Delirium is a serious complication that commonly occurs in critically ill patients in the intensive care unit (ICU). Delirium is frequently unrecognized or missed despite its high incidence and prevalence, and leads to poor clinical outcomes and an increased cost by increasing morbidity, mortality, and hospital and ICU length of stay. Although its pathophysiology is poorly understood, numerous risk factors for delirium have been suggested. To improve clinical outcomes, it is crucial to perform preventive measures against delirium, to detect delirium early using valid and reliable screening tools, and to treat the underlying causes or hazard symptoms of delirium in a timely manner.
Delirium; Intensive care unit; Outcome
Dexmedetomidine may be useful as a sedative agent. However, it has been reported that dexmedetomidine decreases systemic blood pressure, heart rate, and cardiac output in a dose-dependent manner. The purpose of this study was to determine the appropriate dose of intravenously administered dexmedetomidine for sedation.
Forty-five American Society of Anesthesiologists physical status I-II patients under spinal anesthesia received dexmedetomidine 1 µg/kg intravenously as a loading dose. The patients were randomly allocated to one of three groups for maintenance dose: Group A (0.25 µg/kg/hr), Group B (0.50 µg/kg/hr), and Group C (0.75 µg/kg/hr). The hemodynamic variables and the Ramsay Sedation Scale (RSS) score were recorded for all patients. The numbers of patients who developed hypotension, bradycardia, or inadequate sedation necessitating further drug treatment were also recorded.
Systolic blood pressure, heart rate, and SpO2 were decreased, and RSS score was increased significantly at both 20 min and 40 min after injection of dexmedetomidine in the three study groups compared to baseline, without significant differences between the groups. The prevalence of hypotension, but not that of bradycardia or adjunctive midazolam administration, exhibited a positive correlation with the dose of dexmedetomidine.
Intravenous injection of dexmedetomidine 1 µg/kg followed by continuous administration at infusion rates of 0.25, 0.50, or 0.75 µg/kg/hr produced adequate levels of sedation. However, there was a tendency for the incidence of hypotension to increase as the dose increased. To minimize the risk of hemodynamic instability, a dose of 0.25 µg/kg/hr may be the most appropriate for continuous administration of dexmedetomidine.
Continuous dose; Dexmedetomidine; Regional anesthesia; Sedation
Reduction of nasal bone fracture can be performed under general or local anesthesia. The aim of this study was to compare general anesthesia (GA) and monitored anesthetic care (MAC) with dexmedetomidine based on intraoperative vital signs, comfort of patients, surgeons and nurses and the adverse effects after closed reduction of nasal bone fractures.
Sixty patients with American Society of Anesthesiologists physical status I or II were divided into a GA group (n = 30) or MAC group (n = 30). Standard monitorings were applied. In the GA group, general anesthesia was carried out with propofol-sevoflurane-N2O. In the MAC group, dexmedetomidine and local anesthetics were administered for sedation and analgesia. Intraoperative vital signs, postoperative pain scores by visual analog scale and postoperative nausea and vomiting (PONV) were compared between the groups.
Intraoperatively, systolic blood pressures were significantly higher, and heart rates were lower in the MAC group compared to the GA group. There were no differences between the groups in the patient, nurse and surgeon's satisfaction, postoperative pain scores and incidence of PONV.
MAC with dexmedetomidine resulted in comparable satisfaction in the patients, nurses and surgeons compared to general anesthesia. The incidence of postoperative adverse effects and severity of postoperative pain were also similar between the two groups. Therefore, both anesthetic techniques can be used during the reduction of nasal bone fractures based on a patient%s preference and medical condition.
Dexmedetomidine; General anesthesia; Nasal bone fracture
Oropharyngeal manipulation is problematic when patients have a gag reflex. Sedation can suppress gag reflex, but can cause serious airway problems. We compared remifentanil (Group R) and propofol (Group P) in terms of cooperation and loss of gag reflex, while drugs were administered incrementally using target controlled infusion (TCI).
