Hemodynamic Monitoring In The Cardiac Surgical Patient: Comparison of Three Arterial Catheters.

OBJECTIVE: Systemic systolic (SAP) and mean (MAP) arterial pressure monitoring is the cornerstone in hemodynamic management of the cardiac surgical patient, and the radial artery is the most common site of catheter placement. The present study compared 3 different arterial line procedures. It is hypothesized that a 20-G 12.7- cm catheter inserted into the radial artery will be equal to a 20-G 12.7- cm angiocath placed in the brachial artery, and superior to a 20-G 5.00 cm angiocath placed in the radial artery. DESIGN: A prospective randomized control study was performed. SETTING: Single academic university hospital. PARTICIPANTS: Adult patients ≥18 years old undergoing nonemergent cardiac surgery using cardiopulmonary bypass (CPB). INTERVENTIONS: After approval by the Rhode Island Hospital institutional review board, a randomized prospective control study to evaluate 3 different peripheral intraarterial catheter systems was performed: (1) Radial Short (RS): 20-G 5- cm catheter; (2) Radial Long (RL): 20-G 12- cm catheter; and (3) Brachial Long (BL): 20-G 12- cm catheter. MEASUREMENTS AND RESULTS: Gradients between central aortic and peripheral catheters (CA-P) were compared and analyzed before CPB and 2 and 10 minutes after separation from CPB. The placement of femoral arterial lines and administration of vasoactive medications were recorded. After exclusions, 67 BL, 61 RL, and 66 RS patients were compared. Before CPB, CA-P SAP and MAP gradients were not significant among the 3 groups. Two minutes after CPB, the CA-P SAP gradient was significant for the RS group (p = 0.005) and insignificant for BL (p = 0.47) and RL (p = 0.39). Two-group analysis revealed that CA-P SAP gradients are similar between BL and RL (p = 0.84), both of which were superior to RS (p = 0.02 and p = 0.04, respectively). At 10 minutes after CPB, the CA-P SAP gradient for RS remained significant (p = 0.004) and similar to the gradient at 2 minutes. The CA-P SAP gradients increased from 2 to 10 minutes for BL (p = 0.13) and RL (p = 0.06). Two minutes after CPB, the CA-P MAP gradients were significant for the BL (p = 0.003), RL (p < 0.0001), and RS (p < 0.0001) groups. Two-group analysis revealed that the CA-P MAP gradients were lower for the BL group compared with the RL (p = 0.054) and RS (p< 0.05) groups. Ten minutes after CPB, the CA-P MAP gradients in the RL and RS groups remained significant (p < 0.0001) and both greater than the BL group (p = 0.002). A femoral arterial line was placed more frequently in the RS group (8/66 = 12.1%) than in the RL group (3/61 = 4.9%) and the BL group (2/67 = 3.0%). Vasopressin was administered significantly more frequently in the RS group. CONCLUSION: Regarding CA-P SAP gradients, the RL group performed equally to the BL group, both being superior to RS. Regarding CA-P MAP gradients, BL was superior to RL and RS. Clinically, femoral line placement and vasopressin administration were fewer for the BL and RL groups when compared with the RS group. This study demonstrated the benefits of a long (12.7 cm) 20- G angiocath placed in the radial artery.

Caught by POCUS: Post-TAVR Pericardial Effusion.

Point-of-care ultrasound (POCUS) is becoming increasingly popular in the field of anesthesiology and is being incorporated into anesthesia resident education. Ultrasound provides a portable, quick, and inexpensive diagnostic tool to help guide clinicians in their decision making and management of medically complex patients. One important utilization of POCUS is helping to guide management of undifferentiated hypotension. We present a case of a patient who underwent a Transcatheter Aortic Valve Replacement (TAVR) procedure who then suffered from hypotension in the post-anesthesia care unit (PACU). POCUS was used to help identify the cause of the patient's hypotension and led to the diagnosis of a pericardial effusion.

Echocardiographic imaging of a bifurcated double barrel coronary sinus.

