Biomedical subjects

Susanna Price

Publications and source records attributed to Susanna Price.

4 recordsLinked to original sources

PubMed2005

Recombinant human erythropoietin use in a critically ill Jehovah's witness after cardiac surgery.

UNLABELLED: Complex cardiac surgery often requires blood transfusion. Some patients refuse transfusion, even when it is potentially life-threatening to do so. Although recombinant human erythropoietin (rhEPO) has been used to reduce the need for blood transfusion, it has been considered ineffective in critically ill patients. The time course of hematological responses in a Jehovah's Witness patient with acute renal failure and severe cardiac disease suggests that a trial of rhEPO should be considered for salvage therapy in critically ill patients. IMPLICATIONS: The authors describe successful treatment of life-threatening anemia using recombinant human erythropoietin in a critically ill Jehovah's Witness patient after cardiac surgery.

Acute Kidney Injury↗

PubMed2004

'Tamponade' following cardiac surgery: terminology and echocardiography may both mislead.

OBJECTIVE: Echocardiography is widely considered the gold standard for the diagnosis of tamponade. While a relatively common complication of cardiac surgery in adults, determining whether haemodynamics are compromised by a pericardial collection early post-operatively can be difficult. The aim of the current study was to determine the nature and magnitude of the diagnostic challenge posed by cardiac tamponade following cardiac surgery. We therefore examined the accuracy of echocardiography in the diagnosis of tamponade in this patient group. METHODS: From January 2000 to January 2002, 2297 adult patients underwent cardiac surgery in a tertiary referral cardiothoracic centre. A retrospective analysis of prospectively collected data, from all patients diagnosed with post-operative bleeding and/or tamponade was performed. Data included demographics, surgery, anticoagulation/anti-platelet medication, clinical/echocardiographic features of tamponade and surgical findings at re-exploration. RESULTS: The diagnosis of 'tamponade' was confirmed at re-exploration in 148 patients. When it occurred early (<72 h) following cardiac surgery trans-thoracic echocardiography failed to visualise the majority of collections (60%), necessitating trans-esophageal echocardiography. Effusions were small (160+/-17 ml) and localised (92%), showing no echocardiographic features of classical tamponade (79%). Where patients developed tamponade late (>72 h) following cardiac surgery, clinical features were atypical, effusions larger (640+/-71 ml, P<0.0001)) and global (77%). Classical echocardiographic features of tamponade were usually present (70%) and readily visualised using trans-thoracic echocardiography. CONCLUSIONS: Haemodynamically significant pericardial collections occurring early following cardiac surgery rarely cause classical clinical or echocardiographic features of tamponade. Recognition of this as a separate diagnostic entity is necessary to ensure appropriate surgical intervention is not delayed.

Adolescent↗

PubMed2003

Intra-aortic balloon pumping: effects on left ventricular diastolic function.

OBJECTIVE: The intra-aortic balloon pump is the most widely used form of temporary cardiac assist and often utilised in patients before and after cardiac surgery. Several effects of balloon counter-pulsation have been reported previously, but its effect on left ventricular diastolic function has not been thoroughly investigated. The aim of this study is to examine the effect of the intra-aortic balloon pump on left ventricular wall motion and transmitral flow. METHODS: We studied 20 patients in the intensive care unit, less than 36 h following cardiac surgery. We recorded left anterior descending coronary artery and transmitral E-wave flow velocities using transesophageal echocardiography pulsed Doppler. We also recorded left ventricular long axis free-wall movement using M-mode. The intra-aortic balloon pump was set to full augmentation and recordings were made at pumping cycles 1:1, 1:2, 1:3, and when the pump was on stand-by, leaving a minimum of 5 min between the pumping modes to allow the return to control conditions. In order to eliminate time effects, the sequence of recording was varied between patients using a 4 by 4 Latin-square. RESULTS: The peak diastolic left anterior descending coronary artery and transmitral E-wave flow velocities, and left ventricular free-wall early diastolic lengthening velocity increased significantly with intra-aortic balloon pumping cycles 1:1, 1:2 and 1:3 compared to their value with the pump on stand-by, all P < 0.001. The increase in peak transmitral E-wave flow velocity correlated with the increase in peak left anterior descending coronary artery diastolic flow velocity (r = 0.74, P = 0.02), and with the increase in left ventricular free-wall early diastolic lengthening velocity (r = 0.80, P < 0.001). CONCLUSION: Using the intra-aortic balloon pump post-cardiac surgery significantly increases peak diastolic left anterior descending coronary artery flow velocities and left ventricular free-wall early diastolic lengthening velocity, whose increase explains the increase in peak transmitral E-wave velocity. Although coronary flow is epicardial and mitral flow is intracardial, their close relationship suggests an improvement in left ventricular diastolic function with intra-aortic balloon pump.

Aged↗

PubMed2002

Nitric oxide supports atrial function in sepsis: relevance to side effects of inhibitors in shock.

The mechanisms underlying myocardial dysfunction in sepsis remain poorly understood. The theoretical benefits of nitric oxide synthase (NOS) inhibition in reversing the haemodynamic changes that characterise septic shock have not been supported by clinical trials, some of which have demonstrated detrimental myocardial effects. We have therefore assessed the effects of endotoxaemia on NOS enzyme expression as well as a number of functional responses of myocardial tissue from rats. Atrial tissue expressed high levels of mRNA for inducible (i) NOS and released increased levels of nitrite after animals were treated with endotoxin. In parallel, the inotropic response stimulated by isoprenaline was reduced in atria from endotoxin-treated animals, an effect that was reversed when endogenous release of NO was maximised. Our results suggest that myocardial contractility is maintained by NO production and that inhibitors may compromise cardiac output; this may explain the deleterious effects of NOS inhibition on cardiac function in clinical trials.

Animals↗