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Background CT scan measures of emphysema and airway disease have been correlated with lung function in cohorts of subjects with a range of COPD severity. The contribution of CT scan-assessed airway disease to objective measures of lung function and respiratory symptoms such as dyspnea in severe emphysema is less clear. Methods Using data from 338 subjects in the National Emphysema Treatment Trial (NETT) Genetics Ancillary Study, densitometric measures of emphysema using a threshold of −950 Hounsfield units (%LAA-950) and airway wall phenotypes of the wall thickness (WT) and the square root of wall area (SRWA) of a 10-mm luminal perimeter airway were calculated for each subject. Linear regression analysis was performed for outcome variables FEV 1 and percent predicted value of FEV 1 with CT scan measures of emphysema and airway disease. Results In univariate analysis, there were significant negative correlations between %LAA-950 and both the WT ( r = −0.28, p = 0.0001) and SRWA ( r = −0.19, p = 0.0008). Airway wall thickness was weakly but significantly correlated with postbronchodilator FEV 1 % predicted (R = −0.12, p = 0.02). Multivariate analysis showed significant associations between either WT or SRWA (β = −5.2, p = 0.009; β = −2.6, p = 0.008, respectively) and %LAA-950 (β = −10.6, p = 0.03) with the postbronchodilator FEV 1 % predicted. Male subjects exhibited significantly thicker airway wall phenotypes (p = 0.007 for WT and p = 0.0006 for SRWA). Conclusions Airway disease and emphysema detected by CT scanning are inversely related in patients with severe COPD. Airway wall phenotypes were influenced by gender and associated with lung function in subjects with severe emphysema.

The need for satisfactory lung isolation in thoracic surgery and certain minimally invasive cardiac surgeries cannot be overemphasized. Teaching effective lung isolation techniques is, thus, an integral part of any thoracic anesthesia curriculum. In an era of rapid workplace changes, traditional methods of teaching procedures increasingly are being supplemented with more structured simulation-based techniques to teach vital technical and non-technical skills to trainees without compromising patient safety. The Teaching on Wheels Cart (TowCart) is a custom-made, all-in-one, 40 27 37–inch, portable educational workstation developed to teach all the key aspects of successful lung isolation, including flexible bronchoscopy, airway anatomy, and lung isolation techniques. Components include a birds-eye view recording camera (allows recording/assessment of resident performance and subsequent feedback), desktop computer and touch screen (with

Intraoperative transesophageal echocardiography (TEE) has been a valuable tool in cardiac surgery. The TEE probe can easily be inserted after endotracheal intuba tion to provide continuous monitoring and diagnosis during surgery. The role of TEE in the operating room is always expanding. This article examines the role of TEE specifically for cardiopulmonary bypass and perfusion management.

Heparin-induced thrombocytopenia (HIT) and thrombosis is characterized by a progressive thrombocytopenia that most often occurs after 5-10 days of heparin exposure. Patients with a history of HIT requiring anti-coagulation for cardiopulmonary bypass (CPB) may face devastating consequences unless alternative anticoagulants are used. Management options have included postponing surgery until a time at which the antibody has disappeared and the patient's platelets no longer aggregate after exposured to heparin. Alternative pharmacologic means of anticoagulation include the use of low molecular weight heparin (LMWH), ancrod, warfarin, platelet inhibitors, hidudin or argatroban. 1-4 In addition, other drugs with antiplatelet activity, such as the prostacyclin analogue, iloprost, have been administered before heparin administration in an attempt to prevent platelet aggregation. The investigational heparinoid, ORG 10172 (Organon International, The Netherlands), derived from porcine intestinal mucosa, is composed of a heterogeneous mixture of dermatan sulfate, and chondroitin sulfate. This heparinoid has been an effective anticoagulant for CPB in dogs 6 and has also been used successfully as an antithrombotic agent in patients with HIT. 7 Patients with HIT have decreased antibody cross reactivity with ORG 10172. In humans, case reports have been presented by Doherty et al. 8 and Rowlings et al. 9 in which ORG 10172 was used as the anticoagulant for CPB. In this report, we describe thrombosis that occurred in a patient with HIT receiving ORG 10172 during CPB

