Investigation of real-world heparin resistance and anticoagulation management prior to cardiopulmonary bypass: report from a nationwide survey by the Japanese Association for Thoracic Surgery heparin resistance working group.

OBJECTIVE: Heparin resistance is often encountered during cardiopulmonary bypass. Heparin dose and activated clotting time target values for the initiation of cardiopulmonary bypass are not yet universally standardized; further no consensus exists on the management of heparin resistance. This study aimed to investigate the current real-world practice on heparin management and anticoagulant treatment for heparin resistance in Japan. METHODS: A questionnaire survey was conducted at medical institutions nationwide with which The Japanese Society of Extra-Corporeal Technology in Medicine members are affiliated, targeting surgical cases with cardiopulmonary bypass performed from January 2019 through December 2019. RESULTS: Among 69% (230/332) of the participating institutions, the criterion for heparin resistance was defined as "the target activated clotting time value not reached even with an additional dose of heparin administration". Cases of heparin resistance were reported in 89.8% (202/225) of the responded institutions. Of note, 75% (106/141) of the responded institutions reported heparin resistance associated with antithrombin activity ≥ 80%. Antithrombin concentrate was used in 38.4% (238/619 responses) or third dose of heparin in 37.8% (234/619 responses) for advanced heparin resistance treatment. Antithrombin concentrate was found to be effective in resolving heparin resistance in patients having normal, as well as lower antithrombin activity. CONCLUSION: Heparin resistance has occurred in many cardiovascular centers, even among patients with normal antithrombin activities. Interestingly, the administration of antithrombin concentrate resolved heparin resistance, regardless of the baseline antithrombin activity value.

The use of a scented face mask in pediatric patients may facilitate mask acceptance before anesthesia induction.

Background: Scented face masks are commonly used during the induction phase of anesthesia. The present study investigated whether the use of a scented mask improved mask acceptance before the slow induction of anesthesia in pediatric patients. Methods: This prospective, randomized controlled trial enrolled patients aged 2-10 years who were scheduled to undergo surgery under general anesthesia. Patients were randomly assigned to either of regular unscented (control group) or scented (experimental group) face masks before anesthesia induction with a parent. The primary outcome was the mask acceptance score, rated on a validated 4-point from 1 point (not afraid; easily accepts the mask) to 4 points (afraid of a mask; crying or struggling). The secondary outcome was heart rate assessed by pulse oximetry in the pediatric ward before transfer to the operating room (OR), at the entrance to the OR, at the patient notification of mask fitting by the anesthesiologist, and after mask fitting. Results: Seventy-seven patients were accessed for eligibility, with 67 enrolled in the study: 33 in the experimental group and 34 in the control group. Mask acceptance was significantly greater among patients aged 2-3 years in the experimental than in the control group (p < 0.05). Conclusion: The use of a scented mask can improve mask acceptance before anesthesia induction with a parental presence in pediatric patients aged 2-3 years.Clinical Trial Registration: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000040819.

The incidence of hypotension during general anesthesia: a single-center study at a university hospital.

BACKGROUND: Although intraoperative hypotension (IOH) has been emerging as a serious concern during general anesthesia, the incidence of IOH has not been demonstrated clearly in the Japanese population. METHODS: This single-center retrospective study investigated the incidence and the characteristics of IOH in non-cardiac surgery at a university hospital. IOH was defined as at least one fall of MAP during general anesthesia, which was categorized into the following groups: mild (65 to < 75 mmHg), moderate (55 to < 65 mmHg), severe (45 to < 55 mmHg), and very severe (< 45 mmHg). The incidence of IOH was calculated as a percentage of the number of events to the total anesthesia cases. Logistic regression analysis was performed to examine factors affecting IOH. RESULTS: Eleven thousand two hundred ten cases out of 13,226 adult patients were included in the analysis. We found moderate to very severe hypotension occurred in 86.3% of the patients for at least 1 to 5 min, and 48.5% experienced severe or very severe hypotension. The results of the logistic regression analysis indicated female gender, vascular surgery, American Society of Anesthesiologists physical status classification (ASA-PS) 4 or 5 in emergency surgery, and the combination with the epidural block (EDB) were significant factors of IOH. CONCLUSIONS: IOH during general anesthesia was very frequent in the Japanese population. Female gender, vascular surgery, ASA-PA 4 or 5 in emergency surgery, and the combination with EDB were independent risk factors associated with IOH. However, the association with patient outcomes were not elucidated.

