This study was conducted as a pilot without randomization to see if surgery in SCD patients without preoperative blood transfusion is safe. Blood transfusion is commonly used in the comprehensive management of SCD patients. However, it is not without risk of transfusion-related complications, such as alloimmunization (17% to 30%),14
delayed hemolytic transfusion reaction,16
Therefore, the current advice is to decrease exposure to blood products if at all possible.15
Several preoperative transfusion regimens have been used to reduce the risk of perioperative complications in patients with SCD. They include simple and exchange transfusions before LC. However, at present there is no consensus regarding the value of a preoperative transfusion in these patients.9,12,15,18–20
Exchange transfusion is given to lower the level of Hb-S, usually to 30%, or a simple transfusion of 1 or 2 units of blood to raise the overall hemoglobin level to approximately 10g/dL21
to improve the overall oxygen- carrying capacity. In addition, by lowering the level of Hb-S and the number of sickled red blood cells, whole blood viscosity may fall, reducing the risk of VOC.22
In our study, we have adopted 3 practices for blood transfusion in SCD patients who are undergoing surgery. The majority (60%) had their surgery without any form of transfusion, while the remaining 40% had preoperative transfusion in the form of either a simple transfusion (22.5%) or a partial exchange transfusion (17.5%). Simple “top up” is considered much safer than partial exchange transfusion, and its use has been advocated. It is interesting to find in this study a lack of correlation between the level of Hb-S and the incidence of complications. Such a finding may prompt the conduction of a larger prospective randomized trial. Although clinical and laboratory evidence is available that supports the beneficial effects of dilution of sickle cells on outcome,23–26
it is not certain if there is a threshold for such effects or if the effects are proportionate to the percentage of Hb-S. Also, in this study, there were 5 (12.5%) postoperative complications, all of which occurred in Group II that received blood transfusion with no complication in the larger nontransfused Group I (P<.05). Moreover, there was no significant difference in the complications between the simple transfusion and partial exchange transfusion subgroups.
Unlike this study's findings and that of Vichinsky et al12
who showed no improved prophylactic benefit from an aggressive transfusion regimen compared with conservative transfusion regimen, Haberkern et al9
reported that vaso-occlusive pain episodes were highest in the nontransfused group (mean preoperative Hb-S, 88%) and lowest in the aggressive transfusion group patients (Hb-S, 34%), which may suggest a threshold of Hb-S percentage at which vaso-occlusive events are more likely to occur. Many centers, however, have adopted a more conservative policy following the publication of the study by the preoperative transfusion in the SCD group,12
which showed that simple “top up” transfusion was as safe as aggressive exchange transfusion. Also, a recent national survey of practices in the United Kingdom demonstrated no difference in the rate of postoperative complications in patients who received a transfusion and those who did not, suggesting a growing trend in the United Kingdom to avoid transfusion when possible.15
Some centers, like ours, do not routinely transfuse patients before surgery but rely heavily on the delivery of comprehensive care by a multidisciplinary team to prevent the development of postoperative sickle cell events.8
A retrospective observational study8
that examined outcomes in SCD children undergoing 66 surgical procedures without preoperative transfusion showed only one episode of ACS and no pain crises after 46 minor procedures. It was therefore concluded that any potential benefit from transfusion was low, and the risks of transfusion outweigh the benefits. Hence, transfusion is not justified for minor procedures.8
Also Leff et al20
demonstrated that LC can be performed safely in SCD patients without preoperative transfusion even in patients with hemoglobin levels just above 6g/dL before the operation. In a study that included 369 participants in Saudi Arabia, no advantage was demonstrated for preoperative transfusion over no transfusion in terms of reduced sickle-related complications, perioperative infection, and transfusion-related complications.27
No major complications were reported in either the transfusion or no-transfusion groups, but significantly more overall complications occurred in participants receiving transfusion.27
This argues against routine preoperative blood transfusion in SCD patients who are undergoing surgery.
Transfusions are undertaken less frequently in countries such as Jamaica than in North America, and interestingly, observational studies do not report significantly increased morbidity or mortality in operations without transfusion.28,29
Whether this is due to the setting or clinical differences is unclear. Indeed, the demand for blood transfusions is likely to decline with the introduction of alternative treatments, less invasive surgical techniques like laparoscopic surgery with advanced high-energy devices, and improved anesthetic agents. However, more sound evidence in the form of well-run, multi-center, randomized controlled studies is required to optimize the clinical management regimen for these people.