|Year : 2021 | Volume
| Issue : 2 | Page : 138-140
Severe hypotension during vertebral derotation in surgical correction of scoliosis
Ida Bagus Krisna Jaya Sutawan, Putu Pramana Suarjaya, Sanfred Lie, Christopher Ryalino, Adinda Putra Pradhana
Department of Anesthesiology and Intensive Care, Faculty of Medicine, Udayana University, Denpasar, Bali, Indonesia
|Date of Submission||18-Nov-2020|
|Date of Decision||09-Jan-2021|
|Date of Acceptance||18-Jan-2021|
|Date of Web Publication||16-Apr-2021|
Dr. Christopher Ryalino
Department of Anesthesiology and Intensive Care, Faculty of Medicine, Udayana University, Jl. PB Sudirman, Denpasar 80232, Bali
Source of Support: None, Conflict of Interest: None
Hypotension event in intraoperative settings may cause postoperative morbidity in surgical correction of scoliosis. Most often complications of intraoperative hypotension are postoperative ischemic optic neuropathy and postoperative ischemic stroke due to global hypoperfusion. Hypovolemic shock due to bleeding or blood loss is the most common cause of intraoperative hypotension in surgical correction of scoliosis. However, bleeding is not only the main cause of hypotension. A young female underwent surgical correction of scoliosis, during the operation she had a sudden and rapid decrease of blood pressure (BP) but then rapidly improved after the surgeon stopped the surgery which was a de-rotational procedure. Neurogenic shock is one of the complications that may occur during the manipulation of the spinal cord which is marked by a sudden and rapid decrease of BP and usually accompanied by bradycardia due to sudden and rapid loss of autonomic tone. Hypotension in neurogenic shock usually is refractory hypotension which cannot be treated only with fluid resuscitation but also needs vasopressor, thus this neurogenic shock should get immediate and prompt treatment to avoid further complications.
Keywords: Intraoperative hypotension, neurogenic shock, scoliosis surgery, surgical correction of scoliosis
|How to cite this article:|
Jaya Sutawan IB, Suarjaya PP, Lie S, Ryalino C, Pradhana AP. Severe hypotension during vertebral derotation in surgical correction of scoliosis. Bali J Anaesthesiol 2021;5:138-40
|How to cite this URL:|
Jaya Sutawan IB, Suarjaya PP, Lie S, Ryalino C, Pradhana AP. Severe hypotension during vertebral derotation in surgical correction of scoliosis. Bali J Anaesthesiol [serial online] 2021 [cited 2021 Jun 23];5:138-40. Available from: https://www.bjoaonline.com/text.asp?2021/5/2/138/313893
| Introduction|| |
Surgical correction of scoliosis is one of the major surgeries of the spine which important to be done. If left untreated, scoliosis, especially idiopathic scoliosis rapidly progresses and is often fatal by the fourth and fifth decades of life, as a result, pulmonary hypertension, right ventricular failure, or respiratory failure. Idiopathic scoliosis, which is based on age, is one of the classifications of scoliosis, divided to infantile idiopathic scoliosis, juvenile idiopathic scoliosis, and adolescent idiopathic scoliosis. Most of the surgical correction of scoliosis performed on children to adolescents where the bone maturation process still occurs. As these patients still grow and have a long life ahead, one should consider minimizing intraoperative complications that could happen, so it will not impair them in the later day.
Hypotension in intraoperative settings may cause postoperative morbidity in surgical correction of scoliosis. Hypotension may cause various postoperative morbidity such as disturbance of spinal cord blood flow and autoregulation, which may cause ischemia to the spinal cord then manifested as postoperative paralysis. Generally, hypotension in surgical correction of scoliosis is often associated with massive bleeding due to large operating fields and many injured blood vessels during operation. This is a case report of severe intraoperative hypotension that happened so suddenly and rapidly that we could not categorize it as hypovolemic shock.
| Case Report|| |
A 17-year-old female with adolescent idiopathic scoliosis was consulted to the anesthesia department for surgical correction of scoliosis. From the history taking, found out that since high school, the patient felt one of her legs was longer than the other side which causing an unbalance when she was walking. She also felt a lump on her back, and there was back pain when she walks. Currently, the back pain is minimal and improved, pain intensity increased when the patient walks long distances, and pain intensity lessens when the patient lies down. The patient also feels a tingling sensation on her lower extremities when she sits while folding her legs, she denied weakness on her extremities.
Data obtained from the physical examination, patient's weight is 52 kg and height is 160 cm with body mass index 20.3 kg/m2, her axillary temperature 36.5°C; numeric pain rating scale (NPRS) 0/10 without activity and NPRS 1/10 with activity. All other findings and laboratory workups were within normal limits. Thoracolumbar computed tomography scan revealed right convexity thoracic scoliosis with left convexity lumbar scoliosis [Figure 1].
The patient was premedicated with midazolam 2 mg, dexamethasone 10 mg, and pantoprazole 40 mg intravenous. We used target-controlled infusion (TCI) propofol using the Schneider mode, effect-site concentration, titrated gradually to achieve Bispectral index (BIS) value of 40. We administrated fentanyl 150 mcg and to facilitate the intubation we gave atracurium 25 mg. We inserted the invasive blood pressure (BP) monitoring after intubation. Anesthesia maintained with TCI propofol (with BIS value target 40–60), oxygen fraction of 40%, fentanyl intermittently 50 mcg every 1–2 h based on patient's hemodynamic, and atracurium intermittently 0.1 mg/kg every 45 min.
