Brazilian Journal of Anesthesiology
https://app.periodikos.com.br/journal/rba/article/doi/10.1590/S0034-70942004000200004
Brazilian Journal of Anesthesiology
Scientific Article

Análise do comportamento do hemometabolismo cerebral durante endarterectomia carotídea com pinçamento transitório

Analysis of brain hemometabolism behavior during carotid endarterectomy with temporary clamping

Gastão Fernandes Duval Neto; Augusto H. Niencheski

http://dx.doi.org/10.1590/S0034-70942004000200004 Braz J Anesthesiol, vol.54, n2, p.162-177, 2004
PDF Português
PDF English
Downloads: 0
Views: 1066

Resumo

JUSTIFICATIVA E OBJETIVOS: A endarterectomia carotídea com pinçamento transitório altera a relação entre o fluxo sangüíneo cerebral e a demanda metabólica cerebral de oxigênio, com conseqüente geração de uma tendência a hipóxia oliguêmica ou desacoplamento hemometabólico. O objetivo do presente estudo foi identificar as alterações do hemometabolismo cerebral, avaliados através das alterações da saturação da oxihemoglobina no bulbo da veia jugular interna (SjO2), durante endarterectomia carotídea com pinçamento, correlacionando essas alterações com fatores com potencialidade de interferir com as mesmas, principalmente a pressão de CO2 expirada (P ET CO2) e a pressão de perfusão cerebral (PPC). MÉTODO: Participaram do estudo 16 pacientes com doença estenosante unilateral e submetidos a pinçamento arterial transitório durante endarterectomia carotídea. Os parâmetros monitorizados (saturação da oxihemoglobina no bulbo da veia jugular interna, stump pressure e a pressão de CO2 expirado) foram analisados nos seguintes momentos: M1 - pré-pinçamento; M2 - 3 minutos pós-pinçamento; M3 - pré- despinçamento; M4 - pós-despinçamento. RESULTADOS: A comparação entre a SjO2 (%, Média ± DP) nos períodos estudados evidenciou uma diferença entre a registrada nos momentos M1 (52,25 ± 7,87) e M2 (47,43 ± 9,19). Essa redução inicial estabilizou-se durante o pinçamento transitório, com diminuição na comparação entre M2 e M3 (46,56 ± 9,25), sem significado estatístico (p = ns). Na fase pós-despinçamento, M4 (47,68 ± 9,12), a média da SjO2 apresentou uma elevação, quando comparada com os momentos de pinçamento M2 e M3, ainda inferior ao momento pré-pinçamento M1 (M4 x M1 - p < 0,04). Essa diminuição da SjO2 foi acompanhada de diminuição significante da pressão de perfusão cerebral (stump pressure). Os fatores que influenciam essa tendência ao desacoplamento hemometabólico cerebral apresentaram um forte índice de correlação com a P ET CO2. A comparação entre a PPC e a SjO2 apresentou um fraco índice de correlação, sem significância estatística. CONCLUSÕES: Nas condições deste estudo a aferição da SjO2 é um modo de monitorização clínico efetivo e de rápida resposta na evidenciação das alterações da relação FSC/CCO2; o pinçamento carotídeo transitório implica em tendência ao desacoplamento hemometabólico cerebral e conseqüentemente, hipóxia oliguêmica; a PPC de forma isolada, não avalia a situação hemometabólica cerebral (relação entre FSC e o CCO2); a hipocapnia pode levar a situações de desacoplamento hemometabólico; a monitorização da P ET CO2 é forma inócua e eficiente de monitorizar a PaCO2, evitando situações de hipocapnia inadvertidas, com seus efeitos deletérios sobre a relação FSC/CCO2, durante pinçamento carotídeo transitório.

