Severe acute kidney injury due to violent sadomasochistic play

Abstract

Bondage and discipline, dominance and submission, sadism and masochism (BDSM) refers to a variety of primarily erotic practices. Although safety is crucial for most BDSM practitioners, there are violent forms that may cause serious injury. We present the case of 61-year-old man with no history of chronic kidney disease who developed severe acute anuric kidney injury following violent BDSM play. He had been strapped tightly onto a wooden spanking bench and then received approximately 1000 vigorous hits onto his bare buttocks and thighs. Subsequently, he developed haematuria and became anuric. Laboratory testing revealed strongly elevated serum creatinine levels. Kidney biopsy was unremarkable except mild tubulointerstitial damage. Urinary production increased spontaneously again after 4 days, and serum creatinine normalised over the course of 4 weeks. We believe that a combination of intermittent abdominal compartment syndrome and blunt kidney trauma may have been responsible for this severe acute kidney injury.

Background

Bondage and discipline, dominance and submission, sadism and masochism (BDSM) is an umbrella term for a wide variety of largely erotic practices. Prevalence studies have revealed that BDSM is practised, in different types and intensities, by 2%–15% of the general population.^1–3 Whereas BDSM activities are often safe and non-harmful, violent forms of BDSM may result in severe and sometimes life-threatening injuries.^4–7 Here, we present the first case of a patient with anuric acute kidney injury (AKI) resulting from a vigorous BDSM session.

Case presentation

In May 2017, a 61-year-old Caucasian man was referred to our emergency department with anuric AKI. On admission, he reported to have taken part in a BDSM session 3 days earlier. During that session, he had been tied up naked onto a wooden spanking bench, with his buttock and thighs facing upwards and outwards (see figure 1). He pointed out that he had been strapped down very firmly with the ropes cutting into his back and thighs and his organs being squeezed against the wooden bench. He then received a series of violent strokes with both a wooden cane and long whip primarily on his bare buttocks and thighs. He explained that the whole session had lasted for about 30 min and that he had received about 1000 strokes during that time. The next day, he found himself oliguric (about 300 mL/day) with the urine looking dark red. On the following day, he became anuric. He had engaged in similar BDSM activity in the past and regularly experienced haematuria afterwards, but he had never turned anuric before. This prompted him to see his general practitioner yet another day later where laboratory investigations were performed. As blood results revealed severe AKI with a strong increase in serum creatinine (9.0 mg/dL, normal range 0.6–1.2 mg/dL), he was admitted to hospital. On admission, he had pain in those areas where he had been tied or beaten (rib cage/buttocks/ thighs). He had noticed an increase in body weight of about 2 kg since becoming anuric. Other than that, he had no further complaints. His medical history revealed a type 2 diabetes, arterial hypertension, hypercholesterolaemia and status post thyroidectomy. There was no history of chronic kidney disease (normal serum creatinine levels documented in November 2016 by general practitioner).

Figure 1.

Patient tied onto a spanking bench. The image shows our patient, on a different occasion, strapped onto a spanking bench similar to the one used in our case report. Take note that in our case, the spanking bench was wooden, not cushioned, and the patient was tied with several additional ropes.

His long-term medications were metformin, simvastatin, candesartan and levothyroxine. He had not been taking painkillers and denied any drug abuse. On examination, numerous deep grazes and haematoma were observed on his buttocks as well as thighs (see figure 2).

Figure 2.

Clinical course of grazes and haematoma following Bondage and discipline, dominance and submission, sadism and masochism play. (A) Prominent erythema, haematoma and grazes are visible 1 day after the event, that is, 2 days before admission (image taken by the patient). (B) and (C) Healing of grazes and resorption of haematoma is visible on day 6 after the event (ie, day 3 after admission).

Investigations

On admission to hospital, he was hypertensive (blood pressure 180/90 mm Hg) but otherwise had normal vital signs (heart rate 80/min, breathing rate 14/min, 96% oxygen saturation on room air, temperature 36.4°C). Laboratory tests showed yet another increase in serum creatinine (11.4 mg/dL). A mild metabolic acidosis was observed (pH 7.34; base excess 6.0 mmol/L). Potassium level was only marginally increased (5.1 mmol/L). Creatine kinase (CK) levels and lactate dehydrogenase (LDH) levels were elevated (CK: 643 IU/L, normal range: <200 IU/L; LDH: 536 IU/L, normal range <250 IU/L). Total bilirubin and lipase levels were increased as well, but transaminase levels were normal (total bilirubin: 1.5 mg/dL, normal range <1.3 mg/dL; lipase: 1097 IU/L, normal range <400 IU/L). Haemoglobin was 12.7 g/dL. The rest of the blood count as well as coagulation parameters were normal. There was no sign of haemolysis (normal haptoglobin levels on admission).

Microscopic urinalysis with phase contrast microscopy showed microscopic haematuria with a minor increase in (non-dysmorphic) erythrocytes (five per field of vision) but no casts. Spot urinalysis revealed moderate proteinuria with a protein/creatinine ratio of 1.13 g/g. Abdominal ultrasound revealed large and swollen kidneys in line with an AKI. There was no sonographic evidence for hydronephrosis, kidney haematoma, ascites, cholestasis or pancreatitis. In colour Doppler ultrasound, there were no signs of irregular renal perfusion.

To shed more light on the aetiology of the severe AKI, a kidney biopsy was performed. Histopathological analysis including immunohistochemistry showed mild tubulointerstitial damage with irregular round cell infiltrates in the interstitial space (10%–15%) and occasional tubulitis. About 20% of tubules were slightly widened with flattened epithelium. Ten percentage of interstitial fibrosis and tubular atrophy was found. There was no histological evidence for tubulointerstitial or glomerular disease. Tubular casts were not observed.

