This study represents the inaugural exploration into the occurrence rate and risk factors of post-extubation thirst among general anesthesia patients. Due to increased osmolarity or decreased plasma volume, surgical patients often experience thirst during the perioperative period. In this study, the occurrence rate of thirst following extubation in general anesthesia patients was found to be 50.9%. Among the graded levels of thirst, 71.4% of patients reported mild thirst, 23.0% moderate thirst, and 5.6% severe thirst. Statistical analysis was conducted on suspected risk factors among the enrolled cases. Univariate analysis identified 7 factors that influence the occurrence of post-extubation thirst in general anesthesia patients, namely, gender, history of coronary heart disease, surgery duration, intraoperative fluid infusion volume, intraoperative blood loss, intraoperative urine output, and different surgical departments. Binary logistic regression analysis revealed that age, gender, history of coronary heart disease, preoperative fasting duration, and intraoperative fluid infusion volume were independent risk factors for post-extubation thirst in general anesthesia patients. Among these, age, gender, history of coronary heart disease, and intraoperative fluid infusion volume were also identified as risk factors for different levels of thirst.

a physiological perspective, the sensation of thirst primarily arises due to decreased fluid volume and increased concentration of osmotically active particles (osmolarity) [20]. An elevation in the concentration of solutes, including sodium, glucose, and other small particles, increases osmolarity. In males, the stimulation of red blood cell growth and development by male hormones leads to a higher red blood cell count and higher hematocrit compared to females, indirectly affecting blood viscosity and resulting in higher blood viscosity indices in males than in females. Hence, it is worth investigating whether male patients are relatively osmotically active compared to female patients. Currently, there is no relevant research on this, warranting further exploration of the relationship between the two. Cardiovascular diseases often entail changes in hemodynamics and hemorheological parameters (plasma viscosity, whole blood high shear viscosity, whole blood low shear viscosity, hematocrit, fibrinogen). Among these, blood viscosity is a crucial hemorheological parameter. Patients with cardiovascular diseases experience changes due to long-term accumulation of pathological characteristics, necessitating reductions in cardiac circulatory load, constraints on fluid intake, and maintenance of negative fluid balance, ultimately leading to increased plasma osmolarity. When plasma osmolarity rises, cells undergo dehydration, which subsequently raises blood viscosity and frequently exacerbates symptoms of thirst and dry mouth.

High osmolarity and low blood volume result from pathological and physiological factors, preoperative fasting, and perioperative fluid loss. Fasting stimulates hypothalamic osmoreceptors and the thirst center through mechanisms including water loss, reduced blood glucose levels, and depletion of extracellular fluid. Thirst arises when stimulation of the hypothalamic satiety center decreases while stimulation of the feeding center increases [21]. Dilmen et al.‘s study [22] found that preoperative carbohydrate intake, which shortens fasting time, had a positive effect on postoperative thirst, aligning with the conclusions of this study.

Fitzsimons’ study [23] revealed that experimental animals consumed more water when subjected to peritoneal dialysis or blood withdrawal, reducing fluid volume without altering plasma osmolarity. This indicates that decreased plasma volume stimulates the thirst center, generating a sense of thirst and prompting increased water intake [24]. Clinically, hemodynamically unstable patients are often characterized by low blood volume [25]. A meta-analysis [26] concerning the use of hydroxyethyl starch in surgery demonstrated that compared to crystalloids alone, the use of hydroxyethyl starch improved hemodynamic stability and reduced the need for vasopressors (P < 0.001). This implies that hydroxyethyl starch compensates for hemodynamic instability due to low blood volume. Consequently, the higher risk of thirst occurrence associated with supplementing patients with crystalloids and colloids in our study may be attributed to the possible hemodynamic instability induced by colloids. These patients might have experienced insufficient blood volume before surgery. Of course, this conjecture necessitates the exclusion of premises such as the presence of preoperative hypertension and poor vascular elasticity to definitively establish that insufficient blood volume causes hemodynamic instability in patients.

Over the past 20 years, the concept of Enhanced Recovery After Surgery (ERAS) has rapidly and comprehensively developed since its introduction [27]. ERAS aims to apply evidence-based, multi-modal optimization protocols through interdisciplinary collaboration, with innovative minimally invasive surgical techniques as the core, to reduce perioperative futile and ineffective medical interventions, stress responses, organ dysfunction, and related complications. We now anticipate not only successful surgery, reduced operation time, minimal incisions, and postoperative pain, but also a more comfortable perioperative experience based on ERAS principles. Shortening patient recovery time, increasing bed turnover rate, improving medical resource utilization efficiency, and alleviating the burden on healthcare insurance are the ultimate goals [28,29,30].

Up to now, most research on alleviating postoperative thirst has occurred abroad, with relatively little attention in China. The related interventions are relatively simple and non-invasive. It is necessary to intervene in controllable risk factors to reduce the occurrence of postoperative thirst. This study employs thirst as a diagnostic label, aiming to raise awareness among scholars about the high incidence of postoperative thirst and its significant impact on postoperative complications. The goal is to shift the focus towards solving the issue of postoperative thirst and devising relief strategies for high-risk patients.

However, this study has certain limitations. Firstly, the assessment of thirst primarily relies on patients’ subjective feelings without supplementation from relevant scales such as resting salivary flow rate, leading to a positive bias. Secondly, the lack of physiological data such as central venous pressure (CVP) and osmolarity may have affected the accuracy of the analysis. Thirdly, the study subjects were all from the same tertiary comprehensive hospital, lacking external validation. Future research should incorporate data from multiple centers to obtain a more representative sample, thus addressing the root cause to alleviate the degree of thirst and improve postoperative complications.