

These scales play an indispensable role for healthcare professionals. They make it possible to precisely identify the intensity of the pain, whether it is acute, prolonged or chronic, and to adapt the treatments accordingly. In this article, we will examine the importance of these tools, the different types of scales available, their practical use, as well as their integration into patient management. This includes specific cases such as children, the elderly and individuals with verbal communication disorders.

Importance of pain assessment in patients

Consequences of untreated pain

Untreated pain or insufficiently relieved pain can have devastating consequences on patients' health and well-being. It can lead to psychological disorders such as depression and anxiety, disrupting almost all daily activities.

Patients suffering from chronic pain may become inactive, withdraw from society, and focus exclusively on their physical health. This leads to a significant loss of function and significant disability. In addition, chronic pain can cause vegetative disorders such as asthenia, sleep disorders, anorexia, and decreased libido, thus globally affecting the patient's quality of life.

The economic costs of chronic pain are also considerable. For example, in Canada, the costs associated with lost workdays, medications, and medical consultations are estimated at approximately $10 billion per year.

Impact on quality of life and the healing process

Adequate assessment and treatment of pain are essential to maintain and improve patients' quality of life. Poorly managed pain can slow down the healing process and increase the risk of post-operative complications, particularly after surgical procedures.

Furthermore, uncontrolled acute pain can evolve into chronic pain, further complicating management and significantly reducing the patient's quality of life. A holistic approach, including drug treatments and non-drug techniques such as rehabilitation, electrical stimulation, and manual techniques, is often necessary for effective pain management.

This underscores the importance of accurate pain assessment in order to tailor treatments to the specific needs of each patient. Such an approach not only improves their quality of life but also their healing process.

Understand pain scales.

Definition and objective of the scales

Pain scales are systematic tools designed to identify, quantify, and qualify the pain experienced by patients. Their primary objective is to provide an objective and reproducible measure of pain intensity, thereby enabling healthcare professionals to diagnose, treat, and monitor the effectiveness of pain interventions.

These scales play an essential role in harmonizing care practices, optimizing pain monitoring and ensuring reliable traceability of treatments.

Types of pain scales

There are several types of pain scales, each with its own specific characteristics and uses.

Numerical Rating Scale (NRS)

The numerical rating scale (NRS) is one of the simplest and most commonly used methods. It consists of asking the patient to rate their pain on a scale of 0 to 10, where 0 represents the absence of pain and 10 the maximum imaginable pain. This scale is easy to understand and use, and it is applicable to the majority of patients.

Visual Analog Scale (VAS)

The visual analog scale (VAS) is in the form of a graduated ruler or a 10 cm line. The patient positions a cursor or marks a point on the line to indicate their level of pain, ranging from 0 (no pain) to 100 mm (unbearable pain).

This scale is particularly useful for patients who have difficulty with verbal qualifiers or for those who do not speak the dominant language of the country.

Simple Verbal Scale (SVS)

The Simple Verbal Scale (SVS) is based on a series of adjectives to qualify pain, such as "absent", "mild", "moderate", "intense" and "extremely intense". These qualifiers are then transformed into numerical values ranging from 0 to 4. Easy to understand and use, this scale nevertheless has a limit: the individual variations in the perception of verbal terms.

These different scales offer the possibility of choosing the tool best suited to the patient, taking into account their communication abilities and specific situation.

Self-assessment pain scales

Visual Analog Scale (VAS)

The Visual Analog Scale (VAS) is one of the most reliable and widely used methods for self-assessment of pain. It is in the form of a straight line of 100 mm, with the mention "absence of pain" at one end and "unbearable pain" at the other.

The patient places a mark on this line to indicate the intensity of their pain at a given moment. This scale is simple, reproducible, and sensitive to variations in pain intensity. Developed by Huskisson in 1974, it is particularly appreciated for its ease of use and reliability.

Numerical Rating Scale (NRS)

The Numerical Rating Scale (NRS) is another method commonly used for self-assessment of pain. It consists of asking the patient to rate their pain on a scale of 0 to 10, where 0 represents the absence of pain and 10 the maximum imaginable pain.

Easy to understand and use, this scale is a practical tool for caregivers and patients. It is particularly suitable for situations of acute or post-operative pain, where a rapid assessment is necessary.

Simple Verbal Scale (SVS)

The Simple Verbal Scale (SVS) offers a series of hierarchical qualifiers to describe the intensity of pain. Patients can choose from terms such as "no pain", "mild pain", "moderate pain", and "intense pain".

This scale is often more accessible to patients who have difficulty with abstract concepts or who prefer verbal descriptions. It is also useful for a qualitative assessment of pain.