Ultrasonographic images of spina bifida before obstetric anesthesia: a case series.

BACKGROUND: Spina bifida is a relatively common congenital malformation. As the functional prognosis of patients with spina bifida has improved over time, the number of cases resulting in pregnancy and delivery has increased. Lumbar ultrasonography has become a standard and helpful technique before neuraxial anesthesia. We believe that it might be valuable if we use lumbar ultrasonography to evaluate pregnant women with spina bifida before obstetric anesthesia. CASE PRESENTATION: We performed lumbar ultrasonography to evaluate four pregnant women with spina bifida. Patient 1 had no history of surgery. Lumbar radiography before pregnancy showed a bone defect from L5 to the sacrum as a result of incomplete fusion. Magnetic resonance imaging showed a spinal lipoma and a bone defect of the sacrum. Lumbar ultrasonography showed similar findings. We performed general anesthesia for emergency cesarean delivery. Patient 2 underwent surgical repair immediately after birth. Lumbar ultrasonography showed the same bone defect as well as a lipoma beyond the bone defect. We performed general anesthesia for cesarean delivery. Patient 3 had vesicorectal disorders but no prior surgery. Lumbar radiography before pregnancy showed congenital abnormalities such as incomplete fusion, scoliosis, rotation, and a notably small sacrum. Lumbar ultrasonography showed the same bone defect. We performed general anesthesia for cesarean section with no complications. Patient 4 complained of lumbago a few years after her first delivery and received a diagnosis of spina bifida occulta by lumbar radiography, with the incomplete fusion of only the 5th vertebra. Lumbar ultrasonography indicated the same abnormalities. We placed an epidural catheter to avoid the bone abnormality and achieved epidural labor analgesia with no complications. CONCLUSIONS: Lumbar ultrasonography shows anatomic structures easily, safely, and consistently, without X-ray exposure or the need for more expensive modalities. It is a helpful technique to explore anatomic structures potentially complicated by spina bifida before anesthetic procedures.

Characteristics and outcomes of unplanned intensive care unit admission after general anesthesia.

BACKGROUND: Unplanned ICU admission after surgery has been validated as a measure of a quality indicator of perioperative management because it may put surgical patients at risk of increased morbidity and mortality. Postoperative unscheduled admission to the ICU is usually determined either in the post-anesthesia care unit (PACU) or in the general surgical ward; however, it could be expected patient outcomes after ICU admission would be affected by the circumstances. The purpose of this retrospective observational study was to investigate the clinical characteristics and the outcome of unplanned admission to the ICU directly from the PACU or from the ward within 7 days after PACU discharge. METHODS: Forty-three thousand, five hundred fifty-three patients admitted to the PACU after general anesthesia were included in the study. Unplanned ICU admission was defined as the admission which was not anticipated preoperatively but was due to adverse events in the PACU (PACU group) or the ward after discharge from the PACU (Ward group). The following parameters were compared between the groups: patient characteristics, surgical characteristics, length of ICU and hospital stay, the principal adverse event for ICU admission, treatments in the ICU, and in-hospital mortality. The primary outcome was in-hospital mortality and the second was the length of ICU and hospital stay. RESULTS: Among 43,553 patients, 109 patients underwent unplanned ICU admission directly from the PACU (n= 73, 0.17%) or subsequently from the ward (n= 36, 0.08%). The length of both ICU and hospital stay was significantly longer in the Ward group than in the PACU group (1.4 and 19 days vs. 2.5 and 39 days, respectively). There was no significant difference in in-hospital mortality between the groups (4.1% vs. 8.3%, respectively). CONCLUSIONS: The incidence of unplanned ICU admission after PACU stay was low, however, delayed admission to the ICU from the ward may prolong the length of both ICU and hospital stay compared to those directly from the PACU.

Evaluation of the effect of apixaban using a viscoelastic coagulation assay with Russell's viper venom reagent.

BACKGROUND: Conventional coagulation tests, such as prothrombin time and activated partial thromboplastin time, are not sensitive to anticoagulation by apixaban. We evaluated the antithrombotic effect of apixaban using a Russell viper venom (RVV) test for a patient who underwent posterior spine fusion surgery. CASE PRESENTATION: An 84-year-old man was scheduled for percutaneous posterior spine fusion. He continued apixaban until the night before surgery and resumed it on the first day after surgery. We performed an RVV test as point-of-care coagulation monitoring in combination with chromogenic anti-activated factor X (anti-Xa) activity, prothrombin time, and activated partial thromboplastin time. Clotting time with the RVV test was prolonged according to the anti-Xa activity of apixaban, which was in the therapeutic range during surgery. CONCLUSIONS: An RVV test might be useful as a point-of-care assay for estimation of the anti-Xa level induced by apixaban during the perioperative period.

