Wendy K. Bernstein

Radio Frequency Identification Systems Technology in the Surgical Setting

Radio frequency identification (RFID) is a technology that will have a profound impact on medicine and the operating room of the future. The purpose of this article is to provide an introduction to this exciting technology and a description of the problems in the perioperative environment that RFID might address to improve safety and increase productivity. Although RFID is still a nascent technology, applications are likely to become much more visible in patient care and treatment areas and will raise questions for practitioners. We also address both the current limitations and what appear to be reasonable near-future possibilities.

Relationship between blood lactate concentrations and ionized calcium, glucose, and acid-base status in critically ill and noncritically ill patients.

OBJECTIVE To determine the relationships between circulating blood lactate concentrations and several biochemical variables including ionized calcium, glucose, pH, and acid-base status in critically ill and noncritically ill patients. DESIGN A prospective, cohort study. SETTING The critical care research laboratory, intensive care unit (ICU), emergency room (ER), and general ward of a 466 bed university-affiliated hospital. PATIENTS Three-hundred thirty-four critically ill and noncritically ill patients. INTERVENTION None. MEASUREMENTS AND MAIN RESULTS Circulating blood lactate concentrations, ionized calcium concentrations, blood glucose, pH, and base deficit values were simultaneously determined in blood samples from various patient populations. Descriptive data and physiologic parameters were also recorded. Circulating lactate and ionized calcium determinations were performed simultaneously in 334 whole blood samples from 334 subjects. There was neither a statistically significant nor clinically relevant correlation between circulating lactate concentrations and ionized calcium concentrations when lactate values were < or = 2 mmol/L (p = 0.8962, r2 = .01) or when lactate values were > 2 mmol/L (p = .3697, r2 = .09) in a heterogeneous patient population. Our study populations included five subject groups: a) nonhypotensive ICU patients (n = 93), b) nonhypotensive ER patients (n = 85), c) nonhypotensive general ward patients (n = 44), d) hypotensive patients from the ICU, ER, and general wards (n = 39), and e) normal controls (n = 73). There was neither a statistically significant nor clinically relevant correlation between circulating lactate concentrations and ionized calcium concentrations in each of the five populations studied for lactate values either < or = 2 mmol/L or > 2 mmol/L. We studied the relationship between circulating lactate concentrations and blood glucose concentrations (n = 334 patients), arterial pH and base deficit (n = 163 patients), and venous pH and base deficit (n = 171 patients). Statistically significant, but perhaps not clinically relevant correlations were observed when comparing circulating lactate values with blood glucose values (p = .0330, r2 = .12), arterial pH (p = .0007, r2 = .26) and base deficit from arterial specimens (p = .0014, r2 = .25). There were neither statistically significant nor clinically relevant correlations when comparing circulating lactate concentrations with venous pH (p = .9098, r2 = .01) or base deficit determined from venous blood specimens (p = .1365, r2 = .11). CONCLUSIONS a) There is neither a statistically significant nor clinically relevant relationship between whole blood lactate concentrations and ionized calcium concentrations when studying patients with or without hyperlactatemia. b) Although there is a statistically significant correlation between circulating lactate concentrations and blood glucose concentrations, arterial pH or arterial base deficit, such associations do not appear to be clinically important.

Pulmonary function testing.

Purpose of review To review the recent literature related to pulmonary function testing and how it relates to the preoperative evaluation. Recent findings There is increased interest in the field of pulmonary arterial hypertension. It is important to determine the clinical implications of this disease and determine whether preoperative therapy is indeed effective. Also, there is a need for the development of new noninvasive diagnostic techniques to identify patients at risk of pulmonary arterial hypertension. Summary Pulmonary function testing can be used to quantify lung function, confirm an individuals functional status, evaluate regimen effectiveness, and determine disability. They may be essential in all candidates for lung resection. However, there are limits in the current testing of pulmonary function. There is new evidence that exercise testing may provide better diagnostic and prognostic information about patients with cardiovascular and pulmonary disease.

Preoperative Evaluation for Thoracic Surgery

The goal of the preoperative evaluation for thoracic surgery is to assess and implement measures to decrease perioperative complications and prepare high-risk patients for surgery. Major respiratory complications, such as atelectasis, pneumonia, and respiratory failure, occur in 15% to 20% of patients and account for most of the 3% to 4% mortality rate. Development of pulmonary complications has been associated with higher postoperative mortality rates. Strategies aimed at preventing postoperative difficulties have the potential to reduce morbidity and mortality, decrease hospital stay, and improve resource use. One lung ventilation leads to a significant derangement of gas exchange, and hypoxemia can develop due to increased intrapulmonary shunting. Recent advances in anesthetic management, monitoring devices, improved lung isolation techniques, and improved critical care management have increased the number of patients who were previously considered inoperable. In addition, there is a growing tendency to offer surgery to patients with significant lung function impairment; hence a higher incidence of intraoperative gas-exchange abnormalities can be expected. The anesthesiologist must also consider the risks of denying or postponing a potentially curative operation in patients with lung cancer. Detailed consideration of the information provided by preoperative testing is essential to successful outcomes following thoracic surgery.

