Comparisons of the segments of left-sided double-lumen tracheobronchial tubes as industrial products.

BACKGROUND: Although there are at least seven manufacturers producing left-sided double-lumen tubes (DLTs), there have been few reports comparing the segments of these DLTs. In this study, we compared various segments of left-sided DLTs further. MATERIALS AND METHODS: We examined five manufacturers' left-sided DLTs: Mallinckrodt, Portex, Rüsch, Sheridan, and Daiken-medical. We conducted the following six trials or measurements, and three supplemental trials or measurements: First, we tried to pass various sizes of steel balls down each lumen in order from the smallest (3 mm) to largest (4.5 mm). If the ball passed on the first attempt, we tried just once; otherwise, we made a second attempt. Second, we measured the external diameter of tracheal and bronchial cuff using a profile projector. Third, we measured the length of the cuff and tip of the bronchial segment of the tubes using the profile projector. Fourth, we measured various lengths of the tubes. Fifth, we measured the external diameter of both lumens and the tubules for tracheal and bronchial cuff inflation. Finally, we measured various cross-sectional areas including the tracheal lumen, bronchial lumen, and tubules for cuff inflation. We also conducted three supplemental studies. First, we measured air volume in the cuff when intracuff pressure equaled 2 or 3 kPa. Second, we defined the configuration of the tracheal and bronchial cuffs. Third, we defined the presence or absence of bevels and also measured the angle of the bevels using the profile projector. RESULTS: We performed nine trials and measurements and found large disparities between each manufacturer's tubes. CONCLUSIONS: The large disparities found between the measurements of the five manufacturers' tubes may be due to different lots or changes in specifications made by each manufacturer. We found tubes exhibiting lower quality, such as deformations, and non-universal and inconsistent sizing, in the comparison of the manufacturers' tubes. Practitioners should be aware of the features and aspects of these tubes.

Association of hospital and surgeon volume with mortality following major surgical procedures: Meta-analysis of meta-analyses of observational studies.

Accumulation of the literature has suggested an inverse association between healthcare provider volume and mortality for a wide variety of surgical procedures. This study aimed to perform meta-analysis of meta-analyses (umbrella review) of observational studies and to summarize existing evidence for associations of healthcare provider volume with mortality in major operations.We searched MEDLINE, SCOPUS, and Cochrane Library, and screening of references.Meta-analyses of observational studies examining the association of hospital and surgeon volume with mortality following major operations. The primary outcome is all-cause short-term morality after surgery. Meta-analyses of observational studies of hospital/surgeon volume and mortality were included. Overall level of evidence was classified as convincing (class I), highly suggestive (class II), suggestive (class III), weak (class IV), and non-significant (class V) based on the significance of the random-effects summary odds ratio (OR), number of cases, small-study effects, excess significance bias, prediction intervals, and heterogeneity.Twenty meta-analyses including 4,520,720 patients were included, with 19 types of surgical procedures for hospital volume and 11 types of surgical procedures for surgeon volume. Nominally significant reductions were found in odds ratio in 82% to 84% of surgical procedures in both hospital and surgeon volume-mortality associations. To summarize the overall level of evidence, however, only one surgical procedure (pancreaticoduodenectomy) fulfilled the criteria of class I and II for both hospital and surgeon volume and mortality relationships, with a decrease in OR for hospital (0.42, 95% confidence interval[CI] [0.35-0.51]) and for surgeon (0.38, 95% CI [0.30-0.49]), respectively. In contrast, most of the procedures appeared to be weak or "non-significant."Only a very few surgical procedures such as pancreaticoduodenectomy appeared to have convincing evidence on the inverse surgeon volume-mortality associations, and yet most surgical procedures resulted in having weak or "non-significant" evidence. Therefore, healthcare professionals and policy makers might be required to steer their centralization policy more carefully unless more robust, higher-quality evidence emerges, particularly for procedures considered as having a weak or non-significant evidence level including total knee replacement, thyroidectomy, bariatric surgery, radical cystectomy, and rectal and colorectal cancer resections.

