Prediction Model of Extubation Outcomes in Critically Ill Patients: A Multicenter Prospective Cohort Study.

Liberation from mechanical ventilation is of great importance owing to related complications from extended ventilation time. In this prospective multicenter study, we aimed to construct a versatile model for predicting extubation outcomes in critical care settings using obtainable physiological predictors. The study included patients who had been extubated after a successful 30 min spontaneous breathing trial (SBT). A multivariable logistic regression model was constructed to predict extubation outcomes (successful extubation without reintubation and uneventful extubation without reintubation or noninvasive respiratory support) using eight parameters: age, heart failure, respiratory disease, rapid shallow breathing index (RSBI), PaO2/FIO2, Glasgow Coma Scale score, fluid balance, and endotracheal suctioning episodes. Of 499 patients, 453 (90.8%) and 328 (65.7%) achieved successful and uneventful extubation, respectively. The areas under the curve for successful and uneventful extubation in the novel prediction model were 0.69 (95% confidence interval (CI), 0.62−0.77) and 0.70 (95% CI, 0.65−0.74), respectively, which were significantly higher than those in the conventional model solely using RSBI (0.58 (95% CI, 0.50−0.66) and 0.54 (95% CI, 0.49−0.60), p = 0.004 and <0.001, respectively). The model was validated using a bootstrap method, and an online application was developed for automatic calculation. Our model, which is based on a combination of generally obtainable parameters, established an accessible method for predicting extubation outcomes after a successful SBT.

Evaluation of performance of two high-frequency oscillatory ventilators using a model lung with a position sensor.

PURPOSE: High-frequency oscillatory ventilation (HFOV) is thought to protect the lungs of acute respiratory distress syndrome (ARDS) patients. The performance and mechanical characteristics of high-frequency oscillatory ventilators, especially with regard to delivering appropriate tidal volume (V(T)) to compromised lungs, might affect the outcome of patients. We evaluated the performance of two such ventilators using a model lung with a position sensor. METHODS: We tested the Metran R100 and SensorMedics 3100B. V(T) was measured using the model lung with the compliance set at 20 or 50 ml/cmH2O and the resistance at 0 or 20 cmH2O/l/s. Oscillator frequency was set at 5, 7, and 9 Hz, and amplitude was set at 25%, 50%, 75%, and 100% (100% being maximum amplitude available at each setting configuration). RESULTS: At each model lung setting, R100 delivered greater V(T) at 5 Hz. V(T) differences between the ventilators decreased as frequency increased and were negligible at 9 Hz. At each model lung setting and frequency, as amplitude increased from 25% to 100%, V(T) increased proportionally more with R100. With an I:E ratio of 1:1, 3100B delivered greater V(T) than with 1:2. CONCLUSION: Because it is able to deliver comparably greater V(T), R100 may be a better choice for HFOV in critical ARDS patients. Better proportionality may be a result of more effective amplitude titration for adjusting PaCO2 during oscillation.

[Tracheal compression caused by hematoma and felt strips around an anastomosis site following repair of thoracic aneurysm: a case report].

Respiratory complication is common after a repair of thoracic aneurysm, although tracheal compression caused by hematoma and felt strips following surgery is a rare cause. We report the case of a patient who experienced difficult weaning from ventilator after a repair of a thoracic aortic aneurysm and was diagnosed as a tracheal compression outside of trachea revealed by bronchoscopy and chest CT scan. Re-operation was successfully performed to relieve the compression under monitoring by bronchoscopy. Patient was disconnected from the ventilator three weeks after the reoperation and transferred to a rehabilitation hospital.

[Two cases of transfusion-related acute lung injury following massive transfusion during the perioperative period].

Transfusion-related acute lung injury (TRALI) is a serious complication of transfusion of blood and blood components. TRALI is reported to be the most common cause of transfusion-associated death. TRALI has increasingly become known in the medical community. However, TRALI has been overlooked frequently because of poor knowledge of medical staffs. We report two cases of TRALI after massive transfusion due to massive bleeding during cardiovascular surgery. In the perioperative period, the diagnosis of TRALI is difficult to make because of coexistence of various factors leading to hypoxia. Thus, in this report, we discuss the management of these two cases focusing upon the differential diagnosis of TRALI.

Influence of endotracheal tube bore on tidal volume during high frequency oscillatory ventilation: a model lung study.

