Charl J. De Wet

The Importance of Prior Stroke for the Adjusted Risk of Neurologic Injury after Cardiac Surgery for Women and Men

Background Women are at higher risk for stroke after cardiac surgery than men. Prior analysis of risk profiles for perioperative stroke that have mostly combined data from women and men may fail to identify gender-specific risks. The purpose of this study was to evaluate whether patient gender impacts adjusted risk for stroke after cardiac surgery. Methods Demographic and perioperative data were prospectively collected from 2,972 patients undergoing cardiac surgery. Carotid artery ultrasound examination was performed before surgery for patients aged 65 yr or older or when there was a history of transient ischemic attacks or prior stroke. Epiaortic ultrasound was performed at the time of surgery in all patients to assess for atherosclerosis of the ascending aorta. Results Strokes occurred after surgery in 30 women and 18 men (P < 0.0001). Based on multivariate logistic regression analysis, a history of a stroke was the strongest predictor of new stroke for both women and men. Low cardiac output syndrome, atherosclerosis of the ascending aorta, and diabetes mellitus were significantly associated with stroke for women but not for men. Analysis on the data from all patients using a gender-interaction term found that the risk for stroke associated with patient age, atherosclerosis of the aorta, diabetes, and duration of cardiopulmonary bypass was not affected by gender. The prior stroke–gender interaction, however, was significant (P = 0.017), suggesting that a prior cerebrovascular event was a more important predictor of stroke for men than women. Conclusions These data show that prior stroke before surgery is strongly and independently associated with susceptibility for stroke after cardiac surgery, particularly for men. Other risk factors for perioperative stroke, though, do not appear to be influenced by patient gender.

Peripartum Substitution of Inhaled for Intravenous Prostacyclin in a Patient with Primary Pulmonary Hypertension

WE report a parturient with severe primary pulmonary hypertension who was receiving chronic intravenous prostacyclin (epoprostenol, PGI 2 , Flolan®; GlaxoSmith-Kline, Research Triangle Park, NC) and changed to inhaled prostacyclin prepartum. Our strategy was to take advantage of the selective pulmonary artery (PA) vasodilation afforded by inhaled prostacyclin to minimize systemic side effects such as arterial hypotension and antiplatelet effects seen with intravenous administration. We theorized that this approach would allow for uninterrupted PA vasodilation while simultaneously minimizing the risk of antiplatelet effects and would thereby permit safer epidural catheter placement necessary for effective analgesia for planned forceps-assisted vaginal delivery.

Case report: Inferior vena-cava right atrial anastomotic stenosis after bicaval orthotopic heart transplantation

PurposeThis case report describes the occurrence of acute postoperative liver and renal failure after bicaval orthotopic heart transplantation (OHT) due to stenosis of the inferior vena cava (IVC)-right atrial (RA) anastomosis. We also discuss the role of measuring femoral venous pressure and transesophageal echocardiography (TEE) in establishing the diagnosis.Clinical featuresA 42-yr-old female patient with idiopathic dilated cardiomyopathy underwent an OHT, using the bicaval anastomotic technique. During the first 12 hr postoperatively she developed unexplained kidney and liver failure. Her left and right ventricular functions were excellent and the right and left sided filling pressures were normal. The femoral pressure was elevated while the RA pressure was normal. An emergent TEE showed colour-flow and Doppler characteristics consistent with IVC-RA anastomotic stenosis. Emergent surgical re-exploration was undertaken; a hemostatic suture was found at the RA cannulation site that had caused the constriction of the IVC-RA anastomosis.ConclusionsAcute liver and renal failure after OHT can have multiple causes including ischemia due to a low flow state. This case demonstrates the importance of doing a detailed intraoperative TEE after OHT, and the importance of repeating the intraoperative examination after any hemostatic sutures are placed. Femoral venous pressure monitoring can be a useful diagnostic tool in detecting IVC-RA stenosis.RésuméObjectifDécrire l’occurrence d’insuffisance hépatique et rénale aiguës, survenant après une transplantation cardiaque orthotopique (TCO) bicave, causée par la sténose de l’anastomose entre la veine cave inférieure (VCI) et l’oreillette droite (OD). Discuter aussi du rôle de la mesure de la pression veineuse fémorale et de l’échocardiographie transœsophagienne (ETO) dans l’établissement du diagnostic.Éléments cliniquesUne femme de 42 ans, atteinte de cardiomyopathie dilatée, a subi une TCO selon la technique anastomotique bicave. Pendant les 12 premières heures postopératoires, une insuffisance rénale et hépatique inexpliquée s’est développée. La fonction des ventricules gauche et droit était excellente, les pressions de remplissage étaient normales des deux côtés. La pression fémorale était élevée, celle l’OD était normale. Un examen d’ETO d’urgence a montré des caractéristiques de débit chromatique et Doppler compatibles avec une sténose anastomotique VCI-OD. Une ré-exploration chirurgicale urgente a révélé la présence d’une suture hémostatique, au site de canulation de l’OD, causant la constriction de l’anastomose VCI-OD.ConclusionL’insuffisance hépatique et rénale aiguës suivant une TCO peut avoir de multiples causes dont l’ischémie provoquée par un bas débit. Le présent cas démontre l’importance de faire une ETO peropératoire détaillée après la TCO et de répéter cet examen après la mise en place de toute suture hémostatique. Le monitorage de la pression veineuse fémorale peut aider à détecter la sténose VCI-OD.M

Use of the Patient State Index (PSI) to assist in the diagnosis of perioperative neurological injury and brain death.

We present a series of three postoperative cases that were admitted to a cardiothoracic intensive care unit (ICU) after major surgery. Due to the possible presence of residual postoperative neuromuscular blockade after surgery, a processed electroencephalograph (EEG) was applied prior to starting sedation. This was markedly abnormal in all three cases, and not in keeping with the residual anesthesia. The patients were immediately transported for a CT scan. In all three cases there was severe neurological injury incompatible with survival and end of life decisions were made. Although the utility of quantitative EEG technology, like the Bispectral index (BIS) or Patient State Analyzer (PSA), is becoming better defined in the operating room, the role in the ICU is less clear. We propose that the ICU use of the PSA 4000 may have affected our decision weighing the risk versus benefit of transporting a fresh postoperative case to the radiology suite, expedited the neurological diagnosis, and may have reduced overall ICU resource utilization.

A Pregnant Woman in the Third Trimester Diagnosed With Acute Respiratory Failure and Severe Lower-Extremity Edema

A previously healthy 33-year-old pregnant woman gravida 4, para 1, with good prenatal care, presented to an obstetric clinic at 34 weeks’ gestation with new-onset shortness of breath, activity intolerance, and worsening lower-extremity edema. The patient had had an uncomplicated pregnancy 10 years earlier as well as a remote history of methamphetamine abuse. Pulse oximetry revealed oxygen saturation in the low 80% range with a mild response to oxygen supplementation through a nonrebreather mask. A heparin drip was started because of a concern about pulmonary embolism (PE), and the patient was admitted to the ICU for further management.