Pressure-controlled Ventilation Does Not Improve Gas Exchange in Morbidly Obese Patients Undergoing Abdominal Surgery

Background

Morbid obesity results in marked respiratory pathophysiologic changes that may lead to impaired intraoperative gas exchange. The decelerating inspiratory flow and constant inspiratory airway pressure resulting from pressure-controlled ventilation (PCV) may be more adapted to these changes and improve gas exchanges compared with volume-controlled ventilation (VCV).

Methods

Forty morbidly obese patients scheduled for gastric bypass were included in this study. Total intravenous anesthesia was given using the target-controlled infusion technique. During the first intraoperative hour, VCV was used and the tidal volume was adjusted to keep end-tidal PCO₂ around 35 mmHg. After 1 h, patients were randomly allocated to 30-min VCV followed by 30-min PCV or the opposite sequence using a Siemens® Servo 300. FiO₂ was 0.6. During PCV, airway pressure was adjusted to provide the same tidal volume as during VCV. Arterial blood was sampled for gas analysis every 15 min. Ventilatory parameters were also recorded.

Results

Peak inspiratory airway pressures were significantly lower during PCV than during VCV (P? <?0.0001). The other ventilatory parameters were similar during the two periods of ventilation. PaO₂ and PaCO₂ were not significantly different during PCV and VCV.

Conclusion

PCV does not improve gas exchange in morbidly obese patients undergoing gastric bypass compared to VCV.

     

Liver reperfusion-induced decrease in dynamic compliance and increase in airway resistance are ameliorated by preischemic treatment with melatonin through scavenging hydroxyl radicals in rat lungs

Objectives

Acute lung injury is frequently observed in patients subsequent to liver ischemia and reperfusion (I/R) injury. However, the changes in pulmonary function, eg, lung dynamic compliance (C_dyn) and airway resistance (RI), are not well understood. We sought to study the alternations in pulmonary function during liver I/R and the protective effects of preischemic treatment with melatonin.

Methods

Animals were divided into 3 groups: sham-operated, liver I/R, and intraperitoneal (i.p.) pretreatment with melatonin (15 mg/kg). Liver I/R was performed by clamping the hepatic artery and portal vein for 30 minutes followed by releasing for 2 hours. The C_dyn and RI were studied at baseline and at 2 hours of reperfusion. We assessed the level of pulmonary hydroxyl radicals by methylguanidine (MG) content in the bronchoalveolar lavage fluid (BALF) as well as the liver damage using plasma levels of lactate dehydrogenase (LDH), glutamic oxaloacetic transaminase (GOT), and glutamic pyruvic transaminase (GPT).

Results

After 2 hours of liver reperfusion, C_dyn was reduced by ∼25%, while RI increased by ∼16% (P < .05). The decreased C_dyn and increased RI were markedly attenuated by melatonin pretreatment (P < .05). Melatonin pretreatment also protected the liver against I/R injury (P < .05), as seen by reduced LDH, GOT and GPT along with markedly reduced hydroxyl radicals (P < .05).

Conclusions

Preischemic treatment with melatonin protected lung function against damage by liver I/R. The improvement in lung function was strongly associated with decreased hydroxyl radicals in the lungs.     

Remifentanil for the insertion and removal of long-term central venous access during monitored anesthesia care

Study Objective

To determine the analgesic efficacy of three different rates of remifentanil infusion in patients undergoing insertion or removal of long-term central venous access devices during monitored anesthesia care and local anesthetic field infiltration.

Design

Double-blinded, randomized, controlled study.

Setting

Operating theatre of an University hospital.

Patients

44 unpremedicated, ASA physical status 1 and 2 patients, aged 18-65 years, undergoing insertion or removal of a Port-a-Cath or Hickman catheter.

Interventions

Patients sedated with a propofol target-controlled infusion were randomly allocated to three groups: Group R25 (n = 14), Group R50 (n = 15), and Group R75 (n = 15), to receive remifentanil 0.025, 0.05, and 0.075 μg/kg/min, respectively. Rescue remifentanil 0.5 μg/kg was administered for pain scores > 3. The remifentanil infusion rate was maintained constant unless respiratory and/or cardiovascular unwanted events occurred, whereupon the rate was adjusted in 0.01 μg/kg/min decrements as necessary.

Measurements

Pain scores (primary outcome), sedation, and movement scores (secondary outcomes) were assessed during local anesthetic infiltration of the anterior chest wall and 5 other procedural steps.

