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Spontaneous Ear Hemorrhage During Cardiac Surgery

2012; Elsevier BV; Volume: 93; Issue: 3 Linguagem: Inglês

10.1016/j.athoracsur.2011.07.017

1552-6259

Karen Singh, David J. Cook, Rakesh M. Suri, Zhen Ren,

Atrial Fibrillation Management and Outcomes

A 79-year-old patient who underwent mitral valve replacement experienced prolonged elevated central venous pressure associated with poor venous return during a cardiopulmonary bypass. After the procedure, the patient was noted to have spontaneous bleeding from the left ear. Otolaryngologic examination in the operating room showed no trauma in the exterior auditory canal and suggested that the hemorrhage was related to a superior vena cava syndrome and anticoagulation during the cardiopulmonary bypass. Determinants and management considerations of poor venous return, including maintenance of cerebral perfusion pressure, are discussed. A 79-year-old patient who underwent mitral valve replacement experienced prolonged elevated central venous pressure associated with poor venous return during a cardiopulmonary bypass. After the procedure, the patient was noted to have spontaneous bleeding from the left ear. Otolaryngologic examination in the operating room showed no trauma in the exterior auditory canal and suggested that the hemorrhage was related to a superior vena cava syndrome and anticoagulation during the cardiopulmonary bypass. Determinants and management considerations of poor venous return, including maintenance of cerebral perfusion pressure, are discussed. Poor venous return to the cardiopulmonary bypass circuit is a common problem during cardiac surgery. Although common, this issue is usually brief and can be solved by repositioning the venous cannula. Sometimes cardiac anatomy or the specifics of the surgical situation limit the ability to address poor venous return and the frequent sequelae of high central venous pressure (CVP). Under these conditions, a variety of interventions can help to protect the patient from systemic hypoperfusion or potentially compromised cerebral perfusion pressure. This case report illustrates this scenario, the variety of interventions possible, and the unusual finding of spontaneous ear hemorrhage following prolonged elevated CVP in the context of anticoagulation for cardiopulmonary bypass (CPB).A 79-year-old woman with a history of atrial fibrillation, hypertension, rheumatic mitral stenosis, and tricuspid regurgitation presented for mitral replacement and tricuspid repair. After general anesthesia, a femoral arterial line and, via the right internal jugular vein, a 9F introducer and pulmonary artery catheter were placed. After sternotomy, the midascending aorta was cannulated as were the inferior vena cava and superior vena cava (SVC) with two right-angle venous cannulas. Cardiopulmonary bypass was initiated.The aorta was cross-clamped, and the heart was arrested with cardioplegia. The left atrium was opened with an incision posterior to the interatrial groove. Exposure of the mitral valve was facilitated with a fixed-position vein retractor. With cardiac retraction, the CVP was noted to be elevated an average of 30 to 40 mm Hg; this was associated with poor venous return to the bypass circuit, limiting total pump flow to less than the targeted value of 2.4 L · min · m2. The surgeon was notified, but attempts to reposition the SVC cannula did not result in improved venous return or lower CVP readings while allowing at the same time adequate exposure for operation. Vacuum-assisted venous drainage was next attempted but did not improve return or lower CVP. Total pump flow varied between 1.7 and 2.1 L · min · m2.Placement of the bioprosthetic mitral valve was challenging because of the heavily calcified annulus and the direct approach through the left atrium. Venous congestion of the head was observed and mixed venous saturation, monitored in the CPB circuit, began to slowly decrease. In an effort to preserve cerebral perfusion pressure, the mean arterial pressure (MAP) was increased to 80 mm Hg with phenylephrine infusion. The patient was also cooled from 32°C to 28°C to improve matching of systemic oxygen consumption and delivery and to reduce cerebral O2 consumption under the conditions of potentially reduced delivery. Average hemoglobin on bypass was 7.4 g/dL. Total bypass time was 124 minutes; the patient had CVP readings greater than 20 mm Hg for 110 minutes.At the end of the operation, upon removal of drapes, blood could be seen oozing from the patient's left ear. This was clearly not identified as "run down." An otolaryngologist's examination in the operating room confirmed that the bleeding was coming from disrupted epithelium in the outer ear canal. There was no blood behind the tympanic