Should All Patients With Pulmonary Hypertension Undergoing Non-Cardiac Surgery Be Managed by Cardiothoracic Fellowship-Trained Anesthesiologists?

OBJECTIVES: To identify differences in practice patterns and outcomes related to the induction of general anesthesia for patients with pulmonary hypertension (PH) performed by anesthesiologists who have completed a cardiothoracic fellowship (CTA group) vs those who have not (non-CTA group). DESIGN: Retrospective study with propensity score matching. SETTING: Operating room. PARTICIPANTS: All adult patients with PH undergoing general anesthesia requiring intubation at a single academic center over 5 years. INTERVENTIONS: Patient baseline characteristics, peri-induction management variables, post-induction mean arterial pressure (MAP), and other outcomes were compared between CTA and non-CTA groups. METHODS AND MAIN RESULTS: Following propensity scoring matching, 402 patients were included in the final model, 100 in the CTA group and 302 in the non-CTA group. Also following matching, only cases of mild to moderate PH without right ventricular dysfunction remained in the analysis. Matched groups were overall statistically similar with respect to baseline characteristics; however, there was a greater incidence of higher ASA class (P = .025) and cardiology and thoracic procedures (P < .001) being managed by the CTA group. No statistical differences were identified in practice patterns or outcomes related to the induction of anesthesia between groups, except for longer hospital length of stay in the CTA group (P = .008). CONCLUSIONS: These results provide early evidence to suggest the induction of general anesthesia of patients with non-severe PH disease can be comparably managed by either anesthesiologists with or without a cardiothoracic fellowship. However, these findings should be confirmed in a prospective study.

Comparison of Landmark-Guided Versus Fluoroscopy-Guided Cerebrospinal Fluid Drain-Related Complications After Aortic Repairs.

OBJECTIVE: Cerebrospinal fluid drains (CSFDs) are efficacious in preventing spinal cord injury after thoracic or thoracoabdominal aortic repair with extensive coverage. Increasingly, fluoroscopy is used to guide placement instead of the traditional landmark-based approach, but it is unknown which approach is associated with fewer complications. DESIGN: A retrospective cohort study. SETTING: In the operating room. PARTICIPANTS: Patients having undergone thoracic or thoracoabdominal aortic repair with a CSFD over a 7-year period at a single center. INTERVENTIONS: No intervention. MEASUREMENTS AND MAIN RESULTS: Groups were reviewed and statistically compared with respect to baseline characteristics, ease of CSFD placement, and major and minor complications directly related to placement. A total of 150 CSFDs were placed with landmark guidance as opposed to 95 with fluoroscopy guidance. Compared to the landmark group, patients with fluoroscopy-guided CSFDs were older (p < 0.008), had lower American Society of Anesthesiologists physical status scores (p = 0.008), required fewer CSFD placement attempts (p = 0.011), had the CSFD in place for longer duration (p < 0.001), and had a similar incidence of CSFD-related complications (p > 0.999). Composites of both major (4.5% of cases) and minor CSFD-related complications (6.1% of cases), the primary outcomes of the study, occurred with similar incidences between the 2 groups (p > 0.999 for both comparisons) after adjusting potential confounders. CONCLUSIONS: In patients undergoing thoracic or thoracoabdominal aortic repairs, there were no significant differences in the risk of major and minor CSFD-related complications between fluoroscopic guidance and the landmark approach. Although the authors' institution is a high-volume center for this type of procedure, the study was limited by a small sample size. Hence, regardless of the technique used for the placement of CSFD, the risks related to the placement should be balanced carefully against the potential benefits resulting from spinal cord injury prevention. Fluoroscopy-aided insertion of CSFD requires fewer attempts and, hence, may be better tolerated by patients.

Hypothermia and Prolonged Time From Procedure End to Extubation After Endovascular Thoracic Aortic Surgery.