Palavras-chave

CIRURGIA, CIRURGIA, MONITORIZAÇÃO, MONITORIZAÇÃO

Abstract

BACKGROUND AND OBJECTIVES: Carotid endarterectomy with temporary clamping changes cerebral blood flow and cerebral metabolic oxygen demand ratio with consequent oligemic hypoxia or hemometabolic uncoupling. This study aimed at identifying changes in brain hemometabolism, evaluated through changes in oxyhemoglobin saturation in internal jugular vein bulb (SvjO2) during carotid endarterectomy with clamping, and at correlating these changes with potentially interfering factors, mainly end tidal CO2 pressure (P ET CO2) and cerebral perfusion pressure (CPP). METHODS: Sixteen patients with unilateral carotid stenotic disease scheduled to carotid endarterectomy with carotid arterial clamping were enrolled in this study. Parameters including internal jugular bulb oxyhemoglobin saturation, stump pressure and end tidal CO2 pressure were measured at the following moments: M1 - pre-clamping; M2 - 3 minutes after clamping; M3 - pre-unclamping; M4 - post-unclamping). RESULTS: The comparison among SvjO2 (%, mean ± SD) in all studied periods has shown differences between those recorded in moments M1 (52.25 ± 7.87) and M2 (47.43 ± 9.19). This initial decrease stabilized during temporary clamping, showing decrease in the comparison between M2 and M3 (46.56 ± 9.25), without statistical significance (p = ns). At post-unclamping, M4 (47.68 ± 9.12), SvjO2 was increased as compared to M2 and M3 clamping stages, however it was still lower than that of pre-clamping stage M1.(M4 x M1 - p < 0.04) This SvjO2 decrease was followed by significant cerebral perfusion pressure (stump pressure) decrease. Factors influencing this brain hemometabolic uncoupling trend were correlated to P ET CO2. The comparison between CPP and SvjO2 showed weak correlation devoid of statistical significance. CONCLUSIONS: In the conditions of our study, SvjO2 measurement is a fast and effective way of clinically monitoring changes in CBF/CMRO2 ratio. Temporary carotid clamping implies in a trend towards brain hemometabolic uncoupling and, as a consequence, to oligemic ischemia; cerebral perfusion pressure does not assesses brain hemometabolic status (CBF and CMRO2 ratio); hypocapnia, may lead to brain hemometabolic uncoupling; P ET CO2 monitoring is an innocuous and efficient way to indirectly monitor PaCO2 preventing inadvertent hypocapnia and its deleterious effects on CBF/CMRO2 ratio during temporary carotid clamping.

Keywords

MONITORING, MONITORING, SURGERY, SURGERY

Referencias

MCR European Carotid Surgery Trial: interim results for symptomatic patients with severe (70%-99%) or with mild (0%-29%) carotid stenosis. Lancet. 1991;337:1235-1243.

beneficial effect of carotid endarterectomy in symptomatic patients with high grade stenosis. N Engl J Med. 1991;325:445-453.

endarterectomy for asymptomatic carotid artery stenosis. JAMA. 1995;273:1421-1428.

Murie JA, Morris PJ. Carotid endarterectomy in Great Britain and Ireland: trends and current practice. Br J Surg. 1991;78:397-400.

John TG, Naylor AR, Howlett J. An audit of trends and current practice of carotid endarterectomy in Edinburgh (1975-1990). J R Coll Surg Edinb. 1993;38:138-141.

Till JS, Toole JF, Howard . Declining morbidity and mortality of carotid endarterectomy. 1987:823-829.

McCormick PW, Stewart M, Goetting MG. Noninvasive cerebral optical spectroscopy for monitoring cerebral oxygen delivery and hemodynamics. Crit Care Med. 1991;19:89-97.

Obrist W, Langfitt T, Cruz J. Cerebral blood flow and metabolism in comatose patients with acute head injury: Relationship to intracranial hypertension. J Neurosurg. 1984;61:241-253.

Andrews PJ, Dearden NM, Miller JD. Jugular bulb cannulation: description of a canulation technique and validation of a new continuous monitor. Br J Anaesth. 1991;67:553-558.

Cruz J. Hemometabolismo cerebral: de medidas isoladas a medidas de monitorização e terapêutica. Arquivos de Neuro-Psiquiatria. 1993;51:1-7.

Gibbs EL, Lennox WG, Nims LF. Arterial and cerebral venous blood: arterial-venous differences in man. J Biol Chem. 1942;144:325-332.