membrane. Because the external auditory canal was not instrumented, the presumption was that the bleeding was caused by persistently elevated venous pressure in the context of full anticoagulation. The patient was taken to the intensive care unit and extubated later that day. She was neurologically intact and made an uneventful recovery.CommentDuring cardiopulmonary bypass, venous return to the circuit is related to the central venous pressure, the height difference between the draining cannulae and the venous reservoir, and the resistance of the venous cannula and tubing system. Causes of decreased venous return include small cannula size, air lock, mechanical obstruction, or most commonly a poorly positioned cannula. A less common culprit can be a persistent left SVC draining into the coronary sinus [1Balasundaram S. al-Halees Z. Duran C.G. Persistent left superior vena cava: a simple technique for adequate drainage during cardiopulmonary bypass.J Cardiovasc Surg (Torino). 1991; 32: 59-61PubMed Google Scholar]. In some cases, a transesophageal echocardiogram can be a useful tool to help guide venous cannula placement and confirm proper positioning [2Iannoli E.D. The use of transesophageal echocardiography for differential diagnosis of poor venous return during cardiopulmonary bypass.Anesth Analg. 2007; 105: 43-44Crossref PubMed Scopus (8) Google Scholar].If the CVP measurement is obtained above the SVC cannula or snare, poor venous return will be reflected as an elevated CVP reading. If no increase in CVP reading occurs when running fluid through the sideport of the introducer, it can be assumed that the CVP port of the pulmonary artery catheter is caudal to the SVC cannula or snare and will not reflect true CVP. In this case, the CVP should be transduced through the sideport of the introducer [3Urdaneta F. Gravenstein N. Central venous pressure monitoring during bypass.Anesth Analg. 1999; 89: 1326-1327Crossref PubMed Scopus (1) Google Scholar].Vacuum-assisted venous drainage can augment gravity drainage in the setting of poor venous return. While often useful, this technique can lead to entrainment of air into the venous line, particularly in repeated operations. In addition, in vitro studies with CPB circuits have shown that large amounts of air, entrained with vacuum assist, might not be completely cleared by the arterial filter. This finding introduces the possibility of gaseous microemboli being present in the arterial circulation [4Lapietra A. Grossi E.A. Pua B.B. et al.Assisted venous drainage presents the risk of undetected air microembolism.J Thorac Cardiovasc Surg. 2000; 120: 856-862Abstract Full Text Full Text PDF PubMed Scopus (72) Google Scholar]. Regardless, vacuum assist is of limited value when the venous cannula is poorly positioned or partially obstructed.Besides the immediate clinical concern of reduced pump flow, decreased mean arterial pressure, and reduced oxygen delivery, impaired venous drainage can compromise cerebral perfusion pressure (CPP), (CPP = MAP – intracranial pressure (ICP) or CVP). Low CPP can decrease cerebral blood flow and cerebral oxygen delivery. In canines, Plochl and associates [5Plochl W. Cook D.J. Orszulak T.A. Daly R.C. Intracranial pressure and venous cannulation for cardiopulmonary bypass.Anesth Analg. 1999; 88: 329-331PubMed Google Scholar] found that decreased venous return caused by cannula malposition was clearly associated with elevated ICP. While cerebral blood flow is autoregulated over a wide range of perfusion pressures, perfusion pressures close to the lower limit are common during CPB, so increases in CVP or ICP are highly relevant. Elevated ICP is of even greater importance in an elderly cardiac surgical population whose age-related comorbidities can shift the autoregulatory curve to higher values [6Hartman G. Pro: during cardiopulmonary bypass for elective coronary artery bypass grafting, perfusion pressure should routinely be greater than 70 mmHg.J Cardiothorac Vasc Anesth. 1998; 12: 358-360Abstract Full Text PDF PubMed Scopus (15) Google Scholar].Other surgical approaches can reduce the risk of SVC torsion. A transseptal approach to the mitral valve typically requires less traction on the heart. Some have transected the SVC to roll the heart to improve exposure, whereas others have used a dual or triple venous cannula with the transseptal approach. It can be difficult to predict when a problem such as ours is likely, and once the direct left atrial approach is initiated and both cavae are cannulated it is difficult to change the approach. Nevertheless, other surgical approaches to the mitral and venous cannulation can reduce the likelihood of partial SVC obstruction.Poor venous return from the SVC can manifest similar to an acute SVC syndrome, with signs including plethora and