Right heart function during one‐lung ventilation – observations using transoesophageal echocardiography

Abstract

Coronary artery bypass grafting (CABG) is a common surgical procedure with over 19 000 cases carried out in the UK in 2006 ⁄ 07. Persistent chest wall pain following cardiac surgery was termed Post-CABG Pain Syndrome (PCPS) in 1989 [1]. It has a reported incidence of up to 56% and is recognised as an important postoperative complication [2]. Currently PCPS is not considered in our patients' consent procedure. We undertook a survey of 100 CABG patients in order to determine the incidence of PCPS in our population. MethodsWe obtained local ethics committee approval for this structured questionnaire. One hundred consecutive CABG patients were contacted by telephone 8-10 months after their operation. Post CABG Pain Syndrome was defined using previously published criteria [1, 2]: postoperative chest pain (right, left or midline) persisting for more than 3 months. The pain was qualified in terms of its site, nature, severity, neuropathic component, need for analgesics and effect on sleep and activities of daily living. Data were analysed using Fisher's exact test with Bonferroni correction for multiple comparisons and unpaired Student's t-test. A separate questionnaire completed by cardiac surgeons asked about their perceived incidence of PCPS. ResultsCompleted datasets were available for 79 patients; 46% patients met the criteria for a diagnosis of PCPS. Analysis revealed statistically significant higher mean pain scores on ICU (p = 0.012), the ward (p = 0.046) and on discharge (p = 0.024) in the patients with PCPS. Subgroup analysis of other previously reported risk factors for PCPS failed to reach statistical significance. The cardiac surgeons estimated the incidence of PCPS to be 0.01-5%. DiscussionThis study reveals a high incidence (46%) of PCPS in our population that is greatly underestimated by our cardiac surgeons. Our data show that increased postoperative pain is a risk factor for developing PCPS. This is consistent with evidence following other types of surgery [3]. Limitations of this study include selection bias and a small sample size. We conclude that PCPS is a significant when seeking patients' consent. We intend to investigate the link between increased complication that should be included postoperative pain and PCPS further. Treatment-related factors predisposing to chronic pain in patients with breast cancer.

One Lung Ventilation as a Cause of Obstructive Shock

“…However, it has been shown to increase right ventricular end diastolic area but has no effect on right ventricle fractional area change or tricuspid annular plane systolic excursion [7]. This increase in right ventricular end diastolic area is thought to be due to the increase in ventricular after-load from one-lung-ventilation being compensated by an increase in preload in order to maintain stroke volume [8].…”

Transesophageal echocardiography in thoracic anesthesia

“…It may be helpful to guide the decision to initiate cardiopulmonary bypass and to evaluate response to fluid and vasoactive therapy [10 && ,48]. Reduction in RV function is less consistent [49], however it may occur [50], and is more exaggerated with volume-controlled than pressure-controlled ventilation [51 & ]. There are some theoretical advantages in early detection of RV dysfunction and accurate titration of fluid and vasoactive therapy for major thoracic procedures, such as pneumonectomy or lung volume reduction surgery in high-risk patients [10 && ].…”

Anesthetic Management of the Patient With Dilated Cardiomyopathy Undergoing Pulmonary Resection Surgery

“…Despite buffering effects, increases in PVR and PAPs can occur with the onset of OLV, 48,52 creating conditions of increased afterload for the RV. This in turn causes an increase in RV dimensions during both systole 55 and diastole. 52,55 The former is likely a direct result of increased afterload; the latter may represent a compensatory preload reserve effect.…”

“…Perhaps these factors help explain the wide variation seen in animal and clinical studies of OLV and hemodynamics. The initiation of OLV has been correlated with an increase, [48][49][50][51] decrease, [52][53][54] and no change [54][55][56][57][58][59][60] in cardiac output in patients undergoing OLV.…”

“…This in turn causes an increase in RV dimensions during both systole 55 and diastole. 52,55 The former is likely a direct result of increased afterload; the latter may represent a compensatory preload reserve effect. 55 The degree to which RV afterload is increased after the onset of OLV is likely to be affected by the degree to which HPV contracts the pulmonary vascular volume of the nonventilated lung; hypercapnia 67 ; the method of oxygen delivery to the nonventilated lung 50,52 ; surgical factors, including pleural insufflation, thoracotomy, and direct lung compression; and specific anesthetics.…”