Hipotensión controlada en cirugía espinal / Controlled Hypotension in Spinal Surgery

RESUMEN Introducción: La hipotensión controlada implica a cualquier técnica que, utilizada de forma única o combinada, disminuya intencionalmente los valores de tensión arterial durante el período intraoperatorio, con la finalidad de reducir el sangramiento y mejorar la visibilidad del campo quirúrgico. Objetivo: Describir los fundamentos fisiológicos, definiciones, técnicas y complicaciones de la hipotensión controlada aplicada en la cirugía espinal. Métodos: Se realizó una revisión de la literatura, en bases de datos científicas como Cochrane Database of Systematic Reviews, Pubmed/Medline, EMBASE, SCOPUS, Web of Science, Ebsco Host, ScienceDirect, OVID y el buscador académico Google Scholar, en el mes de junio del 2020. Conclusiones: La hipotensión controlada aplicada en la cirugía espinal presenta limitados beneficios quirúrgicos. Sin embargo, no existe un consenso preciso sobre los umbrales hemodinámicos y límites de tiempo requeridos para su utilización, y se asocia a un elevado riesgo de potenciales complicaciones como el delirium, disfunción cognitiva posoperatoria, accidente cerebrovascular isquémico, pérdida visual posoperatoria, lesión renal aguda, lesión miocárdica, déficit neurológico posoperatorio tardío y dolor neuropático crónico; por lo cual no se recomienda su empleo rutinario durante el período intraoperatorio(AU)

ABSTRACT Introduction: Controlled hypotension implies any technique that, used alone or in combination, intentionally lowers blood pressure values during the intraoperative period, in order to reduce bleeding and improve the visibility of the surgical field. Objective: To describe the physiological foundations, definitions, techniques and complications of controlled hypotension in spinal surgery. Methods: A literature review was carried out in scientific databases such as Cochrane Database of Systematic Reviews, Pubmed/Medline, EMBASE, SCOPUS, Web of Science, Ebsco Host, ScienceDirect, OVID and the academic search engine Google Scholar, in June 2020. Conclusion: Controlled hypotension in spinal surgery has limited surgical benefits. However, there is no precise consensus on the hemodynamic thresholds and time limits required for its use, and it is associated with a high risk of potential complications as delirium, postoperative cognitive dysfunction, ischemic stroke, postoperative visual loss, acute kidney injury, myocardial injury, late postoperative neurological deficit and chronic neuropathic pain; therefore, its routine use during the intraoperative period is not recommended(AU)

Prolonged effect of nicardipine used for deliberate hypotension in scoliosis surgery: A case report

Postoperative respiratory complications following scoliosis surgery are high incidence. In this case, fifty year-old male patient was admitted for thoracolumbar screw fixations and developed postoperative pulmonary edema. This was most likely due to prolonged administration of nicardipine, which over time may inadvertently cause hypotension. As a result of volume overload, interstitial pulmonary edema and pleural effusion occurred. Moreover, pulmonary edema and pleural effusion appeared on the right side first and spread to the left. This phenomenon could be explained by the positioning of scoliosis patient. The cause of pulmonary edema was volume overload initiated by prolonged effect of nicardipine.

Controlling deliberate hypotension in hypertensive patients undergoing spinal surgery: a comparison between remifentanil and sodium nitroprusside

BACKGROUND:This study was designed to determine whether remifentanil or sodium nitroprusside (SNP) with sevoflurane anesthesia can induce safe deliberate hypotension (DH) to a target mean arterial pressure (MAP) of 55-65 mmHg in patients with controlled hypertension. METHODS:Thirty patients with controlled hypertension and who were scheduled for posterior lumbar interbody fusion were randomly assigned to receive remifentanil (n = 15, group R) or SNP (n = 15, group S).All the patients received a balanced anesthetic technique including 1.5-2 vol% sevoflurane.Group R received remifentanil by target-controlled infusion.The infusion was initiated with a target concentration at 4 ng/ml and this was adjusted every 1 min by 1 ng/ml to maintain the MAP to the target level of 55-65 mmHg.In group S, the infusion of SNP was initiated at 1 ug/kg/min and this was increased by 0.5 ug/kg/min.Cerebral oximetry was done and the cardiac index was measured with esophageal Doppler. RESULTS:DH was achieved at a MAP = 60 mmHg within 5.7 min for group R and 3.7 min for group S.The intraoperative blood loss was lower in Group R than that in Group S (304 +/- 103 vs 650 +/- 141 ml, P < 0.05).The frequency of added ephedrine injection to control the MAP and discontinuation of the study drug due to a MAP < 60 mmHg were higher in group S than in group R (46% vs 13%, P < 0.05 and 62% vs 20%, P < 0.05, respectively). CONCLUSIONS:Compared to SNP, remifentanil with sevoflurane anesthesia induced safer DH for patients with controlled hypertension.

