Brazilian Journal of Anesthesiology
https://bjan-sba.org/article/doi/10.1590/S0034-70942013000200002
Brazilian Journal of Anesthesiology
Scientific Article

Efeitos do óxido nitroso em hipotensão controlada durante anestesia com baixo fluxo

The effects of nitrous oxide on controlled hypotension during low flow anesthesia

Semiha Barçı; n; Leyla Sahan; Dilsen Ornek; Fazilet Sahin; Oya Kilci; Serpil Deren; Gulay Erdogan; Canan Un; Mehmet Gamli; Bayazit Dikmen

http://dx.doi.org/10.1590/S0034-70942013000200002 Braz J Anesthesiol, vol.63, n2, p.170-177, 2013
PDF Português
PDF English
Downloads: 0
Views: 1009

Resumo

JUSTIFICATIVA E OBJETIVOS: Investigamos o efeito do óxido nitroso (N2O) em hipotensão controlada durante anestesia com baixo fluxo (isoflurano-dexmedetomidina) em termos de hemodinâmica, consumo de anestésico e custos. MÉTODOS: Quarenta pacientes foram randomicamente alocados em dois grupos. Infusão de dexmedetomidina (0,1 µg.kg-1.min-1) foi mantida por 10 minutos. Subsequentemente, essa infusão foi mantida até os últimos 30 minutos de operação a uma dose de 0,7 µg.kg-1.hora-1. Tiopental (4-6 mg.kg-1) e brometo de vecurônio (0,08 0,12 mg.kg-1) foram administrados na indução de ambos os grupos. Isoflurano (2%) foi administrado para manutenção da anestesia. O Grupo N recebeu uma mistura de 50% de O2-N2O e o Grupo A recebeu uma mistura de 50% de O2-ar como gás de transporte. Anestesia com baixo fluxo (1 L.min-1) foi iniciada após um período de 10 minutos de alto fluxo inicial (4,4 L.min-1). Os valores de pressão arterial, frequência cardíaca, saturação periférica de O2, isoflurano inspiratório e expiratório, O2 inspiratório e expiratório, N2O inspiratório e expiratório, CO2 inspiratório, concentração de CO2 após expiração e concentração alveolar mínima foram registrados. Além disso, as taxas de consumo total de fentanil, dexmedetomidina e isoflurano, bem como de hemorragia, foram determinadas. RESULTADOS: A frequência cardíaca diminuiu em ambos os grupos após a carga de dexmedetomidina. Após a intubação, os valores do Grupo A foram maiores nos minutos um, três, cinco, 10 e 15. Após a intubação, os valores de hipotensão desejados foram alcançados em 5 minutos no Grupo N e em 20 minutos no grupo A. Os valores da CAM foram mais altos no Grupo N nos minutos um, três, cinco, 10 e 15 (p < 0,05). Os valores da FiO2 foram mais altos entre 5 e 60 minutos no Grupo A, enquanto foram mais altos no Grupo N aos 90 minutos (p < 0,05). Os valores de Fi Iso (isoflurano inspiratório) foram menores no Grupo N nos minutos 15 e 30 (p < 0,05). CONCLUSÃO: O uso de dexmedetomidina em vez de óxido nitroso em anestesia com isoflurano pela técnica de baixo fluxo atingiu os níveis desejados de pressão arterial média (PAM), profundidade suficiente da anestesia, estabilidade hemodinâmica e parâmetros de inspiração seguros. A infusão de dexmedetomidina com oxigênio-ar medicinal como gás de transporte é uma técnica anestésica opcional.

Palavras-chave

ANALGÉSICOS, Dexmedetomidina, ANESTÉSICOS, Gasoso, óxido nitroso, HIPOTENSÃO CONTROLADA, TÉCNICAS ANESTÉSICAS, Geral, inalatória, baixo fluxo