Outcome and follow-up

Three days after admission, urinary production slowly increased again, but serum creatinine levels remained unchanged. Macroscopic haematuria was no longer present at that time. The patient gained a total of 4 kg of weight and was hypertensive, so antihypertensive medication was started. Blood urea levels peaked at 240 mg/dL (normal range 17–45 mg/dL), but he showed no clinical signs of uraemia. pH and electrolyte levels remained stable, and he developed no dyspnoea. Therefore, haemodialysis was not indicated. Serological autoimmune markers (antinuclear antibody, antineutrophil cytoplasmic antibody and complement factors) were negative. CK levels peaked at 825 IU/L 1 day after admission.

Over the following 3 days, the patient became increasingly polyuric with urinary production of up to 4 L/day. The increasing urinary output was paralleled by a decrease in serum creatinine levels. Electrolyte levels remained stable, and urinary production eventually normalised. Therefore, he was discharged 8 days after admission (serum creatinine at discharge 4.4 mg/dL, blood urea at discharge 180 mg/dL).

Three weeks after discharge, he was seen again by which time serum creatinine and blood urea levels had returned to the normal range, and clinically he was fully recovered.

Discussion

Here, we report the first case of a patient with anuric AKI caused by a violent BDSM session. There are only little data about BDSM-related injuries in the current literature. In fact, we only found two reports that were clearly related to BDSM: in both cases, severe skin burns resulting from sadomasochistic sexual behaviour were presented.^{6 7} In contrast, there are numerous reports about (in part lethal) injuries resulting from autoerotic sexual behaviour (eg, strangulation and electrocution).^{4 5 8} We hypothesise that case reports of patients with BDSM-related injuries are so scarce as the risk for injury is much greater for autoerotic activities, which are generally performed alone with no help in case of complications. Moreover, in BDSM, both parties consent to all activities and therefore are unlikely to seek medical attention even if injuries occur.

We suppose that a combination of at least two factors was responsible for the severe AKI in this patient: intermittent abdominal compartment syndrome and blunt kidney trauma.

As outlined above, the patient reported to have been strapped very fiercely onto a wooden bench, that is, a hard surface. He explained that this position resulted in his organs being squashed vigorously onto the bench. We believe that this situation may have led to an intermittent abdominal compartment syndrome with critically reduced kidney perfusion. Abdominal compartment syndrome is characterised by an increase in intra-abdominal pressure >20 mm Hg that is associated with new organ dysfunction/failure.⁹ Renal dysfunction resulting in AKI is an early sign of abdominal compartment syndrome, but eventually other (abdominal) organs will be affected.¹⁰ This may explain why other abdominal organs were found to be compromised on admission (elevated lipase and bilirubin levels). Typical causes for abdominal compartment syndrome include abdominal surgery, major trauma or intra-abdominal infection/haemorrhage but prone positioning, resulting in an external increase of intra-abdominal pressure, has also been described as a risk factor.^{9 11} Our patient was strapped fiercely onto a wooden surface, which may have led to a similar (external) increase in intra-abdominal pressure. The treatment of choice for abdominal compartment syndrome is abdominal decompression, if necessary with open laparotomy.⁹ Our patient finished his BDSM session after 30 min, which resulted in immediate decompression and possibly prevented further damage.

The second factor, that we consider likely, is blunt kidney trauma. Even though the patient was primarily hit onto his buttocks and thighs, he acknowledged that some strokes may have accidentally hit his back and renal beds. Blunt kidney trauma is well known to cause haematuria and may (temporarily) impair kidney function.^{12 13}

We considered rhabdomyolysis as a potential cause for the AKI. However, CK levels were still rising when the patient was admitted and peaked at ‘only’ 825 IU/L, which we considered too low to cause such a profound AKI.^{14 15} Kidney biopsy showed no casts, which also argues against a relevant rhabdomyolysis.

In summary, we present a patient with anuric AKI resulting from violent BDSM activity and probably mediated by intermittent abdominal compartment syndrome and blunt kidney trauma. This case vividly illustrates the potential dangers associated with extreme forms of BDSM.

Patient’s perspective.

I have been engaging in bondage and discipline, dominance and submission, sadism and masochism (BDSM) for some 7 years now. I will take part in BDSM sessions like the one described in this report roughly about once every 3 months. I had observed my urine to turn dark red afterwards in the past so I was not worried at first when it happened again this time. However, the next day I could not urinate at all, which had never happened before. This concerned me so I went to see my general practitioner. He took blood from me and phoned me later to tell me that my kidney values were dramatically increased and sent me to hospital straight away to be worked up. The doctors there told me about having to take a sample from my kidney and that I may have to start dialysis if my kidneys did not start working again. That really scared me. The whole situation felt strange because I did not feel ill at all but of course, I realised that something was wrong with my kidneys. It took three more days until I started to urinate again and my kidney values finally began dropping again. This came as a great relief. When I learnt 3 weeks later that my kidney values had gone back to normal, I felt very grateful. I had been aware all the time that BDSM can be harmful but this event convinced me to reduce the intensity with which I do it. I take joy in BDSM but of course, I do not want any serious harm to occur to me.

Learning points.

• ‘Bondage and discipline, dominance and submission, sadism and masochism’ are usually safe, but violent forms may result in life-threatening injuries.

• Sustained, external increase of intra-abdominal pressure may lead to an abdominal compartment syndrome and result in acute kidney injury.

• Blunt kidney trauma such as hits on the renal beds may cause haematuria and impair renal function.