Mikyung Yang

Does a Protective Ventilation Strategy Reduce the Risk of Pulmonary Complications After Lung Cancer Surgery? : A Randomized Controlled Trial

BACKGROUNDnProtective ventilation strategy has been shown to reduce ventilator-induced lung injury in patients with ARDS. In this study, we questioned whether protective ventilatory settings would attenuate lung impairment during one-lung ventilation (OLV) compared with conventional ventilation in patients undergoing lung resection surgery.nnnMETHODSnOne hundred patients with American Society of Anesthesiology physical status 1 to 2 who were scheduled for an elective lobectomy were enrolled in the study. During OLV, two different ventilation strategies were compared. The conventional strategy (CV group, n=50) consisted of FIO2 1.0, tidal volume (Vt) 10 mL/kg, zero end-expiratory pressure, and volume-controlled ventilation, whereas the protective strategy (PV group, n=50) consisted of FIO2 0.5, Vt 6 mL/kg, positive end-expiratory pressure 5 cm H2O, and pressure-controlled ventilation. The composite primary end point included PaO2/FIO2<300 mm Hg and/or the presence of newly developed lung lesions (lung infiltration and atelectasis) within 72 h of the operation. To monitor safety during OLV, oxygen saturation by pulse oximeter (SpO2), PaCO2, and peak inspiratory pressure (PIP) were repeatedly measured.nnnRESULTSnDuring OLV, although 58% of the PV group needed elevated FIO2 to maintain an SpO2>95%, PIP was significantly lower than in the CV group, whereas the mean PaCO2 values remained at 35 to 40 mm Hg in both groups. Importantly, in the PV group, the incidence of the primary end point of pulmonary dysfunction was significantly lower than in the CV group (incidence of PaO2/FIO2<300 mm Hg, lung infiltration, or atelectasis: 4% vs 22%, P<.05).nnnCONCLUSIONnCompared with the traditional large Vt and volume-controlled ventilation, the application of small Vt and PEEP through pressure-controlled ventilation was associated with a lower incidence of postoperative lung dysfunction and satisfactory gas exchange.nnnTRIAL REGISTRYnAustralian New Zealand Clinical Trials Registry; No.: ACTRN12609000861257; URL: www.anzctr.org.au.

The changes in coagulation profile and epidural catheter safety for living liver donors: A report on 6 years of our experience

The use of epidural catheters has been a subject of active debate in living liver donors because of the possible postoperative coagulation derangement and the subsequent risk of epidural hematoma. The aim of this study was to evaluate the safety of epidural catheters in relation to the changes in coagulation profile based on a review of previously published literature and the results of our 360 donors. In both the literature and in our cases, platelet count, prothrombin time (PT), and activated partial thromboplastin time (aPTT) in cases of heparin administration showed significant changes (P < 0.05), especially after right lobectomy. Platelet count reached its nadir on postoperative day (POD) 2–3, while PT and aPTT reached their peaks on POD 1–2 and at the end of the operation, respectively. In our donors, the ranges of platelet count, PT, and aPTT for the first 3 PODs were 54–359 ×10/μL, 0.99–2.38 international normalized ratio (INR), and 25.9–300 seconds, respectively, and of note, 5 donors (1.4%) had a platelet count of <80 × 10/μL and 9 donors (2.5%) had a PT of >2.0 INR. Epidural catheterizations were performed in 242 donors, and the catheters were removed on POD 3–4 in 177 donors (73.1%). Mean (range) of platelet count, PT, and aPTT on the day of catheter removal were 168.4 ± 42.9 (82–307) × 10/μL, 1.33 ± 0.18 (0.99–1.93) INR, and 40.9 ± 4.8 (32.0–70.6) seconds, respectively. No epidural hematoma was observed in this study. In conclusion, the discreet use of epidural catheters in live liver donors, in spite of postoperative coagulation derangements, appears to be safe regardless of the type of hepatectomy performed. Liver Transpl 13:62–70, 2007.

Reactive oxygen species by isoflurane mediates inhibition of nuclear factor κB activation in lipopolysaccharide-induced acute inflammation of the lung.

