Reaming of femoral fractures with different reaming irrigator aspirator systems shows distinct effects on cardiac function after experimental polytrauma

Cardiac injuries are recorded after multiple trauma and are associated with a poor patient outcome. Reaming prior to locked intramedullary nailing is a frequently used technique to stabilize femoral diaphysis fractures. However, in polytraumatized patients, complications such as fat emboli and acute respiratory distress syndrome have been associated with reaming. The reaming irrigator aspirator (RIA) system provides concomitant irrigation and suction of the intramedullary contents, and should, therefore, reduce reaming-associated complications. The aim of the study was to investigate cardiac function after multiple trauma with regard to two different RIA devices (RIAI vs RIAII). 15 male pigs were included in the study. Pigs received either sham treatment or multiple trauma (chest trauma, femur fracture, liver laceration, and hemorrhagic shock), followed by intramedullary nailing after reaming with either the RIAI or RIAII system (RIAII: reduced diameter of the reamer, improved control of irrigation and suction). Cardiac function was assessed by transesophageal echocardiography and systemic inflammation as well as local cardiac damage examined. Pigs of both treatment groups showed impaired cardiac function, valvular insufficiency, and cardiac damage. Systemic inflammation and local cardiac alterations were observed which might contribute to early myocardial damage in vivo. Multiple trauma including long-bone fracture and subsequent intramedullary reaming induces cardiac dysfunction and valvular insufficiency, which might be linked to both mechanical cardiac injury and increased systemic inflammation. 6 hours after trauma there are less differences between RIAI and RIAII treatment with regard to post-traumatic cardiac consequences in multiple injured pigs, indicating no beneficial effect of RIAII over RIAI.     

Left ventricular end-diastolic volume from ejection fraction and stroke volume in pigs during IVC occlusion

BACKGROUND: Real-time measurement of left ventricular end-diastolic volume (LVEDV), combined with left ventricular end-diastolic pressure (LVEDP), would allow continuous measurement of intraoperative diastolic function. In pursuit of this goal, we examined stroke volume divided by ejection fraction for calculation of LVEDV(sv/ef). METHODS: Five anesthetized pigs underwent median sternotomy and pericardiotomy. A transit-time ultrasonic flow probe on the ascending aorta provided cardiac output. A micromanometer provided LV end-diastolic pressure. End-diastolic and end-systolic areas were measured from LV short-axis cross sections to obtain ejection fraction. LVEDV(sv/ef) was calculated during IVC occlusion. Steady-state LVEDV(echo) was determined using a three-plane echocardiography model. LVEDV(echo) was used to validate steady-state LVEDA in each experiment. RESULTS: Correlation coefficients for linear and pressure-volume relation analyses ranged from 0.46 to 0.99. The two methods for measuring LVEDV generated compliance curves with an overall reliability coefficient of 0.84. CONCLUSIONS: The LVEDV(sv/ef) method may facilitate real-time determination of LV compliance.     

The effects of amrinone and calcium chloride on pulmonary vasculature and biventricular function in ethchlorvynol-induced lung injury in sheep

The effects of amrinone and CaCl₂ on pulmonary vasculature and biventricular function in sheep with acute lung injury (ALI) were studied. Seven sheep were ventilated with a tidal volume of 10–12 ml.kg^-1 with end-tidal C0₂ of 40 ± 5 mmHg (5.3 ± 0.7 kPa) after acute lung injury was induced with up to 30 mg kg^-1 of ethchlorvynol (ECV). Biventricular function and hemodynamic profiles were estimated with a rapid computerized thermodilution method and modified pulmonary artery catheters after acute lung injury, following a loading dose (1 mg kg^-1) and maintenance dose (5 μg kg^-1 min-1 ) of amrinone and after a bolus dose of CaCl₂ (20 mg kg^-1). ECV successfully induced acute lung damage in sheep, causing significant increases in pulmonary artery pressure (PAP) and pulmonary vascular resistance index (PVRI). Amrinone reversed the unfavorable changes induced by ECV, significantly reducing PAP, PVRI and left ventricular end-diastolic volume (LVEDV). CaCl₂, however, reversed the effect of amrinone and increased PAP, PVRI, and LVEDV but decreased left ventricular ejection fraction.     