Influence of Nitroglycerin-induced Deliberate Hypotension on Pharmacodynamics of Rocuronium / 中国微创外科杂志

0.05). Conclusions The effect of rocuronium can be potentiated by nitroglycerin-induced deliberate hypotension, while time for maximum depression is prolonged.However, the time course of recovery of rocuronium can not be affected markedly.

The Effects of Hemodilution on Critical Oxygen Deliveries during Deliberate Hypotension by Esmolol or Sodium Nitroprusside in Dogs / 대한마취과학회지

BACKGROUND: Acute normovolemic hemodilution (ANH) and deliberate hypotension (DH) are methods used for reducing homologous transfusions in cases of massive intraoperative bleeding. Using the technique of combining ANH and DH, we can save more homologous blood than a single use of ANH or DH, but the risk of tissue hypoxia may increase. METHODS: Fourteen male dogs were used for this study and divided into two groups. After performing ANH by 25 ml/kg, mean arterial pressures were reduced to 60 mmHg by sodium nitroprusside (S group) or esmolol (E group). The critical oxygen delivery and the hemoglobin concentration at the critical oxygen delivery were determined by measurements of hemodynamic change, systemic oxygen delivery and systemic oxygen consumption during subsequent hemodilution. RESULTS: After performing ANH by 25 ml/kg, the cardiac output was significantly increased, and systemic vascular resistance and hemoglobin concentration were significantly decreased compared with control values. The critical oxygen deliveries were 179.6 ml/min in the S group and 169.1 ml/min in the E group. There was a difference in mean systemic oxygen consumption between the S group (123.4 +/- 16.7 ml/min) and E group (112.9 +/- 15.4 ml/min) above the critical oxygen delivery point (mean +/- SD). The hemoglobin concentrations at the critical oxygen delivery were 2.6 +/- 0.7 g/dl in S group and 4.0 +/- 1.3 g/dl in E group (mean +/- SD). CONCLSIONS: The critical oxygen delivery during hemodilution under DH by sodium nitroprusside was 179.6 ml/min and by esmolol was 169.1 ml/min. However, esmolol was higher in hemoglobin concentrations at the critical oxygen delivery than sodium nitroprusside. These results suggest thathemodilution under DH by esmolol rather than sodium nitroprusside requires more careful monitoring of systemic oxygen delivery for prevention of tissue hypoxia.

Hemodynamic Changes in the Deliberate Hypotension with Sodium Nitroprusside or Esmolol in Dogs / 대한마취과학회지

The deliberate hypotension with esmolol or sodium nitroprusside(SNP) was provided subsequently in random order with six dogs. Anesthesia was maintained with 0.8 vol% halothane, end-tidal, in N2O/O2, 50: 50, with vecuronium. Mean arterial pressure was reduced 30-35% to 70 mmHg, with use of SNP or esmolol. Mean arterial pressure, heart rate, mean pulmonary arterial pressure, arterial blood gas analysis, and cardiac output were measured both prior to the deliberate hypotension and at 70 mmHg of mean arterial pressure induced with esmolol or SNP. The following results were observed; 1) The mean doses required were 725+/-250 ug/kg/min in esmolol and 12+/-2 ug/kg/min in SNP. 2) Esmolol was associated with a decrease in cardiac output (from 2.13+/-0.23 to 1.27+/-0.23 L/min), in heart rate (from 128+/-14 to 91+/-11/min), and an increase in central venous pressure (from 9.2+/-3.27 to 11.60+/-3.21 mmHg)(p<0.05). 3) SNP decreased systemic vascular resistance from 41111+/-484 to 2175+/-451 dynessec/cm5 (P<0.05), trended to increase heart rate. 4) A change in arterial blood gas analysis before and during deliberate hypotension with esmolol or SNP was not significant. As to mechanism of hypotensive effect, SNP caused decrease in systemic vascular resistance by 47% but esmolol significantly reduced cardiac output by 40% and heart rate by 29%. The result of present study suggests that when moderately deliberate hypotension with only esmolol was done, the potential for marked myocardial depression must be recognized. The differences in pharmacologic properties for the different hypotensive agents suggest that combinations of these agents may be provide a pharmacologic profile superior to either agent alone.

The Dosage of Sodium Nitroprusside and its Effects on the Cardiovascular System for Deliberate Hypotension in Halothane Anesthesia / 대한마취과학회지

The effects of deliberate hypotension by sodium nitroprusside (SNP) on the cardiovascular system and dosage of SNP were studied in 10 patients undergone Cotrel-Dubousset instrumentation for the operative treatment of scoliosis, spinal stenosis or herniated intervertebral disc. Mean arterial pressure decreased significantly (p0.05), r= -0.2 (p>0.05), and r= - 0.25 (p>0.05) respectively. The amount of whole blood transfused during the operation was 5. 3+/-1 .7 units. Hemoglobin and hematocrit decreased significantly (p<0.05) from 11.3+/-1.3g/dl and 33.7+/-4.1% to 10.1+/-1.5g/dl and 30+/-4.1% during operation.