Patients with abdominal aortic aneurysms (AAA) have a high incidence of associated cardiac disease. If a patient presents with both severe coronary artery disease and a large AAA, a staged procedure of cardiac surgery (CS) followed by AAA resection may present too great a risk of aneurysm rupture and death. A combined procedure may be recommended in this circumstance; however, the literature contains only individual successful case reports of such a procedure. A series of 10 patients who underwent CS and AAA repair to define the risks and outcome of this complex patient population is presented. Methods used included a retrospective analysis of hospital chart data from patients undergoing combined CS and AAA resection from 1980 to the present at this institution. The data analyzed included age, sex, chief complaint, past medical history, indications for surgery, abdominal aneurysm size, coronary anatomy, valvular pathology, preoperative left ventricular function, anesthetic agent and dose, order of surgery, prebypass complications, intraoperative complications, cardiopulmonary bypass time, aortic cross-clamp time, abdominal aortic cross-clamp time, blood product use, and postoperative complications. Seven of the 10 patients had a successful outcome (S group), whereas 3 of the 10 patients died postoperatively (D group). The staged procedure of first performing CS and then the AAA resection has a combined operative mortality of 4%. When the nature of both lesions is severe and a combined procedure is necessary, there is an associated in-hospital mortality of approximately 30% at this institution. The S group patients had an unremarkable postoperative course with a relatively short hospital stay when compared to the staged procedure.

The relationship between preoperative left ventricular (LV) dysfunction and the use of alpha-adrenoceptor agonists during weaning from cardiopulmonary bypass was studied in 102 patients undergoing coronary artery surgery. LV function was evaluated subjectively by examination of the 30 degree right anterior oblique left ventriculogram. Group 1 consisted of 75 patients with normal or mild impairment in LV function, whereas group 2 consisted of 27 patients with moderate-severe LV dysfunction. Cardiovascular parameters were measured at baseline, during hypothermic bypass with the aorta clamped, during normothermic bypass after unclamping, and 1 and 15 minutes after separation from bypass. Thirty-seven patients in group 1 (49%) and 11 patients in group 2 (39%) required some form of inotropic and/or vasopressor support during weaning from bypass. Group 2 required significantly higher cumulative doses of phenylephrine after bypass compared with group 1 (1.69 +/- 0.70 mg, n = 9, v 0.24 +/- 0.04 mg, n = 27, P less than 0.05). Similarly, the dose of norepinephrine infusion in group 2 was 3.3 times that in group 1 (10 +/- 6 micrograms/min, n = 2, v 3 +/- 0.6 micrograms/min, n = 2, P = NS). The higher doses of alpha-adrenoceptor agonists required in patients with moderate-severe LV dysfunction may be due to differences in alpha-adrenoceptor agonist affinity and/or receptor density.

Bilateral sequential lung transplantation is now an accepted therapy for patients with end-stage cystic fibrosis. In our experience, the use of a standard double-lumen endotracheal tube to establish one-lung ventilation during bilateral lung transplantation has been associated with difficulty in clearing the airway of the thick, tenacious secretions characteristically seen in these patients. Intraoperatively, retained secretions have resulted in inadequate ventilation with subsequent hypercarbia, hypoxia, and the need for cardiopulmonary bypass support. We therefore changed our airway management to a single-lumen endotracheal tube combined with a bronchial blocker to establish one-lung ventilation during bilateral lung transplantation. The lumen of a single-lumen tube accommodates larger suction catheters and an adult bronchoscope, which has a larger suction port. We have used this technique in our last five transplantations, finding easier clearing of airway secretions along with markedly improved ventilation compared with management with a double-lumen tube. We recommend this technique of airway management when performing a bilateral single-lung transplantation for end-stage cystic fibrosis.

