An update on the mechanisms and risk factors for anesthesia-related cardiac arrest in children: a narrative review.

The relation between surgery and anesthesia safety in children and a country's Human Development Index (HDI) value has been described previously. The aim of this narrative review was to provide an update on the mechanisms and risk factors of Anesthesia-Related Cardiac Arrest (ARCA) in pediatric surgical patients in countries with different HDI values and over time (pre-2001 vs. 2001‒2024). Electronic databases were searched up to March 2024 for studies reporting ARCA events in children. HDI values range from 0 to 1 (very-high-HDI countries: ≥ 0.800, high-HDI countries: 0.700‒0.799, medium-HDI countries: 0.550‒0.699, and low-HDI countries: < 0.550). Independent of time, the proportion of children who suffered perioperative Cardiac Arrest (CA) attributed to anesthesia-related causes was higher in very-high-HDI countries (50%) than in countries with HDI values less than 0.8 (15‒36%), but ARCA rates were higher in countries with HDI values less than 0.8 than in very-high-HDI countries. Regardless of the HDI value, medication-related factors were the most common mechanism causing ARCA before 2001, while cardiovascular-related factors, mainly hypovolemia, and respiratory-related factors, including difficulty maintaining patent airways and adequate ventilation, were the major mechanisms in the present century. Independent of HDI value and time, a higher number of ARCA events occurred in children with heart disease and/or a history of cardiac surgery, those aged younger than one year, those with ASA physical status III‒V, and those who underwent emergency surgery. Many ARCA events were determined to be preventable. The implementation of specialized pediatric anesthesiology and training programs is crucial for anesthesia safety in children.

Comparison of inflammatory cytokine profiles in plasma of patients undergoing otorhinological surgery with propofol or isoflurane anesthesia.

OBJECTIVE AND DESIGN: The effects of anesthetics on cytokine release in patients without comorbidities who undergo minor surgery are not well defined. We compared inflammatory cytokine profiles in adult patients undergoing minimally invasive surgery who received isoflurane or propofol anesthesia. METHODS: Thirty-four patients without comorbidities undergoing minor surgery were randomly assigned to receive an inhaled anesthetic (isoflurane; n = 16) or an intravenous anesthetic (propofol; n = 18). Blood samples were drawn before premedication and anesthesia (T1), 120 min after anesthesia induction (T2), and on the first post-operative day (T3). Plasma concentrations of interleukins (IL-) 1ß, 6, 8, 10 and 12 and tumor necrosis factor (TNF)-α were measured using flow cytometry. RESULTS: The pro-inflammatory cytokine IL-6 was increased in the isoflurane group at T2 and T3 compared to T1 (P < 0.01). In the propofol group, IL-6 and IL-8 were significantly increased at T3 compared to T1. However, there were no significant differences in cytokine concentrations between the isoflurane and propofol groups. CONCLUSION: An inflammatory response occurred earlier in patients who received an inhaled agent compared with an intravenous anesthetic, but no differences in plasma cytokine profiles were evident between isoflurane and propofol anesthesia in patients without comorbidities undergoing minimally invasive surgeries.

Genotoxicity, cytotoxicity and gene expression in patients undergoing elective surgery under isoflurane anaesthesia.

There are numerous studies reporting on the effects of inhalation anaesthesia in cells of exposed individuals but not much is known about the ability of isoflurane (ISF) to induce oxidative DNA damage. However, surgery is often associated with a temporary perioperative immunological alteration, and some volatile anaesthetics seem to contribute to a transient lymphocytopenia after surgery. We conducted a study to evaluate a possible genotoxic effect, including oxidative DNA damage, and apoptosis in peripheral lymphocytes of 20 patients American Society of Anaesthesiologists physical status I undergoing minor elective surgery lasting at least 120 min, under anaesthesia with ISF. We also investigated the expression of several genes in blood cells. Blood samples were collected at three time points: before anaesthesia (T(1)), 2 h after the beginning of anaesthesia (T(2)) and on the first post-operative day (T(3)). General DNA damage and oxidised bases (Fpg and endo III-sites) in blood lymphocytes were evaluated using the comet assay. Lymphocytes were phenotyped and apoptosis was evaluated by flow cytometry. In addition, expressions of hOGG1 and XRCC1, genes involved in DNA repair, and BCL2, a gene related to apoptosis, were assessed by quantitative real-time polymerase chain reaction. Results showed no statistically significant difference in the level of DNA damage and oxidised bases among the three sampling times. Anaesthesia with ISF did not increase the percentage of cells in early or late apoptosis in cytotoxic or helper T lymphocytes. Lower hOGG1 and BCL2 expressions were detected at T(3) in comparison to the other two previous time points, and there was significantly lower expression of XRCC1 at T(3) in relation to T(2). In conclusion, the exposure to ISF did not result in genotoxicity and cytotoxicity in lymphocytes and in toxicogenomic effect in leukocytes, although DNA repair and apoptosis-related genes were down-regulated on the first post-operative day.

