Hybrid Blood Purification in the Treatment of Multiple Organ Dysfunction Syndrome Following a Wasp Attack

Wasp stings are hazardous for farmers and others engaged in outdoor work or leisure in rural tropical regions. Frequent incidents of severe wasp stings have recently been reported in China, causing considerable mortality and serious public health problems. Multiple wasp stings can cause multiple organ dysfunction syndrome (MODS); however, MODS is a rare phenomenon. Physicians may be the first contact point for patients with wasp stings. Physicians must be aware of the most appropriate approaches to treatment to prevent death or permanent organ damage. Here, we report a case of MODS that involved rhabdomyolysis, acute renal failure, intravascular hemolysis, liver injury, myocardial injury, coagulopathy, respiratory failure, and nervous system damage due to multiple wasp stings. This case report may help inform clinicians managing patients with complications resulting from mass wasp stings.

Informed consent for publication was obtained from the patient and the hospital’s ethics committee.

A 77-y-old male farmer was admitted to our hospital’s nephrology department following a wasp attack while working in a field. Overall, 106 stings were identified on the head, back, and arms. His presenting symptoms included headache, palpitations, nausea, vomiting, and slightly blurred vision. He had initially been taken to a local community health hospital where he received intravenous fluids (approximately 2000 mL) and antihistamine medication. However, his symptoms worsened, and on the day after hospital admission, his urine was dark brown; thus, he was referred to our hospital. The patient had no prior medical history and was conscious on admission. On examination, the patient was tachycardic (heart rate, 130 beats·min⁻¹), with a blood pressure of 166/98 mm Hg, a finger pulse oximetry of 90%, yellowish discoloration of the sclera, and swollen head, face, and limbs. The sting lesions were black with central necrosis (Figure 1). His urine was dark brown to black (Figure 2). Urinalysis results showed 2+ proteinuria and hematuria, and his daily urine output was <400 mL. Laboratory test results indicated severe acute hepatitis, acute myocardial damage, acute renal failure, thrombocytopenia, coagulopathy, and rhabdomyolysis (Table 1).

On admission, oxygen was administered based on the finger pulse oximetry of 90%, and he underwent an electrocardiogram. Electrocardiogram results showed sinus rhythm and ST-T changes (Figure 3). However, the patient had no previous history of heart disease or hypertension and usually did not have specific symptoms such as chest tightness, chest pain, and syncope, among others. A cardiologist was consulted, and it was considered that the wasp stings caused acute myocardial injury. The patient received no special cardiac drug treatment, and as his condition improved, his troponin level fell to the normal range on the 11th day of admission. His head was shaved, all the venom sacs were carefully removed, and each lesion was washed with normal saline. He was administered oral Chinese medicine, which was also applied to each wound. Because of patent protection, the precise ingredients of this Chinese medicine are unknown. It it known by the name “Jidesheng snake tablet.” In China, it is often used in patients stung by wasps and bitten by snakes to reduce wound edema. We did not observe any adverse reactions or evidenced benefit from this traditional Chinese medicine, and it did not complicate the management of our patient.

After rehydration (1000 mL of 0.9% sodium chloride solution within 30 min), we administered the following medications: furosemide (20 mg) via an intravenous bolus, 5% sodium bicarbonate for urine alkalization, methylprednisolone for an anti-inflammatory response (120 mg once a day, then 80 mg after 3 d, 40 mg after 6 d, 20 mg after 10 d, and stopped completely after 15 d), red blood cell suspension and platelet infusion for blood product replacement and support, and polyene phosphatidylcholine to reduce liver transaminases. Following consent provided by the patient’s relatives, a tube was inserted into the right femoral vein, and continuous renal replacement therapy (CRRT) was started as continuous venovenous hemofiltration combined with hemoperfusion (HP) and plasma exchange (PE), with a replacement volume of 2000 mL each round. CRRT was performed for 112 h, and 4 rounds of HP and 6 rounds of PE were performed. On Day 2, the patient became increasingly agitated, removed the right femoral vein catheter, and became unconscious. Pressure was immediately applied to the catheter puncture site to regain hemostasis, CRRT was temporarily suspended, diazepam was administered for sedation, and the left femoral vein was catheterized. Following vein catheterization, CRRT was restarted.Over the next few days, the patient remained unconscious. His blood pressure dropped to 75/51 mm Hg, his finger pulse oximetry dropped to 75%, and his pupils showed anisocoria. He underwent a head computed tomography scan and blood gas analysis, and no abnormalities were observed. Fluids were administered with dopamine to maintain his blood pressure. At this stage, he was dyspneic, and obvious moist rales could be heard in both lungs. Despite increasing the oxygen inhalation concentration, the patient’s fingertip oxygen saturation remained low, and the dyspnea remained unresolved. Therefore, mechanical ventilation in the high acuity intensive care unit was recommended; however, his family did not consent. Oxygen administration via mask and 3 combined blood purification treatments (CRRT + HP + PE) were continued. During this treatment, the patient developed black stools, which were positive for occult blood, and his hemoglobin decreased significantly to 44 g·L⁻¹. This prompted the administration of proton pump inhibitors, fresh plasma, and 2 units of packed red blood cells. Approximately 1 wk later, the patient was less agitated, responded to personal questions, and his blood pressure returned to normal. The CRRT was stopped, and he underwent 3 sessions of intermittent hemodialysis. On Day 10, his urine output increased to 1500 mL per day. On Day 17, his blood creatinine level decreased remarkably and his urine output reached 4000 mL daily; he was conscious and responsive to personal questions. He appeared less restless and irritable than on previous days. After 27 hospital days, the patient had fully recovered, with no complaints of discomfort and with normal urine color and laboratory test results, including myoglobin, troponin, and electrocardiogram.