OBJECTIVE: Perioperative hypothermia (core temperature <36°C) occurs in 50%-to-80% of patients recovering from thoracic aortic surgery, though its effects have not been described fully in this context. The authors, therefore, sought to characterize the incidence of perioperative hypothermia and its association with time from procedure end to extubation in endovascular aortic surgical patients. DESIGN: A retrospective cohort study. SETTING: At a single academic tertiary center. PARTICIPANTS: Patients recovering from thoracic aortic surgery with lumbar drains. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: A total of 196 patients were included in this study, 55 of whom were hypothermic with temperatures <35.0°C at the end of surgery. Though the unadjusted time to extubation was not statistically different in the hypothermic group (median 8 minutes, IQR 5-13.5 minutes) compared to the normothermic group (median 7 minutes, IQR 4-12 minutes; p = 0.062), multivariate predictors of increased time from procedure end to extubation included hypothermia (p = 0.011), age (p = 0.009), diabetes (p = 0.015), history of carotid disease (p = 0.040), and crystalloid volume (p = 0.019). CONCLUSIONS: Hypothermia in patients recovering from endovascular aortic surgery was associated with prolonged time from procedure end to extubation. Because of the retrospective observational nature of the authors' analysis, it was not possible to determine the extent to which prolonged mechanical ventilation was influenced by low temperature.

Dollars for Diagnosis: A Single-Institutional Analysis of Billing for Intraoperative Transesophageal Echocardiography Examinations.

OBJECTIVES: The authors sought to identify correctable reasons for the failed completion of required billing elements necessary for the reimbursement of services for intraoperative transesophageal echocardiography (TEE). DESIGN: This was a retrospective study. SETTING: This study was completed at a single institution and large academic center. PARTICIPANTS: The patient population included all adult patients who underwent cardiac surgery at a single academic center over one year. INTERVENTIONS: This retrospective review of TEE documentation and billing data was performed for the all adults undergoing cardiac surgery over the course of one year. METHODS AND MAIN RESULTS: Documentation characteristics were compared between examinations that were reimbursed and those that were not. Out of 504 TEE examinations, 30% were not reimbursed. For these examinations, there was a lower compliance in the completion of minimum billing requirements, compared with those that were reimbursed; designation as "diagnostic" (29% v 93%, respectively, p < 0.0001), procedure note (70% v 99%, p < 0.0001), and procedure order (67% v 98%, p = 0.0002). The total estimated annual loss in revenue was $36,000. CONCLUSIONS: Understanding documentation requirements for TEE is an overlooked but important part of anesthesiology practice that may lead to substantial cost savings. Completion of a procedure note, procedure order, and documentation of an examination as "diagnostic" was associated with successful billing.

Persistent Pain After Cardiac Surgery: Prevention and Management.

Persistent postoperative pain (PPP) after cardiac surgery is a significant complication that negatively affects patient quality of life and increases health care system burden. However, there are no standards or guidelines to inform how to mitigate these effects. Therefore, in this review, we will discuss strategies to prevent and manage PPP after cardiac surgery. Adequate perioperative analgesia may prove instrumental in the prevention of PPP. Although opioids have historically been the primary analgesic approach to cardiac surgery, an opioid-sparing strategy may prove advantageous in reducing side effects, avoiding secondary hyperalgesia, and decreasing risk of PPP. Implementing a multimodal analgesic plan using alternative medications and regional anesthetic techniques may offer superior efficacy while reducing adverse effects.

Anesthesia for Combined Heart and Liver Transplantation.

A heart or liver transplantation procedure performed in isolation itself presents multiple challenges for the perioperative team. Accordingly, combining both transplants yields a vastly more complicated surgery, with many unique multisystem and multidisciplinary considerations. Although combined heart and liver transplantations are being performed with increasing frequency, nationwide experience is relatively limited at most institutions. The aim of this review is to discuss the perioperative challenges presented to the anesthesiology teams and provide evidence-based guidance for the management of these daunting procedures.

Determinants of Discrepancy in the Left Ventricular Systolic Function Evaluation Between Preoperative and Intraoperative Evaluations.

Unexpectedly decreased left ventricular global systolic function can be difficult to manage, even for patients undergoing elective cardiac surgery, and should prompt a multidisciplinary discussion. Therefore, in this review, we discuss the evidence describing key perioperative variables expected to influence left ventricular systolic function to facilitate this discussion.

