Effect of thoracic epidural anaesthesia on ventilation= perfusion distribution and intrathoracic blood volume before and after induction of general anaesthesia

Hachenberg, T.; Holst, D.; Ebel, C.; Pfeiffer, B.; Thomas, H.; Wendt, Michael; Hedenstierna, Göran

doi:10.1111/j.1399-6576.1997.tb04856.x

Cited by 27 publications

(9 citation statements)

References 18 publications

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“…Neither the arterial-alveolar difference in P O 2 (Aa DO 2 ) nor the direct measurement of shunt showed any significant difference [12,13].…”

Section: Thoracic Epidural Anesthesiamentioning

confidence: 99%

Epidural anesthesia and pulmonary function

Groeben¹

2006

J Anesth

107

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The epidural administration of local anesthetics can provide anesthesia without the need for respiratory support or mechanical ventilation. Nevertheless, because of the additional effects of epidural anesthesia on motor function and sympathetic innervation, epidural anesthesia does affect lung function. These effects, i.e., a reduction in vital capacity (VC) and forced expiratory volume in 1 s (FEV(1.0)), are negligible under lumbar and low thoracic epidural anesthesia. Going higher up the vertebral column, these effects can increase up to 20% or 30% of baseline. However, compared with postoperative lung function following abdominal or thoracic surgery without epidural anesthesia, these effects are so small that the beneficial effects still lead to an improvement in postoperative lung function. These results can be explained by an improvement in pain therapy and diaphragmatic function, and by early extubation. In chronic obstructive pulmonary disease (COPD) patients, the use of thoracic epidural anesthesia has raised concerns about respiratory insufficiency due to motor blockade, and the risk of bronchial constriction due to sympathetic blockade. However, even in patients with severe asthma, thoracic epidural anesthesia leads to a decrease of about 10% in VC and FEV(1.0) and no increase in bronchial reactivity. Overall, epidural administration of local anesthetics not only provides excellent anesthesia and analgesia but also improves postoperative outcome and reduces postoperative pulmonary complications compared with anesthesia and analgesia without epidural anesthesia.

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“…Neither the arterial-alveolar difference in P O 2 (Aa DO 2 ) nor the direct measurement of shunt showed any significant difference [12,13].…”

Section: Thoracic Epidural Anesthesiamentioning

confidence: 99%

Epidural anesthesia and pulmonary function

Groeben¹

2006

J Anesth

107

View full text Add to dashboard Cite

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“…Although a significant SpO 2 decrease in Group R as compared to Group B, in moments M6 and M7 (exactly the moments of high UA pressures and low lung compliance), this was not clinically significant. Considering that both SpO 2 and P ET CO 2 remained within normal levels 20,21 and that there were no major changes in hemodynamic parameters related to thoracic epidural anesthesia 22 as opposed to what has been observed by other authors 24,25 , it is possible that the proposed combined technique has not affected V/Q ratio, intrathoracic blood flow or post-induction short-circuit, as shown by Hahenberg et al 23 . MAC values point to the need of a deeper anesthesia in moments of higher stimuli (M4, M7 and M8).…”

Section: Discussionmentioning

confidence: 39%

“…Apesar de verificada uma queda estaticamente significativa da SpO 2 no Grupo R em relação ao Grupo B nos momentos M6 e M7 (justamente os momentos de alta pressão nas VAS e baixa complacência pulmonar), não teve nenhuma importân-cia clínica. Considerando que tanto a SpO 2 como a P ET CO 2 permaneceram dentro dos limites da normalidade 20,21 e que não houve grandes alterações nos parâmetros hemodinâmi-cos relacionados à peridural torácica 22 , ao contrário do observado por outros autores 24,25 , é possível que a técnica combinada proposta não tenha afetado a relação V/Q, o volume de sangue intratorácico ou o curto-circuito após a indução, conforme demonstrado por Hahenberg e col. 23 .…”

Section: Discussionunclassified

Estudo comparativo entre bupivacaína a 0,25% e ropivacaína a 0,2% em anestesia peridural para cirurgia torácica

Novaes¹,

Francisco²,

Pimenta³

et al. 2001

Rev. Bras. Anestesiol.

