Functional respiratory imaging after neostigmine- or sugammadex-enhanced recovery from neuromuscular blockade in the anesthetised rat: a randomised controlled pilot study / Imagem funcional da respiração após aceleração da recuperação do bloqueio neuromuscular com neostigmina ou sugamadex em ratos anestesiados: estudo piloto controlado e randomizado

Abstract Objectives Reductions in diaphragm activity are associated with the postoperative development of atelectasis. Neostigmine reversal is also associated with increased atelectasis. We assessed the effects of neostigmine, sugammadex, and spontaneous reversal on regional lung ventilation and airway flow. Methods Six Sprague-Dawley rats were paralysed with rocuronium and mechanically ventilated until recovery of the train-of-four ratio to 0.5. We administered neostigmine (0.06 mg.kg-1), sugammadex (15 mg.kg-1), or saline (n = 2 per group). Computed tomography scans were obtained during the breathing cycle. Three-dimensional models of lung lobes were generated using functional respiratory imaging technology, and lobar volumes were calculated during the breathing cycle. The diaphragmatic surface was segmented for the end-expiratory and end-inspiratory scans. The total change in volume was reported by the lung volume change from the end-expiratory scan to the end-inspiratory scan. Chest wall movement was defined as the lung volume change minus the volume change that resulted from diaphragm excursion. Results The two rats that received neostigmine exhibited a smaller relative contribution of diaphragm movement to the total change in lung volume compared with the two rats that received sugammadex or saline (chest wall contribution (%): 26.69 and 25.55 for neostigmine; -2.77 and 15.98 for sugammadex; 18.82 and 10.30 for saline). Conclusion This pilot study in rats demonstrated an increased relative contribution of chest wall expansion after neostigmine compared with sugammadex or saline. This smaller relative contribution of diaphragm movement may be explained by a neostigmine-induced decrease in phrenic nerve activity or by remaining occupied acetylcholine receptors after neostigmine.

Resumo Objetivos As reduções da atividade do diafragma estão associadas ao desenvolvimento de atelectasia no período pós-operatório. A reversão com neostigmina também está associada ao aumento de atelectasia. Avaliamos os efeitos de neostigmina, sugamadex e da reversão espontânea sobre a ventilação pulmonar regional e o fluxo aéreo. Métodos Seis ratos Sprague-Dawley foram paralisados com rocurônio e mecanicamente ventilados até a recuperação da sequência de quatro estímulos atingir relação 0,5. Administramos neostigmina (0,06 mg.kg-1), sugamadex (15 mg.kg-1) ou solução salina (n = 2 por grupo). As tomografias foram feitas durante o ciclo respiratório. Modelos tridimensionais dos lobos pulmonares foram gerados com a tecnologia de imagem funcional respiratória e os volumes lobares foram calculados durante o ciclo respiratório. A superfície diafragmática foi segmentada para as varreduras expiratória final e inspiratória final. A alteração total no volume foi relatada pela alteração do volume pulmonar da varredura expiratória final para a varredura inspiratória final. O movimento da parede torácica foi definido como a variação do volume pulmonar menos a alteração no volume resultante da excursão do diafragma. Resultados Os dois ratos que receberam neostigmina apresentaram uma contribuição relativa menor do movimento do diafragma para a alteração total do volume pulmonar em comparação com os dois ratos que receberam sugamadex ou solução salina (contribuição da parede torácica (%): 26,69 e 25,55 para neostigmina; -2,77 e 15,98 para sugamadex; 18,82 e 10,30 para solução salina). Conclusão Este estudo piloto com ratos demonstrou uma contribuição relativa aumentada de expansão da parede torácica após neostigmina em comparação com sugamadex ou solução salina. Essa contribuição relativa menor de movimento do diafragma pode ser explicada por uma redução induzida por neostigmina na atividade do nervo frênico ou por receptores de acetilcolina permanecerem ocupados após a administração de neostigmina.

