Cryopreventive temperatures prior to chemotherapy.

The superiority of oral cryotherapy (OC) for prevention of chemotherapy-induced oral mucositis (OM) has been demonstrated in several trials. In clinical settings, cooling is usually initiated prior to the chemotherapy infusion. It then continues during the infusion, and for a period after the infusion has been completed. While the cooling period post-infusion depends on the half-life of the chemotherapeutic drug, there is no consensus on when cooling should be initiated prior to the infusion. The lowest achieved temperature in the oral mucosa is believed to provide the best condition for OM prevention. Given this, it was of interest to investigate when along the course of intraoral cooling this temperature is achieved. In total, 20 healthy volunteers participated in this randomized crossover trial. Each subject attended three separate cooling sessions of 30 min each, with ice chips (IC) and the intraoral cooling device (ICD) set to 8 and 15 °C, respectively. At baseline and following 5, 10, 15, 20 and 30 min of cooling, intraoral temperatures were registered using a thermographic camera. The greatest drop in intraoral temperature was seen after 5 min of cooling with IC, ICD8°C and ICD15°C, respectively. A statistically significant difference, corresponding to 1.4 °C, was seen between IC and the ICD15°C (p < 0.05). The intraoral temperature further declined throughout the 30 min of cooling, showing an additional temperature reduction of 3.1, 2.2, and 1.7 °C for IC, ICD8°C and ICD15°C, respectively.

Automated Detection of 3D Landmarks for the Elimination of Non-Biological Variation in Geometric Morphometric Analyses.

Landmark-based morphometric analyses are used by anthropologists, developmental and evolutionary biologists to understand shape and size differences (eg. in the cranioskeleton) between groups of specimens. The standard, labor intensive approach is for researchers to manually place landmarks on 3D image datasets. As landmark recognition is subject to inaccuracies of human perception, digitization of landmark coordinates is typically repeated (often by more than one person) and the mean coordinates are used. In an attempt to improve efficiency and reproducibility between researchers, we have developed an algorithm to locate landmarks on CT mouse hemi-mandible data. The method is evaluated on 3D meshes of 28-day old mice, and results compared to landmarks manually identified by experts. Quantitative shape comparison between two inbred mouse strains demonstrate that data obtained using our algorithm also has enhanced statistical power when compared to data obtained by manual landmarking.

A new tool for quantifying and characterizing asymmetry in bilaterally paired structures.

This paper introduces a new tool to quantify and characterize asymmetry in bilaterally paired structures. This method uses deformable registration to produce a dense vector field describing the point correspondences between two images of bilaterally paired structures. The deformation vector field properties are clustered to detect and describe regions of relevant asymmetry. Three methods are provided to analyze the asymmetries: the global asymmetry score uses cluster features to quantify overall asymmetry, the local asymmetry score quantifies asymmetry in user-defined regions of interest, and the asymmetry similarity measure quantifies pairwise similarity of individual asymmetry. The scores and image distances generated by this tool are shown to correlate highly with asymmetry ratings assigned by an expert.

Rocuronium and sugammadex in patients with myasthenia gravis undergoing thymectomy.

BACKGROUND: The use of neuromuscular blocking agents is still controversial in myasthenic patients but rocuronium could be useful after the introduction of sugammadex as a selective antagonist. The aim of the study was to evaluate the use of rocuronium-sugammadex in myasthenic patients undergoing thoracoscopic thymectomy. METHODS: After ethical approval, 10 myasthenic patients undergoing videothoracoscopic-assisted thymectomy were enrolled in the study. Neuromuscular block was achieved with 0.3 mg/kg rocuronium and additional doses were given according to train-of-four (TOF) monitoring or movement of the diaphragm. Sugammadex 2 mg/kg was given after surgery. Recovery time (time to obtain a TOF value > 0.9) was recorded for all subjects. RESULT: All patients were extubated in the operating room after administration of sugammadex. Mean rocuronium dose was 48 mg and the average operation time was 62 min. Recovery time after sugammadex administration was 111 s (min 35; max 240). CONCLUSIONS: A rapid recovery of neuromuscular function was found in myasthenic patients receiving rocuronium when sugammadex was used for reversal. This combination could be a rational alternative for myasthenic patients for whom neuromuscular blockade is mandatory during surgery.

