Monitored Anesthesia Care for Cardiovascular Interventions

The interventional cardiology is growing and evolving. Many complex procedures are now performed outside the operating room to manage cardiovascular pathologies which had been traditionally treated with cardiac surgery. Appropriate sedation strategy is crucial for improved patient comfort and successful procedure while ensuring safety. Sedation for cardiovascular intervention is frequently challenging, especially in critically-ill, high-risk patients. This review addresses pre-procedure evaluation and preparation of patients, proper monitoring, commonly used sedatives and analgesics, and considerations for specific procedures. Appropriate depth of sedation and analgesia should be balanced with patient, procedural and institutional factors. Understanding of the pharmacology of sedatives/analgesics, vigilant monitoring, ability and proper preparation for management of potential complications may improve outcomes in patients undergoing sedation for cardiovascular procedures.

Perioperative management of patients receiving non-vitamin K antagonist oral anticoagulants: up-to-date recommendations

Indications of non-vitamin K antagonist oral anticoagulants (NOACs), consisting of two types: direct thrombin inhibitor (dabigatran) and direct factor Xa inhibitor (rivaroxaban, apixaban, and edoxaban), have expanded over the last few years. Accordingly, increasing number of patients presenting for surgery are being exposed to NOACs, despite the fact that NOACs are inevitably related to increased perioperative bleeding risk. This review article contains recent clinical evidence-based up-to-date recommendations to help set up a multidisciplinary management strategy to provide a safe perioperative milieu for patients receiving NOACs. In brief, despite the paucity of related clinical evidence, several key recommendations can be drawn based on the emerging clinical evidence, expert consensus, and predictable pharmacological properties of NOACs. In elective surgeries, it seems safe to perform high-bleeding risk surgeries 2 days after cessation of NOAC, regardless of the type of NOAC. Neuraxial anesthesia should be performed 3 days after cessation of NOACs. In both instances, dabigatran needs to be discontinued for an additional 1 or 2 days, depending on the decrease in renal function. NOACs do not require a preoperative heparin bridge therapy. Emergent or urgent surgeries should preferably be delayed for at least 12 h from the last NOAC intake (better if > 24 h). If surgery cannot be delayed, consider using specific reversal agents, which are idarucizumab for dabigatran and andexanet alfa for rivaroxaban, apixaban, and edoxaban. If these specific reversal agents are not available, consider using prothrombin complex concentrates.

Monitored Anesthesia Care for Cardiovascular Interventions

The interventional cardiology is growing and evolving. Many complex procedures are now performed outside the operating room to manage cardiovascular pathologies which had been traditionally treated with cardiac surgery. Appropriate sedation strategy is crucial for improved patient comfort and successful procedure while ensuring safety. Sedation for cardiovascular intervention is frequently challenging, especially in critically-ill, high-risk patients. This review addresses pre-procedure evaluation and preparation of patients, proper monitoring, commonly used sedatives and analgesics, and considerations for specific procedures. Appropriate depth of sedation and analgesia should be balanced with patient, procedural and institutional factors. Understanding of the pharmacology of sedatives/analgesics, vigilant monitoring, ability and proper preparation for management of potential complications may improve outcomes in patients undergoing sedation for cardiovascular procedures.

Dual antiplatelet therapy and non-cardiac surgery: evolving issues and anesthetic implications / 대한마취과학회지

Dual antiplatelet therapy (DAPT) consisting of aspirin plus a P2Y₁₂ inhibitor (clopidogrel, prasugrel, or ticagrelor) is imperative for the treatment of acute coronary syndrome, particularly during the re-endothelialization period after percutaneous coronary intervention (PCI). When patients undergo surgery during this period, the consequences of stent thrombosis are far more serious than those of bleeding complications, except in cases of intracranial surgery. The recommendations for perioperative DAPT have changed with emerging evidence regarding the improved efficacy of non-first-generation drug (everolimus, zotarolimus)-eluting stents (DES). The mandatory interval of 1 year for elective surgery after DES implantation was shortened to 6 months (3 months if surgery cannot be further delayed). After this period, it is generally recommended that the P2Y₁₂ inhibitor be stopped for the amount of time necessary for platelet function recovery (clopidogrel 5–7 days, prasugrel 7–10 days, ticagrelor 3–5 days), and that aspirin be continued during the perioperative period. In emergent or urgent surgeries that cannot be delayed beyond the recommended period after PCI, proceeding to surgery with continued DAPT should be considered. For intracranial procedures or other selected surgeries in which increased bleeding risk may also be fatal, cessation of DAPT (possibly with continuation or minimized interruption [3–4 days] of aspirin) with bridge therapy using short-acting, reversible intravenous antiplatelet agents such as cangrelor (P2Y₁₂ inhibitor) or glycoprotein IIb/IIIa inhibitors (tirofiban, eptifibatide) may be contemplated. Such a critical decision should be individually tailored based on consensus among the anesthesiologist, cardiologist, surgeon, and patient to minimize both ischemic and bleeding risks.