possible cyanosis of the head and neck, distended neck veins, and conjunctival effusion. We conjecture that the bleeding ear was a combined result of persistently elevated CVP and heparinization on bypass. Fortunately, in this case of prolonged poor venous return, the patient suffered no long-term ill effects.The ideal solution to this problem is correction of cannula position or, as in this case, relieving torsion on the SVC. However, when surgical conditions prevent solution, a variety of graded interventions are indicated to improve venous return, balance systemic oxygen supply, and demand and improve cerebral perfusion pressure. Poor venous return to the cardiopulmonary bypass circuit is a common problem during cardiac surgery. Although common, this issue is usually brief and can be solved by repositioning the venous cannula. Sometimes cardiac anatomy or the specifics of the surgical situation limit the ability to address poor venous return and the frequent sequelae of high central venous pressure (CVP). Under these conditions, a variety of interventions can help to protect the patient from systemic hypoperfusion or potentially compromised cerebral perfusion pressure. This case report illustrates this scenario, the variety of interventions possible, and the unusual finding of spontaneous ear hemorrhage following prolonged elevated CVP in the context of anticoagulation for cardiopulmonary bypass (CPB). A 79-year-old woman with a history of atrial fibrillation, hypertension, rheumatic mitral stenosis, and tricuspid regurgitation presented for mitral replacement and tricuspid repair. After general anesthesia, a femoral arterial line and, via the right internal jugular vein, a 9F introducer and pulmonary artery catheter were placed. After sternotomy, the midascending aorta was cannulated as were the inferior vena cava and superior vena cava (SVC) with two right-angle venous cannulas. Cardiopulmonary bypass was initiated. The aorta was cross-clamped, and the heart was arrested with cardioplegia. The left atrium was opened with an incision posterior to the interatrial groove. Exposure of the mitral valve was facilitated with a fixed-position vein retractor. With cardiac retraction, the CVP was noted to be elevated an average of 30 to 40 mm Hg; this was associated with poor venous return to the bypass circuit, limiting total pump flow to less than the targeted value of 2.4 L · min · m2. The surgeon was notified, but attempts to reposition the SVC cannula did not result in improved venous return or lower CVP readings while allowing at the same time adequate exposure for operation. Vacuum-assisted venous drainage was next attempted but did not improve return or lower CVP. Total pump flow varied between 1.7 and 2.1 L · min · m2. Placement of the bioprosthetic mitral valve was challenging because of the heavily calcified annulus and the direct approach through the left atrium. Venous congestion of the head was observed and mixed venous saturation, monitored in the CPB circuit, began to slowly decrease. In an effort to preserve cerebral perfusion pressure, the mean arterial pressure (MAP) was increased to 80 mm Hg with phenylephrine infusion. The patient was also cooled from 32°C to 28°C to improve matching of systemic oxygen consumption and delivery and to reduce cerebral O2 consumption under the conditions of potentially reduced delivery. Average hemoglobin on bypass was 7.4 g/dL. Total bypass time was 124 minutes; the patient had CVP readings greater than 20 mm Hg for 110 minutes. At the end of the operation, upon removal of drapes, blood could be seen oozing from the patient's left ear. This was clearly not identified as "run down." An otolaryngologist's examination in the operating room confirmed that the bleeding was coming from disrupted epithelium in the outer ear canal. There was no blood behind the tympanic membrane. Because the external auditory canal was not instrumented, the presumption was that the bleeding was caused by persistently elevated venous pressure in the context of full anticoagulation. The patient was taken to the intensive care unit and extubated later that day. She was neurologically intact and made an uneventful recovery. CommentDuring cardiopulmonary bypass, venous return to the circuit is related to the central venous pressure, the height difference between the draining cannulae and the venous reservoir, and the resistance of the venous cannula and tubing system. Causes of decreased venous return include small cannula size, air lock, mechanical obstruction, or most commonly a poorly positioned cannula. A less common culprit can be a persistent left SVC draining into the coronary sinus [1Balasundaram S. al-Halees Z. Duran C.G. Persistent left superior vena cava: a simple technique for adequate drainage during cardiopulmonary bypass.J Cardiovasc Surg (Torino). 