Left partial anomalous pulmonary venous connection found during a lobectomy for lung cancer: Report of a case

We report herein the case of a 68-year-old man in whom a partial anomalous pulmonary venous connection (PAPVC) was found during an operation for primary lung cancer. The preoperative clinical findings did not suggest a vascular shunt, and intraoperatively the anomalous vein was seen to drain only from the left upper lobe into the left innominate vein. The lower pulmonary vein connected normally, and there was no atrial septal defect nor any other anomalous condition. A left upper lobectomy with ligation of the anomalous connected vein was performed uneventfully. This type of PAPVC is extremely rare, and is especially noteworthy because there were no clinical signs.     

Stroke volume of the heart and thoracic fluid content during head-up and head-down tilt in humans

BACKGROUND: The stroke volume (SV) of the heart depends on the diastolic volume but, for the intact organism, central pressures are applied widely to express the filling of the heart. METHODS: This study evaluates the interdependence of SV and thoracic electrical admittance of thoracic fluid content (TA) vs. the central venous (CVP), mean pulmonary artery (MPAP) and pulmonary artery wedge (PAWP) pressures during head-up (HUT) and head-down (HDT) tilt in nine healthy humans. RESULTS: From the supine position to 20 degrees HDT, SV [112 +/- 18 ml; mean +/- standard deviation (SD)], TA (30.8 +/- 7.1 mS) and CVP (3.6 +/- 0.9 mmHg) did not change significantly, whereas MPAP (from 13.9 +/- 2.7 to 16.1 +/- 2.5 mmHg) and PAWP (from 8.8 +/- 3.4 to 11.3 +/- 2.5 mmHg; P < 0.05) increased. Conversely, during 70 degrees HUT, SV (to 65 +/- 24 ml) decreased, together with CVP (to 0.9 +/- 1.4 mmHg; P < 0.001), MPAP (to 9.3 +/- 3.8 mmHg; P < 0.01), PAWP (to 0.7 +/- 3.3 mmHg; P < 0.001) and TA (to 26.7 +/- 6.8 mS; P < 0.01). However, from 20 to 50 min of HUT, SV decreased further (to 48 +/- 21 ml; P < 0.001), whereas the central pressures did not change significantly. CONCLUSIONS: During both HUT and HDT, SV of the heart changed with the thoracic fluid content rather than with the central vascular pressures. These findings confirm that the function of the heart relates to its volume rather than to its so-called filling pressures.     

Surgery for Chronic Left Ventricular Aneurysm: Benefits and side effects

Seventy patients who underwent elective resection of symptomatic postinfarction apico-anterior left ventricular (LV) aneurysm with or without coronary revascularization are reviewed. The early (?30 day) mortality was 5.7%. Mural thrombosis occurred in 29 cases (41.4%), unrelated to the degree of preoperative LV impairment and predictable from preoperative LV angiography in only seven cases. The response to surgery comprised significant overall improvement of global LV ejection fraction (LVEF) during rest and of all variables in stress testing. This LVEF recovery correlated significantly with that of peak ejections rate, a variable of myocardial contractility. Contrastingly, right ventricular ejection fraction (RVEF) at rest decreased slightly but significantly without correlation to preoperative RVEF or LVEF. In comparisons between patients with congestive heart failure or angina at rest as dominant symptom, the former group showed greater depression of preoperative watt and LVEF but better postoperative recovery of these variables, while right ventricular deterioration was significant only in the latter. Postoperative recovery was best in patients with poor preoperative LV function (LVEF ? 20%), even when surgery comprised only aneurysmectomy in isolated but ungraftable LAD disease (5 cases). The observed RV deterioration may be ‘nonspecific', but it must be kept in mind as a side effect of the operation, as it detracts unpredictably from postoperative ventricular recovery. Patients with well preserved preoperative LVEF, small LV aneurysm and marginal expected postaneurysmectomy changes according to LaPlace's law are probably at risk, and surgery should then instead be directed towards preserving the remaining viable myocardium by direct revascularization.