Clinical validation of the nursing diagnostic proposition perioperative thirst

Objective: to verify the clinical validity of the proposition of a new nursing diagnosis called perioperative thirst, based on the diagnostic accuracy of its clinical indicators, including the magnitude of effect of its etiological factors. Method: clinical diagnostic validation study with a total of 150 surgical patients at a university hospital. Sociodemographic variables and clinical indicators related to thirst were collected. The latent class analysis technique was used. Results: two models of latent classes were proposed for the defining characteristics. The model adjusted preoperatively included: dry lips, thick saliva, thick tongue, desire to drink water, caregiver report, dry throat and constant swallowing of saliva. In the postoperative period: dry throat, thick saliva, thick tongue, constant swallowing of saliva, desire to drink water, bad taste in the mouth. The factors related to “high ambient temperature” and “dry mouth” are associated with the presence of thirst, as well as the associated conditions “use of anticholinergics” and “intubation”. The prevalence of thirst was 62.6% in the pre and 50.2% in the immediate postoperative period. Conclusion: the diagnostic proposition of perioperative thirst showed good accuracy parameters for its clinical indicators and etiological effects. This proposition in a nursing taxonomy will allow greater visibility, appreciation and treatment of this symptom.


Introduction
Perioperative thirst is a sensory, physiological and subjective experience that refers to the desire to drink water in order to restore body fluid homeostasis, generating intense discomfort when not attended to (1)(2)(3)(4)(5) .
In a scenario where the prevalence of thirst is high, ranging from 79.5% (6) to 89.8% (7) in adults, reaching more than 80% in pediatric patients at different levels of intensity (8) , the intentional inclusion of this discomfort in nursing monitoring becomes relevant and urgent (2,7,9) .
Thirst negatively influences the surgical experience and its presence is pressing and imperative. It is one of the main discomforts mentioned in this period, both in the current experience and in the memory of discomforts from previous surgeries, and it can be even worse than pain (10)(11)(12) . Despite this, many professionals believe that thirst is a consequence of the surgical procedure and must be tolerated by the patient. Therefore, taking care of thirst is still undervalued, underassessed, undermeasured and undertreated by the nursing team (7,10,13) .
Other discomforts and complications relevant to the surgical patient are widely researched and included in clinical protocols, directing their care. However, the clinical relevance of thirst is often minimized when compared to other discomforts and its management is still not carried out in a systematic way (2,7,10) .
Considering this scenario, Brazilian researchers developed a Thirst Management Model, which is composed of four pillars: Identification, Measurement, Safety Assessment and Administration of a thirst relief strategy (2) . This model, when used with the surgical patient in the pre and immediate postoperative period (IPP), allows the team to carry out adequate, safe, and effective management of this discomfort.
By including thirst management in nursing care, it is expected that the patient can have his thirst diagnosed and relief measures applied in a systematic and standardized way. This care allows the patient to have a surgical experience with the least possible suffering, optimizing his recovery and actively improving the quality of care provided (2,7,10) .
One way to emphasize its importance would be to incorporate thirst in international classifications and terminologies, highlighting its main signs and symptoms, as well as its possible causal factors. In this context, the NANDA International taxonomy of nursing diagnoses (NANDA-I) presents an organization of diagnoses that incorporates these elements and has been used in several countries, in addition to serving as a starting point for the development of other nursing terminologies and classifications (14) . Historically, the development of a new diagnosis follows concept and content analysis, culminating in clinical validation.
It is in this context that the proposition of the nursing diagnosis (ND) for perioperative thirst is based.
In the daily care provided by the nursing team, thirst is frequently observed and must have its standardized management. Including perioperative thirst in the nursing diagnostic taxonomy will allow the surgical patient's thirst to be identified and treated.
This proposition has already been evaluated in relation to the concept analysis (3) and its content (4) , with the definition: "Sensory, physiological and subjective experience that refers to the desire to drink water in order to restore the homeostasis of body fluids, generating intense discomfort when not attended to". Homeostatic and non-homeostatic mechanisms participate in the genesis and satiety of thirst and resulting in a diagnostic framework composed of nine defining characteristics: dry mouth, dry throat, dry lips, thick saliva, thick tongue, constant swallowing of saliva, desire to drink water, bad taste in the mouth, caregiver report. The resulting related factors (RF) were: pre-and postoperative fasting, mouth breathing, dehydration, hypovolemia, insensible loss of hydration through breathing, dry mouth, habit of drinking water, high ambient temperature. The

Study design
Clinical validation study of the proposition of the ND "Perioperative Thirst" in two moments (pre-and immediate postoperative period).