Main Results

All infusion rates had equal analgesic efficacy, as shown by comparable pain scores, number of rescue boluses, and number of patients requiring rescue analgesia. Excessive sedation was associated with the highest remifentanil rate such that Group R75 patients were significantly more sedated than Groups R25 or R50 at selective procedural steps (P < 0.05). More Group R75 patients (6/15) required remifentanil rate reduction than did patients from Group R50 (1/15) or Group R25 (0/14), P < 0.01, most commonly because of respiratory depression.

Conclusions

For the insertion or removal of long-term central venous access devices, all three remifentanil infusion rates proved to be equally analgesic-efficient. However, the excessive sedation and tendency to respiratory and cardiovascular events associated with the highest remifentanil infusion rate renders such a rate less desirable for this purpose.     

Classification of the dysmorphology of pectus excavatum

Background/Purpose

To describe the dysmorphology of pectus excavatum, the most common congenital chest wall anomaly.

Methods

A stratified sample of 64 patients, representative of a patient population with pectus excavatum of the Children's Hospital of King's Daughters in Norfolk, Va, was described and classified. The sample was stratified by sex to represent a 4:1 male-to-female ratio. The sample was further stratified to represent categories of age (3-10, 11-16, and 17 years and older). Preoperative photos and baseline chest computed tomography scans were examined and categorized according to the chief criteria, including asymmetry/symmetry of the depression, localized vs diffuse morphology, sternal torsion, cause of asymmetric appearance, and the length of the depression.

Results

Useful morphologic distinctions in pectus excavatum are localized depressions vs diffuse depressions, short and long length, symmetry, sternal torsion, slope/position of absolute depth, and unique patterns such as the horns of steer depression.

Conclusions

These classifications simplify the diagnosis of pectus excavatum, aid in corrective surgery, and should improve correlation of phenotype and genotype in future genetic analysis.     

Liver transplantation in children younger than 1 year--the Cincinnati experience

Background/Purpose

The success of pediatric orthotopic liver transplantation (OLTxp) has improved greatly since its widespread application in the 1980s. No group has benefited more from this than infants younger than 1 year. The authors reviewed their experience in the management and outcome of children who underwent OLTxp when they were younger than 1 year.

Methods

A retrospective review of the medical records of patients who at the time of OLTxp were younger than 1 year was performed. Patients were stratified according to the period when transplanted.

Results

Eighty-one infants younger than 1 year underwent OLTxp. End-stage liver disease secondary to biliary atresia was the most common indication for transplantation. The overall survival was 77%. One-year patient and graft survival improved from 58% and 50% in the period 1986-1989, respectively, to 88% and 81% in the period 2000-2003, respectively. Technical complications such as hepatic artery thrombosis (n = 5) and portal vein thrombosis (n = 8) occurred, and although 4 patients required retransplantation, all but one survived. Complications associated with immunosuppression, sepsis/multisystem organ failure (MSOF) (n = 11), and posttransplant lymphoproliferative disease (PTLD) (n = 1) were the most common cause of poor outcome.

Conclusions

Successful OLTxp in infants is possible with improved posttransplant survival during the study period. Technical complications (hepatic artery thrombosis/portal vein thrombosis) may require retransplantation but were uncommon causes of patient loss. Multisystem organ failure was the most significant adverse complication. The consequences of immunosuppression (MSOF/PTLD) were the most common cause of patient loss. Further improvement in overall survival will require better immunosuppressive strategies.     

Bortezomib is effective to treat acute humoral rejection after liver transplantation

Introduction

Acute humoral rejection (AHR), a rare complication in orthotopic liver transplantation (OLT), responds poorly to conventional therapies. Bortezomib, a proteasome inhibitor, has been shown to be effective in treating plasma cell-derived tumors and acute rejection episodes after renal transplantation. Herein, we have reported our clinical experience with bortezomib as a novel approach to treat AHR after OLT.

Methods

We retrospectively analyzed the 247 adult OLTs performed from January 2007 to April 2011. Patients with AHR who were treated with steroid pulses, rituximab (375 mg/m²), and plasmapheresis (PP) were assigned to group A. Group B subjects were prescribed steroid pulses, rituximab, PP, and bortezomib (1.3 mg/m²), after March 2009.

Results

Among the 9 patients (3.6%) diagnosed with AHR, all subjects in group A (n = 3) died within several days after AHR, whereas 4/6 (66.7%) group B patients were rescued and 3 (50%) survived at a mean follow-up 22.3 months (range, 18-26).

Conclusion

Proteasome inhibitor-based therapies provide a more effective strategy to treat AHR after OLT.     