Evaluation of hemodynamic effects of xenon in dogs undergoing hemorrhagic shock

OBJECTIVES: The anesthetic gas xenon is reported to preserve hemodynamic stability during general anesthesia. However, the effects of the gas during shock are unclear. The objective of this study was to evaluate the effect of Xe on hemodynamic stability and tissue perfusion in a canine model of hemorrhagic shock. METHOD: Twenty-six dogs, mechanically ventilated with a fraction of inspired oxygen of 21% and anesthetized with etomidate and vecuronium, were randomized into Xenon (Xe; n = 13) or Control (C; n = 13) groups. Following hemodynamic monitoring, a pressure-driven shock was induced to reach an arterial pressure of 40 mmHg. Hemodynamic data and blood samples were collected prior to bleeding, immediately after bleeding and 5, 20 and 40 minutes following shock. The Xe group was treated with 79% Xe diluted in ambient air, inhaled for 20 minutes after shock. RESULT: The mean bleeding volume was 44 mL.kg-1 in the C group and 40 mL.kg-1 in the Xe group. Hemorrhage promoted a decrease in both the cardiac index (p<0.001) and mean arterial pressure (p<0.001). These changes were associated with an increase in lactate levels and worsening of oxygen transport variables in both groups (p<0.05). Inhalation of xenon did not cause further worsening of hemodynamics or tissue perfusion markers. CONCLUSIONS: Xenon did not alter hemodynamic stability or tissue perfusion in an experimentally controlled hemorrhagic shock model. However, further studies are necessary to validate this drug in other contexts.

Analgesic effect of ketamine and morphine after tonsillectomy in children

A comparative double blind study of Ketamine and Morphine was conducted on eighty children following tonsillectomy to assess the analgesic, respiratory rate depressant and emesis. Children [6-12 years] were divided into two groups randomly [n=40]. General anesthesia was induced followed by 0.1mg/kg morphine [I/M] and 0.5mg/kg ketamine [I/M] to Group I and Group II respectively before the initiation of surgical procedure. Pain scores [face score and CHEOPS score] were estimated for children at thirty, sixty, one hundred and twenty and two hundred and forty minutes following surgery. Comparison of CHEOPS score estimation reflected that pain scores were statistically significant [P < 0.05] in Group I receiving Morphine as compared to Group II who received Ketamine. The analgesic effect of ketamine and morphine showed statistically insignificant results [P>0.05] in case of face score. Moreover, respiratory rate in Group I had shown statistical association [p<0.05] as compared to the ketamine at 60 and 120 minutes. Furthermore, incidence of vomiting was more in Group I [0.05] as compared to Group II. It can be concluded from the study that ketamine may be used as a suitable substitute to that of morphine in children undergoing tonsillectomy

Effect of buteyko breathing technique on patients with bronchial asthma

A new dawn is emerging by recognizing that correct breathing volume is fundamental to maintaining good health, the new beginning is based on the life's work of Russian scientist professor Konstantin Buteyko. The Buteyko breathing technique method as suggested by Professor Buteyko helps to decrease the number and severity of attacks as well as the dosage of medication. As a result of this therapy, the indicators of acid-alkali balance and lung ventilation improved. The aim of this study was to assess the effect of Buteyko breathing technique on patients with bronchial asthma. Forty patients with bronchial asthma participated in this study, their age ranged between 30 and 50 years. They were divided into two equal groups, group [A] received Buteyko breathing technique [BBT], and the medications prescribed by the physician, while group, [B] did not perform any physical therapy program just their medications prescribed by the physician. The program continued for 6 weeks [2 sessions per week except the 1st week was 4 sessions per week]. Peak expiratory flow rates [PEFR], Control pause test and asthma daily symptoms [asthma control questionnaire] were measured at the beginning and after the treatment program for both groups. Revealed a significant decrease in asthma daily symptoms, a significant improvement in PEFR, and Control pause test in group [A], while there was insignificant change in group [B]. It can be concluded that BBT produce a significant improvement for patients with bronchial asthma as regard daily symptoms, PEFR and Control pause test

Efeito do broncodilatador no tempo de apneia voluntária máxima em pacientes com distúrbios ventilatórios obstrutivos / Bronchodilator effect on maximal breath-hold time in patients with obstructive lung disease

OBJETIVO: Identificar o papel do broncodilatador no tempo de apneia voluntária máxima em pacientes com distúrbios ventilatórios obstrutivos (DVOs). MÉTODOS: Estudo caso-controle incluindo pacientes com DVOs e grupo controle. Foram realizadas espirometrias antes e após o uso de broncodilatador, assim como testes de apneia respiratória, utilizando-se um microprocessador eletrônico e um pneumotacógrafo como transdutor de fluxo. As curvas de fluxo respiratório foram exibidas em tempo real em um computador portátil, e os tempos de apneia voluntária inspiratória e expiratória máximos (TAVIM e TAVEM, respectivamente) foram determinados a partir do sinal adquirido. RESULTADOS: Um total de 35 pacientes com DVOs e 16 controles foram incluídos no estudo. O TAVIM sem o uso de broncodilatador foi significativamente menor no grupo DVO que no grupo controle (22,27 ± 11,81 s vs. 31,45 ± 15,73; p = 0,025), mas essa diferença não foi significativa após o uso de broncodilatador (24,94 ± 12,89 s vs. 31,67 ± 17,53 s). Os valores de TAVEM foram significativamente menores no grupo DVO que no grupo controle antes (16,88 ± 6,58 s vs. 22,09 ± 7,95 s; p = 0,017) e após o uso de broncodilatador (21,22 ± 9,37 s vs. 28,53 ± 12,46 s; p = 0,024). CONCLUSÕES: Estes resultados fornecem uma evidência adicional da utilidade clínica do teste de apneia na avaliação da função pulmonar e do papel do broncodilatador nesse teste.