BACKGROUND:Although anesthetic-induced inhibition of lipopolysaccharide (LPS)-induced lung injury has been recognized, the underlying mechanism is obscure. Some studies suggest that reactive oxygen species (ROS) by isoflurane play a crucial role for anesthetic-induced protective effects on the brain or the heart; however, it still remains controversial. In this study, we examined the role of isoflurane-derived ROS in isoflurane-induced inhibition of lung injury and nuclear factor &kgr;B (NF&kgr;B) activation in LPS-challenged rat lungs. METHODS:Male Sprague-Dawley rats were subjected to inhalation of 1.0 minimum alveolar concentration of isoflurane for 60 minutes, and intratracheal LPS 0.1 mg was administered 60 minutes later. In some cases, ROS scavenger, 2-mercaptopropinyl glycine or N-acetylcysteine was given 30 minutes before isoflurane. ROS generation was measured by fluorometer before LPS challenge and 4 hours after. Isoflurane’s preconditioning effect was assessed by histologic examination, protein content, neutrophil recruitment, and determination of tumor necrosis factor (TNF)-&agr;, interleukin (IL)-1&bgr;, and IL-6 levels in bronchoalveolar lavage fluid and lung tissue. Western blotting measured phosphorylation of inhibitory &kgr;B &agr; (ser 32/36), NF&kgr;B p65, and inducible nitric oxide synthase (iNOS). TNF-&agr; and IL-6 mRNA expression and immunofluorescence staining for iNOS were also assessed. RESULTS:Isoflurane preconditioning reduced inflammatory lung injury and TNF-&agr;, IL-1&bgr;, and IL-6 release in the lung. Isoflurane upregulated ROS generation before LPS but inhibited a ROS burst after LPS challenge. ROS scavenger administration before isoflurane abolished the isoflurane preconditioning effect as well as isoflurane-induced inhibition of phosphorylation of inhibitory &kgr;B&agr;, NF&kgr;B p65, iNOS activation, and mRNA expression of TNF-&agr; and IL-6 in acute LPS-challenged lungs. CONCLUSIONS:This study suggests a crucial role of upregulated ROS generation by isoflurane for modification of inflammatory pathways by isoflurane preconditioning in acute inflammation of the lung.

The Risk of Acute Kidney Injury from Fluid Restriction and Hydroxyethyl Starch in Thoracic Surgery

BACKGROUND:Fluid is restricted in thoracic surgery to reduce acute lung injury, and hydroxyethyl starches (HES) are often administered to reduce fluid amount. This strategy may contribute to the development of acute kidney injury (AKI). We evaluated the incidence, risk factors, and prognosis of AKI in thoracic surgery. We especially focused on whether fluid restriction/HES administration increased AKI. METHODS:This is a retrospective study of patients undergoing thoracic surgery in a tertiary care academic center. Postoperative AKI was diagnosed within 72 hours after surgery based on the Acute Kidney Injury Network criteria. Demographic, intraoperative, and postoperative data were compared between non-AKI and AKI groups. Logistic regression was used to model the association between risk factors and AKI. RESULTS:Final analysis included 1442 patients. Of these, 74 patients developed AKI (5.1%). Crystalloid restriction (⩽3 mL·kg−1·h−1) was unrelated to AKI, regardless of preoperative renal functions (odds ratio [OR], 0.5; 95% confidence interval [CI] 0.2–1.4). AKI occurred more often when HES were administered to the patients with decreased renal function (OR, 7.6; 95% CI, 1.5–58.1) or having >2 risk factors with normal renal function (OR, 7.2; 95% CI, 3.6–14.1). Multivariate analysis revealed several risk factors: angiotensin-converting enzyme inhibitor/angiotensin receptor blockers, open thoracotomy, pneumonectomy/esophagectomy, diabetes mellitus, cerebrovascular disease, low albumin level, and decreased renal function. CONCLUSIONS:Fluid restriction neither increased nor was a risk factor for AKI. HES should be administered with caution in high-risk patients undergoing thoracic surgery.

The Effects of Prehydration on the Properties of Cerebrospinal Fluid and the Spread of Isobaric Spinal Anesthetic Drug

BACKGROUND: In a two-part clinical study, we investigated the effect of the administration of fluids “prehydration” on the physical properties of cerebrospinal fluid (CSF) and intrathecal spread of local anesthetics. METHODS: First, in the clinical spinal anesthesia study, 68 patients were allocated randomly into the prehydration or nonprehydration groups. One group was prehydrated with 10 mL/kg of lactated Ringers solution, and spinal anesthesia was performed with 12 mg of 0.5% isobaric tetracaine in all patients at the lumbar level. The arterial blood pressure, heart rate, and sensory block level were assessed. Second, in a magnetic resonance image study, 24 male volunteers were enrolled. CSF motion variables were measured after infusion of 10 mL/kg of lactated Ringers solution to examine the net flow and volume displacement of the CSF at the L2–3 disk level. RESULTS: In the clinical study, there were no significant differences in arterial blood pressure, heart rate, and median peak sensory block level between the two groups, but the median time to reach peak sensory block level (26.4 ± 15.7 vs 16.5 ± 9.2 min, P < 0.05) was longer in group P. In posthydration magnetic resonance images, the CSF regurgitant fraction (caudal flow) was significantly increased after hydration, but the stroke volume, absolute stroke volume, mean flux, stroke distance, and mean velocity in the cranial direction were significantly decreased. CONCLUSIONS: Rapid crystalloid prehydration can affect CSF flow in the lumbar region, reducing cephalic spread of 0.5% isobaric tetracaine and delaying the time to reach the peak sensory level.

