• Daniel A. Barocas

The letter by Dr Carmignani et al. describes their protocol for minimizing blood loss and transfusion in patients undergoing radical prostatectomy (RP). The authors report that by maintaining mean arterial blood pressure between 55 and 70 mmHg and keeping the patient in 30 ° Trendelenberg position, they achieved a median estimated blood loss of 300 mL and a transfusion rate of 5.8% among 51 consecutive patients. This compares favourably with many open RP series, in which the transfusion rate ranges from about 10% to 30%[1,2]. Without a doubt, many experienced surgeons have found ways to improve on blood loss and transfusion in patients undergoing RP and these authors offer an interesting alternative. In the paper to which this letter refers, we transfused 3.4% of 441 patients that underwent open RP and 0.8% of 830 patients that underwent robotic RP, suggesting that one can match or improve upon their results without resorting to controlled hypotension [3].

My concerns about their study are two-fold. First, methodologically, they present ‘single-arm study’ or ‘case series’. There is no comparison arm, so there is no way to judge improvement in blood loss or transfusion, or change in the risk of adverse events, from what they had done previously. As mentioned, their results are excellent in terms of achieving a low transfusion rate, but are not strikingly better than others. Secondly, keeping patients in a controlled hypotensive state could result in unforeseen neurological and cardiovascular complications. To identify these uncommon complications and determine whether they are increased in patients subjected to this protocol, the authors would have to follow a larger number of patients and report the results alongside a control group.

I applaud the efforts of Dr Carmignani and colleagues to improve patient outcomes of this challenging operation and look forward to seeing more formal studies of this method to evaluate its role in reducing blood loss and transfusion.