OBJECTIVE: To identify the role of bronchodilators in the maximal breath-hold time in patients with obstructive lung disease (OLD). METHODS: We conducted a case-control study including patients with OLD and a control group. Spirometric tests were performed prior to and after the use of a bronchodilator, as were breath-hold tests, using an electronic microprocessor and a pneumotachograph as a flow transducer. Respiratory flow curves were displayed in real time on a portable computer. The maximal breath-hold times at end-inspiratory volume and at end-expiratory volume (BHTmaxV EI and BHTmaxV EE, respectively) were determined from the acquired signal. RESULTS: A total of 35 patients with OLD and 16 controls were included. Prior to the use of a bronchodilator, the BHTmaxV EI was significantly lower in the OLD group than in the control group (22.27 ± 11.81 s vs. 31.45 ± 15.73 s; p = 0.025), although there was no significant difference between the two groups in terms of the post-bronchodilator values (24.94 ± 12.89 s vs. 31.67 ± 17.53 s). In contrast, BHTmaxV EE values were significantly lower in the OLD group than in the control group, in the pre- and post-bronchodilator tests (16.88 ± 6.58 s vs. 22.09 ± 7.95 s; p = 0.017; and 21.22 ± 9.37 s vs. 28.53 ± 12.46 s; p = 0.024, respectively). CONCLUSIONS: Our results provide additional evidence of the clinical usefulness of the breath-hold test in the assessment of pulmonary function and add to the existing knowledge regarding the role of the bronchodilator in this test.

comparison of the sedative, hemodynamic, and respiratory effects of dexmedetomidine and propofol in children undergoing magnetic resonance imaging

To compare the sedative, hemodynamic, and respiratory effects of dexmedetomidine and propofol in children undergoing magnetic resonance imaging procedures. Sixty children between the age of 1 to 7 years were randomly distributed into two groups: The dexmedetomidine [D] group received 1 micro g/kg initial dose followed by continuous infusion of 0.5 micro g/kg/h, and the propofol group [P] received 3 mg/kg initial dose, followed by a continuous infusion of 100 micro g/kg/min. Inadequate sedation was defined as difficulty in completing the procedure because of the child's movement during magnetic resonance imaging. Mean arterial pressure [MAP], heart rate, peripheral oxygen saturation, and respiratory rate [RR] were recorded during the study. Result: The onset of sedation, recovery, and discharge time were significantly shorter in group P than in group D. MAP, heart rate, and RR decreased during sedation from the baseline values in both groups. MAP and RR were significantly lower in group P than in group D during sedation. Dexmedetomidine and propofol provided adequate sedation in most of the children. We conclude that although propofol provided faster anesthetic induction and recovery times, it caused hypotension and desaturation. Dexmedetomidine could be an alternative, reliable sedative drug to propofol in selected patients

Avanços na inaloterapia em pediatria / Advances in inhalation therapy in pediatrics

OBJETIVOS: Revisar os artigos mais relevantes a respeito dos aspectos técnicos da terapêutica inalatória, dos inaladores disponíveis e principalmente dos principais avanços obtidos na inaloterapia em pediatria. FONTES DOS DADOS: Foram revisados os artigos contidos na base de dados MEDLINE a partir de 1983, além de capítulos de livros, e selecionados os de maior importância de acordo com os critérios estabelecidos para este artigo. SÍNTESE DOS DADOS: Os nebulizadores convencionais apresentam uma série de inconveniências, sendo que inaladores com desempenho melhorado pela respiração e os ativados pela respiração são opções mais atrativas. Dentre os inaladores de pó seco, destacam-se os que utilizam mecanismos passivos e ativos de dispersão de pó, que propiciam maiores taxas de deposição pulmonar das drogas. Entre os inaladores pressurizados dosimetrados destacam-se os ativados pela respiração, os coordenados pela respiração e os modificadores de velocidade. Devem ser usados preferencialmente em conjunto com espaçadores, pois a utilização deste aumenta em até duas vezes a deposição pulmonar das drogas. CONCLUSÕES: Para menores de 8 anos, os inaladores pressurizados dosimetrados com espaçadores são os mais adequados, dada a sua praticidade associada à elevada deposição pulmonar que proporcionam. Nos maiores de 8 anos capazes de gerar altos fluxos inspiratórios, os dispositivos de pó são os mais indicados.

