Ultrasound-guided pericapsular nerve group and obturator nerve phenol neurolysis for refractory inpatient hip cancer metastasis pain: a case report

Abstract Introduction: Bone cancer metastasis may produce severe and refractory pain. It is often difficult to manage with systemic analgesics. Chemical neurolysis may be an effective alternative in terminally ill patients. Case report: Female terminally ill patient with hip metastasis of gastric cancer in severe pain. Neurolytic ultrasound-guided blocks of the pericapsular nerve group and obturator nerve were performed with 5% phenol. This led to satisfactory pain relief for 10 days, until the patient's death. Discussion: This approach may be effective and safe as an analgesic option for refractory hip pain due to metastasis or pathologic fracture in terminally ill patients.

Strategy for Calculating Magnesium Sulfate Dose in Obese Patients: A Randomized Blinded Trial.

Background: Magnesium sulfate has analgesic properties during the postoperative period. However, there is a knowledge gap in pharmacology related to the use of the real, ideal, or corrected ideal body weight to calculate its dose in obese patients. This trial compared postoperative analgesia using actual and corrected ideal body weight. Methods: Seventy-five obese patients scheduled to undergo laparoscopic gastroplasty or cholecystectomy under general anesthesia were randomly assigned to three groups. The patients in the control group did not receive magnesium sulfate; the other two groups received magnesium sulfate at 40 mg·kg-1 of actual body weight or corrected ideal body weight. Results: In patients with body mass index >30 mg·kg-2 (mean body mass index ranging from 32.964 kg·m-2 to 33.985 kg·m-2, according to the groups) scheduled for video laparoscopic cholecystectomy, there were no differences in the blood magnesium concentrations in the groups receiving magnesium sulfate throughout the study, regardless of whether the strategy to calculate its dose was based on total or corrected ideal body weight. Patients in the groups receiving magnesium sulfate showed a significant reduction in morphine consumption (p ≤ 0.001) and pain scores (p=0.006) in the postoperative period compared to those in the control group. There were no significant differences in morphine consumption (p=0.323) or pain scores (p=0.082) between the two groups receiving magnesium sulfate. There were no differences in the total duration of neuromuscular block induced by cisatracurium among the three groups (p=0.181). Conclusions: Magnesium sulfate decreased postoperative pain and morphine consumption without affecting the recovery time of cisatracurium in obese patients undergoing laparoscopic cholecystectomy. Strategies to calculate the dose based on the actual or corrected ideal body weight had similar outcomes related to analgesia and the resulting blood magnesium concentration. However, as the sample in this trial presented body mass indices ranging from 30.11 kg·m-2 to 47.11 kg/m-2, further studies are needed to confirm these findings in more obese patients, easily found in centers specialized.

Phrenic Nerve Block and Respiratory Effort in Pigs and Critically Ill Patients with Acute Lung Injury.