Setting and period
The study was carried out in the Post Anesthesia

Population and selection criteria
The study population consisted of patients who underwent elective and urgent surgical procedures.
As inclusion criteria, were stipulated patients aged at least 12 years old and who, when asked about their orientation in time and space, responded assertively. As exclusion criteria, those who were unable to respond to the guidance questions in the IPP and those who were transferred while still on mechanical ventilation to the Intensive Care Unit (ICU).

Sample definition
For the sample calculation, the proposed recommendations were observed for carrying out diagnostic accuracy studies through latent class analysis, in which 5 to 30 patients are indicated for each clinical indicator (15) . In this study, 16 patients were chosen for each defining characteristic (DC) (4) , resulting in 150 patients. Consecutive convenience sampling was used, in which patients were included as they were admitted to the operating room.

Study variables
The sociodemographic variables were: age, gender, skin color, education, weight, height. Variables related to the surgical procedure and site were considered: surgical specialty, scheduling modality, physical status assessment by the American Society of Anesthesiologists, fasting time, bleeding reported in the operative description by the surgeon and anesthesiologist, measurement of thirst intensity by verbal scale numeric (zero, no thirst, to ten, worst possible thirst) and thirst discomfort using the Perioperative Thirst Discomfort Scale (EDESP), an instrument constructed and validated for the Brazilian population, which assesses seven items related to thirst, resulting in an intensity score from zero to 14 (16) and measurement of thirst intensity.
The variables referring to the ND components were evaluated and recorded as absent or present. The operational definitions (3)(4) can be seen in Figure 1.

Dry mouth
The patient is asked to open the mouth and stick out the tongue. Evidence of any apparent dryness, such as dry, sticky mucous membrane, frothy or sticky saliva, or no visible saliva, whitish appearance, or bleeding spots is evaluated. Complement your assessment by questioning the patients about their current perception of dryness in the mouth, comparing it with a condition in which he considers normal moisture in the mouth. Conclusion: If one or two evaluated conditions were met, the patient has a dry mouth.
Dry throat Ask the patient to open his mouth. Assess the absence of moisture in the distal portion of the mouth with the aid of a flashlight. Complement your assessment by questioning the patients about their current perception of throat dryness, burning sensation, throat discomfort such as "scratching", compared to a condition in which he considers throat moisture normal. Rev. Latino-Am. Enfermagem 2023;31:e3975.

Constant swallowing of saliva
Observe the swallowing movements. Actions of constant movement of the tongue in search of saliva, followed by an attempt to swallow. Supplement your assessment by asking the patients if they are trying to swallow saliva to moisten their throat. Conclusion: If the patients have one or more of the evaluated characteristics, they have constant swallowing of saliva.
Desire to drink water Patient verbalizes the desire to drink water. Ask the patient if he feels like drinking water. Conclusion: If the patient responds affirmatively, consider this feature to be present.
Bad taste in the mouth Ask the patient if he has a bad taste in his mouth. Conclusion: If the patient responds affirmatively, consider this feature to be present.
Caregiver's report The caregiver reports that the patient has signs that indicate that he is thirsty. Ask the caregiver or family member about the presence of signs that indicate that the patient is thirsty. Conclusion: If the caregiver answers in the affirmative, consider this characteristic to be present. Additionally, write down what characteristics he observed.

Related Factor Operational Definition
Pre-and post-operative fasting Evaluate the time the patient has been without ingesting solid foods and liquids. Ask the patient when his last intake of solid food and liquids was.
Oral breathing Ask the patient to take a deep breath and watch for mouth breathing. He may have his mouth slightly open while breathing. Check for nasal obstruction.