OBJECTIVES: To review the most relevant articles regarding the technical aspects of inhalation therapy, inhalers currently available, and especially major advances in inhalation therapy in pediatrics. SOURCES: Articles of MEDLINE database from 1983 were reviewed, in addition to book chapters, and the most important studies were selected according to the criteria established for this article. SUMMARY OF THE FINDINGS: Conventional nebulizers have a number of inconveniences, and breath-enhanced and breath-actuated inhalers are more attractive options. Among dry powder inhalers, we highlight those using passive and active powder dispersion mechanisms, which provide higher rates of drug deposition in the lung. Among pressurized metered-dose inhalers, we highlight breath-actuated, breath-coordinated, and velocity-modifying inhalers. These inhalers should be used preferably together with spacers, since the use of spacers produces a twofold increase in pulmonary drug deposition. CONCLUSIONS: For children younger than 8 years, pressurized metered-dose inhalers with spacers are the most appropriate devices, since they provide a practical approach associated with greater lung deposition. In children older than 8 years who can generate high inspiratory flow rates, dry powder devices are best suited.

Minimum alveolar concentrations and hemodynamic effects of two different preparations of sevoflurane in pigs

BACKGROUND: Original sevoflurane (Sevo A) is made with water, while a generic sevoflurane (Sevocris) is produced with propylene glycol as a stabilizing additive. We investigated whether the original and generic sevoflurane preparations differed in terms of their minimum alveolar concentration (MAC) values and hemodynamic effects. METHODS: Sixteen pigs weighing 31.6±1.8 kg were randomly assigned to the Sevo A or Sevocris groups. After anesthesia induction via mask with the appropriate sevoflurane preparation (6 percent in 100 percent oxygen), the MAC was determined for each animal. Hemodynamic and oxygenation parameters were measured at 0.5 MAC, 1 MAC and 1.5 MAC. Histopathological analyses of lung parenchyma were performed. RESULTS: The MAC in the Sevo A group was 4.4±0.5 percent, and the MAC in the Sevocris group was 4.1±0.7 percent. Hemodynamic and metabolic parameters presented significant differences in a dose-dependent pattern as expected, but they did not differ between groups. Cardiac indices and arterial pressures decreased in both groups when the sevoflurane concentration increased from 0.5 to 1 and 1.5 MAC. The oxygen delivery index (DO2I) decreased significantly at 1.5 MAC. CONCLUSION: Propylene glycol as an additive for sevoflurane seems to be as safe as a water additive, at least in terms of hemodynamic and pulmonary effects.

Midazolam oral como medicação pré-anestésica em blefaroplastias / Oral sedation with midazolam in blepharoplasty

OBJETIVO: Avaliar a eficácia e a segurança do emprego oral de midazolam (15 mg) como medicação pré-anestésica em pacientes submetidos a blefaroplastias. MÉTODOS: Foi desenvolvido um ensaio clínico prospectivo, duplo cego, randomizado, controlado com 42 pacientes, risco ASA I e II, divididos em três grupos de 14 pacientes: grupo M (midazolam 15 mg), grupo P (placebo) e grupo SM (sem medicação). Os pacientes foram avaliados quanto ao grau de sedação e dor intraoperatórias e variação entre os períodos pré e transoperatórios da ansiedade, pressão arterial sistólica e diastólica, frequência respiratória e pulso. RESULTADOS: A análise de variância unifatorial com teste de Tukey mostrou que a administração de midazolam ocasionou uma redução significativa da pressão arterial sistólica e da frequência respiratória no período transoperatório em relação aos pacientes que utilizaram placebo ou não fizeram uso de medicamento. Esses efeitos foram discretos e acompanhados de diminuição na percepção da dor, discreta sedação e redução da ansiedade. CONCLUSÃO: A sedação via oral com midazolam em pacientes submetidos a cirurgias palpebrais demonstrou ser eficiente de fácil aplicação e com mínimos efeitos sistêmicos.