Lennox EL, Gibbs EL, Gibbs FA. Relationship of unconsciousness to cerebral blood flow and to anoxemia. Arch Neurol Psychiat. 1935;34:1001-1013.

Ferris E, Engel C, Stevens C. The validity of internal jugular venous blood in studies of cerebral metabolism and blood flow in man. Am J Physiol. 1946;147:517-521.

Feldman Z, Robertson CS. Monitoring of cerebral hemodynamics with jugular bulb catheters. Crit Care Clin. 1997;13:51-77.

Aram M, Poirier N, Laurent B. Correlation between cerebral oxygen saturation measured by nea-spectroscopy and jugular oxygen saturation in patients with severe closed head injury. Anesthesiology. 1999;91:985-989.

Matta BF, Lam AM, Mayberg TS. A critique of the intraoperative use of jugular catheter during neurosurgical procedures. Anesth Analg. 1994;79:745-750.

Hays RJ, Levinson SA, Wylie EJ. Intraoperative measurements of carotid back pressure as a guide to operative management for carotid endarterectomy. Surgery. 1972;72:953-960.

Lanier WL. Cerebral function monitoring during carotid endoarterectomy. J Neurosurg Anaesth. 1989;1:207-210.

Modica PA, Tempelhoff R. A comparison of computerized EEG with internal carotid artery stump pressure for detection of ischemia during carotid endarterectomy. J Neurosurg Anaesth. 1989:211-218.

Spencer MP, Thomas GI, Moehring MA. Relation between midle cerebral artery blood flow velocity and stump pressure during carotid endarterectomy. Stroke. 1992;23:1439-1445.

Finocchi C, Gandolfo C, Carissimi T. Role of transcranial Doppler and stump pressure during carotid endarterectomy. Stroke. 1997;28:2448-2452.

Niinai H, Nakagawa I, Shima T. Continuous monitoring of jugular bulb venous oxygen saturation for evaluation of cerebral perfusion during carotid endarterectomy. Hiroshima J Med Sci. 1998;47:133-137.

Koehler RC, Traystman RJ. Bicarbonate ion modulation of cerebral blood flow during hypoxia and hypercapnia. Am J Physiol. 1982;243:H33-H40.

Wollman H, Smith TC, Stephen GW. Effects of extremes of respiratory and metabolic alkalosis on cerebral blood flow in man. J Appl Physiol. 1968;24:60-65.

Pannier JL, Leusen I. Circulation to the brain of the rat during acute and prolonged respiratory changes in the acid-base balance. Pfluegers Arch. 1973;338:347-359.

Siesjo BK. Acidosis and ischemic brain damage. Neurochem Pathol. 1988;9:31-88.

Harper AM. Autoregulation of cerebral blood flow: influence of the arterial blood pressure on the blood flow through the cerebral cortex. J Neurol Neurosurg Psychiatry. 1966;29:398-403.

Paulson OB, Strandgaard S. Cerebral autoregulation. Cerebrovasc Brain Metab Rev. 1990;2:161-192.

Whitesell R, Asiddao C, Gollman D. Relationship between arterial and peak expired carbon dioxide pressure during anesthesia and factors influencing the difference. Anesth Analg. 1981;60:508-512.

Yamanaka MK, Sue DY. Comparison of arterial-end-tidal PCO2 difference and dead space/tidal volume ratio in respiratory failure. Chest. 1987;92:832-835.

Russell G, Graybeal JM. The arterial to end-tidal carbon dioxide difference in neurosurgical patients during craniotomy. Anesth Analg. 1995;81:806-810.

Deyne M, Vanthuyne S, Vandermeersch E. Cerebral CO2-reacivity is equally maintained by equipotent hypnotic doses of propofol or sevoflurane. Eur J Anesthesiology. 2001;18(^s21):68-72.

5dd7f0920e8825f00413f286 rba Articles
Links & Downloads
2352-2291 (Electrónico) 0104-0014 (Impreso)
Braz J Anesthesiol ©2024 Todos los derechos reservados.

Braz J Anesthesiol

Share this page
Page Sections