Cardiac tamponade results from a critical rise in intrapericardial pressure that affects cardiac filling.Acute cardiac tamponade results from an accumulation of fluid or blood in the pericardial space (cavity). The increased intrapericardial pressure is transmitted to the cardiac chambers and cardiac filling is compromised. The speed of accumlation and the quantity are both important in
deciding if tamponade ensues.
The causes and diagnosis of tamponade have been discussed in the section on pericarditis.Common causes presenting as an emergency are malignant effusion, viral or idiopathic pericarditis, renal failure and hemopericardium.The clinical features are dyspnea, sinus tachycardia,elevated JVP with a further rise during inspiration (Kussmal sign), pulsus paradoxus and a fall in BP and shock in some cases.
Echocardiography is the most important investigation. (See section on Pericarditis).
Pericardial Aspiration
• Obtain an echocardiogram before the pericardiocentesis procedure.
• Perform pericardiocentesis on patients with tamponade and life threatening hemodynamic stability without waiting for any test result.
• Non emergency aspirations should be carried out at a centre where additional investigations can be done on the fluid or a pericardial biopsy performed if necessary.
• Obtain basic blood work from these patients. If time permits, correct any clotting abnormality. Administer fresh frozen plasma if the effusion occurs from thrombolytics, and do not perform pericardiocentesis unless the tamponade is life threatening. Discontinue administration of heparin if the condition is caused by anticoagulation. Pericardiocentesis should be delayed until the clotting profile is normal or protamine is administered, unless the patient is unstable.
The pericardiocentesis procedure is as follows:
• Ensure that the patient is sitting at 30-45° head elevation, which increases pooling of fluid toward the inferior and anterior surface, thus maximizing fluid drainage.
• Select a site i.e. closest to the pericardial space, avoiding vital structures, such as the internal mammary artery, lungs, myocardium, liver, and vascular bundle at the inferior margin of each rib.
• Shave the skin carefully to avoid any trauma. Anesthetize the local site with lidocaine (1-2 per cent). Make a small incision (approximately 5 mm) to decrease the resistance during needle insertion. Separate the subcutaneous tissue with mosquito grasping forceps.
• Connect the needle with a 3-way stopcock. Ensure that the syringe with 1 per cent lidocaine is connected to the 3-way stopcock on the opposite side of the needle connection. Connect the transducer on the side of the 3-way stopcock. Attach a sterile ECG recorder to the metal part of the needle if available.
• Insert the needle through the subxiphoid approach on the left side under fluoroscopy and direct towards left shoulder. Advance the needle and syringe until the needle tip is posterior to the rib cage. The needle should be advanced toward the shoulder at an angle 15-20° fromthe abdominal wall. While advancing the needle toward the pericardial space, aspirate the syringe and inject lidocaine for a better analgesic effect. Continue to advance the needle until fluid is aspirated in the syringe or the ECG monitor shows ST elevation.
• Withdraw the needle slowly with negative pressure on the syringe if the ECG shows ST elevation after clearing the needle with lidocaine. Reinsert the needle in a different direction very slowly until fluid is aspirated in the syringe.
• When the needle tip is inside the pericardial space, a soft floppy-tip guidewire is passed through the needle. Wrap this guidewire around the heart. Remove the needle, and insert a soft catheter with multiple side holes like a pigtail catheter over this wire. Remove the guidewire. Connect the catheter hub with the transducer and syringe with a 3-way stopcock.Place the dressing, and secure the catheter to prevent displacement. Ensure that the catheter is flushed with 1-2 ml of fluid to prevent blockage.
• In a real emergency with hemodynamic collapse aspirate through the needle if a catheter is not available.
• The pericardial catheter can be left in the space for 24 hours with continuous closed drainage occurring, using gravity to increase drainage. The catheter should be removed after 24 hours,if possible, because it increases the chances of infection in the pericardial space. However,keeping the catheter in the pericardial space often is necessary to maintain drainage for longer periods. Negative suction should not be used to maximize the drainage.
• CT-guided pericardiocentesis is a new approach i.e. indicated specifically for patients in whom ultrasound-guided or radiograph-guided pericardiocentesis is unsuccessful.