[Epidemiology of perioperative cardiac arrest and mortality in Brazil: a systematic review]. / Epidemiologia de parada cardíaca e de mortalidade perioperatória no Brasil: revisão sistemática.

BACKGROUND AND OBJECTIVES: The perioperative cardiac arrest (CA) and mortality rates in Brazil, a developing country, are higher than in developed countries. The hypothesis of this review was that knowledge of the epidemiology of perioperative CA and mortality in Brazil enables the comparison with developed countries. The systematic review aimed to verify, in studies conducted in Brazil, the epidemiology of perioperative CA and mortality. METHOD AND RESULTS: A search strategy was carried out on different databases (PubMed, EMBASE, SciELO and LILACS) to identify observational studies that reported perioperative CA and/or mortality up to 48 hours postoperatively in Brazil. The primary outcomes were data on epidemiology of perioperative CA and mortality. In 8 Brazilian studies, there was a higher occurrence of perioperative CA and mortality in males; in extremes of age; in patients in worse physical status according to the American Society of Anesthesiologists (ASA); in emergency surgeries; in general anesthesia; and in cardiac, thoracic, vascular, abdominal and neurological surgeries. The patient's disease/condition was the main triggering factor, with sepsis and trauma as the main causes. CONCLUSIONS: The epidemiology of both perioperative CA and mortality events reported in Brazilian studies does not show important differences and, in general, is similar to studies in developed countries. However, sepsis represents one of the major causes of perioperative CA and mortality in Brazilian studies, contrasting with studies in developed countries in which sepsis is a secondary cause.

Does the choice of the halogenated anesthetic influence renal function during hemorrhagic shock and resuscitation?

INTRODUCTION: Halogenated anesthetics can cause changes in the variables that modify the cardiac output necessary to maintain renal hemodynamic during hemorrhagic shock and resuscitation. However, halogenated anesthetics seem to protect against renal ischemia-reperfusion injury. In a model of pressure-guided hemorrhagic shock in dogs, we studied the comparative effects of three halogenated anesthetics-halothane, sevoflurane, and isoflurane-at equipotent concentrations on renal responses after resuscitation. METHODS: Thirty dogs were anesthetized with 1.0 minimum alveolar anesthetic concentration (MAC) of halothane, sevoflurane, or isoflurane. The dogs were splenectomized and hemorrhaged to hold mean arterial pressure at 40-50 mm Hg over 45 min and then resuscitated with the shed blood volume. Hemodynamic variables were measured at baseline, after 45 min of hemorrhage, and 15 and 60 min after resuscitation. Renal variables were measured at baseline and 15 and 60 min after resuscitation. RESULTS: Hemorrhage induced reductions of mean arterial pressure, filling pressures, and cardiac index (p < 0.05), without significant differences among groups (p > 0.05). After 60 min of shed blood replacement, all groups restored hemodynamic and renal variables to the prehemorrhage levels (p > 0.05), without significant differences among groups (p > 0.05), with the exception of sodium fractional excretion, the values for which were significantly higher in isoflurane group, in relation to the other groups after 15 min of re-transfusion (p < 0.05), and renal vascular resistance, the values for which remain lower than baseline in halothane group (p < 0.05). CONCLUSIONS: We conclude that no difference could be detected between choosing equipotent doses of halothane, sevoflurane, or isoflurane in relation to renal variables in dogs submitted to pressure-adjusted hemorrhagic shock and resuscitation.

Clinical, histological and electron microscopic aspects of vocal fold granulomas.