Comparative Evaluation of Endotoxin Activity Level and Various Biomarkers for Infection and Outcome of ICU-Admitted Patients.

Here, we concurrently measured the endotoxin activity (EA) level and levels of multiple biomarkers in patient blood obtained within 24 h after being admitted into the intensive care unit (ICU) and analyzed whether there were links between these markers and their associations with patient conditions and outcomes. The EA levels highly correlated with disease severity and patient survival, and showed a significant positive association with levels of lactate, procalcitonin, presepsin, and interleukin-6. Notably, the EA level was the marker that most highly correlated with the results of blood culture, and the presepsin level was the marker most highly correlated with the survival outcome at 28 days. Thus, the optimal biomarker should be selected based on whether it will be used to discriminate the presence of an infection or to predict survival.

Anesthesia Management of Special Patient Populations Undergoing Electroconvulsive Therapy: A Review.

Electroconvulsive therapy (ECT) is the safe application of electricity to the scalp of a patient, using brief-pulse stimulation techniques under general anesthesia and muscle paralysis, inducing a series of generalized epileptic seizures. Principal indications for ECT are major depression (unipolar or bipolar) with a lack of response to medications, intolerance to medications due to side effects or coexisting conditions, the need for a rapid response because of other conditions such as catatonia, psychosis, suicidality, or clinically significant dehydration or malnutrition, mania, and schizophreniform disorder or schizoaffective disorder, and, medical disorders such as Parkinson's disease, neuroleptic malignant syndrome, and chronic pain. Anesthesia management of special patient populations undergoing ECT has been described in textbooks and guidelines, but some descriptions may be antiquated. Therefore, this review describes recent knowledge on anesthesia management of patients who require ECT, such as those with neurologic disorders, cardiovascular disorders, pregnancy, and other concurrent medical illness. Based on the findings of a recent paper, ECT may be safer than is widely reported. According to the American Psychiatric Association, ECT has no absolute contraindications; however, some conditions pose a relatively high risk, and there are many other kinds of complications associated with ECT that can lead to death. Understanding such complications and their management strategies can avoid unnecessary discontinuation of treatment due to manageable complications of ECT and, furthermore, ECT clinicians must also consider the risk-benefit ratio when treating high-risk patients.

Bolus administration of ephedrine and etilefrine induces transient vasodilation just after injection in combined epidural and general anesthesia patients: A randomized clinical study.

Hypotension commonly accompanies combined epidural and general anesthesia, and intravenous bolus ephedrine and etilefrine are widely used to correct hypotension. We have noticed that systemic vascular resistance (SVR) transiently decreases just after intravenous bolus administration of these drugs. The goal of the present study was to investigate whether bolus administration of these drugs decrease SVR just after intravenous administration in combined epidural and general anesthesia patients. We investigated 40 patients who were scheduled for elective abdominal surgery. Patients were chosen as subjects if their systolic arterial pressure decreased by 20% or to <100 mmHg at 30 min after the induction of general anesthesia. Baseline hemodynamic values were recorded, and after ephedrine 10 mg injection or etilefrine 2 mg injection (equipotent), the parameters were recorded again at 0.5 min and once each min for the next 5 min thereafter. The 40 patients were enrolled into the ephedrine (n = 20) or etilefrine (n = 20) treatment groups. Patient characteristics were comparable in both groups. After ephedrine injection, SVR decreased significantly at the 1-min time point, whereas after etilefrine injection, SVR decreased significantly at the 0.5- to 2-min time points compared with baseline values. SVR at the 0.5- to 1-min time points was lower in the etilefrine versus the ephedrine group. Both drugs transiently decreased SVR after intravenous injection, but etilefrine decreased SVR much more than ephedrine, indicating that more vasodilation occurred after the injection of etilefrine than after ephedrine. It is thus important to recognize the different characteristics of these drugs.