Appendiceal fecalith is associated with early perforation in pediatric patients

Purpose

A fecalith is a fecal concretion that can obstruct the appendix leading to acute appendicitis. We hypothesized that the presence of a fecalith would lead to an earlier appendiceal perforation.

Methods

Between January 2001 and December 2005, the charts of all patients younger than 18 years old who underwent appendectomy at our institution were reviewed. Duration of symptoms and timing between presentation and operation were noted along with radiologic, operative, and pathologic findings.

Results

There were 388 patients who met the study criteria. A fecalith was present in 31% of patients (n = 121). The appendix was perforated in 57% of patients who had a fecalith vs 36% in patients without a fecalith (P < .001). The overall rate of interval appendectomies was 12%. A fecalith was present on the initial radiologic studies of 36% of the patients who had interval appendectomies, and the appendix was perforated significantly sooner in these patients when compared to those without a fecalith (91 vs 150 hours; P = .036).

Conclusion

The presence of fecalith is associated with earlier and higher rates of appendiceal perforation in pediatric patients with acute appendicitis. An expedient appendectomy should therefore be performed in the pediatric patient with a radiologic evidence of fecalith.     

Thirteen cases of isolated tubal torsions associated with hydrosalpinx in children and adolescents, proposal for conservative management: retrospective review and literature survey

Background/Purpose

Isolated tubal torsion associated with hydrosalpinx is a rare pathology. Our goal was to analyze the clinical and imaging features and discuss the different treatment options available.

Methods

We retrospectively reviewed all the cases of adnexal torsion treated in our department of pediatric surgery over a 10-year period. We searched 2 electronic databases (Medline and Sciencedirect) and targeted reports published during the same period using the key words tubal torsion and hydrosalpinx.

Results

A total of 13 cases, 6 from our hospital and 7 in the medical literature, were identified and analyzed. In 9 (69%) of 13 cases (n = 9/13), torsion and hydrosalpinx occurred on the left fallopian tube. Salpingectomy was performed in 11 of the patients. The resected tubes showed the persistence of ciliated cells associated with signs of moderate ischemic infarction in 50% (n = 3/6) of the cases.

Conclusions

Isolated tubal torsion associated with hydrosalpinx is too often misdiagnosed and treated by salpingectomy regardless of the negative impact on the future reproductive potential of our young patients. As is commonly advocated for ovarian salvage in adnexal torsions, tubal conservation should be favored when possible.     

Interleukin-9 in stable liver transplant recipients

Introduction

Interleukin-9 (IL-9) has recently been described to be involved in the maintenance of a tolerant environment, but there is no evidence of its role in human liver transplantation. The aim of our study was to measure the serum levels of IL-9 in stable liver transplant recipients and examine their influence on immunosuppressant load.

Methods

Serum IL-9 levels were determined in 34 healthy subjects and 30 stable liver transplant recipients who were free of rejection episodes for at least 8 years. The results were analyzed according to the blood levels of calcineurin inhibitors (CNIs) at the time of the study: 13 patients showed high concentrations of either cyclosporine or tacrolimus (high CNI: cyclosporine > 80 ng/mL or tacrolimus > 5 ng/mL) and another 17 patients showed low CNI levels.

Results

The concentrations of IL-9 were significantly higher among liver transplant recipients compared with healthy subjects. In addition, patients with low CNI blood levels showed higher serum levels of IL-9, an effect that was greater with tacrolimus, albeit not significantly.

Conclusions

These preliminary results indicated that increased serum IL-9 concentrations accompanied a lower immunosuppressive load. It remains to be established whether this relates to induction of tolerance in liver transplantation.     

The effect of nitrous oxide on intracuff pressure of the size 2 ProSeal Laryngeal Mask Airway

Study Objective

To investigate intracuff pressure changes in the ProSeal Laryngeal Mask Airway (PLMA) during 50% nitrous oxide (N₂O) anesthesia.

Design

Prospective, randomized study.

Setting

Operating room of a university-affiliated hospital.

Patients

40 ASA 1 and 2 children, aged 2 to 6 years, weighing 10-20 kg, undergoing elective inguinal herniorrhaphy with general anesthesia.

Interventions and Measurements

Patients were assigned to two groups (n = 20). Patients in Group A were anesthetized with 50% N₂O in oxygen and sevoflurane, while patients in Group B were anesthetized with 50% air in oxygen and sevoflurane. PLMA cuffs were inflated with air. PLMA intracuff pressures starting from a baseline pressure of 30 mmHg were recorded using a pressure transducer for 30 minutes. The occurrence of postoperative throat discomfort was recorded.

