OHIA syndrome was initially described in 1993 [10] and to date, fewer than 30 cases have been reported worldwide [11]. The appearance of OHIA syndrome is attributed to increased fluid absorption, which is influenced by various factors such as the duration of surgery, flushing fluid pressure, tumor size and depth, and the presence of false passages or cervical tears [12]. Rapid absorption of all types of fluid media can lead to systemic circulation dilation, resulting in complications such as pulmonary edema and heart failure [13]. In comparison to hypotonic electrolyte-free solutions, isotonic electrolyte solutions are safer dilution fluids. They help minimize the risk of hyponatremia, which can lead to severe brain edema [14]. However, it does not eliminate the risk of congestive cardiac failure and pulmonary edema resulting from excessive fluid absorption. Severe pulmonary edema can lead to systemic tissue edema, throat edema, heart failure, brain edema, and more [1].

In our case, the patient underwent a hysteroscopic myomectomy with NS used as the irrigation medium, and developed hypoxemia and hypokalemia. She also exhibited signs suggestive of pulmonary edema caused by excessive fluid overload, such as a decrease in SpO2, PETCO2, and PO2 levels. Actually, there was a drop in blood pressure of patient since the OHIA syndrome happend. Blood pressure results from the product of the volume of blood ejected by the heart into the arteries (namely, cardiac output) and systemic vascular resistance [15]. During surgery, the patients may experience fluid overload due to fluid absorption, leading to an increase in cardiac afterload and the potential development of heart failure as a consequence of untreated hypertension. Post-anesthesia, peripheral vessels were in a relaxed state with insufficient vascular tension. Cardiac dysfunction resulting in decreased cardiac output, low vascular tone, and increased volume all contribute to a decrease in pressure.

Early diagnosis and treatment of fluid overload can reduce hospitalization rates and slow the progression of heart failure. However, as previously mentioned, early detection of symptoms may be challenging or nearly impossible while the patient is under general anesthesia and unable to communicate any discomfort. According to the guidelines, in order to prevent complications resulting from fluid overload, it is recommended that the surgical team maintain a running balance every 10 min and at the end of each use of the fluid bag [13]. However, accurate fluid monitoring can be challenging in open systems where fluid can escape through various channels, making monitoring inaccurate or impossible.

Real-time monitoring of oxygenation status and electrolytes can be achieved through ABG analysis, although this method is time-consuming and invasive. It is important to note that the risk of fluid absorption cannot be solely judged by the plasma sodium ion content when NS used as the irrigation medium. Hemoglobin levels may decrease due to the dilution of NS, and plasma potassium and calcium ions can also be used as observation indexes. In our case, we observed that the sodium ion content in the plasma did not show any significant fluctuations following the administration of NS. But this did lead to the development of hypoxemia, hypokalemia, and dilutional anemia.

It is important to note that we utilized ultrasound to monitor the patient’s lung in our case. At the first decrease in oxygen saturation (from 99 to 95%), we detected the B-lines through pulmonary ultrasound when there was no obvious hemodynamic change was observed. We strongly suspect that there has been a liquid overload at this time. To further support this diagnosis, we have conducted an ABG analysis. Pulmonary ultrasound plays a vital role in detecting early signs of pulmonary edema resulting from fluid overload. This early identification is essential for ensuring prompt and precise treatment.

For many years, ultrasound technology was considered ineffective for imaging the lungs due to the scattering of sound waves by air, hindering accurate transmission. However, the discovery of B-lines has revolutionized the use of ultrasound for monitoring and diagnosing pulmonary edema. Recent advancements in lung ultrasound technology have revealed that diffuse white lung is an early ultrasonic characteristic of acute pulmonary edema. Real-time monitoring of B-lines can guide fluid resuscitation treatment for critically ill patients [16]. Studies have shown a strong correlation between B-lines artifacts and increased extravascular lung water (EVLW), a clinical indicator of pulmonary edema. Lung ultrasound has demonstrated high accuracy in comparison to CT [8] scans and PiCCO monitoring [17]. B-lines can even be detected in the early stages of pulmonary edema before functional injury occurs [18]. Additionally, the correlation between the number of B-lines, and clinical pulmonary edema is well-established, with quantitative algorithms based on B-line counts expected to provide a valuable clinical tool for evaluating pulmonary edema [19].

Lung ultrasonography is highly accurate and radiation-free, making it a preferable option over chest X-rays or CT scans for daily patient management [20]. It aids in the diagnosis and monitoring of pulmonary diseases in diverse clinical scenarios. In our case, we were unable to promptly transfer a patient for a chest X-ray examination in the surgery, however, lung ultrasound has played a crucial role in our ability to detect pulmonary lesions early on. The arterial gas analysis and SpO2 levels revealed a problem with oxygen exchange, which correlated with the elevated B-lines identified through lung ultrasonography. This result further supports the diagnostic value of pulmonary ultrasound in detecting pulmonary edema in hysteroscopic surgery, even in the absence of pulmonary rales and other clinical symptoms.

Early diagnosis is crucial for effective clinical treatment, while early intervention plays a key role in determining clinical prognosis. Treatment typically involves fluid restriction, diuretics, and close monitoring. The treatment approach depends on the symptoms and severity of the condition. If the patient presents volume overload, the focus of treatment will be on optimising respiratory status through measures such as supplemental oxygen, non-invasive positive pressure ventilation or intubation, as necessary. Additionally, correction of hypervolemia will be achieved by using a loop diuretic. On the other hand, in this case, despite adequate airway and respiratory support being achieved, IV fluids prompted congestion, which improved after negative fluid balance.

In the particular case, we encountered challenges in accurately measuring fluid deficit within an open system. For women with known cardiovascular disease, adapting to sudden significant increases in intravascular fluid can be difficult, increasing the likelihood of complications even at lower levels of fluid deficiency [21]. During surgery, the patient may experience fluid overload, increased cardiac afterload, and the potential for heart failure as a result of untreated hypertension. To address these concerns, we implemented strategies to manage fluid levels during the perioperative period. By restricting intravenous fluids and administering diuretics, we were able to reduce the risk of fluid overload and buy time for subsequent treatments. In our clinical practice, we have observed the benefits of administering furosemide preventively within 30 min of surgery while this method falls under empirical administration and has not been compared to other approaches, there are similar recommendations in the existing literature [11]. By administering preventive medication, we have seen a reduction in clinical symptoms and an improvement in the overall surgical process. In the meantime, it is better to stop the procedure before a potential life-threatening for the patient.