BACKGROUND: In adults, the influence of endotracheal tube bore on tidal volume (VT) during high-frequency oscillatory ventilation (HFOV) has been little studied. MATERIAL/METHODS: Via full-length 6, 7, 8, and 9 mm internal diameter (ID) endotracheal tubes (ETTs), a model lung (TTL, Michigan Instruments, MI) was ventilated using a high-frequency oscillator designed for adult patients (R100; Metran, Japan). Oscillation settings were: frequency, 5, 7, and 9 Hz; mean airway pressure, 15 cmH2O; oxygen inspiratory fraction, 0.21. At each setting: oscillator pressure swing was set at maximum; and each test combination was conducted with the model-lung compliance set at 20 and 50 mL/cmH2O. During the trials, a position sensor attached to the model-lung upper surface provided analog electrical signals for lung movement that were converted to VT evaluation data. Pressure and volume signals were digitized using an analog-to-digital converter and recorded in a computer. At each setting, three waveforms were analyzed and the average value used. RESULTS: At each setting, measured VT was proportional to ETT internal cross-sectional area (CSA). Regression analysis of VT showed correlation with the CSA, as expressed by formula, y=2.173x where x is CSA and y is VT (R2=0.99, p<0.001) at 5 Hz and compliance of 50 cmH2O. CONCLUSIONS: In an adult-simulating model lung, VT during HFOV varies in proportion to ETT CSA.

Analgesic effect of dexmedetomidine in a patient with herpetic stomatitis after living-donor lung transplantation.

A 31-year-old woman suffering from bronchiolitis obliterans received bilateral living-donor lung transplantation to treat end-stage respiratory failure. After 5 days' mechanical ventilation, the patient was successfully extubated. During mechanical ventilation, the patient was sedated with a continuous intravenous infusion of propofol and dexmedetomidine (DEX). To assuage postoperative pain, morphine was infused, first intravenously, then epidurally. The administration of DEX was continued after extubation to prevent agitation. After the administration of epidural morphine was discontinued on day 10 in the intensive care unit (ICU), the patient complained of pain in the oral cavity. Greater pain was reported after the discontinuation of DEX, and symptoms of tachycardia and dyspnea appeared. A dermatologist diagnosed the oral symptoms as herpetic stomatitis, and a course of treatment with aciclovir was begun. A continuous infusion of DEX was again started on the same day, and was continued until ICU day 13. During the administration of DEX, the oral cavity pain was bearable. The patient was successfully discharged from the ICU on ICU day 13. We conclude that DEX could be used to provide analgesia for herpetic stomatitis after living-donor lung transplantation, at a dosage that achieves appropriate sedation.

Rhabdomyolysis induced by Pseudomonas aeruginosa sepsis.

We describe advanced hemodynamic insufficiency and remarkably high myoglobinemia in a 77-year-old man who was admitted to the intensive care unit after total aortic arch replacement. Serum myoglobin showed an unusually high value (peak value, 155,030 ng x ml(-1)). The patient died of sepsis and untreatable metabolic acidosis. Pseudomonas aeruginosa was detected in blood culture specimens after his death. On histopathological examination, dense congregations of gram-negative bacilli were present in clots in blood vessels, while congregations of gram-negative bacilli around the circumference of small blood vessels were particularly apparent in every specimen examined. Moreover, a generalized breakdown of muscle fibers, consistent with findings of rhabdomyolysis, was observed in muscle tissue throughout the body.

[Spinal anesthesia using hyperbaric bupivacaine HCl for cesarean section].

BACKGROUND: We performed this prospective study to determine the proper amount of hyperbaric bupivacaine hydrochloride as a spinal anesthetic agent for cesarean section. METHODS: The parturients were randomly allocated to receive one of four spinal agents in a blind manner; tetracaine 10 mg (control), bupivacaine 10, 12.5 and 15 mg. Morphine HCl 0.1 mg was added to each agent and the total volume was adjusted to 3.1 ml with 10% glucose solution. RESULTS: All the four spinal agents provided an adequate analgesic level (T 5) without serious complications. Among the three dosages of bupivacaine, the time interval requiring for anesthetic level to reach T 5 tended to be shorter with a larger amount of bupivacaine. The incidence of intraoperative supplemental analgesic and hypotension and the dosage of ephedrine used to treat hypotension were greater in the patients anesthetized with tetracaine 10 mg than in those anesthetized with bupivacaine 10 mg, which is equipotent to tetracaine 10 mg. CONCLUSIONS: 1. As a spinal anesthetic agent for cesarean section, hyperbaric bupivacaine is superior to tetracaine. 2. Hyperbaric bupivacaine 10 mg, 12.5 mg or 15 mg can be used safely and effectively as a spinal agent for cesarean section. 3. High dose bupivacaine is recommended in an urgent case, and low dose bupivacaine is recommended when maternal hypotension must be strictly avoided.

[Bispectral index (BIS) in infants anesthetized with sevoflurane in nitrous oxide and oxygen].