Effects of thoracic epidural anaesthesia on pulmonary venous admixture and oxygenation during one-lung ventilation.

BACKGROUND: In this clinical randomized study, the effects of four anaesthesia techniques during one-lung ventilation [total intravenous anesthesia (TIVA) with or without thoracic epidural anaesthesia (TEA) (G-TIVA-TEA and G-TIVA), isoflurane anaesthesia with or without TEA (G-ISO-TEA and G-ISO)] on pulmonary venous admixture (Qs/Qt) and oxygenation (OLV) were investigated. METHODS: In 100 patients (four groups, 25 patients in each) undergoing thoracotomy, a thoracic epidural catheter was inserted pre-operatively. In G-TIVA-TEA and G-ISO-TEA, bupivacaine 0.1% + 0.1 mg/ml morphine was administered intra-operatively (10 ml of first bolus + 7 ml/h infusion). Propofol infusion or isoflurane concentration was adjusted to keep a bispectral index (BIS) of between 40 and 50 in all groups. FiO(2) was 0.8 during OLV and 0.5 before and after OLV. Partial arterial and central venous oxygen pressures (PaO(2) and PvO(2)), arterial and venous oxygen saturations and Qs/Qt values were recorded before, during and after OLV. RESULTS: During OLV, PaO(2) was significantly higher and Qs/QT significantly lower in G-TIVA-TEA and G-TIVA compared with G-ISO-TEA and G-ISO (PaO2: 188 +/- 36; 201 +/- 39; 159 +/- 33; 173 +/- 42 mmHg, respectively; Qs/Qt: 31.2 +/- 7.4; 28.2 +/- 7; 36.7 +/- 7.1; 33.7 +/- 7.7%, respectively). No statistical changes were observed in patients with TEA compared with without TEA in any measurement. CONCLUSION: During OLV, TEA does not significantly affect the oxygenation and Qs/Qt and can be used safely regardless of whether TIVA or inhalation techniques are used.

Effects of intramuscular administration of lidocaine or bupivacaine on induction and maintenance doses of propofol evaluated by bispectral index.

BACKGROUND: Interest in combining local and general anaesthesia has lead to studies investigating possible interactions. In a prospective, randomized, double-blind study, we tested whether local anaesthetics administered i.m. potentiate the hypnotic effect of propofol. METHODS: Sixty patients (three groups, n=20) undergoing lower abdominal surgery with total i.v. propofol anaesthesia were investigated. Patients in Group B received i.m. bupivacaine (5 mg ml(-1)) 1 mg kg(-1), patients in Group L received i.m. lidocaine (100 mg ml(-1)) 2 mg kg(-1) and patients in Group C received i.m. saline 5 ml before operation. Hypnosis was measured with bispectral index (BIS). RESULTS: The induction (BIS <45), and the maintenance doses of propofol (BIS between 40 and 50) were significantly less in Group B and Group L compared with the control group. Induction doses were 1.58 (SD 0.39), 1.56 (0.24) and 2.03 (0.33) mg kg(-1) respectively; P<0.0001. Maintenance doses were 6.33 (2.06), 7.08 (1.23) and 9.95 (2.02) mg kg(-1) respectively in the first hour; P<0.0001. Groups B and L were associated with an attenuated haemodynamic response to both induction and intubation. CONCLUSION: I.M. administered local anaesthetics are associated with a decrease in both the induction and maintenance doses of propofol during total i.v. anaesthesia and a reduction in haemodynamic responses.

Clinical applicability of the substitution of mixed venous oxygen saturation with central venous oxygen saturation.