Dehydration
Note the presence of dry mucous membranes, decreased salivary flow, decreased skin turgor, decreased urinary frequency.
-Dry mucous membranes: The patient is asked to open his mouth and stick out his tongue. Evidence of any apparent dryness, such as dry, sticky mucosa, frothy or sticky saliva, or absence of visible saliva, is evaluated. To complement the assessment, the patient should be asked about his current perception of dryness in the mouth, comparing it with a condition in which he considers that the moisture in the mouth is normal.
-Skin turgor: Make a fold on the back of the patient's hand and observe the formation and maintenance of a skin fold.
If the fold continues after the evaluator's hand is removed, it is deduced that the skin turgor is reduced.

-Evaluate fasting time -Water balance, if any -Assess blood loss -Water replacement In children
Observe signs of dehydration in the child, such as: fatigue, dry mucous membranes, dry lips, return of the abdominal skinfold for more than 2 seconds, crying without tears, irritability, sunken eyes. Note fontanelles. Ask the caregiver about changes in the child related to dehydration (skin turgor, fontanelles, general aspects).

Insensible loss of moisture from respiration
In the postoperative period: Evaluate the inhalational anesthetic procedure and the use of oxygen supplementation by nasal catheter or mask without humidification.

Hypovolemia
Evaluate the description of bleeding during the surgical procedure or in the postoperative period. Check for hypotension, sweating, tachycardia, and other signs of shock. Anesthetic procedure: Use of spinal anesthesia results in vasodilation caused by sympathetic blockade. Agents employed in general anesthesia initially decrease the body's ability to perform vasoconstriction. Write down which anesthetic procedure was used. Hypotension: Check blood pressure. Compare the current pressure with the preoperative baseline pressure: if it is 20% lower than the baseline pressure, the patient can be considered hypotensive.
Heart rate: Check heart rate by palpating and counting the radial pulse. The patient will be tachycardic if the observed value is equal to or greater than 100 beats per minute.

Associated Conditions Operational Definition
Intubation Assess whether there was endotracheal intubation during the anesthetic procedure. Was there orotracheal intubation? What is the duration of the anesthetic procedure? -Beginning of the anesthetic procedure: -End of the anesthetic procedure: Water restriction Evaluate the existence of restriction of intake or infusion of liquids according to the patient's report or in the medical record. Evaluate in the medical record or the patient's report the existence of restriction of fluid intake or infusion.

Use of muscarinic and nicotinic anticholinergics
Assess whether anticholinergics were used during the anesthetic-surgical procedure. Anticholinergic drugs: atropine, biperiden, benactizine, buscopan, dicyclomine, homatropine, ipratropium, trihexaphenid, tropicamide In the IPP, if the patient was unconscious, drowsy or disoriented, the assessment was postponed for the next 15 minutes, until the orientation conditions were adequate.
To assess them, the following questions were asked based on the Orientation item of the Montreal Cognitive Assessment (MoCA) (17) : What is your name? Where are you at this moment? What day is today? Which surgery did you perform?
After data collection, management of the patient's thirst was carried out according to the practice of the institution (2) .

Data analysis
Data were entered into a Microsoft Excel 2016 spreadsheet and analyzed using the statistical software R version 3.6.1. The analysis of latent classes, as well as the presentation of accuracy measures such as sensitivity and specificity (15) , were carried out with the aid of the "poLCA" and "randomLCA" (18) packages.    The RF that showed a significant association with the presence of thirst in the preoperative period were high ambient temperature and dry mouth. Having a dry mouth increased the chances of being thirsty by 37.72 and the ambient temperature increased by 3.60 times.
No AC showed significance with the presence of thirst in the preoperative period. In the IPP, the RF Dry mouth was associated with the presence of thirst, increasing the chances of being thirsty by 28.20. The AC Use of anticholinergics and Intubation showed a significant association with the presence of thirst, increasing the chances of the patient being thirsty by 2.64 and 4.03, respectively (Table 4).