Apneic oxygen insufflation decreases the incidence of hypoxemia during one-lung ventilation in open and thoracoscopic pulmonary lobectomy: A randomized controlled trial

Objective: Hypoxemia is common during one‐lung ventilation (OLV) for thoracic surgery. When hypoxemia occurs, surgery is interrupted for rescue ventilation. Apneic oxygen insufflation (AOI), which provides O2 without applying pressure, may prevent hypoxemia and does not interrupt surgery. The aim of this study was to determine the effectiveness of the AOI technique for preventing hypoxemia during OLV in thoracic surgery. Methods: Patients undergoing open or thoracoscopic pulmonary lobectomy from September to December 2015 were included. Patients were assigned randomly to a non‐AOI group or an AOI group (n = 45 each). OLV was initiated and at the 15‐minute mark (OLV15), patients in the AOI group received oxygen insufflation at 3 L/min to the nonventilated lung for 30 minutes (OLV45). The primary endpoint was the occurrence of hypoxemia (SaO2 <90%) during OLV. Results: The demographic and operative data were similar between the 2 groups. The incidence of hypoxemia was greater in the non‐AOI than the AOI group (18% vs 0%; P = .009). &Dgr;PaO2 (the difference in partial pressure of oxygen in arterial blood between OLV 45 and 15 minutes) was smaller in the AOI than the non‐AOI group (−29 mm Hg vs −69 mm Hg; P = .005). Duration of surgery and incidence of complications did not vary between groups. Conclusions: AOI decreases the incidence of hypoxemia and improves arterial oxygenation during OLV for open and thoracoscopic surgery. AOI may be a valuable option to prevent hypoxemia. It can be used before relying on continuous positive airway pressure or intermittent two‐lung ventilation and result in fewer interruptions in surgery.

Decreased Incidence of Postoperative Delirium in Robot-assisted Thoracoscopic Esophagectomy Compared With Open Transthoracic Esophagectomy.

Background: Postoperative delirium (POD) is one of messy complications related with increased mortality and hospital costs. Patients undergoing esophagectomy are more in danger of delirium than other kinds of surgeries. We investigated the impact of robot-assisted thoracoscopic esophagectomy on the incidence of POD compared with open transthoracic esophagectomy. Materials and Methods: A retrospective review was completed for the patients who underwent esophagectomy from December 2, 2012 and April 15, 2015 (n=529). POD was assessed using Confusion Assessment Method for the Intensive Care Unit. The comparison of group differences between the robotic esophagectomy group (R group) and the open esophagectomy group (O group) was conducted with and without propensity score (PS) matching method. Univariate model was used for 247 PS-matched patients to calculate the odds ratio of potential risk factors of POD. Results: The incidence rate of POD was significantly lower among R group patients than O group (30% vs. 42%; P=0.035) after PS matching method. The risk of POD in R group was 0.55-fold lower than that of O group. Operative time and intraoperative blood loss were also significantly lower in R group patients. Conclusions: In conclusion, robotic thoracoscopic esophagectomy lowers the incidence of POD 0.55-fold compared with open transthoracic esophagectomy.

Comparison Between Phenylephrine and Dopamine in Maintaining Cerebral Oxygen Saturation in Thoracic Surgery: A Randomized Controlled Trial