PURPOSE: To evaluate the safety and usefulness of the use of oral sedation with midazolam (15 mg) in patients submitted to blepharoplasty. METHODS: Randomized double-blind prospective study of 42 patients (surgical risk ASA I and II) divided into three groups of 14 patients each: Group M (midazolam 15 mg), group P (placebo) and group SM (no medication). All patients were evaluated according to the degree of sedation and pain during surgery and the variation of anxiety between the preoperative and intraoperative period, arterial pressure (systolic-SAP and diastolic-DAP), respiratory frequency (RF) and pulsation. RESULTS: Unifatorial variance analysis with Tukey test demonstrated that the use of midazolam provoked a significant SAP and RF reduction during the intraoperative period. These effects were not pronounced and were accompanied by a reduction of pain perception and anxiety and mild sedation. CONCLUSIONS: Oral sedation with midazolam in patients that had undergone eyelid surgical procedures is safe and easy to perform with minimal systemic effects.

Vasosensory responses elicited by Indian red scorpion venom last longer than capsaicin-induced responses.

The present study was conducted to compare the time-related cardiorespiratory changes occurring after the injection of Mesobuthus tamulus (BT; 1 mg/kg) venom and capsaicin (1.2 ng/kg) in the peripheral end of femoral artery in urethane anaesthetised rats. Blood pressure (BP), electrocardiogram (for heart rate; HR) and respiratory movements were recorded for 60 min after venom/capsaicin intra-arterially. Minute ventilation (MV) was computed by using appropriate calibrations. After intraarterial injection of BT venom, there was immediate (within 2 sec) increase in respiratory rate (RR) and MV which reached to 40% within 30 sec, followed by a 40% decrease in RR without any change in MV. Further, there was sustained increase in RR (50%) and MV (65%) up to 60 min. The BP began to increase at 40 sec, peaking at 5 min (50%) and remained above the initial level up to 60 min. The bradycardiac response began after 5 min which peaked (50% of the initial) at 25 min and remained at that level up to 60 min. In capsaicin treated group, there was immediate hyperventilatory (increase in RR and MV) changes within 2 sec which returned to the initial level within 2 min and remained at that level up to 60 min. The capsaicin-induced hypotensive response began within 5 sec which returned to the initial level by 5 min and remained at that level throughout. Capsaicin did not produce any change in HR. These observations suggest that intraarterial injection of BT venom produces prolonged cardiorespiratory alterations as compared to the capsaicin-induced responses.

Comparison of oral ketamine and oral midazolam as sedative agents in pediatric dentistry.

The safe and effective treatment of uncooperative or combative preschool children with extensive dental needs is one of pediatric dentist's ongoing challenges. The traditional methods of behavior management are no longer acceptable to parents as they are not ready to spare more time for dental treatment of their children. Keeping this in mind, the present study was designed and carried out to evaluate the sedative effects of oral ketamine and oral midazolam prior to general anesthesia. Twenty uncooperative children in the age-group of 2-6 years were selected after thorough medical examination and investigations. Informed consent was obtained from the parent. This was a randomized double-blind study. An anesthesiologist administered either 0.5 mg/kg midazolam or 5 mg/kg ketamine orally. The heart rate, respiratory rate, and oxygen saturation were recorded at regular intervals. The sedation and anxiolysis scores were also recorded. The parents were asked to answer a questionnaire at the follow-up session the next day on the surgical experience of the parent and the child and side effects experienced, if any. When the data was subjected to statistical analysis, it was observed that both drugs resulted in adequate sedation at the end of 30 min, with oral midazolam providing significantly better anxiolysis. The heart rate and respiratory rate were marginally higher with oral ketamine. The questionnaire revealed a better response with oral midazolam; side effects were more prominent with oral ketamine.

Comparative study between target-controlled-infusion and continuous-infusion anesthesia in dogs treated with methotrimeprazine and treated with propofol and remifentanil

PURPOSE: To compare two propofol infusion techniques in bitches subjected to ovaryhisterectomy by estimating the efficiency of the propofol target-dose, evaluating the cardiorespiratory and hemogasimetric attributes, and the bispectral scale index (BIS) as well as the recovery period characteristics. METHODS: Twenty anesthetized bitches were divided into two groups of 10 each (G1, G2). Animals of G1 were pre-treated with methotrimeprazine and anesthetized with target-controlled propofol infusion by means of a Harvard infusion pump combined to remifentanil through a syringe pump. RESULTS: Bradycardia and light hypotension, hemogasimetric and respiratory stability besides a good myorelaxation, more evident during continuous infusion and good hypnosis. CONCLUSIONS: Dosis used in both techniques, after methotrimeprazine pre-treatment and combined to the opioid, were efficient for the surgery. The target-controlled anesthesia required a smaller anesthetic consumption (propofol) with faster recovery periods.