BACKGROUND: Strong spontaneous inspiratory efforts can be difficult to control and prohibit protective mechanical ventilation. Instead of using deep sedation and neuromuscular blockade, the authors hypothesized that perineural administration of lidocaine around the phrenic nerve would reduce tidal volume (VT) and peak transpulmonary pressure in spontaneously breathing patients with acute respiratory distress syndrome. METHODS: An established animal model of acute respiratory distress syndrome with six female pigs was used in a proof-of-concept study. The authors then evaluated this technique in nine mechanically ventilated patients under pressure support exhibiting driving pressure greater than 15 cm H2O or VT greater than 10 ml/kg of predicted body weight. Esophageal and transpulmonary pressures, electrical activity of the diaphragm, and electrical impedance tomography were measured in pigs and patients. Ultrasound imaging and a nerve stimulator were used to identify the phrenic nerve, and perineural lidocaine was administered sequentially around the left and right phrenic nerves. RESULTS: Results are presented as median [interquartile range, 25th to 75th percentiles]. In pigs, VT decreased from 7.4 ml/kg [7.2 to 8.4] to 5.9 ml/kg [5.5 to 6.6] (P < 0.001), as did peak transpulmonary pressure (25.8 cm H2O [20.2 to 27.2] to 17.7 cm H2O [13.8 to 18.8]; P < 0.001) and driving pressure (28.7 cm H2O [20.4 to 30.8] to 19.4 cm H2O [15.2 to 22.9]; P < 0.001). Ventilation in the most dependent part decreased from 29.3% [26.4 to 29.5] to 20.1% [15.3 to 20.8] (P < 0.001). In patients, VT decreased (8.2 ml/ kg [7.9 to 11.1] to 6.0 ml/ kg [5.7 to 6.7]; P < 0.001), as did driving pressure (24.7 cm H2O [20.4 to 34.5] to 18.4 cm H2O [16.8 to 20.7]; P < 0.001). Esophageal pressure, peak transpulmonary pressure, and electrical activity of the diaphragm also decreased. Dependent ventilation only slightly decreased from 11.5% [8.5 to 12.6] to 7.9% [5.3 to 8.6] (P = 0.005). Respiratory rate did not vary. Variables recovered 1 to 12.7 h [6.7 to 13.7] after phrenic nerve block. CONCLUSIONS: Phrenic nerve block is feasible, lasts around 12 h, and reduces VT and driving pressure without changing respiratory rate in patients under assisted ventilation.

Analgesic effect of magnesium sulfate during total intravenous anesthesia: randomized clinical study.

INTRODUCTION AND OBJECTIVE: Opioids have usually been used as intraoperative analgesic components, regardless of the many adverse effects they are associated with, such as nausea, vomiting, respiratory depression, and hyperalgesia. Several approaches have been investigated to reduce doses used, and magnesium sulfate has been shown to be a valuable analgesic adjunct. The main objective of the present trial was to evaluate the effectiveness of magnesium sulfate as the chief intraoperative analgesic, and the secondary objectives were to assess propofol consumption, postoperative analgesia, and intraoperative hemodynamic stability. METHODS: In this prospective, double-blind trial, 50 patients scheduled to undergo post-bariatric abdominoplasty under general intravenous anesthesia were divided into two groups, to receive remifentanil or magnesium sulfate as intraoperative analgesic. Fentanyl 1 µg kg-1 was the rescue analgesic. RESULTS: Among the patients in the group receiving Magnesium Sulfate (MSG), 64% did not need supplemental analgesia and none of the patients in the Remifentanil Group (RG) required fentanyl. MSG patients showed propofol consumption 36.6% higher (guided by the Bispectral Index - BIS). MSG patients consumed significantly less ephedrine (mean ± SD) than RG patients, respectively 1.52 ± 4.38 mg and 10 ± 10.39 mg, p < 0.001. Mean values of blood concentrations of magnesium were comparable to values previously described in the literature. CONCLUSION: Magnesium sulfate is a safe and effective option for intraoperative analgesia, when avoiding or decreasing opioid use is required.

Ultrasound-guided pericapsular nerve group and obturator nerve phenol neurolysis for refractory inpatient hip cancer metastasis pain: a case report.

INTRODUCTION: Bone cancer metastasis may produce severe and refractory pain. It is often difficult to manage with systemic analgesics. Chemical neurolysis may be an effective alternative in terminally ill patients. CASE REPORT: Female terminally ill patient with hip metastasis of gastric cancer in severe pain. Neurolytic ultrasound-guided blocks of the pericapsular nerve group and obturator nerve were performed with 5% phenol. This led to satisfactory pain relief for 10 days, until the patient's death. DISCUSSION: This approach may be effective and safe as an analgesic option for refractory hip pain due to metastasis or pathologic fracture in terminally ill patients.

Intraoperative Methadone Reduces Pain and Opioid Consumption in Acute Postoperative Pain: A Systematic Review and Meta-analysis.