UNLABELLED: Granulomas are bilateral and pediculated lesions of the vocal apophysis. Etiologies: intubation, reflux, trauma, vocal abuse, idiopathic origin. AIM: To analyze the clinical and morphological aspects of post intubation granulomas. METHODS: retrospective study of patients submitted to microsurgery for post intubation laryngeal granulomas seen at our Medical School starting in 2002. We analyzed: age, gender, indication and time of intubation, symptoms, videolaryngoscopic diagnosis and biopsy findings. Light microscopy was performed on all specimens, and electron microscopy on three of them. RESULTS: ten patients (7 females and 3 males), between the ages of 2 and 72 years, intubation time between 4h and 21 days. Hoarseness was a frequent symptom, starting in the first week following extubation. Histology shows mild epithelial hyperplasia, severe inflammation and vessel proliferation in the corion. Under SEM, the epithelium presented mild superficial desquamation. Under TEM, intracellular junctions showed widening with structural changes in the desmosomes. In the corion there were vessel proliferations, inflammation and fibroblasts with structural alterations. CONCLUSIONS: post intubation granulomas appear in any age and hoarseness is a frequent symptom. Morphological alterations occur in the corion as vessel proliferations, inflammation, and intracytoplasmatic alterations in fibroblasts suggesting cellular dysfunction and damage.

Gastric mucosal perfusion in dogs: effects of halogenated anesthetics and of hemorrhage.

The gastrointestinal tract is one of the first organs affected by hypoperfusion during hemorrhagic shock. The hemodynamics and oxygen transport variables during hemorrhagic shock and resuscitation can be affected by the anesthetics used. In a model of pressure-guided hemorrhagic shock in dogs, we studied the effects of three halogenated anesthetics--halothane, sevoflurane, and isoflurane--at equipotent concentrations on gastric oxygenation. Thirty dogs were anesthetized with 1.0 minimum alveolar anesthetic concentration (MAC) of either halothane, sevoflurane, or isoflurane. A gastric tonometer was placed in the stomach to determine mucosal gastric CO(2) (PgCO(2)) and for the calculation of gastric-arterial PCO(2) gradient (PCO(2) gap). The dogs were splenectomized and hemorrhaged to hold mean arterial pressure at 40-50 mm Hg over 45 min and then resuscitated with the shed blood volume. Hemodynamics, systemic oxygenation, and PCO(2) gap were measured at baseline, after 45 min of hemorrhage, and at 15 and 60 min after blood resuscitation. Hemorrhage induced reductions of mean arterial pressure and cardiac index, while systemic oxygen extraction increased (p < .05), without significant differences among groups (p > .05). Halothane group showed significant lower PCO(2) gap values than the other groups (p < .05). After 60 min of shed blood replacement, all groups restored hemodynamics, systemic oxygenation, and PCO(2) gap to the prehemorrhage levels (p > .05), without significant differences among groups (p > .05). We conclude that halothane is superior to preserve the gastric mucosal perfusion in comparison to isoflurane and sevoflurane, in dogs submitted to pressure-guided hemorrhagic shock at equipotent doses of halogenated anesthetics.

Postoperative renal function evaluation, through RIFLE criteria, of elderly patients who underwent femur fracture surgery under spinal anesthesia.

INTRODUCTION: The postoperative acute renal failure (ARF) incidence in different kinds of surgery has rarely been studied. Age, cardiac dysfunction, previous renal dysfunction, intraoperative hypoperfusion, and use of nephrotoxic medications are mentioned as risk factors for ARF at the postoperative period. The postoperative ARF definition was based on the creatinine increase by the RIFLE classification (R = risk, I = injury, F = failure, L = loss, E = end stage), which corresponds to a 1.5 creatinine increase, two to three times, respectively, above the basal value. This study aimed to evaluate the postoperative ARF incidence in elderly patients who underwent femur fracture surgery under subarachnoid anesthesia and stratify it by the RIFLE criteria. METHODS: Ninety patients older than 65 years under spinal anesthesia with fixed dosage of 15 mg of 0.5% isobaric bupivacaine associated with morphine 50 mug were studied. Immediate postoperative creatinine was considered basal and compared with maximal creatinine evaluated at 24, 48, and 72 postoperative hours. RESULTS: The mean age of the patients was 80.27 years. ARF incidence was 24.44% and stratified this way: R = 21.11% and I = 3.33%. CONCLUSIONS: In conclusion, the postoperative ARF incidence after femur fracture surgery in patients over 65 years was 24.44%. By analyzing the stratification based on the RIFLE classification, the incidence was categorized as Risk (R) = 21.11% and Injury (I) = 3.33%.

[Synergistic effect between dexmedetomidine and 0.75% ropivacaine in epidural anesthesia]. / Efeito sinérgico entre a dexmedetomidina e a ropivacaína 0,75% na anestesia peridural.

