I read with interest the case report by Sreelakshmi and Eldridge [1] highlighting the risk of hypotension associated with leucocyte depletion filters during autologous blood transfusion. I would like to report a similar case of acute, profound hypotension following transfusion of cell-salvaged blood via a leucocyte depletion filter (LDF) during massive obstetric haemorrhage. A 19-year-old primigravida presented with fetal death in utero, secondary to placental abruption at 38 weeks’ gestation. Uterine ultrasound confirmed the presence of a concealed intrauterine haemorrhage. After immediate resuscitation, induction of labour was initiated with a Syntocinon® infusion. Disseminated intravascular coagulation rapidly ensued. Laboratory tests demonstrated a platelet count of 64 × 109.l−1, activated partial thromboplastin time 51 s, prothrombin time 23 s and fibrinogen 0.6 g.l−1. We transfused the patient with four units of allogenic blood, four adult units of platelets, eight units of fresh frozen plasma and four units of cryoprecipitate. Failure of the labour to progress and a deteriorating clinical picture necessitated surgical evacuation of the uterus. In accordance with the standard protocol for anticipated massive haemorrhage, immediate access to a rapid infuser (Belmont, Billerica, MA, USA) and cell salvage (Haemonetics, Braintree, MA, USA) were arranged. We commenced continuous intra-arterial and central venous pressures monitoring and induced general anaesthesia uneventfully. An interventional radiologist performed balloon-assisted occlusion of the internal iliac arteries before the start of surgery. Uterine incision and delivery of a deceased female infant was associated with a haemorrhage of approximately 6 l. We transfused a further two units of allogenic blood, five units of fresh frozen plasma, one unit of platelets and two units of cryoprecipitate. Despite the degree of blood loss and a haemoglobin concentration measured at 5.7 g d.l−1, intra-arterial blood pressure measurements confirmed a systolic blood pressure of > 120 mmHg. Cell salvage yielded 1600 ml of red cell concentrate, which was administered via an LDF (LeukoGuard RS; Pall, Portsmouth, UK) through the central venous catheter. Within 2 min, she became severely hypotensive (systolic pressure < 70 mmHg), which was incongruent with her previous clinical state. One hundred micrograms of intravenous fentanyl was administered before the episode of hypotension but we did not feel this was causative. Surgical factors did not offer an obvious explanation so, due to a high index of suspicion, we terminated the autologous blood transfusion. We administered a 100 μg bolus of intravenous phenylephrine, which resulted in restoration of the blood pressure to pre-transfusion levels. Recommencing the transfusion resulted in a similar episode of profound hypotension, again treated successfully with a small dose of vasopressor. We then removed the LDF and the transfusion was completed without any adverse effects. After a short period of intensive care, the patient made a full and uncomplicated recovery. This case report adds to the growing body of evidence that infusion of cell-salvaged blood through an LDF may be associated with acute, profound hypotension. Removal of the LDF, as previously suggested in the literature [1, 2], resulted in successful transfusion of the cell-salvaged blood without any obvious adverse effects. Leucocyte depletion filters were originally introduced into obstetric anaesthesia to remove white cells and particulate components of amniotic fluid [3, 4]. The cell salvage process effectively removes amniotic fluid from collected blood [4] and LDFs remove virtually all remaining fetal squames and phospholipid lamellar bodies [5]. However, the significance of fetal squames and lamellar bodies in the maternal circulation has been questioned as previous studies have confirmed their presence in the circulation of otherwise healthy parturients [6] and patients undergoing caesarean section [5]. Negative bacterial culture of cell-salvaged blood that has not undergone LDF filtration has largely eliminated concerns of bacterial transmission [7]. Transfusion of unfiltered autologous blood therefore remains a theoretical rather than a practical risk. The decision to transfuse the cell-salvaged blood without an LDF in this case was based on clinical need, a suspected adverse incident related to the LDF, and the theoretical rather than actual risk of harm associated with administering unfiltered autologous blood. Unfortunately, collecting the cell-salvaged blood into a citrated bag and storing for 60 min before reinfusion, as previously suggested [1], was not practical in this case due to the severity of the haemorrhage. Although hypotension in association with bedside LDFs is thought to occur sporadically [8, 9], it is possible that the phenomenon is more common than once thought, possibly due to low reporting rates of suspected cases. Increasing awareness amongst anaesthetists and encouraging adverse incident reporting will result in more accurate data regarding the frequency of the phenomenon. These data may ultimately lead to revision of national guidelines to reflect a consensus on the clinical application of these filters and appropriate management when adverse effects occur. No external funding and no competing interests declared. Published with the written consent of the patient. Previously posted at the Anaesthesia Correspondence website: http://www.anaesthesiacorrespondence.com.
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Mar 7, 2016
Naresh Kumar + 7
Open Access