BACKGROUND: Methadone is a potent opioid exerting an analgesic effect through N-methyl-D-aspartate receptor antagonism and the inhibition of serotonin and noradrenaline reuptake. It has also been used in several procedures to reduce postoperative pain and opioid use. This meta-analysis aimed to determine whether the intraoperative use of methadone lowers postoperative pain scores and opioid consumption in comparison to other opioids. METHODS: Double-blinded, controlled trials without language restrictions were included from MEDLINE, Embase, LILACS, The Cochrane Central Register of Controlled Trials (CENTRAL), and CINAHL via EBSCOhost. The included studies tracked total opioid consumption, postoperative pain scores, opioid-related side effects, and patient satisfaction until 72 hours postoperatively. Mean difference (MD) was used for effect size. RESULTS: In total, 476 articles were identified and 13 were considered eligible for inclusion in the meta-analysis. In 486 patients (7 trials), pain at rest (MD, 1.09; 95% confidence interval (CI), 1.47-0.72; P < .00001) and at movement (MD, 2.48; 95% CI, 3.04-1.92; P = .00001) favored methadone 24 hours after surgery. In 374 patients (6 trials), pain at rest (MD, 1.47; 95% CI, 3.04-1.02; P < .00001) and at movement (MD, 2.03; 95% CI, 3.04-1.02; P < .00001) favored methadone 48 hours after surgery. In 320 patients (4 trials), pain at rest (MD, 1.02; 95% CI, 1.65-0.39; P = .001) and at movement (MD, 1.34; 95% CI, 1.82-0.87; P < .00001) favored methadone 72 hours after surgery. A Trial Sequential Analysis was performed and the Z-cumulative curve for methadone crossed the monitoring boundary at all evaluations, additionally crossing Required Information Size at 24 and 48 hours at rest. Methadone group also showed lower postoperative opioid consumption in morphine equivalent dosage (mg) at 24 hours (MD, 8.42; 95% CI, 12.99-3.84 lower; P < .00001), 24-48 hours (MD, 14.33; 95% CI, 26.96-1.91 lower; P < .00001), 48-72 hours (MD, 3.59; 95% CI, 6.18-1.0 lower; P = .007) postoperatively. CONCLUSIONS: Intraoperative use of methadone reduced postoperative pain scores compared to other opioids, and Trial Sequential Analysis suggested that no more trials are required to confirm pain reduction at rest until 48 hours after surgery. Methadone also reduced postoperative opioid consumption and led to better patient satisfaction scores through 72 hours postoperatively compared to other opioids.

Individual Positive End-expiratory Pressure Settings Optimize Intraoperative Mechanical Ventilation and Reduce Postoperative Atelectasis.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: Intraoperative lung-protective ventilation has been recommended to reduce postoperative pulmonary complications after abdominal surgery. Although the protective role of a more physiologic tidal volume has been established, the added protection afforded by positive end-expiratory pressure (PEEP) remains uncertain. The authors hypothesized that a low fixed PEEP might not fit all patients and that an individually titrated PEEP during anesthesia might improve lung function during and after surgery. METHODS: Forty patients were studied in the operating room (20 laparoscopic and 20 open-abdominal). They underwent elective abdominal surgery and were randomized to institutional PEEP (4 cm H2O) or electrical impedance tomography-guided PEEP (applied after recruitment maneuvers and targeted at minimizing lung collapse and hyperdistension, simultaneously). Patients were extubated without changing selected PEEP or fractional inspired oxygen tension while under anesthesia and submitted to chest computed tomography after extubation. Our primary goal was to individually identify the electrical impedance tomography-guided PEEP value producing the best compromise of lung collapse and hyperdistention. RESULTS: Electrical impedance tomography-guided PEEP varied markedly across individuals (median, 12 cm H2O; range, 6 to 16 cm H2O; 95% CI, 10-14). Compared with PEEP of 4 cm H2O, patients randomized to the electrical impedance tomography-guided strategy had less postoperative atelectasis (6.2 ± 4.1 vs. 10.8 ± 7.1% of lung tissue mass; P = 0.017) and lower intraoperative driving pressures (mean values during surgery of 8.0 ± 1.7 vs. 11.6 ± 3.8 cm H2O; P < 0.001). The electrical impedance tomography-guided PEEP arm had higher intraoperative oxygenation (435 ± 62 vs. 266 ± 76 mmHg for laparoscopic group; P < 0.001), while presenting equivalent hemodynamics (mean arterial pressure during surgery of 80 ± 14 vs. 78 ± 15 mmHg; P = 0.821). CONCLUSIONS: PEEP requirements vary widely among patients receiving protective tidal volumes during anesthesia for abdominal surgery. Individualized PEEP settings could reduce postoperative atelectasis (measured by computed tomography) while improving intraoperative oxygenation and driving pressures, causing minimum side effects.