BACKGROUND: This study aimed to evaluate clinical characteristics of epidural anesthesia performed with 0.75% ropivacaine associated with dexmedetomidine. METHODS: Forty patients scheduled for hernia repair or varicose vein surgeries under epidural anesthesia participated in this study. They were assigned to: Control Group (n = 20), 0.75% ropivacaine, 20 ml (150 mg); and Dexmedetomidine Group (n = 20), 0.75% ropivacaine, 20 ml (150 mg), plus dexmedetomidine, 1 mg x kg-1. The following variables were studied: total analgesic block onset time, upper level of analgesia, analgesic and motor block duration time, intensity of motor block, state of consciousness, hemodynamics, postoperative analgesia and incidence of side-effects. RESULTS: Epidural dexmedetomidine did not affect onset time or upper level of anesthesia (p > 0.05) however it prolonged sensory and motor block duration time (p < 0.05) and postoperative analgesia (p < 0.05), and also resulted in a more intense motor block, l (p < 0.05). Values of bispectral index were lower in Dexmedetomidine Group (p < 0.05). There was no difference in incidence of hypotension and bradycardia (p > 0.05). Occurrence of side-effects (shivering, vomiting and SpO2 < 90%) was low and similar between groups (p > 0.05). CONCLUSION: There is clear synergism between epidural dexmedetomidine and ropivacaine, further this drug association does not bring about additional morbidity.

Effectiveness and safety of endotracheal tube cuffs filled with air versus filled with alkalinized lidocaine: a randomized clinical trial.

CONTEXT AND OBJECTIVE: High intracuff pressure in endotracheal tubes (ETs) may cause tracheal lesions. The aim of this study was to evaluate the effectiveness and safety of endotracheal tube cuffs filled with air or with alkalinized lidocaine. DESIGN AND SETTING: This was a prospective clinical study at the Department of Anesthesiology, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista. METHODS: Among 50 patients, ET cuff pressures were recorded before, 30, 60, 90 and 120 minutes after starting and upon ending nitrous oxide anesthesia. The patients were randomly allocated to two groups: Air, with ET cuff inflated with air to attain a cuff pressure of 20 cmH2O; and Lido, with ET cuff filled with 2% lidocaine plus 8.4% sodium bicarbonate to attain the same pressure. ET discomfort before tracheal extubation, and sore throat, hoarseness and coughing incidence were studied at the time of discharge from the post-anesthesia care unit, and sore throat and hoarseness were studied 24 hours after anesthesia. RESULTS: Pressures in Lido cuffs were significantly lower than in Air cuffs (p < 0.05). Tracheal complaints were similar for the two groups, except for lower ET discomfort and sore throat incidence after 24 hours and lower systolic arterial pressure at the time of extubation in the Lido group (p < 0.05). CONCLUSION: ET cuffs filled with alkalinized lidocaine prevented the occurrence of high cuff pressures during N2O anesthesia and reduced ET discomfort and postoperative sore throat incidence. Thus, alkalinized lidocaine-filled ET cuffs seem to be safer than conventional air-filled ET cuffs.

Preoperative warming combined with intraoperative skin-surface warming does not avoid hypothermia caused by spinal anesthesia in patients with midazolam premedication.

CONTEXT AND OBJECTIVE: Inadvertent perioperative hypothermia is common during spinal anesthesia and after midazolam administration. The aim of this study was to evaluate the effects of intraoperative skin-surface warming with and without 45 minutes of preoperative warming in preventing intraoperative and postoperative hypothermia caused by spinal anesthesia in patients with midazolam premedication. DESIGN AND SETTING: Prospective and randomized study at Hospital das Clínicas, Universidade Estadual Paulista, Botucatu. METHODS: Thirty patients presenting American Society of Anesthesiologists (ASA) physical status I and II who were scheduled for elective lower abdominal surgery were utilized. The patients received midazolam premedication (7.5 mg by intramuscular injection) and standard spinal anesthesia. Ten patients (Gcontrol) received preoperative and intraoperative passive thermal insulation. Ten patients (Gpre+intra) underwent preoperative and intraoperative active warming. Ten patients (Gintra) were only warmed intraoperatively. RESULTS: After 45 min of preoperative warming, the patients in Gpre+intra had significantly higher core temperatures than did the patients in the unwarmed groups (Gcontrol and Gintra) before the anesthesia (p < 0.05) but not at the beginning of surgery (p > 0.05). The patients who were warmed intraoperatively had significantly higher core temperatures than did the patients in Gcontrol at the end of surgery (p < 0.05). All the patients were hypothermic at admission to the recovery room (T CORE < 36 degrees C). CONCLUSIONS: Forty-five minutes of preoperative warming combined with intraoperative skin-surface warming does not avoid but minimizes hypothermia caused by spinal anesthesia in patients with midazolam premedication.