Does pneumoperitoneum affect perfusion index and pleth variability index in patients receiving combined epidural and general anesthesia?

Plethysmographic variability index (PVI) is a dynamic index used for the purpose of fluid responsiveness in patients, and the effect of pneumoperitoneum on PVI is still unclear. We therefore attempted to determine whether PVI and perfusion index (PI) change before/after pneumoperitoneum in patients receiving combined epidural and general anesthesia, which is a common anesthesia method with intravenous remifentanil. Twenty patients underwent laparoscopic cholecystectomy or colectomy. Immediately before pneumoperitoneum, variables were measured at baseline I and were then measured every min for 5 min after pneumoperitoneum start. Immediately before pneumoperitoneum release, variables were measured at baseline II and were measured every min for 5 min after pneumoperitoneum release. Compared with baseline I values, after pneumoperitoneum start, significant increases occurred in stroke volume variation (SVV) at 1-5 min, and significant decreases occurred in PI at 1-5 min. PVI did not change. Compared with baseline II values, after pneumoperitoneum release, significant increases occurred in PI at 1-5 min, and significant decreases occurred in PVI at 4-5 min and SVV at 1-5 min. In patients receiving combined epidural and general anesthesia, we newly found that PI decreased but PVI remained unchanged with a sufficient dose of remifentanil and epidural anesthesia that can block noxious stimuli and also most sympathetic activity. Furthermore, we reconfirmed that PI increased and PVI decreased upon release of pneumoperitoneum. PI and PVI values must be estimated cautiously during and after pneumoperitoneum.

Subarachnoid Block-Induced Deafferentation Pain Successfully Treated with Pentazocine.

Deafferentation pain induced by subarachnoid block (SAB) is rare, but it can appear in the form of recurrent phantom lower limb pain, new acute-onset stump pain in amputees, lower limb pain in patients with tabes dorsalis, and neuropathic pain. We have previously reported that thiopental is an effective treatment for deafferentation pain induced by therapeutic SAB applied to treat neuropathic pain of central origin. Here, we report the case of an amputee who developed new stump pain in his lower limb immediately after subarachnoid tetracaine was administered prior to appendectomy. A 51-year-old man who had previously undergone right below-knee amputation for acute arterial thrombosis, and who had not previously experienced chronic phantom limb or stump pain, was scheduled for emergency open appendectomy. For anesthesia, we induced SAB with a hyperbaric tetracaine solution. No paresthesia occurred during administration. However, the patient immediately complained of severe, lightning-bolt pain in the right lower limb stump after the SAB was established. He was given intravenous pentazocine, which promptly resolved the pain. Appendectomy was then performed under sedation using intravenous midazolam. The patient did not experience further deafferentation pain during his hospital stay and has reported no stump pain since discharge from the hospital. This case report suggests that SAB induces deafferentation pain in some patients and that this unusual pain can be treated with pentazocine.

Efficacy of prophylactic doses of intravenous nitroglycerin in preventing myocardial ischemia under general anesthesia: A systematic review and meta-analysis with trial sequential analysis.