Fifty seven patients who required awake fiberoptic intubation were randomized to Group R or Group P. After measurement of baseline gag trigger point index (GTPI), TCI was set to effect-site concentration (Ce) of 1 ng/ml (Group R) or 1 µg/ml (Group P), then titrated by 0.5 increment until GTPI score reached 0. The incidence of drop-out and decreased cooperation, Ramsay sedation scale (RSS) and Ce at loss of GR, and complications were assessed.
Seven patients were dropped out in Group P due to deep sedation and disobedient behavior, but none in Group R (P = 0.015). Gag reflex suppressed as RSS increased in both groups (P < 0.001), however, the incidence of elimination of gag reflex clustered at RSS 2 in Group R (P < 0.001), whereas it was evenly distributed in Group P (P = 0.20). The incidence of patients who were spontaneously roused (gag reflex elimination at RSS 1 and 2) were higher in Group R than in Group P (P = 0.002).
Deep sedation and impaired cooperation were observed only in Group P and spontaneously roused patients were higher in Group R, suggesting that remifentanil is more suitable for cooperative elimination of GR.
Gag reflex; Propofol; Remifentanil
We investigated the effects of a magnesium sulfate pretreatment on intubating conditions and cardiovascular responses during rapid sequence tracheal intubation (RSI) in this double-blind randomized study.
Adult patients (n = 154) were randomly allocated to a rocuronium-0.6, rocuronium-0.9, or magnesium group. The magnesium group was pretreated with 50 mg/kg MgSO4, and the other two groups received the same volume of isotonic saline. Anesthesia was induced with alfentanil, propofol, and either 0.6 mg/kg (rocuronium-0.6 and magnesium groups) or 0.9 mg/kg (rocuronium-0.9 group) rocuronium. An anesthesiologist, blinded to the group assignments, performed RSI and assessed the intubating conditions. Systolic arterial pressure (SAP) and heart rate (HR) were recorded before the magnesium sulfate or normal saline was administered, before anesthesia induction, before intubation, and every minute after intubation for 5 min.
Airway features were similar among the three groups. The intubating conditions were improved significantly in the magnesium group (P < 0.001) compared with the other two groups. Significant increases in SAP at 1 min after intubation were observed in the rocuronium-0.6 and -0.9 groups when compared with the magnesium group (P < 0.05). HR was comparable among the three groups (P > 0.05). No hypertensive episode occurred during the immediate post-intubation period in the magnesium group (P = 0.001), and tachycardia occurred most frequently in the rocuronium-0.6 group (P < 0.05).
MgSO4 administered prior to RSI using alfentanil, propofol, and rocuronium may improve intubating conditions and prevent post-intubation hypertension.
Magnesium sulfate; Rapid sequence intubation; Rocuronium
Acute liver failure (ALF) is a rapidly progressing and fatal disease for which liver transplantation (LT) is the only treatment. Posttransplant mechanical ventilation tends to be more prolonged in patients with ALF than in other LT patients. The present study examined the clinical effects of prolonged posttransplant mechanical ventilation (PMV), and identified risk factors for PMV following LT for ALF.
We reviewed data of patients undergoing LT for ALF between January 2005 and June 2011. After grouping patients according to administration of PMV (≥ 24 h), donor and recipient perioperative variables were compared between the groups with and without PMV. Potentially significant factors (P < 0.1) from the univariate intergroup comparison were entered into a multivariate logistic regression to establish a predictive model for PMV.
Twenty-four (25.3%) of 95 patients with ALF who received PMV had a higher mortality rate (29.2% vs 11.3%, P = 0.038) and longer intensive care unit stay (12.9 ± 10.4 vs 7.1 ± 2.7 days, P = 0.012) than patients without PMV. The intergroup comparisons revealed worse preoperative hepatic conditions, more supportive therapy, and more intraoperative fluctuations in vital signs and less urine output in the with- compared with the without-PMV group. The multivariate analysis revealed that preoperative hepatic encephalopathy (≥ grade III), intraoperative blood pressure fluctuation, and oliguria (< 0.5 ml/kg/h) were independent risk factors for PMV.
