Hypotension and bradycardia were common complications during TURP, the reason of these complications are TURP syndrome, hemorrhage, bladder perforation and high spinal anesthesia. The TURP syndrome is a systemic complication caused by excessive absorption of electrolyte-free irrigation fluids [4], the incidence is 0.78–1.4 % [2]. The incidence of bladder perforation is 1 % during TURP [5]. We reported other two cases who presented sudden severe hypotension and bradycardia during greenlight laser TURP which weren’t due to TURP syndrome, hemorrhage or bladder perforation and high spinal anesthesia, but due to parasympathetic reflex.
We suspected it was parasympathetic reflex that lead to hypotension and bradycardia in these two patients. First, the hypotension and bradycardia occured suddenly, the symptom was similar to the classic vagal reflex caused by pulling reaction of viscera during appendectomy under epidural anesthesia [6]. Second, the symptom was improved when the operation was suspended and the atropine and inotropic drugs were used, they were also as same as the treatment of vagal reflex. Third, the symptom was occured when the same operative process was performed. It could be explained by a neural reflex.
The prostate anatomic position also related to parasympathetic activity, because prostate is surrounded by autonomic nerve fibers including sympathetic and parasympathetic nerves. The parasympathetic nervous center is located at S2-S4 section of spinal cord. The peripheral part is composed of inferior hypogastric plexus and pelvic splanchnic nerve. In which, pelvic splanchnic nerve is closer to the apex of prostate at the level of the membranous urethra. Besides, the parasympathetic nerves were mainly located dorsolaterally at the apex according to immunohistochemical analysis [7, 8].
Hypotension and bradycardia are common adverse effects of spinal anesthesia, the incidence is 15–38 % and 10 % respectively [3]. They usually occur in elder patients [9] and they usually occur at the beginning 15 min of intrathecal injection [10]. High spinal block (above T5) [11, 12] and high dose of heavy bupivacaine [12] are main anesthetic factors. But in the two cases we reported here, the hypotension and bradycardia occurred 40-60 min after intrathecal injection. And the spinal puncture was performed at the L3-4 intervertebral space, the level of sensory block was below T10 throughout the operation. The dose of bupivacaine was well controlled. So we think hypotension and bradycardia in our cases were caused by parasympathetic reflex instead of high spinal anesthesia.
The hypotension and bradycardia in our cases were not caused by TURP syndrome. First, TURP syndrome can cause hypervolemia and hyponatraemia [4], but it is rare when normal saline is used as irrigation fluid [13]. In our cases, normal saline is used as irrigation fluid, and there is no manifestation of hypervolemia and hyponatraemia. Second, TURP syndrome can cause a wide variety of symptoms including asymptomatic hyponatremia, ECG changes, fatigue, vomiting, confusion, visual loss, coma and death [14, 15]. So the change of mental state may be the first sign, but it was not appeared in our cases. Third, we didn’t give any treatment of TURP syndrome such as sedation, diuresis and sodium supplement [16], the cases recovered. Finally, TURP syndrome is defined as serum sodium concentration ≤ 125 mmol/l [17], but it was normal in our cases.
The intravesical explosion during TURP can cause bradycardia and hypotension, accompany with nausea, abdominal pain and developed confusion [1]. But this complication usually manifested as a “pop” and can be identified by the urologists and anesthesiologists. The bladder perforation can be observed through cystoscope. So the hypotension and bradycardia in our cases were not caused by bladder perforation.
Because the Hct was stable during operation, the hypotension and bradycardia were not caused by hemorrhage.