Abstract

BACKGROUND AND OBJECTIVES: We investigated the effect of Nitrous Oxide (N2O) on controlled hypotension in low-flow isoflurane-dexmedetomidine anesthesia in terms of hemodynamics, anesthetic consumption, and costs. METHODS: We allocated forty patients randomly into two equal groups. We then maintained dexmedetomidine infusion (0.1 µg.kg-1.min-1) for 10 minutes. Next, we continued it until the last 30 minutes of the operation at a dose of 0.7 µg.kg-1.hour-1. We administered thiopental (4-6 mg. kg-1) and 0.08-0.12 mg.kg-1 vecuronium bromide at induction for both groups. We used isoflurane (2%) for anesthesia maintenance. Group N received a 50% O2-N2O mixture and Group A received 50% O2-air mixture as carrier gas. We started low-flow anesthesia (1 L.min-1) after a 10-minute period of initial high flow (4.4 L.min-1). We recorded values for blood pressure, heart rate, peripheral O2 saturation, inspiratory isoflurane, expiratory isoflurane, inspiratory O2, expiratory O2, inspiratory N2O, expiratory N2O, inspiratory CO2, CO2 concentration after expiration, Minimum Alveolar Concentration. In addition, we determined the total consumption rate of fentanyl, dexmedetomidine and isoflurane as well as bleeding. RESULTS: In each group the heart rate decreased after dexmedetomidine loading. After intubation, values were higher for Group A at one, three, five, 10, and 15 minutes. After intubation, the patients reached desired hypotension values at minute five for Group N and at minute 20 for group A. MAC values were higher for Group N at minute one, three, five, 10, and 15 (p < 0.05). FiO2 values were high between minute five and 60 for Group A, while at minute 90 Group N values were higher (p < 0.05). Fi Iso (inspiratuvar isofluran) values were lower in Group N at minute 15 and 30 (p < 0.05). CONCLUSION: By using dexmedetomidine instead of nitrous oxide in low flow isoflurane anesthesia, we attained desired MAP levels, sufficient anesthesia depth, hemodynamic stability and safe inspiration parameters. Dexmedetomidine infusion with medical air-oxygen as a carrier gas represents an alternative anesthetic technique.

Keywords

Hypotension, Controlled, Anesthesia, Closed-Circuit, Nitrous Oxide, Dexmedetomidine

References

Van Aken H, Miller Jr ED. Deliberate hypotension. Anesthesia. 2000:1470-1490.

Degoute CS, Dubreuil C, Ray MJ. Effects of posture, hypotension, and locally applied vasoconstriction on the middle ear microcirculation in anaesthetized humans. Eur J Appl Physiol. 1994;69:414-420.

Boezaart AP, van der Merwe J, Coetzee AR. Comparison of sodium nitroprusside and esmolol-induced controlled hypotension for functional endoscopic sinus surgery. Can J Anaesth. 1995;42:373-376.

Pilli G, Güzeldemir ME, Bayhan N. Esmolol for hypotensive anesthesia in middle ear surgery. Acta Anaesthesiol Belg. 1996;47:85-91.

Pavlin JD, Colley PS, Weymuller EA Jr. Propofol versus isoflurane for endoscopic sinus surgery. Am J Otolaryngol. 1999;20:96-101.

Madsen JB, Cold GE, Hansen ES, Bardrum B, Kruse-Larsen C. Cerebral blood flow and metabolism during isoflurane-induced hypotension in patients subjected to surgery for cerebral aneurysms. Br J Anaesth. 1987;59:1204-1207.

Toivonen J, Kaukinen S. Clonidine premedication: a useful adjunct in producing deliberate hypotension. Acta Anaesth Scand. 1990;34:653-357.

Woodcock TE, Millard RK, Dixon J, Prys-Roberts C. Clonidine premedication for isoflurane-induced hypotension: Sympathoadrenal responses and a computer-controlled assessment of the vapour requirement. Br J Anaesth. 1988;60:388-394.

Aho M, Lehtinen AM, Erkola O, Kallio A, Korttila K. The effect of intravenously administered dexmedetomidine on perioperative hemodynamics and isoflurane requirements in patients undergoing abdominal hysterectomy. Anesthesiology. 1991;74:997-1002.

Ülger HM, Demirbilek S, Köroğlu A, Borazan H, Ersoy MÖ. Orta kulak cerrahisinde dexmedetomidin ile kontrollü hipotansiyon. İnönü Üniversitesi Tıp Fakültesi Dergisi. 2004;11:237-241.

Imberti R, Preseglio I, Imbriani M, Ghittori S, Cimino F, Mapelli A. Low flow anaesthesia reduces occupational exposure to inhalation anaesthetics. Acta Anaesthesiol Scand. 1995;39:586-591.