STUDY OBJECTIVE: To evaluate the efficacy of intravenous nitroglycerin (TNG) in preventing intraoperative myocardial ischemia (MI) under general anesthesia. Moreover, we analyzed the hemodynamic changes in heart rate (HR), mean blood pressure (MBP), and pulmonary capillary wedge pressure (PCWP) associated with TNG administration both before and after the induction of anesthesia. DESIGN: Meta-analysis. SETTING: Operating room, cardiac surgery or non-cardiac surgery, all surgeries were elective measurements. We performed a computerized search of articles on PubMed, Scopus, and the Cochrane Central Register of Controlled Trials. Meta-analysis was performed using Review Manager. The data from the individual trials were combined using a random-effects model to calculate either the pooled relative risk (RR) or the weighted mean difference (WMD) with 95% confidence interval (CI). We conducted trial sequential analysis (TSA). The primary outcome was the incidence of MI and the secondary outcomes were hemodynamic changes (HR, MBP, and PCWP). MAIN RESULTS: Using electronic databases, we selected 10 trials with a total of 353 patients for our review. Prophylactic intravenous TNG did not significantly decrease the incidence of MI (RR=0.61; CI, 0.33 to 1.13; P=0.12; I2=55). TSA corrected the CI to 0.05 to 7.39 and showed that 9.5% of the required information size was achieved. In terms of hemodynamic changes, intravenous TNG significantly reduced MBP in comparison with the placebo (MBP pre-induction: WMD=-7.27; 95% CI -14.2 to -0.33; P=0.04; I2=97%; MBP post-induction: WMD=-5.13; 95% CI -9.17 to -1.09; P=0.01; I2=73%). CONCLUSIONS: Our analyses showed that prophylactic intravenous TNG does not reduce the incidence of intraoperative MI. Moreover, TSA suggests that further studies are necessary to confirm the results (GRADE: very low). Prophylactic doses of intravenous TNG significantly reduced the MBP both pre and post anesthesia induction (GRADE: very low).

Dexmedetomidine-based intravenous anesthesia of a pediatric patient with glucose-6-phosphate dehydrogenase (G6PD) deficiency: A case report.

RATIONALE: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzyme defect, resulting in deficits in nicotinamide adenine dinucleotide phosphate production, an important intracellular antioxidant enzyme. G6PD-deficient subjects present with a susceptibility of erythrocytes to oxidative stress and hemolysis, and should avoid drugs or stressors that have oxidative actions. Dexmedetomidine is an anesthetic agent with antioxidant actions. PATIENT CONCERNS AND DIAGNOSES: A 5-year-old boy with G6PD deficiency. The patient was diagnosed with G6PD deficiency at birth. His red blood cell levels were indicating Class II G6PD activity by the World Health Organization (WHO) classification, but had no history of hemolytic anemia. INTRAVENTIONS: Because of the patient's anxiety and hyperactivity prior to an operation for upper labial frenum resection, we performed perioperative management using intravenous sedation with dexmedetomidine, which provides upper airway patency and has an antioxidant action. OUTCOMES: There was no abnormal breathing observed during anesthesia, and arousal was smooth with stable hemodynamics. The patient had no symptoms of hemolytic anemia up to 1 week postsurgery. CONCLUSION: Antioxidant sedatives such as dexmedetomidine may be useful for reducing the risk of hemolysis after surgery in infant G6PD deficiency cases.

Weekend versus weekday admission and short-term mortality: A meta-analysis of 88 cohort studies including 56,934,649 participants.

It is widely accepted that higher mortality related to weekend admissions basically exists; however, there has been no systematic exploration of whether weekend admissions are associated with higher risk of death in patients on the basis of certain diagnoses, geographic regions, and study subtypes.A meta-analysis was performed according to the reporting guidelines of the Meta-analysis of Observational Studies in Epidemiology (MOOSE Compliant). Literature search was conducted using electronic databases. Primary outcome was short-term (≤30-day) mortality. Patients were divided into 7 regions (North America, South America, Europe, Asia, Oceania, Africa, and Antarctica) for subgroup analyses and into 7 categories evaluating 24 major diagnoses. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated with DerSimonian and Laird random-effects models.Eighty-eight studies including 56,934,649 participants met our inclusion criteria. Overall pooled adjusted and crude OR of weekend to weekday admission for short-term mortality was 1.12 (95% CI, 1.07-1.18; I = 97%) and 1.16 (95% CI, 1.14-1.19; I = 97%), respectively. In subgroup analyses, higher risk of death on the weekend was significantly identified in patients living in all five continents (North America, South America, Europe, Asia, and Oceania). However, significant weekend effect was identified only in 15 of 24 diagnostic groups. Patients admitted on the weekend were more likely to die in an emergency situation (crude OR = 1.17, 95% CI, 1.12-1.22).Although weekend admissions were associated with higher risk of death compared with weekday admissions on all five continents, the effect was limited to certain diagnostic groups and admission subtypes. Weekend effect remains highly heterogeneous and limited, suggesting that further well-conducted cohort studies might be informative.