BACKGROUND: The coronary sinus (CS) is the terminal collecting vessel of the myocardial venous network, which returns deoxygenated blood used by the heart to the right atrium. The advent of high-fidelity imaging via CT and transesophageal echocardiography (TEE) has further defined the anatomy of the CS and its multiple tributaries. Understanding this anatomy is crucial for cardiac surgical cases that require the cannulation of the coronary sinus to deliver retrograde cardioplegia. However, anatomical variants of the CS may frustrate surgical retrograde catheter placement, in turn increasing the risk of CS injury or leading to inadequate cardioplegia delivery. Here, we present an especially unique CS presentation, a bifurcated, double-barrel CS, which was discovered via intraoperative TEE imaging that revealed a CS with two smaller lumens instead of the singular large os. CASE PRESENTATION: A 67-year-old male presented for ascending aortic dissection repair, aortic valve replacement, and single vessel coronary artery bypass graft. On the pre-bypass TEE exam, the anesthesiologist noted a bifurcated CS with two small lumens. The surgeon utilized this information to select a smaller diameter retrograde catheter to avoid damage or perforation of the vessel. With TEE guidance, the surgeon successfully cannulated one of the CS lumens. However, it was noted upon dosing of retrograde cardioplegia that all tributary vessels attached to the non-cannulated lumen remained devoid of cardioplegia. The surgeon was forced to repeatedly administer anterograde cardioplegia via a handheld catheter through the coronary ostium throughout the case. The operative field was also flooded with topical ice saline slush to ensure cardiac protection. Ultimately, the operation was completed without incident despite the non-ideal conditions resulting from this anatomic variant. CONCLUSIONS: Discovery of this patient's double-barrel CS during the pre-bypass TEE was incidental, showing that such anatomical variants may be completely asymptomatic and benign in the non-operative setting. However, the delivery of cardioplegia proved challenging for this patient, highlighting some degree of risk with certain cardiac interventions. This case demonstrates the utility of intraoperative TEE to quickly ascertain unforeseen anatomical variants of the CS which could compromise the safety of cardiac surgery cases.

Transesophageal echocardiographic imaging of the coronary sinus: a retrospective analysis of mid-esophageal views and a novel transgastric view.

BACKGROUND: Transesophageal echocardiographic imaging plays an important role in assessing coronary sinus anatomy prior to placement of a retrograde cardioplegia cannula. The coronary sinus can be imaged in the long axis by advancing the TEE probe from the mid-esophageal 4-chamber view or using a modified mid-esophageal bicaval view, while a short axis view can be obtained in the mid-esophageal 2-chamber view. While use of a transgastric view is only briefly mentioned in the literature as an alternative to mid-esophageal views, the authors commonly include it in our comprehensive transesophageal echocardiographic exam of the coronary sinus. This study examines the various imaging strategies. We hypothesize that the transgastric view offers comparable coronary sinus imaging to the mid-esophageal views. METHODS: After approval by our institutional review board, the intraoperative transesophageal echocardiographic exams for 50 consecutive elective cardiac surgical patients with a comprehensive echocardiographic assessment of the coronary sinus were retrospectively reviewed and analyzed to evaluate imaging of the coronary sinus in the various views. For each view, we noted and recorded if the coronary sinus and coronary sinus cannula were visualized. Statistical analysis required pairwise comparisons between each of the 4 views. P values were calculated using McNemar's Exact test. RESULTS: Both the coronary sinus and coronary sinus cannula were visualized a majority of the time for each view. There was no statistically significant difference between each view in its ability to visualize the coronary sinus, nor was there a statistically significant difference between each view in its ability to visualize the coronary sinus cannula. CONCLUSIONS: Use of a transgastric window provides the echocardiographer with an effective alternate modality for imaging the coronary sinus when mid-esophageal views are limited.

A Pilot Study to Assess the Clinical Onset of IV Heparin in Interventional Cardiology and Cardiac Surgery.

OBJECTIVES: To determine the onset of heparin anticoagulation, using 2 different measures of activated clotting times (ACT), thromboelastography (TEG; R-time), and anti-Xa levels, after administering low- (100 U/kg) and high- (300 U/kg) dose intravenous (IV) heparin to patients undergoing transcatheter aortic valve replacement (TAVR) and cardiac surgery, respectively. DESIGN: Prospective study. SETTING: Single academic institution. PARTICIPANTS: Patients with normal baseline coagulation presenting for TAVR or cardiac valve surgery. INTERVENTIONS: Coagulation studies were performed at baseline, 30 seconds, 90 seconds, and 180 seconds after IV heparin administration. The tests included iSTAT (iACT) and Hemochron ACT (hACT), TEG R-Time, and anti-Xa levels. At the authors' institution, anti-Xa is the preferred measure of heparin anticoagulation when time permits. ACT, a rapid point- of-care test, is used to assess intraprocedural anticoagulation. MEASUREMENTS AND MAIN RESULTS: After both low- and high-dose heparin, there are peak increases in ACT and anti-Xa at 30 seconds, followed by a decline at 90 seconds and plateau at 180 seconds. The TEG R-time remained elevated (>80 minutes) throughout. For TAVR cases, all anti-Xa was >1.5 IU/mL, and was associated with an iACT >180 seconds and an hACT >200 seconds. For cardiac valve surgery cases, all anti-Xa was >2.4 and associated with an iACT >420 seconds and and hACT >340 seconds. Compared with hACT, iACTs were significantly lower at all time points after low-dose heparin, but not after high-dose heparin. CONCLUSIONS: In this pilot study, heparin anticoagulation was detected as early as 30 seconds after IV administration, based on ACT, anti-Xa levels, and TEG R-time.

Flip Your Perspective: Dextrocardia and its Effect on Monitoring and Management.