Predicting Delayed Ventilator Weaning after Lung Transplantation: The Role of Body Mass Index / 대한구급학회지

BACKGROUND: Weaning from mechanical ventilation is difficult in the intensive care unit (ICU). Many controversial questions remain unanswered concerning the predictors of weaning failure. This study investigates patient characteristics and delayed weaning after lung transplantation. METHODS: This study retrospectively reviewed the medical records of 17 lung transplantation patients from October 2012 to December 2013. Patients able to be weaned from mechanical ventilation within 8 days after surgery were assigned to an early group (n = 9), and the rest of the patients were assigned to the delayed group (n=8). Patients' intraoperative and postoperative characteristics were collected and analyzed, and conventional weaning predictors, including rapid shallow breathing index (RSBI), were also assessed. RESULTS: The results of the early group showed a significantly shorter ICU stay in addition to a shorter hospitalization overall. Notably, the early group had a higher body mass index (BMI) than the delayed group (20.7 vs. 16.9, p = 0.004). In addition, reopening occurred more frequently in the delayed group (1/9 vs. 5/8, p = 0.05). During spontaneous breathing trials, tidal volume (TV) and arterial oxygen tension were significantly higher in the early group compared to the delayed weaning group, but differences in RSBI and respiratory rate (RR) between groups were not statistically significant. CONCLUSIONS: Low BMI might be associated with delayed ventilator weaning in lung transplantation patients. In addition, instead of the traditional weaning predictors of RSBI and RR, TV might be a better predictor for ventilator weaning after lung transplantation.

Percutaneous cardiopulmonary support to treat suspected venous air embolism with cardiac arrest during open eye surgery: a case report / 대한마취과학회지

We report a case of possible venous air embolism (VAE) during trans pars plana vitrectomy with air-fluid exchange of the vitreous cavity. Shortly after initiation of air-fluid exchange, decreases in end-tidal CO2, oxygen saturation, and blood pressure were observed. The patient rapidly progressed to cardiac arrest unresponsive to cardiopulmonary resuscitation, and recovered after the application of percutaneous cardiopulmonary support. Prompt termination of air infusion is needed when VAE is suspected during air-fluid exchange, and extracorporeal life support should be considered in fatal cases. Although the incidence is rare the possibility of VAE during ophthalmic surgery clearly exists, and therefore awareness and vigilant monitoring seem critical.

Sex Differences in Remifentanil Requirements for Preventing Cough during Anesthetic Emergence

PURPOSE: Target-controlled infusion (TCI) of remifentanil can suppress coughing during emergence from general anesthesia; nevertheless, previous studies under different clinical conditions recommend significantly different effective effect-site concentrations (effective Ce) of remifentanil for 50% of patients (EC50). The differences among these studies include type of surgery and patient sex. In recent years, study of sex differences in regards to anesthetic pharmacology has drawn greater interest. Accordingly, we attempted to determine the effective Ce of remifentanil for preventing cough for each sex under the same clinical conditions. MATERIALS AND METHODS: Twenty female and 25 male ASA physical status I-II grade patients between the ages of 20 and 46 years who were undergoing thyroidectomy were enrolled in this study. The effective Ce of remifentanil for preventing cough was determined for each sex using the isotonic regression method with a bootstrapping approach, following Dixon's up-and-down method. RESULTS: Isotonic regression with a bootstrapping approach revealed that the estimated EC50 of remifentanil for preventing coughing during emergence was significantly lower in females {1.30 ng/mL [83% confidence interval (CI), 1.20-1.47 ng/mL]} than in males [2.57 ng/mL (83% CI, 2.45-2.70 ng/mL)]. Mean EC50 in females was also significantly lower than in males (1.23+/-0.21 ng/mL vs. 2.43+/-0.21 ng/mL, p<0.001). Mean arterial pressure, heart rate, and respiratory rate over time were not significantly different between the sexes. CONCLUSION: When using remifentanil TCI for cough prevention during anesthetic emergence, patient sex should be a considered for appropriate dosing.

Predicting Delayed Ventilator Weaning after Lung Transplantation: The Role of Body Mass Index / 대한중환자의학회지

BACKGROUND: Weaning from mechanical ventilation is difficult in the intensive care unit (ICU). Many controversial questions remain unanswered concerning the predictors of weaning failure. This study investigates patient characteristics and delayed weaning after lung transplantation. METHODS: This study retrospectively reviewed the medical records of 17 lung transplantation patients from October 2012 to December 2013. Patients able to be weaned from mechanical ventilation within 8 days after surgery were assigned to an early group (n = 9), and the rest of the patients were assigned to the delayed group (n=8). Patients' intraoperative and postoperative characteristics were collected and analyzed, and conventional weaning predictors, including rapid shallow breathing index (RSBI), were also assessed. RESULTS: The results of the early group showed a significantly shorter ICU stay in addition to a shorter hospitalization overall. Notably, the early group had a higher body mass index (BMI) than the delayed group (20.7 vs. 16.9, p = 0.004). In addition, reopening occurred more frequently in the delayed group (1/9 vs. 5/8, p = 0.05). During spontaneous breathing trials, tidal volume (TV) and arterial oxygen tension were significantly higher in the early group compared to the delayed weaning group, but differences in RSBI and respiratory rate (RR) between groups were not statistically significant. CONCLUSIONS: Low BMI might be associated with delayed ventilator weaning in lung transplantation patients. In addition, instead of the traditional weaning predictors of RSBI and RR, TV might be a better predictor for ventilator weaning after lung transplantation.