PMV was associated with deleterious outcomes. Besides care for known risk factors including hepatic encephalopathy, meticulous attention to managing intraoperative hemodynamic circulatory status is required to avoid PMV and improve the posttransplant prognosis in ALF patients.
Acute liver failure; Liver transplantation; Mechanical ventilation; Prediction
During carotid endarterectomy (CEA), hemodynamic stability and adequate fluid management are crucial to prevent perioperative cerebral stroke, myocardial infarction and hyperperfusion syndrome. Both pulse pressure variation (PPV) and stroke volume variation (SVV), dynamic preload indices derived from the arterial waveform, are increasingly advocated as predictors of fluid responsiveness in mechanically ventilated patients. The aim of this study was to evaluate the accuracy of PPV and SVV for predicting fluid responsiveness in patients undergoing CEA.
Twenty seven patients undergoing CEA were enrolled in this study. PPV, SVV and cardiac output (CO) were measured before and after fluid loading of 500 ml of hydroxyethyl starch solution. Fluid responsiveness was defined as an increase in CO ≥ 15%. The ability of PPV and SVV to predict fluid responsiveness was assessed using receiver operating characteristic (ROC) analysis.
Both PPV and SVV measured before fluid loading are associated with changes in CO caused by fluid expansion. The ROC analysis showed that PPV and SVV predicted response to volume loading (area under the ROC curve = 0.854 and 0.841, respectively, P < 0.05). A PPV ≥ 9.5% identified responders (Rs) with a sensitivity of 71.4% and a specificity of 90.9%, and a SVV ≥ 7.5% identified Rs with a sensitivity of 92.9% and a specificity of 63.6%.
Both PPV and SVV values before volume loading are associated with increased CO in response to volume expansion. Therefore, PPV and SVV are useful predictors of fluid responsiveness in patients undergoing CEA.
Arterial blood pressure; Cardiac output; Carotid endarterectomy; Fluid therapy; Stroke volume
Increased intra-abdominal pressure during laparoscopic surgery causes cephalad displacement of the diaphragm, resulting in the formation of atelectasis, which can be overcome by positive end-expiratory pressure (PEEP). The aim of this prospective study was to investigate the level of optimal PEEP to maintain adequate arterial oxygenation and hemodynamics during robot-assisted laparoscopic radical prostatectomy (RLRP).
One hundred patients undergoing RLRP were randomly allocated to one of five groups (n = 20) (0, 3, 5, 7 and 10 cmH2O of PEEP). Hemodynamic variables and respiratory parameters were measured at baseline with the patient in the supine position; at 30 min, 1, 2, 3 and 4 h during CO2 insufflation with the patient in the post-Trendelenburg position; and after deflation in the supine position with increasing PEEP.
The PaO2 levels and alveolar-arterial difference in oxygen tension (AaDO2) were improved in patients with PEEPs compared with patients in whom PEEP was not used. The application of PEEP (10 cmH2O) resulted in higher PaO2 levels compared to those with lower PEEP levels, but excessive peak airway pressure (PAP) was sometimes observed. The application of a PEEP of 7 cmH2O resulted in similar PaO2 levels without causing excessive PAP. There was a significant difference in central venous pressure between the groups, but there were no significant differences in heart rate, mean arterial pressure or minute ventilation between the groups.
A PEEP of 7 cmH2O is associated with the greater improvement of PaO2 and AaDO2 without causing excessive PAP during RLRP.
Hemodynamics; Laparoscopy; Positive end-expiratory pressure; Robotics; Prostatectomy
Although fentanyl-induced cough is generally transient and benign, it can give rise to serious problems in patients to whom increasing intracranial, intraocular or intraabdominal pressures may create dangerous situations. This case demonstrates aspiration pneumonia as a complication, exhibiting severe cough induced by intravenous injection of fentanyl.