Anesthesia for Resection and Reconstruction of the Trachea and Carina.

Airway surgery poses a host of unique challenges to both the surgical and anesthesiology teams. Accordingly, there are a variety of surgical, anesthetic, and airway management options to be strategically considered. Management can be challenging during multidisciplinary preoperative planning, during the surgical procedure itself, and during recovery. In this review, emphasis is placed on anesthesia challenges for patients undergoing major tracheal or carinal surgery with specific considerations related to perioperative management.

Genome-Wide Association Study Links Receptor Tyrosine Kinase Inhibitor Sprouty 2 to Thrombocytopenia after Coronary Artery Bypass Surgery.

INTRODUCTION: Thrombocytopenia after cardiac surgery independently predicts stroke, acute kidney injury and death. To understand the underlying risks and mechanisms, we analysed genetic variations associated with thrombocytopenia in patients undergoing coronary artery bypass grafting (CABG) surgery. MATERIALS AND METHODS: Study subjects underwent isolated on-pump CABG surgery at Duke University Medical Center. Post-operative thrombocytopenia was defined as platelet count < 100 × 109/L. Using a logistic regression model adjusted for clinical risk factors, we performed a genome-wide association study in a discovery cohort (n = 860) and validated significant findings in a replication cohort (n = 296). Protein expression was assessed in isolated platelets by immunoblot. RESULTS: A total of 63 single-nucleotide polymorphisms met a priori discovery thresholds for replication, but only 1 (rs9574547) in the intergenic region upstream of sprouty 2 (SPRY2) met nominal significance in the replication cohort. The minor allele of rs9574547 was associated with a lower risk for thrombocytopenia (discovery cohort, odds ratio, 0.45, 95% confidence interval, 0.30-0.67, p = 9.76 × 10-5) with the overall association confirmed by meta-analysis (meta-p = 7.88 × 10-6). Immunoblotting demonstrated expression of SPRY2 and its dynamic regulation during platelet activation. Treatment with a functional SPRY2 peptide blunted platelet extracellular signal-regulated kinase (ERK) phosphorylation after agonist stimulation. CONCLUSION: We identified the association of a genetic polymorphism in the intergenic region of SPRY2 with a decreased incidence of thrombocytopenia after CABG surgery. Because SPRY2-an endogenous receptor tyrosine kinase inhibitor-is present in platelets and modulates essential signalling pathways, these findings support a role for SPRY2 as a novel modulator of platelet responses after cardiac surgery.

Elevated Pulse Pressure, Intraoperative Hemodynamic Perturbations, and Acute Kidney Injury After Coronary Artery Bypass Grafting Surgery.

OBJECTIVE: To explore whether baseline pulse pressure (PP) confers an increased risk for acute kidney injury (AKI) independent of intraoperative hypotension or hypertension in patients who undergo coronary artery bypass grafting (CABG) surgery. DESIGN: Retrospective study. SETTING: Single academic center. PARTICIPANTS: 5,808 patients who underwent CABG surgery. MEASUREMENTS AND MAIN RESULTS: Baseline arterial blood pressure was defined as the mean of the first 5 measurements recorded by the automated record keeping system before anesthesia was induced. Weighted duration of intraoperative hypotension and hypertension were defined as the area (min × mmHg) below a mean arterial pressure of 55 mmHg and above a mean arterial pressure of 100 mmHg. Multivariable logistic and proportional odds regression analyses were performed to determine whether baseline PP and weighted duration of intraoperative hypotension and hypertension were independently associated with postoperative AKI. Of the 5,808 patients, PP was <40 mmHg in 90 (1.6%), 40-to-80 mmHg in 2,463 (42.4 %), and >80 mmHg in 3,255 (56%) patients. The incidence of AKI was 57.7%, which included 7.4% (249 patients) and 2.8% (93 patients) who experienced stages 2 and 3 AKI, respectively. In the risk-adjusted analyses, baseline PP was associated with higher odds for postoperative AKI (odds ratio for every 20 mmHg increase in PP, 1.15; 95% confidence interval 1.10-1.21; p < 0.0001) and a higher severity of postoperative AKI (proportional odds ratio, 1.13; 95% confidence interval 1.03-1.24; p = 0.0098). There was no evidence that weighted duration of intraoperative hypotension or hypertension was associated with postoperative AKI or that either interacted with the association of baseline PP with AKI. CONCLUSIONS: Baseline PP was significantly associated with postoperative AKI after CABG surgery, independent of weighted duration of intraoperative hypotension or hypertension.