Dextrocardia is a rare congenital disorder characterized by an anatomically flipped heart that is positioned in the right instead of the left side of the thorax. Anatomical variants, such as this, are vital to be aware of as they can alter patient monitoring and management. In this case report, we describe a patient with dextrocardia whose anatomy affected intraoperative monitoring while undergoing a successful aortic valve replacement surgery.

An unusual cause of intraoperative acute superior vena cava syndrome.

Acute intraoperative superior vena cava (SVC) syndrome is an exceedingly rare complication in the cardiac surgical population. We describe the case of a 71-year-old female undergoing multi-vessel coronary artery bypass grafting who developed acute intraoperative SVC syndrome following internal thoracic artery harvest retractor placement. Her symptoms included severe plethora, facial engorgement and scleral edema, which was associated with hypotension and severe elevation of central venous pressure. Transesophageal echocardiography was crucial in the diagnosis, management, and optimal retractor placement ensuring adequate SVC flow. Potential causes of intraoperative SVC syndrome are reviewed as well as management options.

Echocardiographic quantification of mitral valvular response to myocardial revascularization.

AIMS AND OBJECTIVES: Mild and/or moderate ischemic mitral regurgitation (IMR) may resolve after isolated coronary artery bypass grafting (CABG). It has been shown that the loss of saddle shape of the mitral valve is associated with IMR and is determined by an increase in the nonplanarity angle (NPA). The aim of this prospective, observational study was to test the hypothesis that NPA might decrease immediately after CABG alone in patients with mild to moderate IMR. MATERIALS AND METHODS: This prospective, observational study was conducted in an academic, tertiary care hospital. Twenty patients underwent 2D and 3D transoesophageal echocardiography (TEE) and mitral valve assessment before and immediately after the CABG. NPA, circularity index, and other geometric variables were obtained. They were compared using paired t test. The SPSS (Version 15.0, Chicago, IL, USA) was used for statistical analysis. P <0.05 was considered significant. RESULTS: The NPA was similar in the pre- and post-bypass periods (148° ± 15°, 148° ± 19°, P = 0.88). Circularity index (0.93 ± 0.13, 0.97 ± 0.11, P = 0.41) also was similar. CONCLUSIONS: There was no change in the mitral valve NPA with revascularization alone in patients with mild or moderate IMR. Mitral valve does not change its planarity (NPA) with revascularization alone in patients with IMR.

Doctors' perceptions of laboratory monitoring in office practice.

BACKGROUND: Laboratory monitoring has been increasingly recognized as an important area for improving patient safety in ambulatory care. Little is known about doctors' attitudes towards laboratory monitoring and potential ways to improve it. METHODS: Six focus groups and one individual interview with 20 primary care doctors and nine specialists from three Massachusetts communities. RESULTS: Participants viewed laboratory monitoring as a critical, time-consuming task integral to their practice of medicine. Most believed they commit few laboratory monitoring errors and were surprised at the error rates reported in the literature. They listed various barriers to monitoring, including not knowing which doctor was responsible for ensuring the completion of laboratory monitoring, uncertainty regarding the necessity of monitoring, lack of alerts/reminders and patient non-adherence with recommended monitoring. The primary facilitator of monitoring was ordering laboratory tests while the patient is in the office. Primary care doctors felt more strongly than specialists that computerized alerts could improve laboratory monitoring. Participants wanted to individualize alerts for their practices and warned that alerts must not interrupt work flow or require too many clicks. CONCLUSIONS: Doctors in community practice recognized the potential of computerized alerts to enhance their monitoring protocols for some medications. They viewed patient non-adherence as a barrier to optimal monitoring. Interventions to improve laboratory monitoring should address doctor workflow issues, in addition to patients' awareness of the importance of fulfilling recommended therapeutic monitoring to prevent adverse drug events.

Using health information technology to improve drug monitoring: a systematic review.

PURPOSE: To conduct a systematic review of current evidence regarding the use of health information technology (HIT) interventions to improve drug monitoring in ambulatory care. METHODS: We searched PubMed, CINAHL, the Cochrane Library, and other computerized databases from 1 January 1998 to 30 June 2008 using the key words "drug monitoring," "medical records systems, computerized," "ambulatory care," and "outpatients." We manually reviewed reference lists of articles identified through computer searches and asked experts in the field to review our search strategy and results for completeness. RESULTS: Seven relevant studies were identified. Four of these studies assessed real-time interventions that used alerts to physicians at the time of medication ordering to ensure adequate monitoring, only one of which showed an improvement in monitoring. Of three studies using HIT outside the physician encounter, two suggested some improvement in monitoring rates. Methodological limitations were apparent in all studies identified. CONCLUSIONS: Few studies have assessed the effectiveness of HIT interventions to improve drug monitoring, and among them, there is no clear consensus regarding the most consistently effective approaches to reducing drug monitoring errors. There is a clear need for well designed randomized trials to evaluate possible interventions to reduce drug monitoring errors. Such studies should incorporate health outcomes and detailed cost analyses to further characterize the feasibility of successful interventions.