OBJETIVO: Comparar duas técnicas de infusão de propofol em cadelas submetidas à ovariohisterectomia, estudando a eficácia da dose alvo de propofol, avaliando os atributos cardiorrespiratórios, hemogasométricos e escala do índice bispectral, (BIS) bem como as características do período de recuperação. MÉTODOS: Foram anestesiadas 20 cadelas, distribuídos em dois grupos (GI e GII). Em GI, os animais foram pré-tratados com levomepromazina e anestesiados com propofol por infusão alvo controlada, através de bomba de infusão Harvard pump, associado com remifentanila, através de bomba de seringa. Em GII, os animais receberam o mesmo tratamento de GI, só que ao invés de receberem o propofol por infusão alvo controlada, receberam o propofol em infusão contínua de velocidade fixa. RESULTADOS: Bradicardia e discreta hipotensão, estabilidade hemogasométrica e respiratória, além de um bom miorrelaxamento, mais evidente na infusão contínua e boa hipnose. CONCLUSÕES: As doses de propofol utilizadas em ambas as técnicas, após o pré-tratamento de levomepromazina e associadas ao opióide, foram eficazes para a realização cirúrgica. A técnica de anestesia alvo controlada obteve um menor consumo de anestésico (propofol) com períodos mais rápidos de recuperação.

Comparison of analgesic efficacy of fentanyl and sufentanil for chest tube removal after cardiac surgery.

Chest tube removal in the postcardiac surgical patients is a painful and distressful event. Fentanyl and sufentanil have not been used for pain control during chest tube removal in the postoperative period. We compared efficacy offentanyl and sufentanil in controlling pain due to chest tube removal. One hundred and forty one adult patients undergoing cardiac surgery were recruited in a prospective, randomized, double blind, placebo controlled study. Patients were randomized to receive either 2 microg/Kg fentanyl IV or 0.2 microg/Kg sufentanil IV or 2 ml isotonic normal saline, 10 min before removing chest tubes. Pain intensity was assessed by measuring visual analog scale pain score 10 minutes before removing chest tubes and 5 min and 20 min after removing chest tubes. Level of sedation, heart rate, arterial pressure, oxygen saturation, and respiratory rate were recorded by a blinded observer at the same time intervals. Mean pain intensity scores 10 minutes before removal of chest tubes infentanyl, sufentanil and control groups were 23.88+/-5.2, 25.10+/-5.39 and 23.64+/-6.10 respectively. The pain scores 5 minutes after chest tube removal were reduced to 20.11+/-6.9 (p<0.05) in the fentanyl group and 13.60+/-6.60 (p<0.05) in the sufentanil group, whereas in control group pain scores increased to 27.97+/-8.39 (p<O.05). The pain scores in sufentanil group were significantly lower compared with fentanyl or control group. Sedation scores remained low in all groups and patients remained alert and none of the patients showed any adverse effects of opioids. Heart rate, arterial pressure and respiratory rate had least variations in sufentanil group than fentanyl or control group.

Comparison of sevoflurane and isoflurane in OPCAB surgery.

Maintenance of anaesthesia with volatile anaesthetic agents affects the perioperative course of patients undergoing off-pump coronary artery bypass (OPCAB) surgery. This facilitates adequate depth of anaesthesia, reduction in need of analgesic dosage, early extubation and transfer from Intensive Care Unit. We compared two volatile anaesthetic agents sevoflurane and isoflurane in terms of haemodynamic effects, amount of analgesic needed during surgery, quantity of agent needed for maintenance of anaesthesia and postoperative recovery in 40 patients undergoing OPCAB surgery. Anaesthesia was induced with fentanyl, midazolam and thiopentone, and vecuronium was used for muscle relaxation. An Octopus stabiliser was used and coronary anastomosis was performed using internal mammary artery and saphenous vein grafts. Routine monitoring was performed. The depth of anaesthesia was monitored using Bispectral index monitor. The inspired/expired concentration of anaesthetic agents to maintain the desired BIS and the amount of volatile anaesthetic agent needed was also noted. The amount of analgesic used intraoperatively was noted in both the groups. The 'time of awakening' defined as eye opening on verbal commands, and time of extubation were noted. There were no differences in haemodynamic parameters, depth of anaesthesia, and quantity of agent needed, but patients in isoflurane group required more intraoperative analgesics than sevoflurane group. Time of awakening (48+/-13 vs 114 +/- 21 mins; P < 0.001) and subsequent extubation (124 +/- 25 vs 177 +/- 36 mins, P<0.001) was earlier in sevoflurane group than isoflurane group. There was no evidence of perioperative myocardial infarction in both the groups. We conclude that sevoflurane and isoflurane can both be safely used in OPCAB surgery, but the awakening and extubation times are significantly less with sevoflurane.