Platelet Counts and Postoperative Stroke After Coronary Artery Bypass Grafting Surgery.

BACKGROUND: Declining platelet counts may reveal platelet activation and aggregation in a postoperative prothrombotic state. Therefore, we hypothesized that nadir platelet counts after on-pump coronary artery bypass grafting (CABG) surgery are associated with stroke. METHODS: We evaluated 6130 adult CABG surgery patients. Postoperative platelet counts were evaluated as continuous and categorical (mild versus moderate to severe) predictors of stroke. Extended Cox proportional hazard regression analysis with a time-varying covariate for daily minimum postoperative platelet count assessed the association of day-to-day variations in postoperative platelet count with time to stroke. Competing risks proportional hazard regression models examined associations between day-to-day variations in postoperative platelet counts with timing of stroke (early: 0-1 days; delayed: ≥2 days). RESULTS: Median (interquartile range) postoperative nadir platelet counts were 123.0 (98.0-155.0) × 10/L. The incidences of postoperative stroke were 1.09%, 1.50%, and 3.02% for platelet counts >150 × 10/L, 100 to 150 × 10/L, and <100 × 10/L, respectively. The risk for stroke increased by 12% on a given postoperative day for every 30 × 10/L decrease in platelet counts (adjusted hazard ratio [HR], 1.12; 95% confidence interval [CI], 1.01-1.24; P= .0255). On a given day, patients with moderate to severe thrombocytopenia were almost twice as likely to develop stroke (adjusted HR, 1.89; 95% CI, 1.13-3.16; P= .0155) as patients with nadir platelet counts >150 × 10/L. Importantly, such thrombocytopenia, defined as a time-varying covariate, was significantly associated with delayed (≥2 days after surgery; adjusted HR, 2.83; 95% CI, 1.48-5.41; P= .0017) but not early postoperative stroke. CONCLUSIONS: Our findings suggest an independent association between moderate to severe postoperative thrombocytopenia and postoperative stroke, and timing of stroke after CABG surgery.

Altered aquaporin 9 expression and localization in human hepatocellular carcinoma.

BACKGROUND: In addition to the biochemical components secreted in bile, aquaporin (AQP) water channels exist in hepatocyte membranes to form conduits for water movement between the sinusoid and the bile canaliculus. The aim of the current study was to analyse AQP 9 expression and localization in human hepatocellular carcinoma (HCC) and non-tumourigenic liver (NTL) tissue from patients undergoing hepatic resection. METHODS: Archived tissue from 17 patients was sectioned and analysis performed using an antibody raised against AQP 9. Slides were blind-scored to determine AQP 9 distribution within HCC and NTL tissue. RESULTS: Aquaporin 9 was predominantly expressed in the membranes of hepatocytes and demonstrated zonal distribution relative to hepatic sinusoid structure in normal liver. In HCC arising in the absence of cirrhosis AQP 9 remained membrane-localized with zonal distribution in the majority of NTL. By contrast, AQP 9 expression was significantly decreased in the HCC mass vs. pair-matched NTL. In HCC in the presence of cirrhosis, NTL was characterized by extensive AQP 9 staining in the membrane in the absence of zonal distribution and AQP 9 staining in NTL was significantly greater than that observed in the tumour mass. CONCLUSIONS: These data demonstrate that human HCC is characterized by altered AQP 9 expression and AQP 9 localization in the NTL mass is dependent on underlying liver pathology. Given the central role of AQPs in normal liver function and the potential role of AQPs during transformation and progression, these data may prove valuable in future diagnostic and/or therapeutic strategies.