Renal function and histology after acute hemorrhage in rats under dexmedetomidine action.

PURPOSE: About 50 % of indications for dialysis in acute renal failure are related to problems originated during the perioperative period. Intraoperative hemodynamic changes lead to renal vasoconstriction and hypoperfusion. Previous studies have not defined the dexmedetomidine renal role in hemorrhage situations. This study evaluated the effect of dexmedetomidine on renal function and histology after acute hemorrhage in rats. METHODS: Covered study with 20 Wistars rats, anesthetized with sodium pentobarbital, 50 mg.kg(-1), intraperitoneal, randomized into 2 groups submitted to 30% volemia bleeding: DG - iv dexmedetomidine, 3 microg.kg(-1) (10 min) and continuous infusion - 3 microg.kg(-1).h(-1); CG - pentobarbital. For renal clearance estimative, sodium p-aminohippurate and iothalamate were administered. Studied attributes: heart rate, mean arterial pressure, rectal temperature, hematocrit, iothalamate and p-aminohippurate clearance, filtration fraction, renal blood flow, renal vascular resistance, and histological evaluations of the kidneys. RESULTS: DG showed smaller values of heart rate, mean arterial pressure, and renal vascular resistance, but iothalamate clearance and filtration fraction values were higher. There was similarity in p-aminohippurate clearance and renal blood flow. Both groups had histological changes ischemia-like, but dexmedetomidine determined higher tubular dilatation scores. CONCLUSION: In rats, after acute hemorrhage, dexmedetomidine determined better renal function, but higher tubular dilation scores.

[Comparison of waste anesthetic gases in operating rooms with or without an scavenging system in a Brazilian University Hospital]. / Comparação de resíduos de gases anestésicos em salas de operação com ou sem sistema de exaustão em hospital universitário brasileiro.

BACKGROUND AND OBJECTIVES: Occupational exposure to waste anesthetic gases in operating room (OR) without active scavenging system has been associated with adverse health effects. Thus, this study aimed to compare the trace concentrations of the inhaled anesthetics isoflurane and sevoflurane in OR with and without central scavenging system. METHOD: Waste concentrations of isoflurane and sevoflurane were measured by infrared analyzer at different locations (near the respiratory area of the assistant nurse and anesthesiologist and near the anesthesia station) and at two times (30 and 120minutes after the start of surgery) in both OR types. RESULTS: All isoflurane and sevoflurane concentrations in unscavenged OR were higher than the US recommended limit (2 parts per million), regardless of the location and time evaluated. In scavenged OR, the average concentrations of isoflurane were within the limit of exposure, except for the measurements near the anesthesia station, regardless of the measurement times. For sevoflurane, concentrations exceeded the limit value at all measurement locations and at both times. CONCLUSIONS: The exposure to both anesthetics exceeded the international limit in unscavenged OR. In scavenged OR, the concentrations of sevoflurane, and to a lesser extent those of isoflurane, exceeded the recommended limit value. Thus, the OR scavenging system analyzed in the present study decreased the anesthetic concentrations, although not to the internationally recommended values.

Larynx and cervical trachea in humidification and heating of inhaled gases.

To evaluate the participation of the larynx and cervical trachea in conditioning inspired gases, we randomly allocated 16 mixed-breed dogs to two groups: group TT (tracheal tube; n = 8) and group LMA (laryngeal mask airway; n = 8). The dogs were anesthetized with pentobarbital sodium and mechanically ventilated for 3 hours. The parameters studied were temperature and absolute humidities of ambient, inhaled, and tracheal air. There was a small increase in tracheal air temperature compared to inhaled air temperature, but no significant difference between groups. The absolute humidity of tracheal air was greater in group LMA than in group TT (23 mg H2O * L(-1) and 14 mg H2O * L(-1), respectively; p < .0001). The difference in absolute humidity between the tracheal air and the inhaled air was higher in group LMA at all times (p < .0001). We conclude that the larynx and cervical trachea of the dog participate in humidification and heating of inhaled air by means of air contact with mucosa in this airway segment.