Intra-abdominal Hypertension and Postoperative Kidney Dysfunction in Cardiac Surgery Patients

OBJECTIVE To determine the incidence of intra-abdominal hypertension (IAH) in adult cardiac surgery patients and its association with postoperative kidney dysfunction. DESIGN Prospective cohort study. SETTING Single tertiary-care university hospital. PARTICIPANTS Forty-two adult patients having cardiac surgery with cardiopulmonary bypass. INTERVENTIONS Intra-abdominal pressure (IAP) was measured preoperatively, immediately after surgery, and at the following time points after surgery: 3 hours, 6 hours, 12 hours, and 24 hours. Urine neutrophil gelatinase-associated lipocalin (NGAL) levels were measured as a marker of kidney dysfunction at the following time points: prior to surgery, immediately after surgery, 4 to 6 hours after surgery, and 16-to-18 hours after surgery. MEASUREMENTS AND MAIN RESULTS Two hundred fifty-two IAPs were measured, and 90 (35.7%) showed IAH. Thirty-five of 42 patients (83.3%) had IAH at 1 time point or more. Peak urine NGAL levels were lower in patients with normal IAP (mean difference = -130.6 ng/mL [95% CI = -211.2 to -50.1], p = 0.002). There was no difference in postoperative kidney dysfunction by risk, injury, failure, loss of kidney function, and end-stage kidney disease (RIFLE) criteria in patients with normal IAP (mean difference = -31.4% [95% CI = -48.0 to 6.3], p = 0.09). IAH was 100% sensitive for predicting postoperative kidney dysfunction by RIFLE criteria, but had poor specificity (54.8%). CONCLUSIONS IAH occurs frequently during the perioperative period in cardiac surgery patients and may be associated with postoperative kidney dysfunction.

Incidental Finding of a Left Atrial Myxoma During Emergency Surgery for Thoracic Aortic Dissection

HE INCREASED USE of perioperative transesophageal echocardiography in cardiac surgery has resulted in the discovery of unexpected and previously undiagnosed findings. It has been reported that the incidence of abnormal findings in patients undergoing transesophageal echocardiography is approximately 11% and includes patent foramen ovale, simultaneous valvular abnormalities, and cardiac masses. 1 The authors believe that this was the first case report of the management of incidental finding of a left atrial mass during the transesophageal echocardiography examination of a patient who was undergoing emergency repair of a type-A aortic dissection. Unexpected findings on intraoperative transesophageal echocardiography may be difficult findings with which to deal in the setting of emergency surgery, especially when the patient is otherwise asymptomatic and the mass is an incidental finding. While it may seem straightforward to remove a small but potentially harmful intracardiac mass, there are inherent risks with the procedure due to the additional effort, time, and complication rate. Moreover, there are no randomized, controlled clinical trials to guide the decision as to whether the incidental atrial myxoma should be removed in these patients. In this case, the finding of a large atrial mass altered the surgical plan in a positive way and directly impacted the longterm outcome for the authors’ patient. CASE PRESENTATION

An Unusual Right Atrial Mass: A Misdiagnosis Identified by Intraoperative Transesophageal Echocardiography

Fig 2. Modified midesophageal bicaval view showing the intrahepatic inferior vena cava. A74-YEAR-OLD WOMAN presented without symptoms to her primary care physician for an annual physical examination. She had a history of type II diabetes mellitus, hypertension, tobacco use, and dyslipidemia. A urinalysis revealed microscopic hematuria, and a screening electrocardiogram showed poor R-wave progression. Transthoracic echocardiography revealed a mobile, solid mass (approximately 1.3 cm by 1.2 cm) in her right atrium. Subcostal views demonstrated the presence of the mass in the inferior vena cava (IVC), but the mass appeared to have originated from the right atrium. The patient was referred for transesophageal echocardiography (TEE) to better define the mass, and TEE was suggestive of a right atrial myxoma. The patient subsequently was referred to a cardiothoracic surgeon for a myxoma resection. Intraoperative TEE was performed before sternotomy. A midesophageal bicaval view showed a solid, mobile atrial mass;

Calm Before the Storm: An Uncomplicated Epicardial Lead Extraction Resulting in DIC and Patient Demise.

A previously stable 77-year-old man with significant cardiac history underwent an uneventful extraction of a Citrobacter-infected and eroded pacemaker lead. His postoperative course was acutely complicated by respiratory failure and quickly progressed into disseminated intravascular coagulation, acute renal failure, shock liver, and ventricular tachycardic arrest. I believe that this is the first case report of such a drastic turn of events after a routine pacemaker lead extraction.

Anesthetic issues for robotic cardiac surgery.

As innovative technology continues to be developed and is implemented into the realm of cardiac surgery, surgical teams, cardiothoracic anesthesiologists, and health centers are constantly looking for methods to improve patient outcomes and satisfaction. One of the more recent developments in cardiac surgical practice is minimally invasive robotic surgery. Its use has been documented in numerous publications, and its use has proliferated significantly over the past 15 years. The anesthesiology team must continue to develop and perfect special techniques to manage these patients perioperatively including lung isolation techniques and transesophageal echocardiography (TEE). This review article of recent scientific data and personal experience serves to explain some of the challenges, which the anesthetic team must manage, including patient and procedural factors, complications from one-lung ventilation (OLV) including hypoxia and hypercapnia, capnothorax, percutaneous cannulation for cardiopulmonary bypass, TEE guidance, as well as methods of intraoperative monitoring and analgesia. As existing minimally invasive techniques are perfected, and newer innovations are demonstrated, it is imperative that the cardiothoracic anesthesiologist must improve and maintain skills to guide these patients safely through the robotic procedure.

Dissection of the Left Main Coronary Artery during Percutaneous Intervention: Successful Surgical Management

Coronary dissection during diagnostic catheterization presents a therapeutic challenge. Medical management or percutaneous intervention may be an option in a stable patient. Unstable patients should promptly undergo surgical revascularization. We report on a patient in whom dissection of the left main coronary artery, the left anterior descending artery, and a diagonal branch occurred during catheterization. Clear signs of myocardial ischemia indicated immediate surgery. Coronary artery bypass grafting was carried out within a very short time frame and the patient survived. This case demonstrates the value of an expeditious surgical treatment strategy.