AbstractFluid is usually restricted during thoracic surgery, and vasoactive agents are often administered to maintain blood pressure. One-lung ventilation (OLV) decreases arterial oxygenation; thus oxygen delivery to the brain can be decreased. In this study, we compared phenylephrine and dopamine with respect to maintaining cerebral oxygenation during OLV in major thoracic surgery.Sixty-three patients undergoing lobectomies were randomly assigned to the dopamine (D) or phenylephrine (P) group. The patients’ mean arterial pressure was maintained within 20% of baseline by a continuous infusion of dopamine or phenylephrine. Maintenance fluid was kept at 5u200amL/kg/h. The depth of anesthesia was maintained with desflurane 1MAC and remifentanil infusion under bispectral index guidance. Regional cerebral oxygen saturation (rScO2) and hemodynamic variables were recorded using near-infrared spectroscopy and esophageal cardiac Doppler.The rScO2 was higher in the D group than the P group during OLV (OLV 60u200amin: 71u200a±u200a6% vs 63u200a±u200a12%; Pu200a=u200a0.03). The number of patients whose rScO2 dropped more than 20% from baseline was 0 and 6 in the D and P groups, respectively (Pu200a=u200a0.02). The D group showed higher cardiac output, but lower mean arterial pressure than the P group (4.7u200a±u200a1.0 vs 3.9u200a±u200a1.2u200aL/min; 76.7u200a±u200a8.1 vs 84.5u200a±u200a7.5u200amm Hg; Pu200a=u200a0.02, Pu200a=u200a0.02). Among the variables, age, hemoglobin concentration, and cardiac output were associated with rScO2 by correlation analysis.Dopamine was superior to phenylephrine in maintaining cerebral oxygenation during OLV in thoracic surgery.

Epinephrine decreases the dose of hyperbaric bupivacaine necessary for tourniquet pain blockade during spinal anesthesia for total knee replacement arthroplasty

PurposeWe quantified the dose-sparing effect of epinephrine by comparing the median effective dose (ED50) of intrathecal hyperbaric bupivacaine co-administered with epinephrine with the ED50 of intrathecal hyperbaric bupivacaine alone.MethodsThree groups were randomly generated from 162 patients undergoing total knee replacement arthroplasty under combined spinal and epidural anesthesia: Group B (bupivacaine), Group BE1 (bupivacaine plus epinephrine 100xa0μg), and Group BE2 (bupivacaine plus epinephrine 200xa0μg). Each group was further divided by bupivacaine doses of 6, 7, 8, 9, 10, or 11xa0mg. The anesthesia was defined as successful if a bilateral T12 sensory block occurred within 15xa0min, and no intraoperative epidural supplement was required. The ED50 and ED95 for successful anesthesia and successful tourniquet pain blockade were determined separately by probit regression analysis.ResultsThe ED50 and ED95 of intrathecal hyperbaric bupivacaine for successful anesthesia were not different among the groups: the ED50 values were 7.1xa0mg [95xa0% confidence interval (95xa0% CI) 6.0–8.0xa0mg] in Group B, 6.2xa0mg (95xa0% CI 4.8–7.2xa0mg) in Group BE1, and 6.3xa0mg (95xa0% CI 4.9–7.2xa0mg) in Group BE2. However, the ED50 and ED95 values for tourniquet pain control were significantly smaller in Groups BE1 and BE2 than in Group B: the ED50 values were 7.2xa0mg (95xa0% CI 6.3–7.9xa0mg), 5.5xa0mg (95xa0% CI 4.1–6.3xa0mg), and 5.3xa0mg (95xa0% CI 3.7–6.2xa0mg) in Groups B, BE1, and BE2, respectively. The incidence of tourniquet pain was significantly lower in Groups BE1 and BE2 than in Group B. The time to patients’ requests for supplemental analgesia was significantly longer in Groups BE1 and BE2 than in Group B.ConclusionsIntrathecal epinephrine did not decrease the dose of intrathecal hyperbaric bupivacaine required for successful anesthesia. However, it reduced the dose required for tourniquet pain blockade.

Non-intubated video-assisted thoracoscopic lung biopsy for interstitial lung disease: a single-center experience

BackgroundnThe mortality and morbidity associated with video-assisted thoracoscopic (VATS) lung biopsy for interstitial lung disease (ILD) are not negligible. We evaluated whether non-intubated VATS lung biopsy, which avoids intubation and general anesthesia, can be safely performed in ILD subjects.nnnMethodsnThis retrospective study compared the incidence of complications and surgical mortality between 25 consecutive intubated subjects and 10 non-intubated subjects (a total of 35 consecutive subjects) at a single institution.nnnResultsnNo major surgical complications or deaths were reported in either group, and non-intubated VATS biopsies were safely performed in subjects with relatively low carbon monoxide diffusing capacity (P=0.08) or poor American Society of Anesthesiologists physical status scores (ASA) (P=0.02).nnnConclusionsnThese preliminary results suggest that non-intubated VATS lung biopsy is a safe and feasible option in patients with ILD.