Baum JA. Low flow anaesthesia in clinical practice. Low flow anaesthesia: The theory and practice of low flow, minimal flow, and closed system anaesthesia. 2001:220-268.

Tobias JD, Berkenbosch JW. Paediatr Anaesth.. 2002;12:171-175.

Baxter AD. Low and minimal flow inhalation anaesthesia. Can J Anaesth. 1997:643-653.

Baum JA, Aitkenhead AR. Low-flow anaesthesia. Anaesthesia. 1995;50(^sSuppl):37-44.

F Barton, Nunn JF. Totally closed circuit nitrous oxide/oxygen anaesthesia. Br J Anaesth. 1975;47(3):350-357.

Aantaa R, Jaakola M-L, Kallio A, Kanto . Reduction of the minimum alveolar concentration of usoflurane by dexmedetomidine. Anesthesiology. 1997;86:1055-1060.

Bertrand D, Boivin G, Manel J, Laxenaire MC. Effects of isoflurane on bleeding in microsurgery of the middle ear. Ann Fr Anesth Reanim. 1987;6:416-418.

Lam AM, Gelb AW. Cardiovascular effects of isoflurane-induced hypotension for cerebral aneurysm surgery. Anesth Analg. 1983;62:742-748.

Van Aken H, Fitch W, Graham DI, Brüssel T, Themann H. Cardiovascular and cerebrovascular effects of isofluraneinduced hypotension in the baboon. Anesth Analg. 1986;65:565-574.

Macnab MS, Manninen PH, Lam AM, Gelb AW. The stress response to induced hypotension for cerebral aneurysm surgery: a comparison of two hypotensive techniques. Can J Anaesth. 1988;35:111-115.

Newman B, Gelb AW, Lam AM. The effect of isoflurane-induced hypotension on cerebral blood flow and cerebral metabolic rate for oxygen in humans. Anesthesiology. 1986;64:307-310.

Haraldsted VY, Asmussen J, Herlevsen P, Cold GE. Cerebral arteriovenous difference of oxygen during gradual and sudden increase of the concentration of isoflurane for induction of deliberate hypotension. Acta Anaesthesiol Scand. 1992;36:142-144.

Dal D, Çeliker V, Özer E, Başgül E, Salman MA, Aypar Ü. Induced hypotension for tympanoplasty: a comparison of desflurane, isoflurane and sevoflurane. Eur J Anaesthesiol. 2004;21:902-906.

Kick O, Van Aken H, Wouters PF, Verbesselt K, Van Hemelrijck J. Vital organ blood flow during deliberate hypotension in dogs. Anesth Analg. 1993;77:737-742.

Toivonen J, Virtanen H, Kaukinen S. Labetalol attenuates the negative effects of deliberate hypotension induced by isoflurane. Acta Anaesthesiol Scand. 1992;36:84-88.

Nicholas JF, Lam AM. Isoflurane-induced hypotension does not cause impairment in pulmonary gas exchange. Can Anaesth Soc J. 1984;31:352-358.

Aantaa R, Jaakola ML, Kallio A, Kanto J, Scheinin M, Vuorinen J. A comparison of dexmedetomidine, and alpha 2-adrenoceptor agonist, and midazolam as i.m. premedication for minor gynecological surgery. Br J Anaesth. 1991;67:402-409.

Jaakola ML, Ali-Melkkilä T, Kanto J, Kallio A, Scheinin H, Scheinin M. Dexmedetomidine reduces intraocular pressure, intubation responses and anaesthetic requirements in patients undergoing ophthalmic surgery. Br J Anaesth. 1992;68:570-575.

Watts A, Luney SR, Lee D, Gelb AW. Effect of nitrous oxide on cerebral blood flow velocity after induction of hypocapnia. J Neurosurg Anaesthesiol. 1998;10:142-145.

Morgan GE, Mikhail MS, Murray MJ, Larson CP. Clinical Anesthesiology. 2001.

Bozkurt P, Saygı NE, Tomatır E, Yeker Y. N2O-free low-flow anesthesia technique for children. Acta Anaesthesiol Scand. 2005;49:1330-1333.

5dd42a530e88251b27c63493 rba Articles
Links & Downloads
2352-2291 (Electronic) 0104-0014 (Printed)
Braz J Anesthesiol ©2024 All rights reserved.

Braz J Anesthesiol

Share this page
Page Sections