Old Meets New: Commentary on High-Volume, Multilevel Local Anesthetics-Epinephrine Infiltration in Kyphoscoliosis Surgery: Blood Conservation.

Correction of spinal deformity is a major surgery that carries a risk of high-volume blood loss with an increased incidence of unnecessary transfusion. Over the past decade, a dramatic expansion of the scope of anesthesia has made the anesthetist intervention in various procedures more evident in providing various types of anesthesia and pain management techniques.

Hence, I would like to appreciate the effort that has been done by Mazy et al., who raised an important and easy method in controlling blood loss and reducing the risk of unnecessary blood transfusion during kyphoscoliosis surgery.[1]

“High-volume, multilevel Local Anesthetics-Epinephrine infiltration in kyphoscoliosis surgery: Blood conservation” is a prospective randomized, double-blind study published in the current issue of the Journal. The study was done at a university hospital in Egypt, investigating the effect of preemptive high-volume multilevel epinephrine cocktail infiltration on bleeding control with no reliance upon deliberate hypotension. The research was done in a university hospital to facilitate the collection of more number of patients and to increase the variety of procedures. However, similar work can be done in other big hospitals according to the subspecialty of those hospitals and the number of patients they accommodate.

The authors chose the posterior spinal fusion for kyphoscoliosis correction as a single surgical approach to avoid bias in the results. The study medications contained 2 mg/kg plain bupivacaine 0.5% and lidocaine 5 mg/kg for analgesia plus epinephrine 5 mcg/mL in a total volume of 100 mL/10 cm of the wound length (Group I), which was replaced by the same volume normal saline in the control group (Group C). The infiltration was performed at two levels: subcutaneous level 30–40 mL/10 cm of the wound length, 10 min prior to skin incision, subsequently followed by the muscular level infiltration 20–30 mL/10 cm, from superficial to deep level on the vertebral lamina.

The primary outcome of the study was to estimate the intraoperative blood loss, which has been shown to be significantly reduced in the infiltration group. The secondary outcomes involved the number of transfused blood units and the transfused fluid volume, which were shown to be less in the same group. The dry field in the study group permitted higher mean blood pressure values and avoided the effects of deliberate hypotension correction. The better operative field visibility reduced the operative time in the same group.

The authors relied on the preemptive effect of the medication, by which an important and easy method to reduce blood loss during kyphoscoliosis surgery was investigated. Future work may be needed to support the idea of preemptive effect of infiltration using ultrasound-guided superficial and deep infiltration shortly before preparing the scene to the operation.

Local anesthetics interrupt the neural conduction by inhibiting sodium influx through channels within neuronal membranes. Vasopressors activate the alpha-1 adrenergic receptors. Combination of both local anesthetics and vasopressors provides hemostasis in the operative field and delay anesthetic absorption.[2]

The choice of the tumescent anesthesia practice allows the infiltration of higher volumes of diluted local anesthetics and epinephrine till the tissues become tense, with the advantages of reducing blood loss by dual effect of the infiltrate as a vasoconstrictor plus the hemostatic compression effect of the tumescent. Tumescent was used initially during liposuction procedures, but now, it is widely conducted in various types of surgeries.

Mechanism of action and pharmacodynamics of the combined medications with the effect of tumescent is enriching the outcome while reducing the side effects, that permits slower absorption of the medications with maintaining a safe local anesthetic blood level, reduces the risk for systemic toxicity, and prolongs the duration of action.[3]

The use of tranexamic acid in all patients during the current study would reduce the transfusion requirements and the amount of intraoperative bleeding, especially from the bony parts which were not affected by the local infiltration. Tranexamic acid is a synthetic antifibrinolytic amino acid derivative that forms a reversible complex with both plasmin and plasminogen by binding on the surface of fibrin at lysine-binding sites, inhibiting fibrinolysis at the surgical wound.[4]

The problem of extensive blood loss should be kept in mind by the whole team because a clean surgical field is not only important for hemodynamic stability but also to improve the surgical view which is crucial in all types of surgeries, most notably scoliosis surgery, hence decreasing the incidence of postoperative morbidity and mortality.[5] Understanding the different types of kyphoscoliosis, available resources, and possible complications should be considered before starting the study design and plan of work.

Reducing blood loss and other methods of blood conservation during kyphoscoliosis surgery contribute challenges to anesthetists and surgeons during the perioperative period. A single or combined different techniques can be used.[5] Various methods for blood loss reduction include controlled hypotension, local vasoconstrictor, epidural blockade, the use of systemic medications such as desmopressin, and tranexamic acid, or the use of local hemostatic sponge or wax.[6]

Granata et al. and Weis et al. investigated the risk of increased blood loss in kyphoscoliosis patients with neuromuscular disease, as those patients may suffer from coagulation disorders and require extensive fusion with increased blood loss. Posterior fusion procedure may cause more bleeding than the anterior one.[78]

Starting from the preanesthetic visit and before plans of medication used, anesthetists have to consider the patient demography; intra-abdominal pressure changes; preoperative hemoglobin level and coagulation profile; associated neuromuscular diseases; and the surgery design including the surgical approach and instrumentation use, along with the number of levels, which may be considered a key factor in predicting intraoperative and total blood loss.

Local infiltration into the paraspinal muscles with vasoconstrictor-containing solutions is widely used, but more evidence is needed to support the results. From my point of view, there is continuing controversy as regards the suitable journal for similar articles publication. Blood conservation methods are mostly managed by anesthetists, but sometimes, surgeons’ contribution may play a role. Obviously, there are more publications dealing with similar ideas but published mostly in nonanesthesia-related journals. However, this concept needs to be modified.