Coagulation assessment with thromboelastography during abdominal endovascular aneurysm repair in a patient with hemophilia A.

BACKGROUND: As both APTT and APTT-based coagulation method cannot distinguish heparin effect from intrinsic coagulation factor deficiency, we implemented thromboelastography (TEG) for the coagulation assessment in a patient with hemophilia A undergoing an endovascular surgery with heparinization. CASE PRESENTATION: A 68-year-old male with hemophilia A underwent endovascular aortic repair for abdominal aortic aneurism. TEG results showed recovery of coagulation time (R) in both kaolin assay (CK) and kaolin-heparinase assay (CKH) after factor VIII replacement before heparinization. Against our expectations, R-CKH was slightly prolonged (9.0 min) during heparinization. After the administration of protamine sulfate, R in both assays showed similar values within the normal ranges. CONCLUSIONS: The combination of CK and CKH assays could be useful to estimate factor VIII (FVIII) level when heparin concentration is low or without heparin; however, caution should be necessary for estimation of FVIII level by TEG under the effect of medium- or high-dose heparin.

Safety of Fibrinogen Concentrate and Cryoprecipitate in Cardiovascular Surgery: Multicenter Database Study.

OBJECTIVES: To investigate whether administering fibrinogen concentrate or cryoprecipitate is associated with increased postoperative thromboembolic events and improved mortality in patients undergoing thoracic aortic surgery. DESIGN: Multicenter retrospective cohort study using propensity-score analyses and multivariate logistic regression analysis to control for confounders. SETTING: Four hospitals (1 national cardiovascular center and 3 university hospitals). PARTICIPANTS: Patients undergoing thoracic aortic surgery with cardiopulmonary bypass between January 2010 and October 2012 (n = 1,047). INTERVENTIONS: Outcomes in patients treated with fibrinogen concentrate or cryoprecipitate (fibrinogen group) were compared with those who did not receive these products (no fibrinogen group) based on propensity-score matching. Multivariate logistic regression analysis then was performed to confirm the results. MEASUREMENTS AND MAIN RESULTS: Among 1,047 patients enrolled in this study, 247 patients received fibrinogen concentrate or cryoprecipitate. The median amount of administered fibrinogen was 3 g (interquartile range 2-4 g). Eighty-seven patients were excluded from the propensity-score matching because of missing data. Propensity-score-matched analysis showed no significant difference in the incidence of thromboembolic events or 30-day mortality rate between the groups. Multivariate analysis revealed that the fibrinogen group showed no significant difference in thromboembolic events (odds ratio 1.22; 95% confidence interval 0.76-1.95; p = 0.408) or mortality rate (odds ratio 0.44; 95% confidence interval 0.18-1.12; p = 0.081) compared with those in the no fibrinogen group. CONCLUSIONS: Administering fibrinogen concentrate or cryoprecipitate was associated with neither thromboembolic events nor 30-day mortality in patients undergoing thoracic aortic surgery. Administering fibrinogen concentrate or cryoprecipitate is safe and does not appear to increase thromboembolic events and mortality in thoracic aortic surgery patients.

Successful management of living donor liver transplantation for biliary atresia with single ventricle physiology-from peri-transplant through total cavopulmonary connection: A case report.

Children with single ventricle physiology have complete mixing of the pulmonary and systemic circulations, requiring staged procedures to achieve a separation of these circulations, or Fontan circulation. The single ventricle physiology significantly increases the risk of mortality in children undergoing non-cardiac surgery. As liver transplantation for patients with single ventricle physiology is particularly challenging, only a few reports have been published. We herein report a case of successful LDLTx for an 8-month-old pediatric patient with biliary atresia, heterotaxy, and complex heart disease of single ventricle physiology. The cardiac anomalies included total anomalous pulmonary venous return type IIb, intermediate atrioventricular septal defect, tricuspid regurgitation grade III, coarctation of aorta, interrupted inferior vena cava, bilateral superior vena cava, and polysplenia syndrome. Following LDLTx, the patient sequentially underwent total cavopulmonary shunt + Damus-Kaye-Stansel at 3 years of age and extracardiac total cavopulmonary connection (EC-TCPC) completion at 5 years of age; 7 years have now passed since LDLTx (2 years post-EC-TCPC). We describe the details of the management of LTx in the presence of cardiac anomalies and report the long-term cardiac and liver function, from peri-LDLTx through EC-TCPC completion.