A randomized double-blinded trial of chloral hydrate with or without hydroxyzine versus placebo for pediatric dental sedation

Chloral hydrate and hydroxyzine are a drug combination frequently used by practitioners to sedate pediatric dental patients, but their effectiveness has not been compared to a negative control group in humans. The aim of this crossover, double-blinded study was to evaluate the effect of these drugs compared to a placebo, administered to young children for dental treatment. Thirty-five dental sedation sessions were carried out on 12 uncooperative ASA I children aged less than 5 years old. In each session patients were randomly assigned to groups P (placebo), CH (chloral hydrate 75 mg/kg) and CHH (chloral hydrate 50 mg/kg plus hydroxyzine 2.0 mg/kg). Vital signs and behavioral variables were evaluated every 15 min. Comparisons were statistically analyzed using Friedman and Wilcoxon tests. P, CH and CHH had no differences concerning vital signs, except for breathing rate. All vital signs were in the normal range. CH and CHH promoted more sleep in the first 30 min of treatment. Overall behavior was better in CH and CHH than in P. CH, CHH and P were effective in 62.5 percent, 61.5 percent and 11.1 percent of the cases, respectively. Chloral hydrate was safe and relatively effective, causing more satisfactory behavioral and physiological outcomes than a placebo.

A associação hidrato de cloral- hidroxizina tem sido utilizada na clínica odontológica para sedar crianças, mas sua efetividade ainda não foi comparada a um controle negativo em humanos. O objetivo deste estudo prospectivo foi avaliar o efeito dessas drogas, comparadas a um placebo, em crianças submetidas a tratamento odontológico. Trinta e cinco sessões de sedação foram realizadas em 12 crianças menores de 5 anos, não cooperativas, ASA classe I. Em cada sessão os pacientes foram aleatoriamente alocados para os grupos P (placebo), CH (hidrato de cloral 75 mg/kg) e CHH (hidrato de cloral 50 mg/kg mais hidroxizina 2,0 mg/kg). Sinais vitais e comportamento foram avaliados a cada 15 min, e comparados pelos testes de Friedman e Wilcoxon. Os grupos não apresentaram diferenças quanto às variáveis fisiológicas, exceto a freqüência respiratória. Todos sinais vitais registrados estiveram dentro de faixa aceitável. CH e CHH promoveram mais sono nos primeiros 30 min de tratamento. O comportamento geral foi melhor em CH e CHH do que em P. CH, CHH e P foram efetivos em 62,5 por cento, 61,5 por cento e 11,1 por cento dos casos, respectivamente. O hidrato de cloral foi seguro e relativamente efetivo, levando a resultados fisiológicos e comportamentais melhores que o placebo.

Antagonism of morphine-induced central respiratory depression by donepezil in the anesthetized rabbit

Morphine is often used in cancer pain and postoperative analgesic management but induces respiratory depression. Therefore, there is an ongoing search for drug candidates that can antagonize morphine-induced respiratory depression but have no effect on morphine-induced analgesia. Acetylcholine is an excitatory neurotransmitter in central respiratory control and physostigmine antagonizes morphine-induced respiratory depression. However, physostigmine has not been applied in clinical practice because it has a short action time, among other characteristics. We therefore asked whether donepezil (a long-acting acetylcholinesterase inhibitor used in the treatment of Alzheimer's disease) can antagonize morphine-induced respiratory depression. Using the anesthetized rabbit as our model, we measured phrenic nerve discharge as an index of respiratory rate and amplitude. We compared control indices with discharges after the injection of morphine and after the injection of donepezil. Morphine-induced depression of respiratory rate and respiratory amplitude was partly antagonized by donepezil without any effect on blood pressure and end-tidal C0(2). In the other experiment, apneic threshold PaC0(2) was also compared. Morphine increased the phrenic nerve apnea threshold but this was antagonized by donepezil. These findings indicate that systemically administered donepezil partially restores morphine-induced respiratory depression and morphine-deteriorated phrenic nerve apnea threshold in the anesthetized rabbit.