When the surgeon performed vertebral derotation [Figure 2], there was a rapid and sudden decrease of systolic BP from 110 mmHg to 70 mmHg then 20 mmHg, no palpable pulse, oxygen saturation not detected, this event happened approximately a minute, however, there was still electrocardiogram rhythm on the monitor with heart rate of 85–88 bpm. Immediately we informed the surgeon to stop the procedure. We administrated ephedrine 20 mg and the BP was starting to increase gradually from 30 mmHg to 120 mmHg. The rest of the surgery was uneventful [Figure 3].
We performed a wakeup test before skin closure, which was satisfactory. She was extubated after the operation and admitted to the intensive care unit (ICU) for observation. We prescribed fentanyl per patient-controlled analgesia for postoperative pain management. She was discharged from ICU 48 h later with no known complication and was discharged from hospital 7 days after the surgery.
| Discussion|| |
To maintain the physiologic function of the patient within normal limits during operation is one of the important roles of an anesthesiologist. The goal is to prevent postoperative morbidity and mortality. BP is one of many physiologic monitoring parameters that are often being used. Decreased BP, often referred to as hypotension, is one of the intraoperative complications that may cause intraoperative or postoperative morbidity and mortality.,
Furthermore, there is still an unclear definition of intraoperative hypotension which caused an anesthesiologist to hesitate to diagnose, thus late to give treatment. A systematic review on 387 literature about intraoperative hypotension found out that there were differences in intraoperative hypotension definition in 140 literatures. Duration of hypotension is expressed in the number of minutes such as 1, 2, 3, 5, and 10 min of the BP below the designated threshold. However, the most frequently used definition is systolic BP <80 mmHg, decreased in BP 20% from baseline, and or using combined absolute and relative threshold such as systolic BP below 100 mmHg and/or decreased BP 30% from baseline with duration of 1–5 min.
A wide range of complications may occur from intraoperative hypotension. In general, some common morbidity due to intraoperative hypotension includes stroke, myocardial ischemia, and kidney failure. Ischemic optic neuropathy (ION) is one of the causes of postoperative visual loss. Several risk factors associated with ION for patients undergoing spine surgery include long duration of surgery in a prone position, male sex, Wilson frame use, and greater estimated blood loss with intraoperative hypotension. ION occurs in 20% of patients who had intraoperative systolic BP below 80 mmHg.
Aside from ION, typical morbidity associated with intraoperative hypotension in spine surgery is spinal cord ischemia or infarction. Incident of spinal cord ischemia or infarction is much less than cerebral ischemia or infarction, accounting for only 1% of all strokes. The most probable cause of infarcts occurring after hypotension or arterial insufficiency seems to be global hypoperfusion of the spinal cord which manifested as central and transverse infarcts.
A study on 44 patients with various types of scoliosis showed that approximate bleeding from surgical correction of scoliosis is 2569 ml. However, not all hypotension that occurs in surgical correction of scoliosis is caused by bleeding. The type of shock that most likely to occur during surgical correction of scoliosis is a neurogenic shock. Neurogenic shock can occur due to a spinal cord injury and then causes loss of tone in the autonomic nervous system. This results in disruption of the descending sympathetic pathways that leads to unopposed vagal tone in the vascular smooth muscle, causing decreased systemic vascular resistance and vasodilation.
Although the terms are sometimes used interchangeably, neurogenic shock describes the hemodynamic changes following spinal cord injury, whereas spinal shock is characterized by a reversible reduction of sensory, motor, or reflex function of the spinal cord below the level of injury. Based on the characteristic of sudden and rapid hypotension that occurred soon after vertebral derotation, our case showed a neurogenic shock. Furthermore, the hypotension resolved after the surgeon stopped the vertebral derotation. The rapid and sudden onset of hypotension tends to occur from a spinal cord injury that causes loss of tone in the autonomic nervous system, then results in disruption of the descending sympathetic pathways results in unopposed vagal tone in the vascular smooth muscle, causing decreased systemic vascular resistance and vasodilation. This hypotension can be resolved by stopping the procedure and by giving a vasopressor.
A neurogenic shock that occurs from manipulation or spinal cord injury is characterized by a sudden loss of autonomic tone, resulting in rapid and sudden hypotension and relative bradycardia. Therefore, close monitoring of BP is necessary during the manipulation of the spinal cord. Close monitoring of BP can be achieved using invasive monitoring; thus, we can monitor beat-to-beat BP.
In contrast to hypotension due to bleeding, hypotension in neurogenic shock is often refractory to fluid resuscitation and occurs rapidly and suddenly. Therefore, hypotension in neurogenic shock must be treated immediately to avoid the risk of secondary spinal cord ischemia due to impairment of autoregulation. The initial step is to stop the surgery or procedure, then consider giving medication to treat the hypotension. If hypotensive patients have normal chronotropic and inotropic, then vasopressors such as phenylephrine, ephedrine, and norepinephrine should be considered. Epinephrine and vasopressin infusions may be used in refractory cases of hypotension. If bradycardia is present, patients may respond to atropine, glycopyrrolate, or vasoactive infusions with chronotropic, vasoconstrictor, and inotropic properties such as dopamine or norepinephrine. Methylxanthines (theophylline and aminophylline) and propantheline have also been used for refractory bradycardia.
| Conclusion|| |
Intraoperative hypotension is one of the causes of morbidity in surgical correction of scoliosis. Neurogenic shock usually occurs rapid and sudden, so in this surgery where manipulation of the spinal cord is performed, it is best to use invasive monitoring such as intra-arterial BP to close monitor beat-to-beat BP. Neurogenic shock is usually refractory to fluid resuscitation, so it is necessary to give vasopressors to treat the hypotension that occurs.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]