Epidemiology of perioperative cardiac arrest and mortality in Brazil: a systematic review / Epidemiologia de parada cardíaca e de mortalidade perioperatória no Brasil: revisão sistemática

Abstract Background and objectives: The perioperative cardiac arrest (CA) and mortality rates in Brazil, a developing country, are higher than in developed countries. The hypothesis of this review was that knowledge of the epidemiology of perioperative CA and mortality in Brazil enables the comparison with developed countries. The systematic review aimed to verify, in studies conducted in Brazil, the epidemiology of perioperative CA and mortality. Method and results: A search strategy was carried out on different databases (PubMed, EMBASE, SciELO and LILACS) to identify observational studies that reported perioperative CA and/or mortality up to 48 hours postoperatively in Brazil. The primary outcomes were data on epidemiology of perioperative CA and mortality. In 8 Brazilian studies, there was a higher occurrence of perioperative CA and mortality in males; in extremes of age; in patients in worse physical status according to the American Society of Anesthesiologists (ASA); in emergency surgeries; in general anesthesia; and in cardiac, thoracic, vascular, abdominal and neurological surgeries. The patient's disease/condition was the main triggering factor, with sepsis and trauma as the main causes. Conclusions: The epidemiology of both perioperative CA and mortality events reported in Brazilian studies does not show important differences and, in general, is similar to studies in developed countries. However, sepsis represents one of the major causes of perioperative CA and mortality in Brazilian studies, contrasting with studies in developed countries in which sepsis is a secondary cause.

Resumo Justificativa e objetivos: As incidências de parada cardíaca (PC) e de mortalidade perioperatória no Brasil, um país em desenvolvimento, são mais elevadas em relação às dos países desenvolvidos. A hipótese desta revisão é que o conhecimento da epidemiologia de PC e de mortalidade perioperatória no Brasil possibilita sua comparação com a dos países desenvolvidos. A revisão sistemática teve como objetivo verificar, em estudos realizados no Brasil, a epidemiologia de PC e de mortalidade perioperatória. Conteúdo: Realizou-se estratégia de busca em diferentes bases de dados (PubMed, EMBASE, SciELO e LILACS) para a identificação de estudos observacionais que reportaram PC e/ou mortalidade perioperatória até 48 horas pós-operatório no Brasil. Os desfechos primários foram dados de epidemiologia de PC e de mortalidade perioperatória. Em 8 estudos nacionais, identificou- se maior ocorrência de PC e de mortalidade perioperatória no sexo masculino, em extremos de idade, em pacientes em pior estado físico segundo a American Society of Anesthesiologists (ASA), em cirurgias de emergência, em anestesia geral, e em cirurgias cardíaca, torácica, vascular, abdominal e neurológica. A doença/condição do paciente foi o principal fator desencadeante, tendo como causas principais a sepse e o trauma. Conclusões: Nos estudos nacionais, a epidemiologia dos eventos tanto de PC como de mortalidade perioperatória não apresenta diferenças importantes, e de maneira geral, é semelhante à de estudos de países desenvolvidos. Entretanto, a sepse, nos estudos nacionais, representa uma das principais causas de PC e de mortalidade perioperatória, diferenciando-se dos estudos de países desenvolvidos nos quais a sepse é causa secundária.

Does sealing endotracheal tube cuff pressure diminish the frequency of postoperative laryngotracheal complaints after nitrous oxide anesthesia?

STUDY OBJECTIVES: To study endotracheal tube (ETT) cuff pressures during nitrous oxide (N2O) anesthesia when the cuffs are inflated with air to achieve sealing pressure, and to evaluate the frequency of postoperative laryngotracheal complaints. DESIGN: Prospective, randomized, blind study. SETTING: Metropolitan teaching hospital. PATIENTS: 50 ASA physical status I and II patients scheduled for elective abdominal surgery. INTERVENTIONS: Patients received standard general anesthesia with 66% N2O in oxygen. In 25 patients, the ETT cuff was inflated with air to achieve a sealing pressure (Pseal group). In 25 patients, the ETT cuff was inflated with air to achieve a pressure of 25 cm H2O (P25 group). MEASUREMENTS AND MAIN RESULTS: ETT intracuff pressures were recorded before (control) and at 30, 60, 90, 120, and 150 minutes during N2O administration. We investigated the frequency and intensity of sore throat, hoarseness, and dysphagia in patients in the Post-Anesthesia Care Unit (PACU) and 24 hours following tracheal extubation. The cuff pressures in the Pseal group were significantly lower than in the P25 group at all time points studied (p < 0.001), with a significant increase with time in both groups (p < 0.001). The cuff pressures exceeded the critical pressure of 30 cm H2O only after 90 minutes in the Pseal group and already by 30 minutes in the P25 group. The frequency and intensity of sore throat, hoarseness, and dysphagia were similar in both groups in the PACU and 24 hours after tracheal extubation (p > 0.05). CONCLUSIONS: Minimum ETT sealing cuff pressure during N2O anesthesia did not prevent, but instead attenuated, the increase in cuff pressure and did not decrease postoperative laryngotracheal complaints.