Predictors of major complications after elective abdominal surgery in cancer patients.

BACKGROUND: Patients undergoing abdominal surgery for solid tumours frequently develop major postoperative complications, which negatively affect quality of life, costs of care and survival. Few studies have identified the determinants of perioperative complications in this group. METHODS: We performed a prospective observational study including all patients (age > 18) undergoing abdominal surgery for cancer at a single institution between June 2011 and August 2013. Patients undergoing emergency surgery, palliative procedures, or participating in other studies were excluded. Primary outcome was a composite of 30-day all-cause mortality and infectious, cardiovascular, respiratory, neurologic, renal and surgical complications. Univariate and multiple logistic regression analyses were performed to identify predictive factors for major perioperative adverse events. RESULTS: Of a total 308 included patients, 106 (34.4%) developed a major complication during the 30-day follow-up period. Independent predictors of postoperative major complications were: age (odds ratio [OR] 1.03 [95% CI 1.01-1.06], p = 0.012 per year), ASA (American Society of Anesthesiologists) physical status greater than or equal to 3 (OR 2.61 [95% CI 1.33-5.17], p = 0.003), a preoperative haemoglobin level lower than 12 g/dL (OR 2.13 [95% CI 1.21-4.07], p = 0.014), intraoperative use of colloids (OR 1.89, [95% CI 1.03-4.07], p = 0.047), total amount of intravenous fluids (OR 1.22 [95% CI 0.98-1.59], p = 0.106 per litre), intraoperative blood losses greater than 500 mL (2.07 [95% CI 1.00-4.31], p = 0.043), and hypotension needing vasopressor support (OR 4.68 [95% CI 1.55-27.72], p = 0.004). The model had good discrimination with the area under the ROC curve being 0.80 (95% CI 0.75-0.84, p < 0.001). CONCLUSIONS: Our findings suggest that a perioperative strategy aimed at reducing perioperative complications in cancer surgery should include treatment of preoperative anaemia and an optimal fluid strategy, avoiding fluid overload and intraoperative use of colloids.

Smartphone-based behavioural intervention alleviates children's anxiety during anaesthesia induction: A randomised controlled trial.

BACKGROUND: Preoperative anxiety negatively influences children's anaesthetic and surgical experience, and results in postoperative complications, such as emergence delirium and behavioural changes. Nonpharmacological management using alternative therapies that alleviate psychological stress can be as important as pharmacological ones in reducing children's anxiety. Nevertheless, their validity as an effective anxiety-reducing strategy in children remains controversial. OBJECTIVE(S): To verify whether nonpharmacological strategies, that is, leaflet and distraction with smartphone application presented to parents/guardians and children, respectively, were effective in preventing children's anxiety during anaesthesia induction. DESIGN: Randomised clinical trial. SETTING: A tertiary care teaching hospital. PATIENTS: In total, 84 children (aged 4 to 8 years; American Society of Anesthesiologists I and II) undergoing minor-to-moderate elective surgical procedures and their parents/guardians. INTERVENTIONS: Children were randomised into four groups: control group, in which the parent/guardian was verbally informed about the anaesthetic procedure; the informed group, in which the parent/guardian was also provided with an information leaflet about the anaesthetic procedure; the smartphone group, in which the parent/guardian was verbally informed and the child received a smartphone application to play with while in the holding area before entering the operating room and the smartphone and informed group, in which the parent/guardian also received an information leaflet and the child, a smartphone application to play with while in the holding area before entering the operating room. MAIN OUTCOME MEASURES: Children's anxiety at two time points: in the holding area of the surgical centre and in the operating room during induction of anaesthesia by facemask. RESULTS: Median (IQR) anxiety levels were greater at time point operating room for children in the control group (55.0; range: 30.0 to 68.4) than in the other groups: informed group, 28.4 (23.4 to 45.0); smartphone group, 23.4 (23.4 to 30.0); smartphone and informed group, 23.4 (23.4 to 25.9). CONCLUSION: The behavioural distraction strategies using smartphones were effective in preventing an increase in children's anxiety during anaesthesia induction. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT02246062.

