Preliminary experience with continuous right ventricular pressure and transesophageal echocardiography monitoring in orthotopic liver transplantation.

BACKGROUND: Despite increasing attention in the cardiac anesthesiology literature, continuous measurement of right ventricular pressure using a pulmonary artery catheter has not been described in orthotopic liver transplantation, despite similarities in the anesthetic approach to the two populations. We describe our preliminary experience with this technique in orthotopic liver transplantation, and by combining various derived measures with trans-esophageal echocardiography, make some early observations regarding the response of these measures of right ventricular function during the procedure. METHODS: In this case series, ten patients (five men and five women) undergoing orthotopic liver transplantation in our institution had their surgeries performed while monitored with a pulmonary artery catheter with continuous right ventricular port transduction and trans-esophageal echocardiography. We recorded various right ventricular waveform (early-to-end diastolic pressure difference, right ventricular outflow tract gradient, right ventricular dP/dT and right ventricular end-diastolic pressure) and echocardiographic (right ventricular fractional area change, tricuspid annular plane systolic excursion, right ventricular lateral wall strain) and described their change relative to baseline at timepoints five minutes before and after portal vein reperfusion, immediately after hepatic artery reperfusion and on abdominal closure. RESULTS: Except for tricuspid annular plane systolic excursion at five minutes prior to reperfusion (mean -0.8 cm; 95% CI-1.4, -0.3; p = 0.007), no echocardiographic metric was statistically significantly different at any timepoint relative to baseline. In contrast, changes in right ventricular outflow tract gradient and right ventricular dP/dt were highly significant at multiple timepoints, generally peaking immediately before or after reperfusion before reducing, but not returning to baseline in the neohepatic phase. Nine of 10 participants in this series demonstrated a degree of dynamic right ventricular outflow tract obstruction, which met criteria for hemodynamic significance (> 25 mmHg) in two participants. These changes were not materially affected by cardiac index. CONCLUSIONS: Dynamic right ventricular outflow tract obstruction of varying severity appears common in patients undergoing orthotopic liver transplantation. These results are hypothesis generating and will form the basis of future prospective research.

Obstructive Shock Because of the Incorrect Setup of a Digital Drainage System After Pulmonary Lobectomy.

We report a case of life-threatening obstructive shock from extreme negative intrapleural pressure that occurred because of the incorrect setup of a digital drainage system after video-assisted thoracic surgery. These devices are increasingly prevalent because of their precision and portability. Those using such devices should be cognizant of their potential pitfalls.

Coolsense® versus EMLA® for peripheral venous cannulation in adult volunteers: A randomised crossover trial.

Peripheral venous cannulation (PVC) is a commonly performed invasive medical procedure. Topical treatments such as the eutectic mixture of local anaesthetics (EMLA®, Aspen Pharmacare Australia Pty Ltd, St Leonards, NSW) attenuate the associated pain, but are limited by requiring up to one hour of application before becoming effective. The Coolsense® (Coolsense Medical Ltd., Tel Aviv, Israel) pain numbing applicator is a new device using a cryoanalgesic means to anaesthetise skin within seconds. Coolsense is being increasingly used for cannulation, but comparative studies are lacking. We recruited 64 healthy adult volunteers to this open-label two sequence, two period randomised crossover trial. Participants had two 20 gauge venous cannulae inserted, one on the dorsum of each hand. Each cannulation attempt was preceded by treatment with Coolsense or an EMLA patch containing 2.5% lidocaine and 2.5% prilocaine. The primary outcome was participant pain using the 0-10 numerical pain rating scale. Secondary outcomes were participant satisfaction scores on a 0-10 scale, treatment preference, and failed cannulation attempts. Participants were randomly assigned to either the Coolsense EMLA (n = 32) or EMLA Coolsense (n = 32) sequence. All participants completed the trial. The pooled mean paired difference of the numerical pain rating scale was -1.84 (95% confidence intervals -1.28 to -2.41; P < 0.001) in favour of EMLA. The pooled mean paired difference for satisfaction score was 2.26 (95% confidence intervals 1.46 to 3.07; P < 0.001) higher with EMLA. Most participants preferred EMLA over Coolsense (P < 0.001). There was no significant difference regarding failed cannulation between the two treatments (P = 0.14). Among healthy individuals undergoing elective PVC, EMLA was associated with reduced pain, increased satisfaction, and was the preferred treatment compared to Coolsense.

CT pulmonary angiography and pulmonary embolism following 5809 primary joint arthroplasties.

AIM: Controversy surrounds prevention, detection and clinical relevance of pulmonary embolism (PE) following arthroplasty in orthopaedic patients. We aimed to review the rates of computer tomography pulmonary angiography (CTPA), PE and fatal PE following total joint replacement. METHOD: Mixed retrospective/prospective review of CTPA requests and PE incidence amongst patients undergoing primary knee and hip arthroplasty. RESULTS: The overall PE rate was 112/5809 (1.93%): 38/3473 (1.1%) and 74/2336 (3.5%) following total hip arthroplasty (THA) and total knee arthroplasty (TKA), respectively. Two deaths from PE occurred, both after TKA, a procedural mortality rate of 0.086%; the overall mortality rate was 0.034%. The rate of CTPA requests increased for the initial 7 years as did the rate of PE, in the last 2 years both rates fell. CONCLUSION: The findings are discussed in context of published data and with reference to studies suggesting the high sensitivity of CTPA may over diagnose clinically significant PE following arthroplasty if ordered without a robust method of determining the pre-test probability.

Transcranial magnetic stimulation in schizophrenia.

Transcranial magnetic stimulation (TMS) is a non-invasive and painless way of stimulating the neural tissue (cerebral cortex, spinal roots, and cranial and peripheral nerves). The first attempts at stimulating the neural tissue date back to 1896 by d'Arsonval; however, it was successfully carried out by Barker and colleagues in Sheffield, UK, in 1985. It soon became a useful tool in neuroscience for neurophysiologists and neurologists and psychiatrists. The original single-pulse TMS, largely used as an investigative tool, was further refined and developed in the early 1990s into what is known as repetitive TMS (rTMS), having a frequency range of 1-60 Hz. The stimulation by both TMS and rTMS of various cortical regions displayed alteration of movement, mood, and behavior, leading researchers to investigate a number of psychiatric and neuropsychiatric disorders, as well as to explore its therapeutic potential. There is now a large amount of literature on the use of TMS/rTMS in depression; however, its use in schizophrenia, both as an investigative and certainly as a therapeutic tool is relatively recent with a limited but increasing number of publications. In this article, we will outline the principles of TMS/rTMS and critically review their use in schizophrenia both as investigative and potential therapeutic tools.