1991; 32: 59-61PubMed Google Scholar]. In some cases, a transesophageal echocardiogram can be a useful tool to help guide venous cannula placement and confirm proper positioning [2Iannoli E.D. The use of transesophageal echocardiography for differential diagnosis of poor venous return during cardiopulmonary bypass.Anesth Analg. 2007; 105: 43-44Crossref PubMed Scopus (8) Google Scholar].If the CVP measurement is obtained above the SVC cannula or snare, poor venous return will be reflected as an elevated CVP reading. If no increase in CVP reading occurs when running fluid through the sideport of the introducer, it can be assumed that the CVP port of the pulmonary artery catheter is caudal to the SVC cannula or snare and will not reflect true CVP. In this case, the CVP should be transduced through the sideport of the introducer [3Urdaneta F. Gravenstein N. Central venous pressure monitoring during bypass.Anesth Analg. 1999; 89: 1326-1327Crossref PubMed Scopus (1) Google Scholar].Vacuum-assisted venous drainage can augment gravity drainage in the setting of poor venous return. While often useful, this technique can lead to entrainment of air into the venous line, particularly in repeated operations. In addition, in vitro studies with CPB circuits have shown that large amounts of air, entrained with vacuum assist, might not be completely cleared by the arterial filter. This finding introduces the possibility of gaseous microemboli being present in the arterial circulation [4Lapietra A. Grossi E.A. Pua B.B. et al.Assisted venous drainage presents the risk of undetected air microembolism.J Thorac Cardiovasc Surg. 2000; 120: 856-862Abstract Full Text Full Text PDF PubMed Scopus (72) Google Scholar]. Regardless, vacuum assist is of limited value when the venous cannula is poorly positioned or partially obstructed.Besides the immediate clinical concern of reduced pump flow, decreased mean arterial pressure, and reduced oxygen delivery, impaired venous drainage can compromise cerebral perfusion pressure (CPP), (CPP = MAP – intracranial pressure (ICP) or CVP). Low CPP can decrease cerebral blood flow and cerebral oxygen delivery. In canines, Plochl and associates [5Plochl W. Cook D.J. Orszulak T.A. Daly R.C. Intracranial pressure and venous cannulation for cardiopulmonary bypass.Anesth Analg. 1999; 88: 329-331PubMed Google Scholar] found that decreased venous return caused by cannula malposition was clearly associated with elevated ICP. While cerebral blood flow is autoregulated over a wide range of perfusion pressures, perfusion pressures close to the lower limit are common during CPB, so increases in CVP or ICP are highly relevant. Elevated ICP is of even greater importance in an elderly cardiac surgical population whose age-related comorbidities can shift the autoregulatory curve to higher values [6Hartman G. Pro: during cardiopulmonary bypass for elective coronary artery bypass grafting, perfusion pressure should routinely be greater than 70 mmHg.J Cardiothorac Vasc Anesth. 1998; 12: 358-360Abstract Full Text PDF PubMed Scopus (15) Google Scholar].Other surgical approaches can reduce the risk of SVC torsion. A transseptal approach to the mitral valve typically requires less traction on the heart. Some have transected the SVC to roll the heart to improve exposure, whereas others have used a dual or triple venous cannula with the transseptal approach. It can be difficult to predict when a problem such as ours is likely, and once the direct left atrial approach is initiated and both cavae are cannulated it is difficult to change the approach. Nevertheless, other surgical approaches to the mitral and venous cannulation can reduce the likelihood of partial SVC obstruction.Poor venous return from the SVC can manifest similar to an acute SVC syndrome, with signs including plethora and possible cyanosis of the head and neck, distended neck veins, and conjunctival effusion. We conjecture that the bleeding ear was a combined result of persistently elevated CVP and heparinization on bypass. Fortunately, in this case of prolonged poor venous return, the patient suffered no long-term ill effects.The ideal solution to this problem is correction of cannula position or, as in this case, relieving torsion on the SVC. However, when surgical conditions prevent solution, a variety of graded interventions are indicated to improve venous return, balance systemic oxygen supply, and demand and improve cerebral perfusion pressure. During cardiopulmonary bypass, venous return to the circuit is related to the central venous pressure, the height difference between the draining cannulae and the venous reservoir, and the resistance of the venous cannula and tubing system. Causes of decreased venous return include small cannula size, air lock, mechanical obstruction, or most commonly a poorly positioned cannula. A less common culprit can be a persistent left SVC draining into the coronary sinus [1Balasundaram S. al-Halees Z. Duran C.G. Persistent left superior vena cava: a simple technique for adequate drainage during cardiopulmonary bypass.J Cardiovasc Surg (Torino). 