Hetero-assessment pain scales

Face Legs Activity Cry Consolability (FLACC)

The FLACC scale, which stands for Face, Legs, Activity, Cry, Consolability, is a behavioral measurement tool designed to assess pain in children aged 2 months to 7 years, as well as in people unable to communicate their pain, including intubated adults in intensive care units (ICU). This scale is based on the evaluation of five specific criteria:

• Facial expression: A normal expression or a smile (score 0), a grimace or an occasional frown (score 1), or a constant tremor of the chin and a tight jaw (score 2).
• Legs: Normal or relaxed position (score 0), agitated or tense (score 1), or kicking or folded (score 2).
• Activity: Calm and in normal position (score 0), agitated or writhing (score 1), or arched, rigid or startled (score 2).
• Crying: No crying (score 0), occasional moans or complaints (score 1), or constant crying, screaming, or sobbing (score 2).
• Consolability: Calm and relaxed (score 0), reassured by occasional contact (score 1), or difficult to console (score 2).

Each criterion is rated from 0 to 2, allowing a total score ranging from 0 to 10. This scale is particularly useful in situations where self-assessment of pain is impossible. It is an essential tool for caregivers to better understand and manage pain.

Neonatal Pain and Discomfort Scale (NPDS)

The Newborn Infant Pain and Discomfort Scale (EDIN) is specifically developed to assess pain in newborns. It relies on an analysis of several behavioral and physiological parameters to determine the level of pain experienced.

Criteria evaluated include :

• Facial expression
• Arm and leg movements
• Breathing
• State of alertness

Each criterion is rated according to a specific scale, and the scores obtained are combined to calculate an overall score that reflects the intensity of the pain.

EDIN is particularly useful in neonatal care units where newborns, unable to communicate their pain verbally, require special attention. This tool allows caregivers to effectively identify and manage pain in these vulnerable patients.

Assessing pain in specific populations

Children and pain assessment

Pain assessment in children presents unique challenges due to their cognitive development and their variable ability to communicate. For children under 4 years of age, hetero-evaluation scales, based on observation of behavior, are the most suitable.

Among the commonly used tools is the EVENDOL (EValuation ENfant DOuLeur), which measures pain through five behavioral criteria: vocal or verbal expression, facial expression, movements, positions, and relationship with the environment. This scale is recommended for assessing all pain in children, from birth up to 7 years of age.

For older children, between 4 and 6 years old, the modified faces scale (FPS-R) is often used. This method presents a series of faces illustrating different levels of pain, ranging from a smiling face (no pain) to a crying face (intense pain). Children can then point to the face that best corresponds to their feelings, which greatly facilitates the assessment.

From the age of 6, children are generally able to use more complex self-assessment scales, such as the visual analog scale (VAS) or the numerical scale (NRS). These tools allow them to quantify their pain more precisely and autonomously.

Evaluating pain in elderly, non-communicative patients

Pain assessment in the elderly, especially those who are non-communicative or suffer from verbal communication disorders, requires specific approaches. In these situations, hetero-evaluation scales are often the most appropriate.

Although originally designed for newborns, the Newborn Infant Pain and Discomfort Scale (NIPDS) can serve as a model for assessing pain in non-communicative elderly individuals. However, there are more specific tools adapted to this population. For example, the Behavioral Pain Scale (BPS) allows pain to be assessed through observable behaviors, such as facial expression, limb movements, and vocalizations. This method is valuable for detecting and measuring pain in people unable to express it verbally.

It is essential to consider the specific characteristics of each patient, including their medical history, cognitive status, and communication ability. By adapting the pain scale to their specific needs, we ensure an accurate assessment and appropriate management of their pain.

Integration of pain scales in patient management

Training of healthcare staff in the use of scales

Training of care staff is essential to ensure effective and consistent use of pain scales. Caregivers must be well informed and trained on the different scales available, their advantages and limitations, as well as how to use them appropriately. This training includes both theoretical knowledge of the scales and clinical practices for concrete and effective application.

It is important to raise awareness among healthcare teams about the importance of pain assessment and the need to integrate it into daily care routines, in the same way as measuring pulse, blood pressure, and temperature. The designation of pain specialists, specifically trained, can also be implemented to provide appropriate responses and ensure consistency in the pain management strategy.

The role of pain scales in optimizing treatment

Pain scales play a central role in optimizing treatment. They make it possible to quantify and qualify pain, which is essential for adjusting treatments according to the specific needs of each patient.

By asking the patient to evaluate their current pain, as well as their highest and lowest pain levels in the last 24 hours, caregivers can gain a comprehensive view of the pain's evolution. This allows them to adapt treatments accordingly. The use of pain scales is also a valuable tool for monitoring the effectiveness of treatments and making adjustments if necessary. For example, if a patient reports an increase in pain despite treatment, caregivers can review the therapeutic strategy and modify medications or interventions to improve pain control.

