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Cardiac magnetic resonance imaging (MRI) on small animals is possible but remains challenging and not well standardized. This publication aims to provide an overview of the current techniques, applications and challenges of cardiac MRI in small animals for researchers interested in moving into this field. Solutions have been developed to obtain a reliable cardiac trigger in both the rat and the mouse. Techniques to measure ventricular function and mass have been well validated and are used by several research groups. More advanced techniques like perfusion imaging, delayed enhancement or tag imaging are emerging. Regarding cardiac applications, not only coronary ischemic disease but several other pathologies or conditions including cardiopathies in transgenic animals have already benefited from these new developments. Therefore, cardiac MRI has a bright future for research in small animals

A generalized skin erythema and severe hypotension developed following administration of protamine for the reversal of heparin anticoagulation after an unsuccessful attempt at percutaneous transluminal angioplasty in a patient who had never been exposed to protamines before. Evidence of classical pathway complement activation was present indicating that this reaction could have been triggered by a non-immunological mechanism. The patient could not adequately be resuscitated because of the presence of severe coronary artery disease

We studied 22 patients undergoing aortic surgery, allocated randomly to receive, before induction of anaesthesia, a single i.v. dose of enalapril 50 micrograms kg-1 or saline. During infrarenal aortic cross-clamping, we observed similar reductions in oxygen uptake in the two groups, despite greater systemic oxygen delivery in enalapril-treated patients; angiotensin-converting enzyme inhibition prevented the reduction in cardiac output and attenuated the decrease in glomerular filtration. Changes in glomerular filtration secondary to aortic clamping were related positively to changes in renal plasma flow (r = 0.83 (saline group) and r = 0.65 (enalapril group)). Creatinine clearance on the first day after operation was significantly higher in the enalapril compared with the saline group. We conclude that enalapril pretreatment is effective in improving systemic oxygen delivery, renal plasma flow and glomerular filtration during aortic abdominal surgery

SUMMARY To determine if functional residual capacity (FRC), compliance of the respiratory system (C), or underlying pulmonary disease are predictive for the efficacy of high frequency jet ventilation (HFJV) on pulmonary gas exchange, we investigated six adult patients within 4 h of abdominal surgery and six patients with severe adult respiratory distress syndrome. Gas exchange during intermittent positive pressure ventilation (IPPV) was compared with that during HFJV at frequencies of 100 b.p.m. (HFJV100) and 200 b.p.m. (HFJV200), resulting in a minute ventilation of about 400 ml kg−1 with both ventilatory frequencies, and in both groups of patients. Baseline FRC and C were measured during IPPV with the multiple-breath nitrogen washout method and from expiratory pressure-volume curves, respectively. Changes in the alveolar-arterial oxygen difference (PAO2−PaO2): FlO2 ratio induced by HFJV correlated negatively with C (HFJV100: r = −0.78, P <0.005; HFJV200: r = −0.84, P < 0.005); that is, greater oxygenation was obtained in patients with a better compliance. Similarly, changes in arterial partial pressure of carbon dioxide (Paco2) induced by HFJV correlated negatively with C (HFJV100: r = −0.77, P < 0.001; HFJV200: r = —0.61, P < 0.05). In contrast, there was no significant correlation between FRC measured during IPPV and changes in (PAO2−PaO2): FlO2 ratio or Paco2 induced by HFJV, as these changes were influenced more by the patient's pulmonary disease than by baseline FRC. These results should be interpreted in the context of different underlying pathophysiological mechanisms reducing FRC in both groups of patients

Patients undergoing cardiac surgery with moderate hypothermic cardiopulmonary bypass (CPB) were allocated randomly to receive either saline (control group, n = 29) or a high-dose regimen of aprotinin (aprotinin group, n = 28). In both groups, CPB was associated with similar and transient increases in effective renal plasma flow (+54% in controls and +48% in aprotinin-treated patients) and in fractional excretion of sodium and potassium, but glomerular filtration rate remained unchanged. Plasma and urinary ratios of 6-keto-PGF1 alpha to thromboxane B2 (TxB2) increased significantly, indicating systemic and renal release of vasodilatory prostaglandins. Osmolar clearance correlated with urinary excretion of cyclic GMP (r = 0.79 and 0.86 in the control and aprotinin groups, respectively) and 6-keto-PGF1 alpha (r = 0.63 and 0.69 in the control and aprotinin groups, respectively). Compared with preoperative values, plasma atrial natriuretic peptide increased after weaning from CPB (+71% and +93% in the control and aprotinin groups, respectively). Aprotinin had no apparent adverse effect on renal function and it did not alter mechanisms involving prostanoids and atrial natriuretic peptide during cardiac surgery

We have investigated patients undergoing cardiac surgery with hypothermic bypass to see if the addition of skin surface warming during systemic rewarming on bypass (heated group, n = 43) would improve perioperative thermal balance compared with conventional management without skin warming (control group, n = 43) in an open, randomized, controlled study. Intraoperative skin warming with a water mattress and forced warm air over the face, neck and shoulders attenuated the afterdrop in nasopharyngeal temperature after weaning from bypass (2.3 (1.2) degrees C and 1.3 (0.5) degrees C in the control and heated groups, respectively) (P < 0.05) and resulted in higher rectal temperature 4 h after surgery. Despite similar standard coagulation tests, heated patients had lower blood loss via the chest tubes (600 (264) ml vs 956 (448) ml in control patients) (P < 0.05) and less requirements for i.v. colloid infusion (1662 (404) ml vs 1994 (389) ml) (P < 0.05). There was a significant inverse correlation between rectal temperature on arrival in the ICU and postoperative blood loss (r = 0.57, P < 0.001). These data suggest that additional skin surface warming with a water mattress and forced warm air helped to preserve perioperative thermal balance and may contribute to reduced bleeding after cardiac surgery