Wasp venom can result in multiple detrimental effects such as hemolysis, thrombocytopenia, neurotoxicity, anaphylactic shock and, in severe cases, MODS. Wasp venom is complex and consists predominantly of enzymes, peptides, and biogenic amines.^{,  ,}  Melittin is a major venom component; it alters the integrity of the cell membrane and is strongly hemolytic. Hyaluronidase hydrolyzes the hyaluronic acid between cells, probably facilitating a smooth entry of toxins into body tissues, possibly exacerbating local inflammation. In this study, the patient had normal platelets on admission, which decreased to 42 × 10⁹·L⁻¹ on Day 8 of admission. A report in India demonstrated that thrombocytopenia was found in patients stung by wasps, and the authors suggested that thrombocytopenia is a direct result of wasp venom’s effect on platelets. The severity of a person’s condition after wasp stings depends mainly on the strength of the venom and severity of the stings. Mild cases show allergic reactions with local redness and pain, and most of these do not require medical attention.

Nervous system toxicity after wasp sting injury is rare, but several cases have been reported worldwide. These typically involve cranial neuropathy, stroke, and encephalitis.^, During the disease, patients have differing degrees of altered mental state and decreased pulse oximetry, suggestive of diminished peripheral perfusion. Patients with neurological damage due to wasp stings often have a poor prognosis, and the severity is related to a patient’s age, sting site, the number of wasp stings, health condition, and degree of inflammatory response. Early hybrid blood purification treatment should be considered for patients with altered sensorium/consciousness after multiple wasp stings.

Acute laryngeal edema, anaphylactic shock, and respiratory muscle paralysis are all early causes of death in patients with severe reactions to multiple wasp stings, followed by MODS and infections. Allergic reaction is the earliest and most common clinical manifestation of a wasp sting. The symptoms of an allergic reaction can be divided into 4 grades; allergic reactions above grade II require an immediate injection of epinephrine. The human physiological response to wasp stings includes a potent immune response, including the release of many inflammatory mediators, which are amplified step by step through the cascading effects of the inflammatory process. Endothelial cell damage, inflammatory mediators, and the resulting abnormal blood coagulation are key factors affecting organ function, causing abnormal blood vessel tension and inhibiting myocardial pump function, ultimately leading to organ damage.

The first 24 h to 2 wk after a person is stung by a swarm of wasps is a critical period to prevent and treat MODS. Urine output and color changes must be recorded every hour for the first 48 h. The observation of a patient’s appetite, abdominal pain, bloating, nausea, vomiting, stool color, and skin and mucous membrane color is necessary. Routine blood tests, kidney and liver function tests, and muscle enzyme spectrum tests are needed each day, in addition to administering fluid replacement, antihistamines, and urine alkalization. Blood purification treatment may be required.

Multiple organ damage and inflammatory reactions caused by wasp venom provide a theoretical basis for glucocorticoid use to control inflammatory mediators. Reportedly, patients with MODS respond well to intravenous steroid administrations; however, a standard uniform dosage of glucocorticoids treating wasp stings has not been reported. According to a 2018 consensus of Chinese experts on the standardized diagnosis and treatment of wasp stings, patients with mild stings can be prescribed intravenous methylprednisolone (40–80 mg) or hydrocortisone (200–400 mg) once daily, and those with moderate or severe stings can be administered intravenous methylprednisolone (120–240 mg) once daily. When the systemic allergic reaction had subsided, hemolysis and rhabdomyolysis were reduced; this high dose of methylprednisolone was reduced by 50% every 3 d to 40 mg, maintained for 2 to 3 d, and gradually stopped within 3 wk.

In our region, the peak period for wasp stings is from August to October. In general, blood purification can be considered when a presenting patient has sustained >20 stings or when the patient presents with early hemolysis, rhabdomyolysis, kidney damage, or a decreased finger pulse oximetry. When blood purification is deemed necessary, hybrid blood should be encouraged. We recommend that patients in serious conditions should be first stabilized with CRRT before performing PE or HP. Combining blood purification and glucocorticoid therapy is key to treating severe wasp stings and preventing MODS.^, A single mode of blood purification is insufficient to meet all the therapeutic needs of the affected patient. Glucocorticoids, rehydration, and early CRRT are essential to rapidly clear the body of wasp venom and prevent multisystem damage. The patient had abnormal coagulation function and required PE to supplement plasma proteins and coagulation factors. Although blood perfusion removes whatever venom remains in circulation through adsorption, combined blood purification can better remove toxins and inflammatory mediators, stabilize hemostasis, and thus, support and protect organ function. In renal failure, hemodialysis can be used clinically to clear small molecules, such as creatinine, create a synergistic effect in treating severe wasp stings, and achieve an optimal outcome.

This case report involved a patient who experienced a severe reaction to multiple wasp stings, resulting in MODS. He received fluids, antishock and antiallergic medications, blood transfusion, glucocorticoids, CRRT, PE, and HP treatment and recovered completely. For patients who develop MODS due to multiple wasp stings, a standard single blood purification mode may be insufficient to meet treatment needs. Hybrid blood purification may be more effective in removing wasp toxins and inflammatory mediators and stabilizing hemostasis while supporting and protecting organ function. Our case emphasizes that early detection of rare complications, such as MODS, prompts referral and early intervention, and, if indicated, aggressive blood purification therapy can help achieve satisfactory recovery and prevent death.

The authors thank Editage (www.editage.cn) for English language editing.

Author Contributions: Study conception, data compilation and analysis, and writing the manuscript (RL); study conception and writing the manuscript (YY); writing the manuscript (ZZ, ER); approval of final manuscript (RL, ZZ, ER, YY).

Financial/Material Support: None.

Disclosures: None.