OBJECTIVE: To examine the clinical applicability of substituting central venous oxygen saturation (ScvO2) for mixed venous oxygen saturation (SmvO2) in monitoring global tissue oxygenation. DESIGN: Prospective clinical investigation. SETTING: University hospital. PARTICIPANTS: Seventy-three adult patients. INTERVENTIONS: Venous oxygen saturation was recorded, and oxygen saturation difference between SmvO2 and ScvO2 (DeltaSmvcv) was calculated in 2 groups of patients (group I, sepsis patients [n = 41], and group II, general anesthesia for cardiovascular surgery patients [n = 32]) during initial placement of pulmonary artery catheters. MEASUREMENTS AND MAIN RESULTS: Patients were classified as follows: class A, patients having a DeltaSmvcv >-5%; class B, patients having a DeltaSmvcv between -5% and +5%; and class C, patients having a DeltaSmvcv >+5 %. Statistically significant differences were observed in cardiac index, oxygen delivery index, and oxygen extraction ratio between class A and B in both groups. Class C of group II showed the worst correlation between SmvO2 and ScvO2 and had significantly lower arterial carbon dioxide tension values than class A and B. CONCLUSION: Pulmonary artery blood sampling should not be replaced with central venous blood. Hypocapnia and increased oxygen extraction ratio seem to be the major factors that worsen the relationship between ScvO2 and SmvO2.

Techniques and complications of one-lung ventilation in children with suppurative lung disease: experience in 15 cases.

OBJECTIVE: To evaluate lung isolation with Fogarty catheters and to analyze respiratory consequences of one-lung ventilation (OLV) in children with suppurative lung disease. DESIGN: Prospective. SETTING: University hospital. PARTICIPANTS: Fifteen children undergoing thoracotomy. INTERVENTIONS: Bronchial blockade with a 7F Fogarty catheter was attempted. In case of incomplete blockade or failure in directing the catheter into the desired mainstem bronchus, endobronchial intubation was done. Volume-controlled ventilation was performed with fraction of inspired oxygen (F(I)O2), 0.5; inspiratory-to-expiratory (I: E) ratio, 1:2; and 10 mL/kg tidal volume during two-lung ventilation (TLV). F(I)O2 was increased to 1.0 by the initiation of OLV. If peak airway pressure exceeded basal values during TLV by 35%, tidal volume was reduced to 8 mL/kg, inspiratory pause was zeroed, and I:E ratio was increased to 1:1. Hemodynamic and respiratory parameters were recorded during TLV and 30 minutes after initiation of OLV. Peripheral oxygen saturation and end-tidal carbon dioxide tension were recorded every 5 minutes. MEASUREMENTS AND MAIN RESULTS: Right lung isolation was successfully obtained by Fogarty catheters in 10 children undergoing right thoracotomy. Endobronchial intubation was performed in 2 children (40%) undergoing left thoracotomy. Three children (20%) developed episodes of severe hypercapnia and hypoxia requiring treatment during OLV. All of the parameters recorded at 30 minutes of OLV revealed statistically significant differences from TLV. OLV was transiently discontinued in 1 child. CONCLUSION: The use of Fogarty embolectomy catheters for lung isolation in children undergoing thoracotomy is recommended. Respiratory problems are not rare during OLV in children with suppurative lung disease and require immediate management.

Blood S-100 protein concentration in children undergoing cardiac surgery.

OBJECTIVES: To investigate plasma levels of the betabeta isomer of S-100 protein and to assess the relationship between post-cardiopulmonary bypass (CPB) levels of this marker and a variety of perioperative and patient factors in children undergoing cardiac surgery. DESIGN: Prospective study. SETTING: University hospital. PARTICIPANTS: Twenty-five children. INTERVENTIONS: Blood samples (2 mL) for S-100 determinations were collected after the induction of anesthesia, 30 minutes after aortic cross-clamping, 1 hour after the termination of CPB, and 5 and 24 hours after the operation. Electroencephalogram activity was recorded, and neurologic examination was performed on all children 1 day before and 10 days after the operation. Lowest values of nasopharyngeal temperature, mean arterial pressure, arterial carbon dioxide tension (PaCO2), pH, and hematocrit during CPB were recorded. MEASUREMENTS AND MAIN RESULTS: The overall change in S-100 during the study period was found to be statistically significant (p < 0.0001). Correlation between deltaS-100 and age (r = -0.45; p = 0.04), body surface area (r = -0.63; p = 0.002), nasopharyngeal temperature (r = -0.55; p = 0.01), and PaCO2 (r = -0.55; p = 0.009) was statistically significant in infants and children. Multivariate regression analysis indicated significant effects of PaCO2 and body surface area on deltaS-100 levels and area under the curve values. CONCLUSION: In contrast to newborns, infants and older children showed prominent increases in S-100 protein concentration. Lack of pathologic electroencephalogram findings and neurologic signs in the postoperative period precludes the clinical use of S-100 protein concentration as a sensitive marker of cerebral injury.