Preoperative combined with intraoperative skin-surface warming avoids hypothermia caused by general anesthesia and surgery.

STUDY OBJECTIVES: To evaluate the effects of intraoperative skin-surface warming with and without 1 hour of preoperative warming, in preventing intraoperative hypothermia, and postoperative hypothermia, and shivering, and in offering good conditions to early tracheal extubation. DESIGN: Prospective, randomized, blind study. SETTING: Teaching hospital. PATIENTS: 30 ASA physical status I and II female patients scheduled for elective abdominal surgery. INTERVENTIONS: Patients received standard general anesthesia. In 10 patients, no special precautions were taken to avoid hypothermia. Ten patients were submitted to preoperative and intraoperative active warming. Ten patients were only warmed intraoperatively. MEASUREMENTS AND MAIN RESULTS: Temperatures were recorded at 15-minute intervals. The patients who were warmed preoperatively and intraoperatively had core temperatures significantly more elevated than the other patients during the first two hours of anesthesia. All patients warmed intraoperatively were normothermic only at the end of the surgery. The majority of the patients warmed preoperatively and intraoperatively or intraoperatively only were extubated early, and none had shivering. In contrast, five unwarmed patients shivered. CONCLUSIONS: One hour of preoperative warning combined with intraoperative skin-surface warming, not simply intraoperative warming alone, avoided hypothermia caused by general anesthesia during the first two hours of surgery. Both methods prevented postoperative hypothermia and shivering and offered good conditions for early tracheal extubation.

The effect of intracuff alkalinized 2% lidocaine on emergence coughing, sore throat, and hoarseness in smokers.

OBJECTIVE: We evaluated whether endotracheal tube (ETT) intracuff alkalinized lidocaine was superior to saline in blunting emergence coughing, postoperative sore throat, and hoarseness in smokers. METHODS: In our prospective, double-blind trial, we enrolled 50 smoking patients undergoing surgery under general anesthesia including nitrous oxide (N2O). Patients were randomly allocated to receive either ETT intracuff 2% lidocaine plus 8.4% sodium bicarbonate (L group), or ETT intracuff 0.9% saline (S group). The ETT cuff was inflated to achieve a cuff pressure that prevented air leak during positive pressure ventilation. Incidence of emergence coughing, sore throat, and hoarseness were analyzed. The volume of inflation solution, the intracuff pressure, the duration of anesthesia, the time elapsed to extubation after discontinuation of anesthesia, and the volume of the inflation solution and the air withdrawn from the ETT cuff were also recorded. RESULTS: Intracuff alkalinized 2% lidocaine was superior to saline in blunting emergence coughing (p < 0.001). The incidence of sore throat was significantly lower in the L group at the post-anesthesia care unit (PACU) (p = 0.02). However, at 24 hours after extubation, sore throat incidence was similar in both groups (p = 0.07). Incidence of hoarseness was similar in both groups. Intracuff pressure in the saline group increased with time while the intracuff pressure in the lidocaine group remained constant. CONCLUSION: The present study demonstrated that the intracuff alkalinized 2% lidocaine was superior to saline in decreasing the incidence of emergence coughing and sore throat during the postoperative period in smokers.

Anesthesia-related mortality in pediatric patients: a systematic review.