Does intravenous atropine affect stroke volume variation in man?

OBJECTIVES: Currently there are no reports of the effect of increasing heart rate (HR) induced by intravenous atropine on stroke volume variation (SVV). We hypothesized that increasing HR alters the value of SVV. This prospective study aimed to investigate changes in SVV values by increasing HR induced by intravenous atropine in patients with good cardiac function. We also re-evaluated the effect of intravenous atropine alone on hemodynamics including new hemodynamic parameters such as SVV. METHODS: Patients were chosen as participants of this study if, 30 minutes after anesthesia induction, HR was below 65 beats/min. Baseline hemodynamic values were recorded, and then the patients received intravenous atropine (0.01 mg/kg; max 0.5 mg). These values were recorded again after intravenous atropine every minute for 5 minutes. RESULTS: Ten American Society of Anesthesiologists (ASA) physical status I-II patients aged 37-65 years who were scheduled for elective surgery were included. Intravenous atropine significantly increased HR at the 1-5 minute time points, mean arterial pressure at the 1-4 minute time points, and cardiac output at the 1-3 minute time points compared with baseline values but did not significantly change SVV, stroke volume index, pressure of end-tidal CO2, and systemic vascular resistance. CONCLUSION: Administration of intravenous atropine did not change SVV, and we present this as a novel finding.

Pneumoperitoneum affects stroke volume variation in humans.

PURPOSE: Stroke volume variation (SVV) is affected by many factors. Although elevated intra-abdominal pressure and a pneumoperitoneum have been shown to increase SVV in animals, a recent human study showed that SVV did not change as a pneumoperitoneum was established. However, we considered the results of this study questionable, and we therefore attempted to study whether SVV changes both before and after pneumoperitoneums in humans. METHODS: We performed a prospective observational study in 19 patients undergoing cholecystectomy or colectomy while on mechanical ventilation. Immediately before pneumoperitoneum, baseline registrations of variables were obtained (baseline I), which were measured every min for 5 min after the pneumoperitoneum was initiated. Immediately before the pneumoperitoneum was released, another baseline registration of variables was obtained (baseline II); these variables were then measured every min for 5 min. RESULTS: After the pneumoperitoneum was initiated, there were significant increases in SVV at the 2- to 5-min time points. After release of the pneumoperitoneum, there were significant decreases in SVV at the 1- to 5-min time points. CONCLUSION: A pneumoperitoneum increased SVV, which is similar to the findings of previous animal studies but is different from a previous clinical study. Upon release of the pneumoperitoneum, SVV decreased significantly, which is new information. SVV values must be estimated cautiously during a pneumoperitoneum.

Does intravenous landiolol, a ß1-adrenergic blocker, affect stroke volume variation?