To the Editor, Difficulties with tracheal intubation significantly contribute to the morbidity and mortality associated with anesthesia. The ideal device in a difficult airway scenario, especially an unanticipated difficult airway, is one that is designed to be used as a standard laryngoscope but also provides improved views of the larynx. The GlideScope videolaryngoscope (GVL; Verathon, Bothell, WA, USA) is a camera laryngoscope, which displays a colour view of the pharyngeal and laryngeal structures on a dedicated 7-in. liquid crystal display (LCD) monitor. Despite the excellent experience with this device in improving glottis visualization and achieving a high first-time endotracheal intubation success rate, there have been previous descriptions of difficulties directing and advancing the endotracheal tube through the vocal cords and reports of complications associated with its use. We have encountered two additional problems with the GVL. First, the screen has a tendency to reflect the operating room lights causing it to glare and therefore lessen the image quality. Second, when several anesthesia team members were required to assist with a difficult airway, optimal positioning of the mobile stand was cumbersome, making it difficult for some team members to see the 7-in. monitor. A key feature of the GVL system is its video output, which can be used to display the video on a separate screen. At our institution, each cardiothoracic operating room is equipped with the Black Diamond Video Distribution System (Alameda, CA, USA), which permits the display of different sources of digital information in up to four overhead 46-in. high definition (HD) 1080p LCD monitors (Fig. 1a, b). Herein we describe the use of an interface that simultaneously transfers and displays the GVL image on two of the overhead monitors. We added three components to the GVL monitor to transfer and process the video: (1) a video output cable P/N 0600-0239 (Verathon, Bothell, WA, USA), which allows the connection to any NTSC-compatible device; (2) an SDDVI converter (Black Diamond Video, Alameda, CA, USA); and (3) a digital video interfacing (DVI)-I dual link cable. The video output cable allows the connection of the GVL video output (resolution 320 9 240) to the SD-DVI converter. The converter performs the video processing to provide a smooth clear HD video, and its output connects to a convenient DVI-I dual link wall plate connector via a 15-ft DVI cable (Fig. 1c). This HD video is transmitted to the video distribution system console where it can be selected for simultaneous display on the 46-in. HD monitors (model LN46A550P3F, Samsung Electronics America, Mount Arlington, NJ, USA). In the first 20 cases, our initial experience with the system was excellent. Being able to enlarge the image better defines and identifies anatomic structures, and, due to the strategic position of the 46-in. HD screens, the images can be seen by all members of the anesthesia team during the procedure. The interface system is attached to the mobile stand such that only the connection to the wall plate is necessary to allow for immediate display of the image on the overhead monitors. Also, we have not observed any interference between the operating room lights and the 46-in. HD screens. In conclusion, improving the image display can potentially increase the success rate of procedures and minimize associated complications. Furthermore, the GVL is S. Bustamante, MD (&) J. Trepal E. Kraenzler, MD Cleveland Clinic, Cleveland, USA e-mail: bustams@ccf.org

One-lung ventilation is used to facilitate thoracic and cardiac surgery. This article describes the development and clinical use of a new device, the bronchial blocker tube, to establish one-lung ventilation. The bronchial blocker tube has two circular lumen joined together, one for ventilation and one for acceptance of a bronchial blocker. In this setting, the bronchial blocker is a separate device which is replaceable, rotatable, and removable. In the authors' experience, the bronchial blocker tube was effective and easy to use.

The objective of this study was to evaluate a new reflectance pulse oximeter sensor. The prototype sensor consists of 8 light-emitting diode (LED) chips (4 at 665 nm and 4 at 820 nm) and a photodiode chip mounted on a single substrate. The 4 LED chips for each wavelength are spaced at 90-degree intervals around the substrate and at an equal radial distance from the photodiode chip. An optical barrier between the photodiode and LED chips prevents a direct coupling effect between them. Near-infrared LEDs (940 nm) in the sensor warm the tissue. The microthermocouple mounted on the sensor surface measures the temperature of the skin-sensor interface and maintains it at a present level by servoregulating the current in the 940-nm LEDs. An animal study and a clinical study were performed. In the animal study, 5 mongrel dogs (weight, 10-20 kg) were anesthetized, mechanically ventilated, and cannulated. In each animal, arterial oxygen saturation (SaO2) was measured continuously by a standard transmission oximeter probe placed on the dog's earlobe and a reflectance oximeter sensor placed on the dog's tongue. In the first phase of the experiment, signals from the reflectance sensor were recorded while the dog was immersed in ice water until its body temperature decreased to 30 degrees C. In the second phase, the animal's body temperature was normal, and the oxygen content of the ventilator was varied to alter the SaO2. In the clinical study, 18 critically ill patients were monitored perioperatively with the prototype reflectance sensor. The first phase of the study investigated the relationship between local skin temperature and the accuracy of oximeter readings with the reflectance sensor. Each measurement was taken at a high saturation level as a function of local skin temperature. The second phase of the study compared measurements of oxygen saturation by a reflectance oximeter (SpO2[r]) with those made by a co-oximeter (SaO2[IL]) and a standard transmission oximeter (SpO2[t]). Linear regression analysis was used to determine the degree of correlation between (1) the pulse amplitude and skin temperature; (2) SpO2(r) and SaO2(IL); and (3) SpO2(t) and SaO2(IL). Student's t test was used to determine the significance of each correlation. The mean and standard deviation of the differences were also computed. In the animal study, pulse amplitude levels increased concomitantly with skin temperature (at 665 nm, r = 0.9424; at 820 nm, r = 0.9834; p < 0.001) and SpO2(r) correlated well with SaO2(IL) (r = 0.982; SEE = 2.54%; p < 0.001).(ABSTRACT TRUNCATED AT 400 WORDS)