Hysteroscopic surgery is widely used in clinical practice owing to its advantages such as minimized trauma and improved postoperative recovery. Specific distending medium was used to irrigate the uterine cavity during the operation to form a clear operative field. However, certain problems persist with hysteroscopic surgery. There are numerous types of hysteroscopic surgery, including hysteroscopic endometrial polypectomy, hysteroscopic intrauterine adhesion surgery, and hysteroscopic myomectomy. While most hysteroscopic procedures are very safe, a small number, such as severe endometrial adhesions and uterine fibroids, cause serious complications due to prolonged operation time or a large amount of uterine perfusion fluid, etc. Garry et al. [1] suggested that a large amount of distending medium in hysteroscopic surgery enters the patient’s circulatory system in two ways: absorption in the uterine venous sinus and absorption in the fallopian tube and peritoneal membrane. Marco et al. [2] demonstrated that absorption of large amounts of distending medium can cause diluent hyponatremia and operative hysteroscopy intravascular absorption syndrome (OHIA), which can lead to pulmonary edema, brain edema, heart failure and other complications.

However, James et al. [3] showed that hysteroscopic surgery can help patients with uterine problems, even if it carries some risks. In total, the advantages of hysteroscopic surgery outweigh the disadvantages. Accordingly, reducing the risk of OHIA in patients is worth pursuing. A study by Liao et al. [4] showed that correct diagnosis and treatment play an important role in reducing serious outcomes such as cardiopulmonary complications.

The unipolar energy system is still used for hysteroscopic surgery in certain hospitals. The bulging medium used during surgery is a non-electrolyte solution. The risk of perioperative diluent hyponatremia increases with the duration of the operation. Haruko Okazaki et al. [5] demonstrated that patients undergoing hysteroscopic surgery developed severe hyponatremia, brain edema, and postoperative epilepsy during the operation. Studies have shown that these complications are due to the continuous absorption of distending medium by open blood vessels in the uterus during hysteroscopic surgery. As a result, a large amount of hypotonic perfusion fluid is absorbed. This results in fluid volume overload, diluent hyponatremia, and continuous decrease of plasma colloid osmotic pressure, which, in turn, lead to circulatory dysfunction such as acute pulmonary edema and a series of nervous system dysfunctions such as convulsions and coma [6, 7, 8]. Garry et al. [9] suggest that after a large amount of absorption into the body during hysteroscopic surgery, the concentration of sodium ions in the extracellular fluid and the extracellular osmotic pressure can both be reduced. Cells pump intracellular sodium out of the cell through Na${}^{+}$/K${}^{+}$ -ATPase on the membrane surface to compensate for extracellular low sodium.

Furthermore, Askin et al. [10] showed that the concentration of sodium ions in extracellular fluid and osmotic pressure decreased due to the massive absorption of perfusion fluid during hysteroscopic surgery; tissue cells, in turn, pump intracellular sodium ions out of the cell through the Na${}^{+}$/K${}^{+}$ -ATPase on the membrane surface to compensate for the decrease of osmotic pressure of extracellular fluid, thus alleviating the swelling of cells. When the compensatory capacity of the body is exceeded, it leads to hyponatremia, which can have a severe impact on the body.

Acute hyponatremia [11] can cause central neuropathy, which can lead to epilepsy and encephalopathy. In addition, there are symptomatic cases starting 24 hours after surgery, when the patient has usually been discharged from the hospital [12]; the potential for risk in here is self-evident.

With the development of technology, the use of bipolar energy system for hysteroscopic surgery and the use of saline for distending medium can reduce the risk of nonelectrolytes entering the body during surgery and causing diluent hyponatremia. However, prolonged operation time and increased fluid intake during operation may bring about hypervolemia [13], leading to OHIA during hysteroscopic surgery. OHIA refers to a series of complications caused by fluid overload due to hysteroscopic surgery, such as pulmonary edema and heart failure. Ming-Tse Wang et al. [14] demonstrated that although many rules of hysteroscopic surgery have been formulated and followed, the incidence of increased circulating blood volume caused by hemodilution still exists in hysteroscopic surgery. Excessive fluid intake during surgery can cause fluid overload in the body. It has been reported that even if bipolar electrodes are used to reduce the intrauterine pressure as much as possible, OHIA may still occur during hysteroscopic surgery [15].

The influence of dilatant fluid temperature on body temperature during hysteroscopic surgery is also an important area of concern. Body temperature is a key indicator of the human body, and body temperature regulation is one of the body’s primary regulatory mechanisms. Numerous factors cause perianesthesia hypothermia, including the influence of anesthetic drugs on thermoregulation, the excessively low ambient temperature in the operating room. Perioperative hypothermia can lead to surgical site infection, increased intraoperative bleeding, adverse cardiac events, postoperative shivering, and prolonged hospital stay. Bay et al. [16] studied body temperature, oxygen consumption and cardiac output of 24 patients with postoperative shivering and those without shivering 20 minutes following the operation. They found that postoperative shivering increased the body’s oxygen consumption, leading to an increased probability of myocardial ischemia and myocardial infarction in elderly and other high-risk patients. Through multivariate analysis of 100 patients, Frank et al. [17] associated perioperative hypothermia with myocardial complications. The study showed that patients with hypothermia had an increased probability of myocardial ischemia and ventricular arrhythmias. Evidently, hypothermia is associated with the development of heart disease.

Hypothermia can also affect a patient’s ability to clot blood and increase the risk of bleeding. Schmied et al. [18] studied the amount of blood loss during hip surgery in 60 patients under normal temperature and mild hypothermia. The study found that core cold temperatures of just 1.6 °C increased blood loss by 500 mL (30%) and significantly increased the risk of allogeneic blood transfusion. At the same time, hypothermia can increase the risk of postoperative infection by inducing thermoregulation of vasoconstriction [19] and reducing the body’s immune function [20], thus increasing the risk of postoperative infection.

Hypothermia can also cause a delay in waking up. Sessler et al. [21] showed that enzymes regulating organ functions and metabolizing drugs are highly sensitive to temperature. Low temperature can alter the pharmacodynamics of many drugs, especially volatile anesthetics. Haier T et al. [22] compared the effects of normal temperature and mild low temperature on vecuronium and recovery time. They found that hypothermia can prolong the action time of muscle relaxants. Likewise, Bansinath et al. [23] compared dogs’ personality and cardiovascular responses at different temperatures and showed that hypothermia can reduce the clearance rate of drugs.

It is imperative to determine and develop ways of offsetting the deleterious effects of OHIA during surgery. Proven methods include warming the distending medium, using as low pressure as possible, shortening the operating time, using narrow hysteroscopes that have lower flow, and using bipolar hystereoscopes, if possible. At the same time, it is crucial to explore the appropriate temperature of perfusion fluid, master advanced monitoring methods, popularize advanced surgical energy and perfusion systems, and improve the surgical team’s understanding as well as diagnosis and treatment of complications in hysteroscopic surgery.

XC—extraction, drafting, design, revision manuscript; XD—extraction manuscript. All authors read and approved the final manuscript.

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This study was supported by Beijing Xicheng District Health Commission Young Science and Technology Talents (Science and Technology Nova) Training Program (#XWKX2022-21).

The authors declare no conflicts of interest.