This systematic review of the Brazilian and worldwide literature aimed to evaluate the incidence and causes of perioperative and anesthesia-related mortality in pediatric patients. Studies were identified by searching EMBASE (1951-2011), PubMed (1966-2011), LILACS (1986-2011), and SciElo (1995-2011). Each paper was revised to identify the author(s), the data source, the time period, the number of patients, the time of death, and the perioperative and anesthesia-related mortality rates. Twenty trials were assessed. Studies from Brazil and developed countries worldwide documented similar total anesthesia-related mortality rates (<1 death per 10,000 anesthetics) and declines in anesthesia-related mortality rates in the past decade. Higher anesthesia-related mortality rates (2.4-3.3 per 10,000 anesthetics) were found in studies from developing countries over the same time period. Interestingly, pediatric perioperative mortality rates have increased over the past decade, and the rates are higher in Brazil (9.8 per 10,000 anesthetics) and other developing countries (10.7-15.9 per 10,000 anesthetics) compared with developed countries (0.41-6.8 per 10,000 anesthetics), with the exception of Australia (13.4 per 10,000 anesthetics). The major risk factors are being newborn or less than 1 year old, ASA III or worse physical status, and undergoing emergency surgery, general anesthesia, or cardiac surgery. The main causes of mortality were problems with airway management and cardiocirculatory events. Our systematic review of the literature shows that the pediatric anesthesia-related mortality rates in Brazil and in developed countries are similar, whereas the pediatric perioperative mortality rates are higher in Brazil compared with developed countries. Most cases of anesthesia-related mortality are associated with airway and cardiocirculatory events. The data regarding anesthesia-related and perioperative mortality rates may be useful in developing prevention strategies.

Comparison of waste anesthetic gases in operating rooms with or without an scavenging system in a Brazilian University Hospital / Comparação de resíduos de gases anestésicos em salas de operação com ou sem sistema de exaustão em hospital universitário brasileiro

Abstract Background and objectives Occupational exposure to waste anesthetic gases in operating room without active scavenging system has been associated with adverse health effects. Thus, this study aimed to compare the trace concentrations of the inhalational anesthetics isoflurane and sevoflurane in operating room with and without central scavenging system. Method Waste concentrations of isoflurane and sevoflurane were measured by infrared analyzer at different locations (near the respiratory area of the assistant nurse and anesthesiologist and near the anesthesia station) and at two times (30 and 120 min after the start of surgery) in both operating room types. Results All isoflurane and sevoflurane concentrations in unscavenged operating room were higher than the US recommended limit (2 parts per million), regardless of the location and time evaluated. In scavenged operating room, the average concentrations of isoflurane were within the limit of exposure, except for the measurements near the anesthesia station, regardless of the measurement times. For sevoflurane, concentrations exceeded the limit value at all measurement locations and at both times. Conclusions The exposure to both anesthetics exceeded the international limit in unscavenged operating room. In scavenged operating room, the concentrations of sevoflurane, and to a lesser extent those of isoflurane, exceeded the recommended limit value. Thus, the operating room scavenging system analyzed in the present study decreased the anesthetic concentrations, although not to the internationally recommended values.

Resumo Justificativa e objetivos A exposição ocupacional aos resíduos de gases anestésicos em salas de operação (SO) sem sistema ativo de exaustão tem sido associada a efeitos adversos à saúde. Assim, o objetivo do estudo foi comparar os resíduos dos anestésicos inalatórios isoflurano e sevoflurano em SO com e sem sistema de exaustão. Método Concentrações residuais de isoflurano e sevoflurano foram mensuradas por analisador infravermelho em diferentes locais (próximo à área respiratória do auxiliar de enfermagem e do anestesiologista e próximo à estação de anestesia) e em dois momentos (30 e 120 min após o início da cirurgia) em ambos os tipos de SO. Resultados Todas as concentrações de isoflurano e sevoflurano nas SO sem sistema de exaustão foram mais elevadas em relação ao valor limite recomendado pelos EUA (2 partes por milhão), independentemente do local e momento avaliados. Nas SO com sistema de exaustão, as concentrações médias de isoflurano ficaram dentro do limite de exposição, exceto para as mensurações próximas à estação de anestesia, independentemente dos momentos avaliados. Para o sevoflurano, as concentrações excederam o valor limite em todos locais de medição e nos dois momentos. Conclusões A exposição a ambos os anestésicos excedeu o limite internacional nas SO sem sistema de exaustão. Nas SO com sistema de exaustão, as concentrações de sevoflurano, e em menor extensão, as de isoflurano excederam o valor limite recomendado. Dessa forma, o sistema de exaustão das SO analisado no presente estudo diminuiu as concentrações dos anestésicos, embora não tenha reduzido a valores internacionalmente recomendados.