Main Results

In Group A, who inhaled 50% N₂O for 30 minutes, intracuff pressures reached 86.7 ± 10.4 mmHg, while in Group B, who inhaled 50% air for 30 minutes, intracuff pressures were 29.7 ± 1.0 mmHg. The postoperative throat complication rate in Group A was 45%, which was significantly higher than in Group B (5%).

Conclusion

PLMA intracuff pressure increased significantly during 50% N₂O anesthesia. The children's postoperative throat complication rate also was increased.     

Early Humoral-Mediated Graft Injuries in ABO-Incompatible Kidney Transplantation in Human Beings

Introduction

Acute humoral rejection is the most important risk factor for early graft loss in ABO-incompatible (ABO-i) renal transplantation (RTx) and is present from the early period after RTx. However, the characteristics of early humoral-mediated graft injury are pathologically uncertain.

Objective

To analyze tissue from 10 protocol graft biopsies performed in 10 patients within 30 days post-RTx to clarify the pathologic features of early humoral-mediated graft injuries in ABO-i RTx.

Methods

Pathologic findings were examined using light and electron microscopy and immunofluorescence studies for C4d. Protocol biopsies were performed within 30 days after RTx in the absence of an episode of dysfunction (creatinine concentration 1.21-1.81 mg/dL).

Results

The immunofluorescence study demonstrated C4d deposition in peritubular and glomerular capillaries. Acute glomerulitis with infiltration of mononuclear cells and neutrophils was observed in 3 patients. Furthermore, glomerulitis was accompanied by endothelial cell injuries, widening of subendothelial spaces with a double-contoured glomerular basement membrane, and mesangiolysis.

Conclusion

In ABO-i RTx, early humoral-mediated graft injuries were observed in approximately 30% of patients despite normal graft function. They were characterized by C4d deposition and glomerular capillary injury. These findings suggest that renal glomeruli are the first site of graft injury by anti-A or anti-B blood type antibody with complement activation in ABO-i RTx.     

Development of an artificial placenta: CO2 elimination and hemodynamics as a function of arteriovenous blood flow

Background

As a first step toward the development of an artificial placenta, we investigated the relationship between blood flow rate through an arteriovenous (A-V) circuit/oxygenator and both CO₂ elimination and hemodynamic stability in a small animal model.

Methods

Male New Zealand rabbits (N = 10) with an average weight of 2.7 ± 0.2 kg were anesthetized, paralyzed, and heparinized before carotid-jugular cannulation. A tracheostomy tube, an arterial catheter, and an aortic flow probe were placed. Arteriovenous flow through a custom-made, low-resistance, 0.5 m² hollow fiber oxygenator was initiated. Oxygen sweep flow was maintained at 300 mL/min, whereas blood flow was controlled at 10 to 40 mL/(kg min). Ventilation was discontinued during each blood flow rate trial. Hemodynamic and preoxygenator and postoxygenator blood gas data were recorded 30 minutes after initiation of each flow rate. CO₂ removal was the product of the oxygen sweep gas flow rate and the sweep flow exhaust CO₂ content as determined by capnometry. Data were analyzed by analysis of variance with post hoc Dunnett's t test.

Results

CO₂ removal increased and Paco₂ decreased as a function of A-V blood flow rate. Simultaneously, systolic blood pressure did not significantly change. CO₂ removal was effective at device flows greater than 20% of cardiac output.

Conclusion

In this rabbit model, A-V blood flows at 25% to 30% of cardiac output allow full gas exchange without hemodynamic compromise. This model raises the possibility of using A-V support and an artificial placenta in newborns with respiratory failure.     

Morphea of the breast—an uncommon cause of breast erythema

Background

Breast-associated morphea (BAM) can mimic benign and malignant inflammatory breast disorders. The aim of the current study was to document our experience with this rare sclerosing dermatologic disorder.

Method

We conducted a retrospective study at a single institution of all patients who had pathological diagnosis of morphea between January 1995 and October 2007.

Results

We identified 15 patients with pathological evidence of morphea involving the breast. Two thirds of these patients were initially misdiagnosed with inflammatory breast cancer or breast infections. While 2 patients had previous exposure to external beam radiation, the remaining patients had no identifiable predisposing risk factors. BAM resulted in limited morbidity and did not result in significant disfiguration. Treatment included topical steroids, topical calcineurin inhibitor, and surgical excision.