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“…and of reduced EtCO 2 in the bupivacaine group suggests a ventilation-to-perfusion mismatch, probably secondary to the respiratory component, since there was no documented shift in the distribution of intrathoracic blood volume or pulmonary blood volume during epidural anesthesia. 22 Increased smooth muscle tone or stimulation of other contractile elements in the airways induced by TEA should be associated with increased airway resistance. Although the values of respiratory system resistance (R, rs and its components) and interrupter lung resistance (Rmin, L) found in both groups were signifi cantly higher than the corresponding values previously reported in normal anesthetically paralyzed humans, 23 no signifi cantly higher values were found in the bupivacaine group.…”

Section: Discussionmentioning

confidence: 99%

Thoracic sympathetic block reduces respiratory system compliance

2007

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ORIGINAL ARTICLE INTRODUCTIONAdequate postoperative analgesia is considered to be a major key for reducing pul monary morbidity and improving the outcome. l-3 Thoracic epidural anesthesia (TEA) has been proposed as a reliable analgesic method following thoracic surgery.3 Most of these benefi ts, however, relate to the postoperative or to the so-called perioperative period. Some case reports have suggested that sympathetic block secon dary to thoracic or spinal anesthesia might cause impaired intraoperative ventilation by increasing airway resistance and bronchial reactivity. 4,5 A similar controversy surrounds some aspects of respiratory mechanics in anesthetized humans. Although previous studies have demonstrated that systemic local anesthetic secondary to TEA does not alter airway resistance in humans, and even attenuates bronchial hyperreactivity, 6,7 the effects of thoracic sympathetic block on respiratory mechanics, particularly on its compliance, have been poorly explained.Pressure-volume curves are a feasible method for studying respiratory system mechanics, and the use of a low-fl ow infl ation technique has been established as a reliable and quick method for obtaining these curves. 8,9 The remaining doubts are whether the advantageous postoperative effects of TEA begin intraoperatively, and whether these benefi ts outweigh the undesirable intraoperative effects of thoracic sympathetic block. OBJECTIVETo evaluate the effects of intraoperative thoracic sympathetic block on the elastic, viscoelastic and resistive properties of the respiratory system and its components (chest wall and pulmonary parenchyma), through analysis of pressure-volume curves obtained under quasi-static conditions. METHODS Patient selection Patient selectionPatients requiring pulmonary segmental resection, pulmonary lobectomy, pulmonary biopsy or mediastinal nodular resection were eligible for the study. Those classifi ed on the American Society of Anesthesiologists (ASA) scale as having a physical status score of 3 or higher were excluded, as were those presenting with moderate or severe obstructive respiratory disease, or any degree of restrictive respiratory disease, as diagnosed by spirometry and/or clinical signs. Written informed consent was obtained from each patient, and the study was approved by the hospital's Ethics Committee.Patients were randomly assigned to one of two anesthetic solutions that were injected into the epidural space: 15 ml of 0.5% bupivacaine plus epinephrine 1:200,000 and 2 mg morphine chlorohydrate (bupivacaine group), or 15 ml 0.9% NaCl plus epinephrine 1:200,000 and 2 mg morphine chlorohydrate (placebo group). Randomization and blindness were achieved by having an anesthesiologist who was not involved in the study make the draw for the two solutions by means of a randomization table that identifi ed the patients. Anesthesia AnesthesiaAll patients were administered epidural and general anesthesia. They were premedicated with 10 mg of diazepam orally the night before surgery and 0.1 mg/kg of ...

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Effect of thoracic epidural anaesthesia on ventilation= perfusion distribution and intrathoracic blood volume before and after induction of general anaesthesia

Abstract: TEA has no effect on VA/Q distribution, gas exchange and intrathoracic blood volume in the awake state and does not influence development of Qs/QT and VA/Q inequality after induction of general anaesthesia.

Cited by 27 publications

References 18 publications

Epidural anesthesia and pulmonary function

Epidural anesthesia and pulmonary function

Estudo comparativo entre bupivacaína a 0,25% e ropivacaína a 0,2% em anestesia peridural para cirurgia torácica

Thoracic sympathetic block reduces respiratory system compliance

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