Duloxetine as an Analgesic Reduces Opioid Consumption After Spine Surgery: A Randomized, Double-Blind, Controlled Study.

OBJECTIVES: Multimodal analgesia is widely advocated for the control of perioperative pain in an effort to reduce the use of opioid. Duloxetine is a selective inhibitor of serotonin and norepinephrine reuptake with efficacy for chronic pain conditions. The primary objective of this study was to evaluate the efficacy of two 60 mg oral doses of duloxetine in terms of fentanyl consumption during the postoperative period in patients undergoing elective spine surgery. MATERIALS AND METHODS: This study was prospective, double-blind, randomized, and placebo controlled. Patients received either 60 mg duloxetine or an identical placebo 1 hour before surgery and again the following morning. The study participants were allocated into 2 groups: Group C (control) participants received the placebo and Group D (duloxetine) participants received 60 mg duloxetine. The total consumption of fentanyl 48 hours after surgery was measured. Secondary end points were pain scores and the presence or absence of adverse effects, such as headache, nausea, vomiting, itching, dizziness, and drowsiness. RESULTS: Demographic characteristics did not differ between groups. There was a significant difference in fentanyl consumption in the first 24 hours between Groups C and D (mean difference, 223.11±39.32 µg; P<0.001). Fentanyl consumption also differed between Groups C and D after 48 hours (mean difference, 179.35±32.55 µg; P<0.000). The pain scores over 48 hours did not significantly differ between groups. The incidence of side-effects was similar in both groups. DISCUSSION: Duloxetine was effective as an adjunct for postoperative analgesia and reduced opioid consumption.

Estudo retrospectivo do tratamento clínico da úlcera indolente em cães da raça Boxer / Retrospective study on clinical management of indolent ulcers in Boxer dogs

Indolent ulcers are superficial corneal ulcers secondary to several changes on the corneal surface. They are frequently observed in middle-aged Boxer dogs, cause pain of acute onset and requires appropriate treatment. Aiming to evaluate the efficacy of clinical managements on the rate of healing of indolent ulcers, a retrospective study was conducted (1997-2008). Results demonstrated that proteinase inhibitors were the most often prescribed medication, and its administration did not interfere on the healing rate, as well as observed in dogs that received 1 percent atropine, antibiotics and anti-inflammatory drugs. Healing was delayed in dogs administered orally with vitamin C, but the healing process was faster on those dogs that went through corneal debridement/cauterization. In conclusion, to know the various types of treatments seems to be fundamental for the rapid resolution of the disease. It is suggested that debridement/cauterization, administration of proteinase inhibitor eye drops, prophylactic topical antibiotics and oral vitamin C, should be considered as an effective clinical management for indolent ulcers in Boxer dogs.

Úlceras indolentes são úlceras corneais superficiais e espontâneas, que apresentam curso prolongado e que tendem a recidivar. Comumente observadas em cães de meia idade da raça Boxer, provoca dor de início agudo e necessita de tratamento específico, já que este, quando não realizado corretamente, pode prolongar o curso da lesão por semanas a meses. Com o objetivo de avaliar a eficácia dos tratamentos clínicos quanto à rapidez na resolução do quadro, realizou-se estudo retrospectivo (1997 a 2008). Observou-se que os inibidores das proteinases foram as medicações mais frequentemente prescritas e que sua administração não interferiu no tempo de cicatrização corneal, o que também foi observado nos casos em que se administrou antibióticos e antinflamatórios tópicos e sistêmicos e/ou atropina 1 por cento. A administração de vitamina C retardou, de maneira estatisticamente significante, o tempo de cicatrização. Por outro lado, a realização do debridamento/cauterização corneal acelerou, significativamente, o processo. Conhecer os diversos tipos de tratamentos parece ser fundamental no sucesso e rapidez da resolução da doença. Os autores sugerem que a realização do debridamento/cauterização corneal, administração de inibidores das proteinases e antibióticos tópicos, associados à vitamina C por via oral, seja considerado um tratamento clínico efetivo na rápida resolução da doença.