Conclusions

Our experience with BAM emphasizes the benefit of early tissue biopsy in patients with unexplained breast erythema to confirm a clinical diagnosis and thus guide subsequent therapeutic interventions.     

Determination of apparent diffusion coefficient to quantitatively study partial hepatic ischemia reperfusion injury in a rabbit model

Background

Animal models of partial hepatic ischemia-reperfusion injury (IRI) have potential benefits for decision making and clinical management after liver transplantation or massive hepatic resection. We evaluated changes in apparent diffusion coefficient (ADC) in rabbits with partial hepatic IRI using 3.0 T magnetic resonance diffusion-weighted imaging (DWI).

Methods

Rabbits underwent 60 minutes of left lobar ischemia followed by 0.5, 2, 6, 12, 24, or 48 hours of reperfusion (n = 6 each). DWI spin echo-echo planar imaging (SE-EPI) was performed with b values of 50, 100, 200, 300, 500, and 600 s/mm².

Results

There was a significant difference between the ADCs at 0.5 hour and sham groups when b values were <300 s/mm² and between the six hour and sham groups with b = 50 and 100 s/mm². The ADC values were lower in the 24-hour group with b values of 50, 100, 200, and 300 s/mm² (all P < .01) but significantly increased in the 48-hour group when b = 500 and 600 s/mm² compared with the sham group (all P < .01). ADC did not change significantly in the 2-hour and 12-hour groups compared with the control group.

Conclusions

In this study 3.0 T DWI dynamically monitored the pathological processes of liver IRI, revealing the microvascular disorder with a perfusion-sensitive ADC at the lower b values (<300 s/mm²), particularly in the early stages.     

β1-integrin mediates pressure-stimulated phagocytosis

Background

Extracellular pressure alterations in infection, inflammation, or positive pressure ventilation may influence macrophage phagocytosis. We hypothesized that pressure modulates β1-integrins to stimulate phagocytosis.

Methods

We assayed fibroblast phagocytosis of fluorescent latex beads at ambient or 20 mm Hg increased pressure, and macrophage integrin phosphorylation by Western blot.

Results

Pressure did not alter phagocytosis in β₁-integrin null GD25 fibroblasts, but stimulated phagocytosis in fibroblasts expressing wild-type β₁-integrin. In phorbol myristate acetate-differentiated THP-1 macrophages, pressure stimulated β₁-integrin T788/789 phosphorylation, but not S785 phosphorylation. Furthermore, pressure stimulated phagocytosis in cells expressing an inactivating S785A point mutation or a T788D substitution to mimic a constitutively phosphorylated threonine, but not in cells expressing an inactivating TT788/9AA mutation.

Conclusions

The effects of pressure on phagocytosis are not limited to macrophages but generalize to other phagocytic cells. These results suggest that pressure stimulates phagocytosis via increasing β₁-integrin T789 phosphorylation. Interventions that target β₁-integrin threonine 789 phosphorylation may modulate phagocytic function.     

Intratracheal pulmonary ventilation improves gas exchange during laparoscopy in a pediatric lung injury model

Background/Purpose

This study was aimed at determining whether intraoperative intratracheal pulmonary ventilation (ITPV) could prevent/treat respiratory complications of laparoscopy in a model of pediatric pulmonary insufficiency.

Methods

Severe lung injury was induced in 0- to 2-month-old lambs (n = 5) by endotracheal saline lavage. Animals then underwent establishment of CO₂ pneumoperitoneum. Intraperitoneal pressures were progressively raised from 0 to 15 mm Hg, at intervals of 5 mm Hg. At each interval, blood gas and hemodynamic data were recorded, 20 minutes after initiation of both conventional ventilation and pure ITPV. All ventilatory parameters were constant and identical on both modes of ventilation.

Results

On conventional ventilation, severe respiratory acidosis and hypoxemia ensued at intraperitoneal pressures of 5 mm Hg and 10 mm Hg or more, respectively. Compared with conventional ventilation, ITPV led to statistically significant decreases in Pco₂ at intraperitoneal pressures of 5 mm Hg (43.2 ± 5.2 vs 56.1 ± 6.6 mm Hg) and 10 mm Hg (45.1 ± 3.2 vs 61 ± 6.3 mm Hg) and to significant increases in Po₂ at 10 mm Hg (92 ± 10.2 vs 61 ± 8.1 mm Hg), resolving the acidosis and hypoxemia at those pressure levels.