Perioperative Factors Associated With Chronic Central Pain After the Resection of Intramedullary Spinal Cord Tumor.

OBJECTIVE: Some patients experience severe chronic pain after intramedullary spinal cord tumor (IMSCT) resection, but the underlying mechanisms have yet to be fully elucidated. We aimed to investigate perioperative factors associated with chronic pain after IMSCT resection. MATERIALS AND METHODS: We analyzed data from a postal survey and the medical records of patients who had undergone IMSCT resection in our institution between 2000 and 2008. Chronic pain was assessed using the Neuropathic Pain Symptom Inventory score, and its associations with factors related to tumor pathology, patient demographics, neurological findings, surgery, anesthesia, and perioperative management were determined. RESULTS: Seventy-eight consecutive patients (55 men and 23 women; age 17 to 79 y) were included in the statistical analysis of the present study. In univariate analyses, sex, body mass index, preoperative tumor-related pain, preoperative nonsteroidal anti-inflammatory drugs, intraoperative hypotension, postoperative corticosteroids, and decrease in Japanese Orthopaedic Association (JOA) scores were found to be associated with postsurgical chronic central pain. Logistic regression analysis identified 3 significant factors: a decline in JOA scores compared with preoperative values (odds ratio [OR], 3.33; 95% confidence interval [CI], 1.18-9.42; P=0.023), intraoperative hypotension (OR, 3.01; 95% CI, 1.02-8.97; P=0.047), and postoperative corticosteroids (OR, 3.21; 95% CI, 1.02-10.09; P=0.046). DISCUSSION: Decline in JOA score, intraoperative hypotension, and postoperative corticosteroids are independently associated with postsurgical chronic central pain. Intraoperative hypotension and the use of postoperative corticosteroids can be avoided or modified during perioperative management. As results from animal studies have indicated that the administration of corticosteroids may intensify chronic pain, further studies in larger cohorts are required to definitively determine the effect of corticosteroids on postsurgical central pain.

Deep anesthesia worsens outcome of rats with inflammatory responses.

OBJECTIVE: We tested the hypothesis that deep anesthesia with sevoflurane, known as a potent immunomodulator, for 4 h would worsen the 24-h outcomes of rats through modulation of the inflammatory responses. METHODS: Forty-nine male Wistar rats, administered low dose of lipopolysaccharide (0.5 mg/kg) intravenously to elicit moderate inflammatory responses mimicked mild surgical stress, underwent one minimum alveolar concentration (MAC) or 2 MAC sevoflurane anesthesia for 4 h. The 24-h survival rate, arterial blood gases, plasma interleukin (IL)-6 and tumor necrosis factor (TNF)-α concentrations, and rate of T lymphocyte apoptosis in spleen were evaluated. We further examined the effects of hypotension and TNF-α discharge on the survival rate. RESULTS: The survival rate in 2 MAC group was significantly lower accompanied with decreased base excess and increased level of cytokines (IL-6, TNF-α) compared to 1 MAC group. The apoptosis rate did not differ between the two groups. Neither norepinephrine infusion to restore hypotension nor administration of anti-TNF-α antibody improved the outcome in the 2 MAC group. CONCLUSIONS: Deep anesthesia with sevoflurane even for a short-term period augments the release of inflammatory cytokines evoked by inflammatory insults like surgical stress, impairs the acid-base balance, and subsequently deteriorates the outcomes.

Neutrophil gelatinase-associated lipocalin regulates gut microbiota of mice.

BACKGROUND AND AIM: Because neutrophil gelatinase-associated lipocalin (NGAL) is known to provide significant bacteriostatic effects during infectious conditions, we tested the hypothesis that this protein is up-regulated and secreted into the intraluminal cavity of the gut under critically ill conditions and is thus responsible for the regulation of bacterial overgrowth. METHODS: With our institutional approval, male C57BL/6J mouse (6-7 weeks) were enrolled and applied for lipopolysaccharide or peritonitis model compared with naïve control. We assessed NGAL protein concentrations in intestinal lumen and up-regulation of NGAL expression in intestinal tissues in in vivo as well as ex vivo settings. Simultaneously, we examined the effects of NGAL protein administration on the growth of Escherichia coli (E. coli) in in vivo and in vitro experimental settings. The localization of NGAL in intestinal tissues and lumen was also assessed by immunohistological approach using NGAL antibody. RESULTS: Both lipopolysaccharide and peritonitis insults evoked the marked up-regulation of NGAL mRNA and protein levels in gut tissues such as crypt cells. In addition, the administration of NGAL protein significantly inhibited the outgrowth of enteric E. coli under both in vitro and in vivo conditions, accompanied by histological evidence. CONCLUSION: Neutrophil gelatinase-associated lipocalin protein accompanied by apparent bacteriostatic action accumulated in the intestinal wall and streamed into the mucosal layer during critically ill state, thereby possibly shaping microbiota homeostasis in the gut.

