《级麻醉学研究生》PPT课件.ppt

Abdominal compartment syndrome (ACS) REPORTER: 2006级麻醉学研究生 宋宗斌 DefinitionDefinition ACS: Symptomatic organ dysfunction that ACS: Symptomatic organ dysfunction that results from increased results from increased intra-abdominal pressure (IAP) intra-abdominal pressure (IAP) . . If the abdomen is closed, intra-abdominal If the abdomen is closed, intra-abdominal pressure may rise to a level (25 cmH2O) where it pressure may rise to a level (25 cmH2O) where it leads to significant cardiovascular, respiratory, renal leads to significant cardiovascular, respiratory, renal and cerebral dysfunctionand cerebral dysfunction Etiology Massive volume resuscitation in the leading cause of ACS. Inflammatory states with capillary leak, fluid sequestration, inadequate tissue perfusion, and lactic acidosis can develop ACS. Gastric overdistention following endoscopy has resulted in ACS. Pathophysiology Causes of acutely increased IAP Trauma or intra abdominal hemorrhage Abdominal surgery Retro-peritoneal hemorrhage Peritonitis Laparoscopy and pneumoperitoneum Repair of large incisional hernia Abdominal banding with postoperative Velcro belt to prevent incisional hernia Massive fluid resuscitation: 5 L in 24 hrs Ileus Pathophysiology The IAP is usually 0 mmHg during spontaneous respiration, and is slightly positive in the patient on mechanical ventilation. IAP increases in direct relation to body mass index, and in one report, supine hospitalized patients had a mean baseline value of 6.5 mmHg The compliance of the abdominal wall generally limits the rise in IAP but increases rapidly after a critical IAP. Critical IAP varies from patient to patient, based on abdominal wall compliance on perfusion gradient. IAH often defined as IAP 12mmHg Clinical Manifestations CARDIAC vessel compression IAH Intrathoracic pressure Venous return SVR heart compression Cardiac output PCWP and CVP Hypovolemia Clinical Manifestations CENTRAL NERVOUS SYSTEM IAH Intrathoracic pressure Intravenous tension Intracranial pressure IAH Hypovolemia Cerebral perfusion pressure Clinical Manifestations PULMONARY IAH Intrathoracic pressure Airway pressures Compliance Shunt fraction Vd/Vt PaO2 PaCO2 Clinical Manifestations GASTROINTESTINAL Celiac blood flow SMA blood flow Mucosal blood flow pHi RENAL Urinary output Renal blood flow GFR Clinical Manifestations HEPATIC Portal blood flow Mitochondrial function Lactate clearance ABDOMINAL WALL Compliance Rectus sheath blood flow clinical feature Intra-abdominal hypertension Graveness abdominal distention and oliguresis Distress of respiratory Diagnosis IAP20 mmHg APP50 mmHg Single or multiple organ system failure Abdominal perfusion preesure (APP )= mean arterial pressure IAP. Diagnosis The diagnosis of this syndrome is difficult because it usually occurs in critically ill patients with other causes of circulatory or respiratory failure. One should always consider the abdominal compartment syndrome when confronted with acute circulatory failure with wide systolic- diastolic pressure variation and elevated filling pressures. Management PROPOSED GRADING OF ABDOMINAL COMPARTMENT SYNDROME Grade Pressure (mmHg) Management I10-15Maintenance of normovolemia II16-25Volume administration III26-35Decompression IV35Re-exploration OPERATIVE DECOMPRESSION Conclusion ACS is a clinical entity caused by an acute, progressive increase in IAP. Multiple organ systems are affected, usually in a graded fashion. The gut is the organ most sensitive to IAH. Treatment involves expedient decompression of the abdomen. Since this syndrome affects patients who are already physiologically c