Discussion
The Perioperative thirst is an intense and highly prevalent perioperative discomfort (6)(7)9,(19)(20) . The literature reveals the recent interest in this topic in the nursing community, with its management being structured in the identification, measurement, safety assessment for carrying out interventions and the application of relief strategies (2,21) .
The intensity and discomfort of thirst are high.
Five characteristics had frequencies greater than 50% in the preoperative period, with the DC Dry mouth and Dry lips being the highest incidences. In the IPP, seven of the nine DCs had an incidence greater than 50%, again highlighting the DC Dry mouth and Dry lips with the highest occurrences. The study of the characteristics related to perioperative thirst is important, as they are also linked to the perception of the intensity and discomfort of thirst for the patient (16,20) .
The pre-and postoperative fasting time was the RF present in the entire sample studied. Fasting is part of the guidelines to ensure the safety of the anestheticsurgical procedure, with a time of up to two hours being recommended for clear liquids (23) , with evidence showing improvement in the patient's experience and reduction of discomforts, including thirst (9) . Nevertheless, it is identified that the implementation of adequate fasting times in clinical practice is challenging, even in institutions that aim to implement multimodal protocols (9) . The RF Dehydration, Insensible loss of hydration and Hypovolemia were observed in the IPP.
Dry mouth refers to dryness or lack of moisture in the oral cavity, caused by a decrease or absence of salivary flow. The reduction in salivary flow decreases the lubrication of the oral cavity, leading to the perception of roughness. It has a high prevalence in surgical patients, ranging from 69.2% (20) to 87.3% (13) .
The DC Dry throat and Constant saliva swallowing presented better accuracy performance and were reported by patients with thirst in the perioperative period (25)(26)(27) .
Swallowing saliva is one of the main strategies used by the patient in an attempt to relieve thirst, and can be performed through the administration of artificial components or mechanically or chemically stimulated by chewing gum (28) .
This finding corroborates research related to the neurophysiology of thirst and its relief. Swallowing movements (tongue protrusion, sensations from the tongue and swallowing) are linked to thirst relief, by anticipatory mechanisms related to pre-absorptive satiety (1) . The use of perioperative thirst relief strategies is based on this mechanism (2,21,(29)(30)(31) .
The DC Bad taste in the mouth refers to an unpleasant taste and may be related to preoperative fasting time, or the use of medication during the anesthetic-surgical procedure. The sensation of a bad taste in the mouth is frequently reported by surgical patients and is associated with the presence of thirst (27,32) .
The dry mouth item was removed from the DC because, despite this characteristic being the most frequent in the studied sample, it is significantly linked to factors that cause thirst, assuming an etiological nature.
Dry mouth is an important stimulus for fluid intake, which is caused by states of dehydration, medication actions or other causes (1,33) . Some hypotheses were raised by the authors as to why dry mouth did not present a good fit in the two models. A simple explanation is the sample size Defining characteristics are observable indicators/ inferences that are grouped together as manifestations of a diagnosis (14) . It is important to emphasize that not all clinical indicators are essential for attributing a diagnosis. Each of the indicators presents different gradients of commitment to the diagnosis and may be present or absent depending on the clinical spectrum of the diagnosis (34) .
Fasting is one of the main factors related to perioperative thirst. The mean number of fasting hours was 13:10 (±5:11) hours, a value higher than the time recommended by clinical evidence (23) . Excessive fasting time and its repercussions for the surgical patient are widely discussed in the medical literature, as well as the difficulty in adopting shorter times in clinical practice (5,9,19,35) .
Associated conditions refer to medical diagnoses, surgical procedures, prescription of pharmaceutical agents that are not modifiable independently by the professional nurse (14) . The AC Use of anticholinergics and Intubation are significantly associated with the presence of thirst, a fact explained by signs of dryness of structures in the oral cavity (1,7,19,35) .
A study that presented the risk factors for thirst, observed that the use of glycopyrrolate -an anticholinergic drug used to reduce saliva secretion -was the main risk factor for moderate to severe thirst in the IPP in the PACU (71.7% versus 66.4%, p = 0.047; adjusted odds ratio: 1.46, p = 0.013). This study demonstrates that anticholinergics are related to the presence and intensity of thirst in patients in the IPP (7) .
As a limitation of the study, the accuracy analyzes