Conclusions

Compared with conventional ventilation, ITPV improves both CO₂ removal and oxygenation during CO₂ pneumoperitoneum in a pediatric lung injury model. Intratracheal pulmonary ventilation may be a safer intraoperative mode of ventilation for neonates and children with respiratory failure who require laparoscopy.     

Telbivudin as prophylaxis for hepatitis B virus recurrence after liver transplantation: a case series in single-center experience

Background

Hepatitis B virus (HBV) recurrence after orthotopic liver transplantation (OLT) represents a severe condition that requires prophylaxis with specific immunoglobulin and lamivudine. Few studies have addressed the efficiency of other effective antiviral drugs posttransplantation or their impact on early renal function after transplantation. Herein, we have reported experience among seven transplanted patients prescribed Telbivudin (600 mg/d) while on the waiting list followed by treatment for 3 months after OLT.

Methods

Our series consisted of men with HBV-related end-stage liver disease. Once the patient started antiviral treatment, the viral load decreased rapidly while on the waiting list. All patients were evaluated for liver and renal functions immunosuppressive drug trough levels, CPK before (T0), as well as at 1 month (T1), and 3 months after liver transplant (T3).

Results

All patients received a CNI-based regimen. Their mean creatinine clearance (MDRD) was 72.5 mL/min at T0, 69.2 mL/min at T1, and 71.0 mL/min at T3. Neither CPK or serum transaminase levels increased throughout the study. Once HBV-DNA was cleared while on the waiting list, it remained negative throughout the follow-up period.

Conclusion

Telbivudin prophylaxis for HBV was safe and effective without any significant deleterious effect on liver or renal function tests after liver transplantation.     

Clinical value of office-based endoscopic incisional biopsy in diagnosis of nasal cavity masses

Objective

To evaluate clinical features and the diagnostic accuracy of office-based endoscopic incisional biopsy in patients with nasal cavity masses.

Study Design

Diagnostic test assessment with chart review.

Setting

Tertiary referral center.

Subjects and Methods

From January 1997 to August 2006, preoperative diagnosis was achieved using endoscopic incisional biopsy in 521 patients. Cytopathologic and histologic findings were categorized as malignancy, benign neoplasm, or non-neoplastic lesion. Preoperative imaging was done in 462 patients (computed tomography: 438 cases; magnetic resonance imaging: 24 cases). We investigated the accuracy of endoscopic incisional biopsy and preoperative imaging by comparing it with pathologic results from tumor resection as the “gold standard.”

Results

Most of the patients had unilateral nasal symptoms (e.g., nasal obstruction, unilateral epistaxis, unilateral facial pain), and the clinical symptoms were of little diagnostic value in the differentiation of tumor and inflammatory lesion. The sensitivity and specificity of endoscopic incisional biopsy were 43.7 and 98.9 percent, respectively, for the diagnosis of nasal cavity malignancies, and 78.2 and 96.2 percent, respectively, for the diagnosis of benign neoplasms. The sensitivity and specificity of preoperative imaging were 78.3 and 97.5 percent, respectively, for the diagnosis of nasal cavity malignancies and 66.4 and 86.3 percent, respectively, for the diagnosis of benign neoplasms. Combining the two modalities increased diagnostic accuracy in nasal cavity masses.

Conclusion

Endoscopic incisional biopsy alone did not ensure accurate diagnosis of nasal cavity tumors, but in combination with preoperative imaging it was helpful for the diagnosis of nasal cavity malignancies.     

Intravenous landiolol, a novel β(1)-adrenergic blocker, reduces the minimum alveolar concentration of sevoflurane in women

Study Objective

To investigate the effect of intravenous (IV) landiolol, a novel β₁-adrenergic blocker, on the minimum alveolar concentration (MAC) of sevoflurane in adult women.

Design

Prospective, randomized study.

Setting

University hospital.

Patients

42 ASA physical status 1 and 2 women, aged 24-57 years, who were scheduled to undergo elective abdominal surgery.

Interventions

Anesthesia was induced in all patients by vital capacity rapid inhalation induction of sevoflurane. In the landiolol group, administration of landiolol began when patients took a vital-capacity breath: 0.125 mg/kg/min for one minute and then 0.04 mg/kg/min. Normal saline was administered in the control group.

Measurements

MAC was determined by a technique adapted from the conventional up-down method.

Main Results

The MAC of sevoflurane was 2.2% ± 0.2% in the control group and 1.7% ± 0.2% in the landiolol group, a statistically significant difference (P = 0.0005).

Conclusions

IV landiolol reduces the MAC of sevoflurane in women by approximately 20%.