Anaesthesia and intensive care
-
Anaesth Intensive Care · Dec 2007
Clinical TrialUSCOM (Ultrasonic Cardiac Output Monitors) lacks agreement with thermodilution cardiac output and transoesophageal echocardiography valve measurements.
The USCOM (Ultrasonic Cardiac Output Monitors) device is a non-invasive cardiac output monitor, which utilises transaortic or transpulmonary Doppler flow tracing and valve area estimated using patient height to determine cardiac output. We evaluated USCOM against thermodilution cardiac outputs and transoesophageal echocardiography valve area measurements in 22 ASA PS4 cardiac surgical patients. Data collection commenced following pulmonary artery catheter insertion, with cardiac output measurements repeated after sternotomy closure. ⋯ The USCOM estimates of valve area based on height showed poor correlation with the echocardiographic measurements of aortic and pulmonary valves (r = 0.57 and r = 0.17, respectively). It was concluded that USCOM showed poor agreement with thermodilution. The estimated valve area was identified as one source of error.
-
Anaesth Intensive Care · Dec 2007
Case ReportsThe management of a super morbidly obese parturient delivering twins by caesarean section.
A super morbidly obese (230 kg, body mass index 76 kg/m2) patient presented to our service for a planned elective caesarean section for twin delivery. She subsequently underwent a non-elective caesarean section after normal working hours under combined spinal epidural anaesthesia with invasive monitoring. Complex cases such as this, especially in the obstetric setting, require thorough multidisciplinary planning, communication and expertise but can be safely and successfully performed in dedicated stand-alone centres.
-
Anaesth Intensive Care · Dec 2007
Propofol-induced changes in myoplasmic calcium concentrations in cultured human skeletal muscles from RYR1 mutation carriers.
Malignant hyperthermia is a pharmacogenetic disorder caused by autosomal dominant mutations in the ryanodine receptor type 1 gene. Propofol has been reported as a safe anaesthetic for malignant hyperthermia susceptible patients but has not been tested on cultured cells from patients with the ryanodine receptor type 1 mutation. The aim of this study was to determine whether propofol could trigger abnormal calcium fluxes in human myotubes isolated from malignant hyperthermia susceptible patients harbouring the native ryanodine receptor type 1 mutation. ⋯ The half-maximal activation concentrations (EC50) for propofol from patients 1 and 2 were 181.1 and 420.5 microM, respectively. Increases in calcium concentrations in response to propofol dosage were limited to doses at least 100-fold greater than those used in clinical settings. These observations correlate well with clinical observations that propofol does not trigger malignant hyperthermia in susceptible humans.
-
Anaesth Intensive Care · Dec 2007
Thrombocytopenia in septic shock patients--a prospective observational study of incidence, risk factors and correlation with clinical outcome.
The objectives of the study were to study the incidence of various degrees of severity of thrombocytopenia in septic shock, the risk factors for its development and the correlation with clinical outcome. Complete blood counts, chemistry panel, arterial lactate, serum cortisol, APACHE II score, logistic organ dysfunction score and SOFA score were determined in 69 septic shock patients within 24 hours of admission or onset of septic shock. We followed the patients until they died or for six months to determine the mortality rate. ⋯ Thrombocytopenic patients had 1.4 times the risk of mortality and lower survival probability at six months (log rank test P = 0.03). In conclusion, thrombocytopenia is common in septic shock and is associated with worse clinical outcome. Higher SOFA score, low P(a)Os/FiO2 ratio and high vasopressor dose are independent risk factors for development of thrombocytopenia in septic shock.
-
Anaesth Intensive Care · Dec 2007
Perioperative complications in patients with drug-eluting stents: a three-year audit at Geelong Hospital.
Drug-eluting stents are a recommended treatment for lesions in the coronary arteries. Stent insertion requires the patient remain on anti-platelet medication for a minimum of six months after insertion. A serious consequence of ceasing anti-platelet medication is late stent thrombosis leading to myocardial infarction in the territory of the drug-eluting stent. ⋯ The risk of myocardial infarction when clopidogrel is stopped prior to surgery is 20%, if alternative anti-thrombotic prophylaxis is not used. This risk persists beyond one year after insertion of drug-eluting stents. Some treatments appear to be effective in reducing the risk of myocardial infarction.