What rules of thumb do clinicians use to decide whether to antagonize nondepolarizing neuromuscular blocking drugs?

BACKGROUND: In anesthesia practice, inadequate antagonism of neuromuscular blocking drugs (NMBD) may lead to frequent prevalence of residual neuromuscular block that is associated with morbidity and death. In this study we analyzed the clinical decision on antagonizing NMBD to generate hypotheses about barriers to the introduction of experts' recommendations into clinical practice. METHODS: Sequential surveys were conducted among 108 clinical anesthesiologists to elicit the rules of thumb (heuristics) that support their decisions and provide a measurement of the confidence the clinicians have in their own decisions in comparison with their peers' decisions. RESULTS: The 2 most frequently used heuristics for administering reversal were "the interval since the last NMBD dose was short" and "the breathing pattern is inadequate," chosen by 73% and 71% of the clinicians, respectively. Clinicians considered that the prevalence of clinically significant residual block is higher in their colleagues' practices than in their own practice (60% vs 16%, odds ratio=7.8, 95% confidence interval, 3.8 to 16.2, P=0.0001). The clinicians were less likely to use antagonists if >60 minutes had elapsed after a single dose of atracurium (0.5 mg/kg) (31%) in comparison with after rocuronium 0.6 mg/kg (53%) (P=0.0035). CONCLUSIONS: In our institution, the clinical decision to antagonize NMBD is mainly based on the pharmacological forecast and a qualitative judgment of the adequacy of the breathing pattern. Clinicians judge themselves as better skilled at avoiding residual block than they do their colleagues, making them overconfident in their capacity to estimate the duration of action of intermediate-acting NMBD. Awareness of these systematic errors related to clinical intuition may facilitate the adoption of experts' recommendations into clinical practice.

Non-asthmatic patients show increased exhaled nitric oxide concentrations.

OBJECTIVE: Evaluate whether exhaled nitric oxide may serve as a marker of intraoperative bronchospasm. INTRODUCTION: Intraoperative bronchospasm remains a challenging event during anesthesia. Previous studies in asthmatic patients suggest that exhaled nitric oxide may represent a noninvasive measure of airway inflammation. METHODS: A total of 146,358 anesthesia information forms, which were received during the period from 1999 to 2004, were reviewed. Bronchospasm was registered on 863 forms. From those, three groups were identified: 9 non-asthmatic patients (Bronchospasm group), 12 asthmatics (Asthma group) and 10 subjects with no previous airway disease or symptoms (Control group). All subjects were submitted to exhaled nitric oxide measurements (parts/billion), spirometry and the induced sputum test. The data was compared by ANOVA followed by the Tukey test and Kruskal-Wallis followed by Dunn's test. RESULTS: The normal lung function test results for the Bronchospasm group were different from those of the asthma group (p <0.05). The median percentage of eosinophils in induced sputum was higher for the Asthma [2.46 (0.45-6.83)] compared with either the Bronchospasm [0.55 (0-1.26)] or the Control group [0.0 (0)] (p <0.05); exhaled nitric oxide followed a similar pattern for the Asthma [81.55 (57.6-86.85)], Bronchospasm [46.2 (42.0 -62.6] and Control group [18.7 (16.0-24.7)] (p< 0.05). CONCLUSIONS: Non-asthmatic patients with intraoperative bronchospasm detected during anesthesia and endotracheal intubation showed increased expired nitric oxide.