This collaborative approach between the patient and the care team is essential for optimal management. In addition, pain scales are used to determine the intervention threshold, i.e., the level of pain at which specific actions must be taken to relieve the patient. This helps maintain an acceptable level of pain and significantly improve patients' quality of life.

Challenges and limitations of current pain scales

Limitations of self-assessment scales

Pain self-assessment scales, although useful, have significant limitations that can affect their reliability and effectiveness. One of the main difficulties lies in the understanding and use of these tools by some patients. For example, elderly people or those with cognitive impairments may find it difficult to establish a relationship between a numerical rating and the intensity of their pain, especially with the numerical scale.

Moreover, there is a risk of underestimation or overestimation of pain due to various factors. Some patients underestimate their pain for fear of bothering caregivers or because of preconceived notions. Conversely, conditions such as anxiety, hypochondria, or hysteria can lead to overestimation. Older people, in particular, often tend to evaluate the functional consequences of their pain rather than its intensity, which can skew the results.

Sensory disturbances, impaired alertness, coma, aphasia, dementia, and behavioral disorders are all factors that complicate the use of self-assessment tools. Even the simple verbal scale, often considered the most suitable in geriatrics, is not exempt from these limitations.

The search for better evaluation methods

Faced with these limitations, it is imperative to continue to innovate and develop more effective evaluation methods. Technological advances and a better understanding of pain open up promising perspectives. For example, artificial intelligence and machine learning could analyze facial expressions and behavioral signs for a more objective assessment, especially in non-communicative patients.

Furthermore, combining multiple scales and evaluation methods could improve the reliability of the results. For example, the joint use of the visual analog scale (VAS), the numerical scale (NS), and the simple verbal scale (SVS) could offer a more complete view of the intensity of pain experienced. This multimodal approach would overcome the limitations of each scale while providing a more comprehensive assessment.

Ongoing research in this area is essential for designing pain assessment tools that are more sensitive, more specific, and better suited to the diverse needs of patients, regardless of their age or health status.

Conclusion

Pain assessment plays an important role in healthcare, allowing to quantify and effectively manage patient suffering. Pain scales, whether self-assessment or hetero-assessment, are essential tools for healthcare professionals.

It is essential to choose the most appropriate scale for the patient, taking into account their age, health status, and communication abilities. In addition, training healthcare personnel in the use of these tools is essential to ensure accurate assessment and optimal pain management. The limitations of current scales must be recognized, and further research is needed to develop new, more reliable, and accurate assessment methods.

By systematically integrating pain assessment into care routines, we can significantly improve the quality of life for patients and optimize their treatment. It is imperative to take action by adopting these practices in healthcare facilities to provide more personalized and more effective care.

FAQ

What are the pain scales?

The main pain scales include:

• Numerical Rating Scale (NRS): The patient rates their pain on a scale from 0 to 10, where 0 represents no pain and 10 represents the maximum pain imaginable.
• Visual Analog Scale (VAS): A graduated ruler from 0 to 10 cm where the patient places a cursor to indicate their pain level.
• Simple Verbal Scale (SVS): A series of adjectives (absent, mild, moderate, intense, extremely intense) that are converted into numerical values.

What are the 10 levels of pain?

Pain scales are used to assess pain intensity using several methods. Here are the main levels based on the numerical and visual analog scales:

• 0: No pain
• 1-3: Slight pain
• 3-5: Moderate pain
• 5-7: Intense pain
• 7 and above: Very intense or unbearable pain

These levels may vary slightly depending on the scale used, but they provide a common basis for pain assessment.

What is the Visual Analog Scale (VAS)?

The visual analog scale (VAS) is a pain self-assessment tool based on a graduated ruler from 0 to 10. Here's how the pain levels are defined:

• 0-3: Mild pain
• 3-5: Moderate pain
• 5-7: Intense pain
• Greater than 7: Very intense pain

The VAS is simple and reproducible, but it can be difficult for some patients to understand, especially children, the elderly, or the visually impaired.

What are the 10 degrees of pain?

Commonly used pain scales do not precisely define 10 specific degrees, but here are some popular methods:

• Numerical Rating Scale (NRS): Assesses pain from 0 (no pain) to 10 (worst pain imaginable).
• Visual Analog Scale (VAS): A 10 cm line where 0 mm corresponds to no pain and 100 mm to unbearable pain. Values are often converted to millimeters.
• Simple Verbal Scale (SVS): Uses adjectives (absent, mild, moderate, intense, extremely intense) converted into numerical values ranging from 0 to 4.