Ketamine infusion versus isoflurane for the maintenance of anesthesia in the prebypass period in children with tetralogy of Fallot.

OBJECTIVE: To evaluate the use of ketamine in comparison with isoflurane in the maintenance of anesthesia in children with tetralogy of Fallot. DESIGN: Prospective, randomized study. SETTING: University hospital. PARTICIPANTS: Fifty children scheduled for correction of tetralogy of Fallot. INTERVENTIONS: After intubation, patients were assigned randomly to receive 2 different anesthesia maintenance regimens: group I, isoflurane, 0 to 1% plus fentanyl, 0.1 microg/kg/min; group II, ketamine, 0 to 5 mg/kg/h, plus fentanyl, 0.1 microg/kg/min. Isoflurane concentration and ketamine infusion rate were adjusted to maintain arterial pressure within 25% of baseline. Hemodynamic and respiratory parameters were recorded at the end of 4 intervals: T0, before induction of anesthesia; T1, induction to 10 minutes postintubation; T2, 10 minutes postintubation to poststernotomy; and T3, poststernotomy to completion of catheterizations. MEASUREMENTS AND MAIN RESULTS: In comparing group I with group II, significant differences were observed in mean arterial pressure (p < 0.0001), heart rate (p < 0.01), arterial oxygen saturation (p < 0.0001), arterial oxygen tension (p < 0.001), arterial carbon dioxide tension (p < 0.001), arterial pH (p < 0.0001), base excess (p < 0.05), and arterial to end-tidal carbon dioxide tension difference (p < 0.01) at T3. CONCLUSION: The use of ketamine anesthesia is recommended as an alternative maintenance regimen in children undergoing definitive correction of tetralogy of Fallot.

Comparison of volume controlled with pressure controlled ventilation during one-lung anaesthesia.

Pressure controlled ventilation (PCV) is an alternative mode of ventilation which is used widely in severe respiratory failure. In this study, PCV was used for one-lung anaesthesia and its effects on airway pressures, arterial oxygenation and haemodynamic state were compared with volume controlled ventilation (VCV). We studied 48 patients undergoing thoracotomy. After two-lung ventilation with VCV, patients were allocated randomly to one of two groups. In the first group (n = 24), one-lung ventilation was started by VCV and the ventilation mode was then switched to PCV. Ventilation modes were performed in the opposite order in the second group (n = 24). We observed that peak airway pressure (P = 0.000001), plateau pressure (P = 0.01) and pulmonary shunt (P = 0.03) were significantly higher during VCV, whereas arterial oxygen tension (P = 0.02) was significantly higher during PCV. Peak airway pressure (Paw) decreased consistently during PCV in every patient and the percentage reduction in Paw was 4-35% (mean 16.1 (SD 8.4) %). Arterial oxygen tension increased in 31 patients using PCV and the improvement in arterial oxygenation during PCV correlated inversely with preoperative respiratory function tests. We conclude that PCV appeared to be an alternative to VCV in patients requiring one-lung anaesthesia and may be superior to VCV in patients with respiratory disease.

Comparison of the effects of sodium nitroprusside and isoflurane during rewarming on cardiopulmonary bypass.