PURPOSE: There are no reports about the effect of bradycardia on stroke volume variation (SVV), and we hypothesized that induced bradycardia alters the value of SVV. Landiolol, an ultra-short-acting adrenergic ß1-receptor blocking agent, was reported to induce bradycardia without decreasing blood pressure. The initial aim of this prospective study was to investigate changes in SVV values by induced bradycardia in patients with good cardiac function. METHODS: At 30 min after anesthesia induction, if heart rate (HR) was >80 bpm, the patient was chosen as a subject. Ten ASA physical status I-II patients aged 38-75 years who were scheduled for elective abdominal surgery were included in this study. Baseline values were recorded, and then administration of landiolol was started at 125 µg/kg/min for 1 min and then continued at 40 µg/kg/min. SVV and other parameters were recorded at baseline and 3 min after continuous landiolol injection. RESULTS: Landiolol significantly decreased systolic arterial pressure, and diastolic arterial pressure, contrary to our expectations, and also HR, SVV, cardiac output, stroke volume index, and pressure of end-tidal CO(2), whereas systemic vascular resistance values increased significantly. CONCLUSIONS: SVV decreased after continuous administration of a ß1-adrenergic blocker, probably because of a decrease in the difference of maximum stroke volume (SV) and minimum SV, or the downward shift of the Frank-Starling curve that occurred after landiolol administration. We believe that SVV values might be overestimated or misinterpreted when HR is decreased by landiolol and might not necessarily indicate that the patient is hypervolemic or normovolemic.

Vigilance of hemodynamic changes immediately after transferring patients is crucial.

PURPOSE: A decrease in blood pressure is sometimes observed when a postsurgical patient is transferred to another bed after recovering from anesthesia. However, the mechanism behind this hypotension has not been completely elucidated. The purpose of this study was to investigate and compare changes in hemodynamic properties for possible causes of hypotension before and after transfer to another bed of postsurgical patients receiving general anesthesia, combined epidural and general anesthesia, or combined spinal and general anesthesia. METHODS: We studied 69 patients undergoing elective surgery who were randomized to receive anesthesia by one of the three methods. After surgery, the tracheal tube was removed, and each patient was transferred to another bed. Hemodynamic data recorded immediately before and after transfer of the patient to another bed were compared. RESULTS: After transfer of patients receiving general anesthesia or combined epidural and general anesthesia, systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and cardiac output (CO) decreased; heart rate (HR) and systemic vascular resistance (SVR) did not change. However, after transfer of patients receiving combined spinal and general anesthesia, SAP, DAP, HR, and CO decreased, but SVR did not change. CONCLUSION: The decrease in blood pressure observed after transfer of a postsurgical patient to another bed after general, combined epidural and general, and combined spinal and general anesthesia was associated with a decrease in CO and no change in SVR, but HR decreased after combined spinal and general anesthesia, whereas it was unchanged after general and combined epidural and general anesthesia. The decrease in blood pressure is assumed to be caused by a decrease in venous return, and several reflexes might participate in this decrease of blood pressure, especially after combined spinal and general anesthesia.

Do induced hypertension and hypotension affect stroke volume variation in man?

STUDY OBJECTIVE: To investigate changes in stroke volume variation (SVV) by both induced hypertension (pressor test) and hypotension (depressor test), and also by induced hypotensive anesthesia in patients with good cardiac function. DESIGN: Prospective, controlled clinical study. SETTING: University hospital. PATIENTS: 31 ASA physical status 1 and 2 patients, aged 39-62 years, who were scheduled for elective surgery. INTERVENTIONS: We conducted three studies: a pressor test study, a depressor test study, and an induced hypotensive anesthesia study. In the pressor test, patients received a bolus of phenylephrine 0.001 mg/kg to increase systolic arterial pressure (SAP) by 30% to 40% compared with baseline. In the depressor test, patients received a bolus of nitroglycerine 0.005 mg/kg to decrease SAP by 30% to 40% compared with baseline. In the induced hypotensive anesthesia test, patients received intravenous (IV) nitroglycerine continuously until mean arterial pressure (MAP) was reduced to 60-70 mmHg. MEASUREMENTS: When arterial pressure reached the target pressure for each study type, SVV and other parameters were recorded. MAIN RESULTS: Induced hypertension (pressor test) decreased SVV, while induced hypotension (depressor test) and induced hypotensive anesthesia increased SVV. CONCLUSIONS: SVV does not misinterpret preload dependency assessment of patients receiving medications to increase or to lower blood pressure.