Non-asthmatic patients show increased exhaled nitric oxide concentrations

OBJECTIVE: Evaluate whether exhaled nitric oxide may serve as a marker of intraoperative bronchospasm. INTRODUCTION: Intraoperative bronchospasm remains a challenging event during anesthesia. Previous studies in asthmatic patients suggest that exhaled nitric oxide may represent a noninvasive measure of airway inflammation. METHODS: A total of 146,358 anesthesia information forms, which were received during the period from 1999 to 2004, were reviewed. Bronchospasm was registered on 863 forms. From those, three groups were identified: 9 non-asthmatic patients (Bronchospasm group), 12 asthmatics (Asthma group) and 10 subjects with no previous airway disease or symptoms (Control group). All subjects were submitted to exhaled nitric oxide measurements (parts/billion), spirometry and the induced sputum test. The data was compared by ANOVA followed by the Tukey test and Kruskal-Wallis followed by Dunn's test. RESULTS: The normal lung function test results for the Bronchospasm group were different from those of the asthma group (p <0.05). The median percentage of eosinophils in induced sputum was higher for the Asthma [2.46 (0.45-6.83)] compared with either the Bronchospasm [0.55 (0-1.26)] or the Control group [0.0 (0)] (p <0.05); exhaled nitric oxide followed a similar pattern for the Asthma [81.55 (57.6-86.85)], Bronchospasm [46.2 (42.0 -62.6] and Control group [18.7 (16.0-24.7)] (p< 0.05). CONCLUSIONS: Non-asthmatic patients with intraoperative bronchospasm detected during anesthesia and endotracheal intubation showed increased expired nitric oxide.

Sputum induction as a research tool for the study of human respiratory mucus.

The study objectives were to compare in vitro transportability and physical properties of respiratory mucus, obtained invasively by direct collection (DC) right after endotracheal intubation and non-invasively by sputum induction with 3% hypertonic saline solution inhalation (SI) 24 h before the anesthesia. Twenty-two patients with no pulmonary disease scheduled for elective abdominal surgical procedures were studied. The parameters analyzed and the main results are as follows. (1) Transportability by cilia (MCT), SI was higher than DC (0.94+/-0.25 and 0.62+/-0.25; P<0.001). There was a significant correlation between the two methods and DC could be estimated by: DC=0.21+(0.44 SI) (r=0.44; P<0.001). (2) Transportability by cough (CC), SI was higher than DC (68.23+/-32.1 and 33.58+/-19.04 mm; P=0.002). (3) Contact angle (CA), SI was lower than DC (10+/-3 degrees and 22+/-14 degrees ; P=0.025). (4) Rheological properties (no significant difference obtained between SI and DC). These results indicated that SI changes mucus physical properties and transportability in non-expectorators.

Guidelines for inspiratory flow setting when measuring the pressure-volume relationship.

UNLABELLED: Acquisition of pressure-volume (PV) curves to improve ventilation strategy is time consuming when using static methods. Low-flow techniques use less time, but compliance values can be decreased by the resistance to flow in airways and tracheal tube (P-t). In this study, we determined the impact of three flows on the resistive component of airway pressure during anesthesia. We studied 10 ASA status P1/P2 patients with normal respiratory function. Airway and esophageal pressures were measured while volume-control ventilated with 6, 12, and 30 L/min continuous flows. PV curves, lower inflection point, respiratory system, and chest wall compliances at 250, 500, 750, and 1000 mL tidal volume were established before and after removing P-t. Data were submitted to analysis of variance. The inflection point was lower for the lower flow when comparing 6 and 12 with 30 L/min (P < 0.001). No difference was found between 6 and 12 L/min. Removal of P-t showed a difference only for 30 L/min (P = 0.004). Higher flows generated lower compliances. P-t subtraction reduced compliances only for 30 L/min. Chest wall compliances showed no difference between flows. We concluded that flows < or =12 L/min minimize P-t during intraoperative PV curves acquisition. Compliances suggest 6 L/min as the most adequate flow. IMPLICATIONS: We suggest guidelines for inspiratory flow setting when measuring the pressure-volume relationship during anesthesia based on the comparison among three different continuous flow values, aiming at better intraoperative respiratory settings in patients with normal respiratory function.