Aspiration; Cough; Fentanyl; Pneumonia; Vomiting
The airway management of patients with subglottic stenosis poses many challenges for the anesthesiologists. Many anesthesiologists use a narrow endotracheal tube for airway control. This, however, can lead to complications such as tracheal mucosal trauma, tracheal perforation or bleeding. The ASA difficult airway algorithm recommends the use of supraglottic airway devices in a failed intubation/ventilation scenario. In this report, we present a case of failed intubation in a patient with subglottic stenosis successfully managed during an i-gel™ supraglottic airway device. The device provided a good seal, and allowed for controlled mechanical ventilation with acceptable peak pressures while the patient was in the beach-chair position.
Airway management; Subglottic stenosis
Propionic acidemia (PA) is a rare autosomal recessive disorder of metabolism caused by deficient activity of the mitochondrial enzyme propionyl-CoA carboxylase. The clinical manifestations are metabolic acidosis, poor feeding, lethargy, vomiting, osteoporosis, neurological dysfunction, pancytopenia, developmental retardation and cardiomyopathy. Liver transplantation has recently been considered as one of the treatment options for patients with PA. This case report describes several anesthetic considerations for patients with PA undergoing liver transplantation. Understanding the patient's status and avoiding events that may precipitate metabolic acidosis are important for anesthetic management of patients with PA. In conclusion, anesthesia should be focused on minimizing the severity of metabolic acidosis with following considerations: (1) maintaining optimal tissue perfusion by avoiding hypotension, (2) preventing hypoglycemia, and (3) providing bicarbonate to compensate for the acidosis.
Liver transplantation; Propionic acidemia
There are various causes to a low level of consciousness in patients in the intensive care unit. Neurological injury, infection, and metabolic disarray are considered as some of the causes. A 39 year-old female patient was transferred to our hospital with septic shock due to ascending colon perforation. The patient had previously received ovarian cancer surgery and a cycle of chemotherapy at another hospital. Emergent operation for colon perforation was successful. After the operation, she was treated in the intensive care unit for infectious and pulmonary complications. She suddenly showed deterioration in her level of consciousness and had a generalized seizure. At the time of her seizure, she had severe hyperammonemia. Brain CT showed severe cerebral edema that was absent in the CT scan taken 2 days before. Continuous renal replacement therapy was conducted but was ineffective in lowering the level of serum ammonia and the patient subsequently died.
Hyperammonemia; Seizures; Status epilepticus
There are no reports regarding pneumomediastinum caused by thoracic epidural block complications. We believe that it is possible to experience an occurrence of pneumomediastinum caused by air in the epidural space after performing a thoracic epidural block using the loss of resistance (LOR) technique with air. We report a witnessed case where pneumomediastinum appeared after a thoracic epidural block. Pneumorrrhachis, paravertebral muscle emphysema, and pneumomediastinum were diagnosed by Positron Emission Tomography-Computed Tomography. Although extremely rare, pneumomediastinum can be caused by an epidural block using LOR technique with air. In order to avoid the above danger, the use of saline or very minimal amount of air is required during a careful LOR technique.
Emphysema; Epidural injection; Pneumomediastinum
Anxiety influences brain wave activity. E-Entropy module-derived spectral entropy is an electroencephalographic derivative used to monitor the depth of sedation. This study assessed the effect of preoperative anxiety on the spectral entropy parameters of response entrophy (RE) and state entrophy (SE).
Trait anxiety was measured in 92 American Society of Anesthesiologists physical status I-II patients with the Spielberger State-Trait Anxiety Inventory (STAI) form X2 and state anxiety with STAI-X1 just before anesthesia. RE, SE, blood pressure and heart rate were measured before induction. Propofol was infused via a target controlled infusion pump. At loss of consciousness (LOC), the effect-site concentration (Ce), RE, SE and total amount of propofol were recorded. Patients were stratified into three groups based on their state and trait anxiety scores to evaluate the effect of anxiety level on entropy values.