OBJECTIVES: Afterdrop in core temperatures after discontinuation of cardiopulmonary bypass (CPB) is reported to be a sign of inadequate total body rewarming on CPB. The purpose of this study was to compare the effects of three different drug regimens on hemodynamic stability and the uniformity of rewarming during the rewarming period of CPB. DESIGN: This prospective randomized study was performed in the Anesthesiology Department of the University of Istanbul. PARTICIPANTS: Sixty-six patients undergoing uncomplicated valve replacement and aortocoronary bypass grafting surgery were studied. INTERVENTIONS: Anesthesia was maintained with isoflurane and fentanyl infusion during the prebypass and the postbypass periods. Patients were allocated into three groups by the initiation of CPB. Group 1 (n = 22): fentanyl infusion + diazepam + sodium nitroprusside (SNP) in the rewarming period), group 2 (n = 22): fentanyl infusion + isoflurane, group 3, control (n = 22): fentanyl infusion + diazepam. Rectal, esophageal, and forearm temperatures were monitored throughout the study. MEASUREMENTS AND MAIN RESULTS: None of the durational and temperature data showed significant differences between groups 1 and 2. In the control group, afterdrop in esophageal temperature was significantly higher than groups 1 and 2 (group 1: -1.4 +/- 0.9 degrees C, group 2: -1.44 +/- 0.8 degrees C, group 3: -2.1 +/- 0.65 degrees C). In group 1, the number of patients whose mean arterial pressure (MAP) decreased below 45 mmHg was significantly higher than group 2 (p = 0.002). Mean SNP infusion rate and mean isoflurane concentration during the rewarming period were calculated as 1.55 +/- 0.8 micrograms/kg/min and 0.775 +/- 0.27%, respectively. CONCLUSIONS: Isoflurane produced more stable hemodynamic conditions than SNP during the rewarming period, improved the uniformity of rewarming, and permitted earlier extubation in the intensive care unit (ICU). It is concluded that isoflurane alone is capable of fulfilling the anesthesia needs during hypothermia and the rewarming period of CPB.

Comparison of pressure- and flow-triggered pressure-support ventilation on weaning parameters in patients recovering from acute respiratory failure.

OBJECTIVE: To compare the effects of pressure- and flow-triggered pressure-support ventilation on weaning parameters during recovery from acute respiratory failure. DESIGN: Prospective, randomized, clinical trial. SETTING: Intensive care unit in a university hospital. PATIENTS: Sixteen orotracheally intubated adult patients recovering from acute respiratory failure of various etiologies, without chronic obstructive pulmonary disease. INTERVENTIONS: Randomized application of pressure- and flow-triggered pressure-support ventilation at 100% and 75% ventilatory support levels in each triggering system. A total of four conditions were applied for 30 mins each in all patients. MEASUREMENTS AND MAIN RESULTS: Ventilatory, respiratory, and hemodynamic data were measured. For the measurement of weaning parameters, pressure and volume signals were directed to a computerized respiratory monitor by means of an esophageal probe and a flow sensor between the "Y" piece of the ventilatory circuit and the endotracheal tube. During both pressure-triggered (trigger sensitivity of -1 cm H2O) and flow-triggered (trigger sensitivity of 0.7 to 2.0 L/min) pressure-support ventilation with a ventilator, peak airway pressures were applied so as to decrease the work of breathing performed by the patient to zero (full ventilatory support). Partial ventilatory support was applied at 75% of the peak airway pressures achieved during full ventilatory support with each triggering system. A total of four experimental conditions were evaluated at identical FiO2 and positive and-expiratory pressure levels during pressure-support ventilation in each patient. Total ventilation volumes, arterial blood gas data, and hemodynamics did not differ among the four experimental conditions. During partial ventilatory support, the work of breathing, rapid shallow breathing index, and esophageal pressure increased significantly with both triggering systems when compared with data obtained at full ventilatory support. The mean data for the weaning parameters during the condition of partial ventilatory support were comparable between pressure- and flow-triggered pressure-support ventilation (i.e., 0.38 +/- 0.24 vs. 0.42 +/- 0.26 joule/L for work of breathing, 2.6 +/- 1.6 vs. 3.3 +/- 1.7 cm H2O for tracheal occlusion pressure, and 40.2 +/- 12.9 vs. 50.4 +/- 18.3 breaths/min/L for rapid shallow breathing index, respectively). CONCLUSIONS: The application of either a pressure- or flow-triggered system during pressure-support ventilation with the ventilator did not significantly affect short-term changes in gas exchange, respiratory mechanics, and inspiratory workload in patients recovering from acute respiratory failure of various etiologies without chronic obstructive pulmonary disease.