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

STUDY OBJECTIVE: To investigate the effect of intravenous (IV) landiolol, a novel ß(1)-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%.

Immediate alleviation of chronic pain by bone drilling and probable involvement of bone tissue in pain sensitisation.

Three patients presented with severe spontaneous pain, allodynia and numbness on the lateral side of the left heal, foot and/or toe due to L5 and/or S1 root injury, as a result of repeated failed back surgeries including Love's surgery and laminaectomy (failed back surgery syndrome). The neuropathic pain in the lower extremities did not respond to somatic nerve block, lumbar-sympathetic ganglion block, spinal cord stimulation, and/or medications. At the spots in the foot showing the most severe allodynia, bones were drilled with fluoroscopic assistance. Spontaneous pain diminished immediately and allodynia was completely resolved. Visual analogue scale score decreased immediately after bone drilling. The analgesic effect was maintained for 30-45 weeks. In three patients, drilling until the marrow cavity of the bones at painful sites effectively relieved chronic neuropathic pain with lasting analgesic effect.

Assessment of the effect of rapid crystalloid infusion on stroke volume variation and pleth variability index after a preoperative fast.

OBJECTIVE: Stroke volume variation (SVV) during controlled mechanical ventilation is a useful predictor in response to volume expansion, and pleth variability index (PVI), a novel algorithm allowing for automated and continuous calculation of the respiratory variations in the pulse oximeter waveform amplitude, can also predict fluid responsiveness non-invasively in mechanically ventilated patients. The aim of this study was (1) to determine whether acute fluid infusion affects SVV and PVI, and (2) to compare the two values in the case of acute fluid infusion after a preoperative fast following general anesthesia induction. METHODS: After tracheal intubation, the patients' lungs were mechanically ventilated. Subjects were anesthetized using sevoflurane and were given a rapid, constant-rate infusion of crystalloid (500 ml in 15 min). Systolic arterial pressure (SAP), diastolic arterial pressure (DAP), heart rate (HR), cardiac output (CO), cardiac index (CI), SVV, and PVI were measured at baseline and after 250 and 500 ml had been infused, and these values were compared. RESULTS: SAP, DAP, CO, and CI were unchanged after the infusion. HR and SVV decreased significantly after the infusion. SVI increased significantly after the infusion. There was a significant difference in PVI only between the post 250 ml and post 500 ml infusions. CONCLUSIONS: A rapid infusion of 250-500 ml of a crystalloid in nearly healthy subjects who had fasted overnight returned their SVV to within the normal range. In such cases, SVV is a more sensitive predictor of fluid responsiveness than is PVI, and the infusion gradually increased SVI.

Prophylactic continuous administration of landiolol, a novel ß1 blocker, blunts hyperdynamic responses during electroconvulsive therapy without altering seizure activity.

Abstract Objective. In previous reports, it has been shown that many drugs may act against hyperdynamic responses during electro-convulsive therapy (ECT). The aim of this study was to conduct a randomized, placebo-controlled crossover study to investigate the hemodynamic responses and seizure duration during ECT by continuous administration of two doses of landiolol, a novel short-acting ß1-adrenergic blocker, including standard and high-dose. Methods. Thirty-two patients undergoing ECT participated in this study. The control treatment was infusion of saline alone. The standard-dose of landiolol, 0.125 mg/kg per min, was infused over a 1-min period as a standard treatment. The high-dose landiolol treatment was 0.25 mg/kg per min, also infused over a 1-min period. After landiolol treatments, patients received landiolol at 0.04 mg/kg per min. Propofol and succinylcholine was then administered, and electrical stimulation was applied. Results. Both peak heart rate and mean arterial pressure after ECT was lowest with high-dose landiolol treatment. Motor and EEG seizure duration did not differ among the treatments. Conclusion. The results of this study show that high-dose landiolol treatment blunts hyperdynamic responses during ECT. Furthermore, landiolol does not reduce the seizure duration.