• Pericardiocentesis with intrapericardial sclerotherapy also is effective in treating patients with malignant pericardial effusion.
deciding if tamponade ensues.
The causes and diagnosis of tamponade have been discussed in the section on pericarditis.Common causes presenting as an emergency are malignant effusion, viral or idiopathic pericarditis, renal failure and hemopericardium.The clinical features are dyspnea, sinus tachycardia,elevated JVP with a further rise during inspiration (Kussmal sign), pulsus paradoxus and a fall in BP and shock in some cases.
Echocardiography is the most important investigation. (See section on Pericarditis).
Pericardial Aspiration
• Obtain an echocardiogram before the pericardiocentesis procedure.
• Perform pericardiocentesis on patients with tamponade and life threatening hemodynamic stability without waiting for any test result.
• Non emergency aspirations should be carried out at a centre where additional investigations can be done on the fluid or a pericardial biopsy performed if necessary.
• Obtain basic blood work from these patients. If time permits, correct any clotting abnormality. Administer fresh frozen plasma if the effusion occurs from thrombolytics, and do not perform pericardiocentesis unless the tamponade is life threatening. Discontinue administration of heparin if the condition is caused by anticoagulation. Pericardiocentesis should be delayed until the clotting profile is normal or protamine is administered, unless the patient is unstable.
The pericardiocentesis procedure is as follows:
• Ensure that the patient is sitting at 30-45° head elevation, which increases pooling of fluid toward the inferior and anterior surface, thus maximizing fluid drainage.
• Select a site i.e. closest to the pericardial space, avoiding vital structures, such as the internal mammary artery, lungs, myocardium, liver, and vascular bundle at the inferior margin of each rib.
• Shave the skin carefully to avoid any trauma. Anesthetize the local site with lidocaine (1-2 per cent). Make a small incision (approximately 5 mm) to decrease the resistance during needle insertion. Separate the subcutaneous tissue with mosquito grasping forceps.
• Connect the needle with a 3-way stopcock. Ensure that the syringe with 1 per cent lidocaine is connected to the 3-way stopcock on the opposite side of the needle connection. Connect the transducer on the side of the 3-way stopcock. Attach a sterile ECG recorder to the metal part of the needle if available.
• Insert the needle through the subxiphoid approach on the left side under fluoroscopy and direct towards left shoulder. Advance the needle and syringe until the needle tip is posterior to the rib cage. The needle should be advanced toward the shoulder at an angle 15-20° fromthe abdominal wall. While advancing the needle toward the pericardial space, aspirate the syringe and inject lidocaine for a better analgesic effect. Continue to advance the needle until fluid is aspirated in the syringe or the ECG monitor shows ST elevation.
• Withdraw the needle slowly with negative pressure on the syringe if the ECG shows ST elevation after clearing the needle with lidocaine. Reinsert the needle in a different direction very slowly until fluid is aspirated in the syringe.
• When the needle tip is inside the pericardial space, a soft floppy-tip guidewire is passed through the needle. Wrap this guidewire around the heart. Remove the needle, and insert a soft catheter with multiple side holes like a pigtail catheter over this wire. Remove the guidewire. Connect the catheter hub with the transducer and syringe with a 3-way stopcock.Place the dressing, and secure the catheter to prevent displacement. Ensure that the catheter is flushed with 1-2 ml of fluid to prevent blockage.
• In a real emergency with hemodynamic collapse aspirate through the needle if a catheter is not available.
• The pericardial catheter can be left in the space for 24 hours with continuous closed drainage occurring, using gravity to increase drainage. The catheter should be removed after 24 hours,if possible, because it increases the chances of infection in the pericardial space. However,keeping the catheter in the pericardial space often is necessary to maintain drainage for longer periods. Negative suction should not be used to maximize the drainage.
• CT-guided pericardiocentesis is a new approach i.e. indicated specifically for patients in whom ultrasound-guided or radiograph-guided pericardiocentesis is unsuccessful.
• Pericardiocentesis with intrapericardial sclerotherapy also is effective in treating patients with malignant pericardial effusion.
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