STAI-X1 was significantly correlated with RE and SE for LOC (ρ = 0.230, P = 0.028 and ρ = 0.308, P = 0.003, respectively) and also with STAI-X2 (ρ = 0.411, P = 0.001, respectively). SE was higher in the high state anxiety group than in the low state anxiety group (P = 0.017). The other measured variables were not correlated with any anxiety scales.
The state of anxiety increases RE and SE values at LOC induced with propofol. High state anxiety is associated with higher SE than apparent at low state anxiety. When determining the propofol-induced LOC by spectral entropy, anxiety levels should be considered.
Anxiety; Electroencephalography; Entropy; Propofol
Dexmedetomidine is an α2-adrenoreceptor agonist with sedative, analgesic and anxiolytic effects, and it has more selective α2-adrenergic effect than clonidine. We evaluate the effect of preansethetic dexmedetomidine 1 µg/kg single infusion on sedation, hemodynamics, anesthetic consumption, and recovery profiles during anesthesia.
Forty-two female patients with American Society of Anesthesiologists physical status I or II undergoing gynecologic surgery with anticipated operation time of 2 h, were randomly assigned to receive dexmedetomidine 1 µg/kg (Dex group) or saline (control group) iv over 10 min before anesthetic induction. After tracheal intubation with propofol 2 mg/kg, cisatracurium 0.15 mg/kg iv, anesthesia was maintained with sevoflurane, O2 50%, N2O 50% around a BIS value of 40.
After study drug infusion, BIS of Dex group was lower than that of control group (93.9 ± 3.1 vs 51.5 ± 5.2, P < 0.05). Mean arterial pressure (MAP) and heart rate (HR) after intubation were increased in control group, but did not change in Dex group. During maintenance, there was no difference in MAP between groups, but HR of Dex group was lower compared to that of control group. End-tidal concentration (2.0 ± 0.5 vol% vs 1.4 ± 0.3 vol%, P < 0.05) and total cumulative consumption of sevoflurane (34.6 ± 3.8 ml vs 26.5 ± 5.3 ml, P < 0.05) were lower in Dex group than in control group. Recovery profiles, modified Aldrete score, postoperative nausea vomiting, and visual analogue pain score were not significantly different between groups.
Preanesthetic dexmetomidine 1 µg/kg single infusion is a simple, easy, and economic general anesthetic adjuvant that maintains stable hemodynamics and decrease anesthetic consumption without the change of recovery profiles.
Dexmedetomidine; Economics; Hemodynamics; Recovery of function; Sevoflurane
The required dose of anesthetics is generally smaller in patients with low cardiac output (CO). A high CO decreases the blood concentration of anesthetics during induction and maintenance of anesthesia. However, a high CO may also shorten the delivery time of anesthetics to the effect site, e.g. the brain. We assessed the time required for induction of anesthesia with propofol administered by target-controlled infusion (TCI), and investigated factors that modify the pharmacodynamics of propofol.
After measuring CO and blood volume (BV) by dye densitometry, propofol was infused using TCI to simulate a plasma concentration of 3 µg/ml. After infusion, the time taken to achieve bispectral index (BIS) values of 80 and 60 was determined. Age, sex, lean body mass (LBM), and cardiovascular parameters were analyzed as independent variables. The dependent variables were the time taken to achieve each BIS value and the plasma concentration of propofol (Cp) 10 min after the commencement of infusion.
Multiple regression analysis revealed that a high CO significantly reduced the time taken to reach the first end point (P = 0.020, R2 = 0.076). Age and LBM significantly prolonged the time taken to reach the second end point (P = 0.001). Cp was negatively correlated with BV (P = 0.020, R2 = 0.073).
Cardiac output was a statistically significant factor for predicting the time required for induction of anesthesia in the initial phase, whereas, age and LBM were significant variables in the late phase. The pharmacodynamics of propofol was intricately altered by CO, age, and LBM.
Cardiac output; Consciousness monitors; Pharmacokinetics; Propofol