[Preoperative Management of Thrombotic Disease].

As the growing population needs to receive antithrombotic therapy, perioperative management of anti- thrombotic therapy, with anticoagulation and/or antiplatelet has become a major concern to physicians taking care of surgical patients. Balancing the risk of bleeding with continuation and thrombosis with discontinuation requires consideration of each patient's risks for thrombotic complications and probability of bleeding in surgical procedures. Warfarin has been a mainstay of chronic anticoagulation therapy, and patients receiving warfarin need interruption of warfarin prior to the surgery and a preoperative bridge therapy with an alternative anticoagulant, typically unfractionated or low molecular weight heparin. The novel oral anticoagulants including dabigatran, rivaroxaban, edoxaban and apixaban have shorter half-lives and may not need the preoperative bridge therapy. However they raised other concerns for perioperative management including prolonged elimination half-life in patients with compromised kidney, poor correlation between routine laboratory tests and clinical effectiveness of anticoagulation or lack of a specific antidote.

Persistent hyperglycemia modulates gut immune function and microbiota in rats.

BACKGROUND: Since hyperglycemia-induced cellular dysfunction could be associated with alterations of the immune system, we tested the hypothesis that hyperglycemia augments the aberrant immune responses such as inflammation and differentiation of CD4(+) T lymphocytes in the mesenteric lymph nodes (MLNs), and induces alterations of microbiota both under physiological and pathological conditions. METHODS: Male Wistar rats were randomly allocated into 4 groups: Control and Endotoxemia (lipopolysaccharide, LPS 1 mg/kg) with or without hyperglycemia. The hyperglycemia groups were administered glucose solution (10-40 %), while the normoglycemia groups were administered saline. Alterations of the mRNA expressions of inflammatory cytokines and CD4(+) T lymphocyte transcriptional factor expressions in the MLNs, and those of the intestinal microbiota were analyzed at 24 hr. RESULTS: Hyperglycemia was kept approximately 250-350 mg/dL during the 24 hr study period. At the end of 24 hr, hyperglycemia augmented the mRNA expressions of interleukin (IL)-1ß and IL-6 in the MLNs, while both the helper T (Th) 2 and regulatory-T (Treg) transcriptional factors were simultaneously up-regulated under non-endotoxemic condition. LPS injection significantly modulated the obligate anaerobe bacterial populations of the Bacteroidetes class, and altered the population sizes of the Clostridium perfringens and the Bacteroides fragilis subgroup. Hyperglycemia did not enhance these alterations of the microbiota evoked by LPS, although it did modify the bacterial populations of the L. reuteri subgroup and staphylococci in healthy condition without endotoxemia. CONCLUSIONS: The present study indicates that both gut immune function and microbiota are significantly modulated by persistent hyperglycemia.

The effects of epidural anesthesia on growth of Escherichia coli at pseudosurgical site: the roles of the lipocalin-2 pathway.

BACKGROUND: Neutrophil-derived lipocalin-2 exerts bacteriostatic effects through retardation of iron uptake by the Gram-negative organisms like Escherichia coli. We tested the hypothesis that the expression of lipocalin-2, a bacteriostatic protein, was upregulated by induction of surgical site infection (SSI) with E coli in healthy and diseased rats and that epidural anesthesia modulated its expression. METHODS: Male Wistar rats were randomized into a healthy or disease group, the latter of which was administered lipopolysaccharide. Both groups were further divided into 3 subgroups, the control, saline, and lidocaine groups: group healthy control (n = 10), healthy saline (n = 10), and healthy lidocaine (n = 10) versus group disease control (n = 15), disease saline (n = 18), and disease lidocaine (n = 19), respectively. While saline was epidurally administered to the control and saline groups, lidocaine was administered to the lidocaine groups. Except for the control groups, E coli was injected to the pseudosurgical site to mimic SSI after abdominal surgery. Plasma concentrations of inflammatory cytokine and lipocalin-2 were measured. At 72 hours, the surgical site tissues were obtained to evaluate mRNA expression of lipocalin-2 and E coli DNA expression. RESULTS: All disease subgroups showed markedly increased plasma inflammatory cytokines versus the healthy subgroups. Among the disease subgroups, plasma concentrations of lipocalin-2 and tissue mRNA expression of lipocalin-2 were significantly increased in group disease lidocaine versus the others. Concurrently, E coli DNA expression in the tissue specimens was also significantly lower in group disease lidocaine as compared with group disease saline. CONCLUSIONS: Epidural anesthesia was associated with an increase in the expression lipocalin-2 and a decrease in the expression of E coli DNA at pseudosurgical sites in sick but not healthy rats. These observations suggest a potential mechanism by which epidural anesthesia could reduce the risk of SSI.