BACKGROUND: The bispectral index (BIS) has been shown to be useful in monitoring a degree of hypnosis in anesthetized adults. Although several studies have been performed to evaluate BIS in pediatric patients, it is unclear whether BIS monitor can be applied to infants. This study was designed to evaluate if the BIS monitor can be used in infants as a measure to monitor a degree of hypnosis. METHODS: Forty-three infants were divided into two age groups according to their age: group A (3-6 months; n = 31) and B (7-12 months; n = 12). And the patients in the younger group were randomly allocated to one of two groups, A (+) (premedicated with oral midazolam 0.5 mg.kg-1; n = 19) and A (-) (without premedication; n = 12). BIS values and other parameters were recorded at a steady state of end-tidal sevoflurane concentration (2.5, 2, and 1.5%) and immediately before extubation. RESULTS: At each concentration of sevoflurane and extubation, the BIS values were lower in group A (+) than in group B (P < 0.05). In infants < or = 6 months of age, premedication did not affect the BIS values. CONCLUSION: There were significant differences of BIS values between < or = 6 months and > or = 7 months old infants. BIS values should be interpreted cautiously in infants younger than 6 months.

[Anesthesia for 15 morbidly obese parturients undergoing cesarean section].

From 1994 to June 2001, 15 parturients weighing more than 100 kg underwent cesarean section at our institution. Their medical and anesthetic records were reviewed retrospectively. They consisted of 10 primiparous and 5 multiparous patients. Mean body weight was 108.4 +/- 6.3 kg (mean +/- SD) and body mass index (weight in kilograms/[height in meters]2) was 41.6 +/- 2.8 kg.m-2 (min 36.6, max 49.7). Maternal complications included preeclampsia (n = 7, 46.7%), diabetes mellitus (n = 6, 40%) and asthma (n = 1). Of 15 patients, cesarean section was performed under spinal anesthesia in 11 patients and under epidural anesthesia in 4, and none received general anesthesia. All the patients gave live births. Intraoperative complications included hypotension (n = 6) and nausea (n = 3). All of them were free from the morbid postoperative complications except wound dehiscence occurring in four patients.

[Anesthetic management of a child with dilated cardiomyopathy associated with congenital fiber-type disproportion].

A 3-year-old girl, who presented with dilated cardiomyopathy in conjunction with congenital fiber-type disproportion, underwent open reduction for congenital dislocation of the hip. Preoperative echocardiography demonstrated left ventricular dilatation with an ejection fraction (EF) of 0.33. Anesthesia was induced with intravenous ketamine and fentanyl, and maintained with fentanyl administered incrementally to a total dose of 10 micrograms.kg-1 and 1-1.5% isoflurane. During operation, we continuously monitored left ventricular wall motion and measured left ventricular diastolic dimension (LVDd), systolic dimension (LVDs), cardiac output (CO), EF, and fractional shortening (FS) with transesophageal echocardiography (TEE). At the end of surgery, preload (LVDd) and LV contractility (CO, EF, FS) decreased, but LV wall motion remained almost stable throughout the procedure. In conclusion, TEE was useful for intraoperative management of a child with dilated cardiomyopathy.

[The effect of ketamine on reducing postoperative agitation after sevoflurane anesthesia in pediatric strabismus surgery].

We investigated the effect of ketamine on reducing postoperative agitation after sevoflurane anesthesia in children undergoing elective strabismus surgery. Fifty-five children, 3-9 years of age, were randomly assigned to the following three groups; ketamine (group K, n = 18), pentazocine (group P, n = 19), and flurbiprofen axetil(group F, n = 18). Group K received ketamine 1 mg.kg-1 intravenously, followed by infusion of ketamine 1 mg.kg-1.hr-1 during surgery, group P received pentazocine 0.2 mg.kg-1 intravenously after induction of anesthesia, and Group F received intravenous flurbiprofen axetil, 1 mg.kg-1 5 minutes before the end of surgery. Agitation (evaluated by Aono's four-point scale; AFPS) and awareness (evaluated by Steward score) were assessed just before tracheal extubation(T 1), 5 minutes after tracheal extubation(T 2), arrival at the ward(T 3), and 60 minutes after arrival at the ward(T 4). We considered AFPS > or = 3 patients as "agitated" and APFS < or = 2 patients as "not agitated". At T 1 and T 2, the incidence of agitation(AFPS > or = 3) in group K was less than that of group F and group P. However, in group K, more patients needed oxygen supplement after extubation. We concluded that coadministration of ketamine could be beneficial for reducing postoperative agitation after sevoflurane anesthesia in pediatric strabismus surgery.