1991; 32: 59-61PubMed Google Scholar]. In some cases, a transesophageal echocardiogram can be a useful tool to help guide venous cannula placement and confirm proper positioning [2Iannoli E.D. The use of transesophageal echocardiography for differential diagnosis of poor venous return during cardiopulmonary bypass.Anesth Analg. 2007; 105: 43-44Crossref PubMed Scopus (8) Google Scholar]. If the CVP measurement is obtained above the SVC cannula or snare, poor venous return will be reflected as an elevated CVP reading. If no increase in CVP reading occurs when running fluid through the sideport of the introducer, it can be assumed that the CVP port of the pulmonary artery catheter is caudal to the SVC cannula or snare and will not reflect true CVP. In this case, the CVP should be transduced through the sideport of the introducer [3Urdaneta F. Gravenstein N. Central venous pressure monitoring during bypass.Anesth Analg. 1999; 89: 1326-1327Crossref PubMed Scopus (1) Google Scholar]. Vacuum-assisted venous drainage can augment gravity drainage in the setting of poor venous return. While often useful, this technique can lead to entrainment of air into the venous line, particularly in repeated operations. In addition, in vitro studies with CPB circuits have shown that large amounts of air, entrained with vacuum assist, might not be completely cleared by the arterial filter. This finding introduces the possibility of gaseous microemboli being present in the arterial circulation [4Lapietra A. Grossi E.A. Pua B.B. et al.Assisted venous drainage presents the risk of undetected air microembolism.J Thorac Cardiovasc Surg. 2000; 120: 856-862Abstract Full Text Full Text PDF PubMed Scopus (72) Google Scholar]. Regardless, vacuum assist is of limited value when the venous cannula is poorly positioned or partially obstructed. Besides the immediate clinical concern of reduced pump flow, decreased mean arterial pressure, and reduced oxygen delivery, impaired venous drainage can compromise cerebral perfusion pressure (CPP), (CPP = MAP – intracranial pressure (ICP) or CVP). Low CPP can decrease cerebral blood flow and cerebral oxygen delivery. In canines, Plochl and associates [5Plochl W. Cook D.J. Orszulak T.A. Daly R.C. Intracranial pressure and venous cannulation for cardiopulmonary bypass.Anesth Analg. 1999; 88: 329-331PubMed Google Scholar] found that decreased venous return caused by cannula malposition was clearly associated with elevated ICP. While cerebral blood flow is autoregulated over a wide range of perfusion pressures, perfusion pressures close to the lower limit are common during CPB, so increases in CVP or ICP are highly relevant. Elevated ICP is of even greater importance in an elderly cardiac surgical population whose age-related comorbidities can shift the autoregulatory curve to higher values [6Hartman G. Pro: during cardiopulmonary bypass for elective coronary artery bypass grafting, perfusion pressure should routinely be greater than 70 mmHg.J Cardiothorac Vasc Anesth. 1998; 12: 358-360Abstract Full Text PDF PubMed Scopus (15) Google Scholar]. Other surgical approaches can reduce the risk of SVC torsion. A transseptal approach to the mitral valve typically requires less traction on the heart. Some have transected the SVC to roll the heart to improve exposure, whereas others have used a dual or triple venous cannula with the transseptal approach. It can be difficult to predict when a problem such as ours is likely, and once the direct left atrial approach is initiated and both cavae are cannulated it is difficult to change the approach. Nevertheless, other surgical approaches to the mitral and venous cannulation can reduce the likelihood of partial SVC obstruction. Poor venous return from the SVC can manifest similar to an acute SVC syndrome, with signs including plethora and possible cyanosis of the head and neck, distended neck veins, and conjunctival effusion. We conjecture that the bleeding ear was a combined result of persistently elevated CVP and heparinization on bypass. Fortunately, in this case of prolonged poor venous return, the patient suffered no long-term ill effects. The ideal solution to this problem is correction of cannula position or, as in this case, relieving torsion on the SVC. However, when surgical conditions prevent solution, a variety of graded interventions are indicated to improve venous return, balance systemic oxygen supply, and demand and improve cerebral perfusion pressure.