Long-term outcomes of percutaneous radiofrequency thermocoagulation of gasserian ganglion for 2nd- and multiple-division trigeminal neuralgia.

OBJECTIVES: The objective of this study was to examine the long-term outcome of percutaneous radiofrequency thermocoagulation (PRT) of the Gasserian ganglion for the 2nd division and multiple division trigeminal neuralgia (TN), compared to the isolated 3rd division TN. METHODS: One hundred and forty-eight procedures performed in 89 patients with typical TN between April 2004 and September 2011 in a single pain center were retrospectively analyzed. Baseline characteristics of these patients, immediate outcome, duration pain-free, and complications were obtained from their medical records and questionnaires sent in June 2012. Duration pain-free was assessed by Kaplan-Meier analysis. RESULTS: Of the 148 PRT of the Gasserian ganglion, 37 procedures were performed for isolated 2nd-division TN (V2 TN), 67 procedures were for both 2nd- and 3rd-division TN (V2 + V3 TN), and 38 procedures were for isolated 3rd-division TN (V3 TN). The remaining 6 procedures were performed for V1 + V2 TN and V1 + V2 + V3 TN. Immediate success rates of PRT for V2 TN, V2 + V3 TN, and V3 TN were 100%, 86.6%, and 100%, respectively, whereas the durations pain-free for V2 TN and V2 + V3 TN were significantly shorter than that for V3 TN (9, 12, and 36 months, respectively: P = 0.012). CONCLUSION: For 2nd-division TN and multiple-division TN, less long-term pain relief after PRT of the Gasserian ganglion can be expected compared with that for isolated trigeminal 3rd-division neuralgia, even if immediate pain relief is achieved.

Evaluation of noninvasive positive pressure ventilation after extubation from moderate positive end-expiratory pressure level in patients undergoing cardiovascular surgery: a prospective observational study.

BACKGROUND: It remains to be clarified if the application of noninvasive positive pressure ventilation (NPPV) is effective after extubation in patients with hypoxemic respiratory failure who require the sufficient level of positive end-expiratory pressure (PEEP). This study was aimed at examining the effect and the safety of NPPV application following extubation in patients requiring moderate PEEP level for sufficient oxygenation after cardiovascular surgery. METHODS: With institutional ethic committee approval, the patients ventilated invasively for over 48 h after cardiovascular surgery were enrolled in this study. The patients who failed the first spontaneous breathing trial (SBT) at 5 cmH2O of PEEP, but passed the second SBT at 8 cmH2O of PEEP, received NPPV immediately after extubation following our weaning protocol. Respiratory parameters (partial pressure of arterial oxygen tension to inspiratory oxygen fraction ratio: P/F ratio, respiratory ratio, and partial pressure of arterial carbon dioxide: PaCO2) 2 h after extubation were evaluated with those just before extubation as the primary outcome. The rate of re-intubation, the frequency of respiratory failure and intolerance of NPPV, the duration of NPPV, and the length of intensive care unit (ICU) stay were also recorded. RESULTS: While 51 postcardiovascular surgery patients were screened, 6 patients who met the criteria received NPPV after extubation. P/F ratio was increased significantly after extubation compared with that before extubation (325 ± 85 versus 245 ± 55 mmHg, p < 0.05). The other respiratory parameters did not change significantly. Re-intubation, respiratory failure, and intolerance of NPPV never occurred. The duration of NPPV and the length of ICU stay were 2.7 ± 0.7 (SD) and 7.5 (6 to 10) (interquartile range) days, respectively. CONCLUSIONS: While further investigation should be warranted, NPPV could be applied effectively and safely after extubation in patients requiring the moderate PEEP level after cardiovascular surgery.