Autoclaved gelatin [haemagel] versus 6% hydroxyethyl starch 200/0.5 [Haes-steril] for plasma volume expansion in critically-ill patients

Synthetic colloids are used to optimize hemodynamics in the critically ill patients and a debate about the most suitable one is still present. The influence of short term infusion of autociaved gelatin [Haemagel] and 6% hydroxyethyi starch 200/0.5 [Haes-steril] on hemodynamic, respiratory, coagulation, renal and oncotic parameters were examined in a prospective randomized study. Thirty patients suffering from systemic hypoperfusion due to sepsis in ICU of Suez Canal University Hospital were assigned into 2 equal groups. In GEL group; 1000 ml of Haemagel was infused within an hour, while in HES group: 1000 ml of 6% Haes-steril 200/0.5 was given within an hour The hemodynamic, respiratory, hematological. coagulation, renal and colloidal osmotic pressure parameters were recorded before and after infusion of both colloids. There was a significant similar increase in hemodynamic variables [Mean arterial pressure, central venous pressure, cardiac index, stroke volume index and left ventricular stroke work index] in both groups. Also, a significant improvement in tissue perfusion as judged by decreased arterial lactate was found. There were no significant differences in any of the measured respiratory parameters [respiratory rate, arterial oxygen saturation, arterial blood gases and intrapulmonary shunt] in the studied groups. No significant intergroup difference in any haemodynamic or respiratory variable was demonstrated. A significant expansion in plasma volume as indicated by the significant reduction in haematocrit was detected. There were insignificant changes in coagulation profile [prothrombin time, activated partial thrombopiastin time, bleeding time and fibrinogen] in either group except the platelet count which was significantly reduced in both groups without any recorded bleeding complications. Creatinine, blood urea nitrogen, sodium and potassium didn't change and were comparable in the two groups Colloidal osmotic pressure and urine output increased significantly in either group. Anaphylactic reactions were not observed in any of the patients However, no significant differences between both groups in haematological. coagulation, renal and oncotic parameters were found. Both autoclaved gelatin [Haemagel] and 6% hydroxyethyl starch 200/0.5 [Haes-steri!] are safe and equally effective colloids for plasma volume expansion tn critically ill patients without apparent adverse effects on respiration, coagulation and renal functions

Ketamine anaesthesia following premedication of rabbits with vitamin C

The effects of vitamin C on ketamine anesthesia was studied. In normal rabbits the onset and duration of ketamine induced anesthesia were 6.0+/-0.5 and 36.0+/-0.9 min, respectively. Pre-treatment of rabbits with 30, 60 and 240 mg/kg, i.m. of vitamin C followed by ketamine 40 mg/ kg i.m. resulted in significant (p<0.05)decrease in the onset and increase in duration of ketamine anesthesia to 5.0 +/-0.06 and 37.0+/-0.7;4.0 +/-0.5 and 39.0*0.6;2.0+/-2.3 and 44.0+/-0.8 min, respectively. There was also significant (p<0.05)decrease in the heart rates in the animals treated with vitamin C and ketamine combinations. Serum analysis showed a significant (p<0.05)increase in blood glucose. The observed decreased in serum calcium and phosphorous following ketamine injection was prevented by pretreatment with vitamin C. These results suggest that vitamin C at higher doses could potentiate ketamine anesthesia in rabbits.

Effect of household exposure to environmental tobacco smoke on airflow mechanics in asymptomatic healthy women.

BACKGROUND & OBJECTIVES: Exposure to environmental tobacco smoke (ETS) can lead to airflow limitation, similar to that seen in smokers. However, the effects have not been conclusively proven. In the present study an attempt was made to characterize the effect of ETS exposure at home on airflow mechanics in asymptomatic healthy women. METHODS: Fifty women volunteers with no apparent health related problem, exposed to household ETS (group I), and 50 age-matched women not exposed (group II) were studied. Vital capacity (VC), forced expiratory flow in first second (FEV1), FEV1/VC ratio, peak expiratory flow (PEF), maximal midexpiratory flow (FEF(25-75%)), airway resistance (R(aw)) and specific airway conductance (sG(aw)) were measured, and compared between the two groups. Conditional logistic and linear regression analysis were done to assess contribution of household ETS exposure to decreased lung function. RESULTS: FEV1 and PEF values were marginally lower among women in group I (mean difference 0.13 l and 0.20 l/sec respectively). FEF(25-75%), R(aw) and sG(aw) were significantly impaired in this group. Ten (20.0%) women in group I and five (10.0%) in group II had abnormal R(aw) (adjusted odds ratio 6.72, 95% confidence limits 1.15-39.42), while eight (16.0%) women in group I and one (2.0%) in group II had abnormal sG(aw) (adjusted odds ratio 21.08, 95% confidence limits 1.30-341.05). Cumulative life time ETS exposure was, not significantly related to a reduction in FEV1, VC, PEF, FEF(25-75%), R(aw) or sG(aw) after adjustments for potential confounders. INTERPRETATION & CONCLUSION: Exposure to household ETS resulted in subtle impairment of airflow mechanics in asymptomatic women, possibly attributed to small airway narrowing. Further investigations are required to study the progression of this impairment with time.