RESUMO
BACKGROUND: Difficult mask ventilation is common and is known to be associated with sleep-disordered breathing (SDB). It is our hypothesis that the incidence of expiratory retropalatal (RP) airway closure (primary outcome) during nasal positive pressure ventilation (PPV) is more frequent in patients with SDB (apnea hypopnea index ≥5 h-1) than non-SDB subjects. METHODS: The severity of SDB was assessed before surgery using a portable sleep monitor. In anaesthetized and paralysed patients with (n=11) and without SDB (n=9), we observed the behaviour of the RP airway endoscopically during nasal PPV with the mouth closed and determined the dynamic RP closing pressure, which was defined as the highest airway pressure above which the RP airway closure was reversed. The static RP closing pressure was obtained during cessation of mechanical ventilation in patients with dynamic RP closure during nasal PPV. RESULTS: The expiratory RP airway closure accompanied by expiratory flow limitation occurred more frequently in SDB patients (9/11, 82%) than in non-SDB subjects (2/9, 22%; exact logistic regression analysis: P=0.022, odds ratio 3.6, 95% confidence interval 1.1-15.4). Receiver operating characteristic curve analyses indicated AHI >10h-1 and presence of habitual snoring as clinically useful predictors for the occurrence of RP closure during PPV. Dynamic RP closing pressure was greater than the static RP closing pressure by approximately 4-5 cm H2O. CONCLUSIONS: Valve-like dynamic RP closure that limits expiratory flow during nasal PPV occurs more frequently in SDB patients.
Assuntos
Anestesia Geral , Palato Mole/fisiopatologia , Respiração com Pressão Positiva/métodos , Síndromes da Apneia do Sono/fisiopatologia , Apneia Obstrutiva do Sono/fisiopatologia , Administração Intranasal , Adulto , Idoso , Obstrução das Vias Respiratórias/epidemiologia , Obstrução das Vias Respiratórias/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Paralisia/induzido quimicamente , Polissonografia , RoncoRESUMO
Respiratory management during general anesthesia aims to safely secure the airway and maintain adequate ventilation to deliver oxygen to the vital organs, maintaining homeostasis even during surgery. Despite its clinical importance, anesthesiologists often encounter difficulties in properly managing respiration during the perioperative period, leading to severe respiratory complications. In this year's JA symposium, 5 editorial board members of Journal of Anesthesia (JA) who are experts in the field of respiratory management in anesthesia discussed the following topics: quitting smoking before surgery: exposure to passive smoke is damaging to children, ventilator-associated pneumonia, high inspiratory oxygen concentration and lung injury, aspiration pneumonia, and postoperative respiratory management strategy in patients with obstructive sleep apnea. We hope that this special article regarding this year's JA symposium may be useful for JA readers to manage clinical anesthesia on a daily basis.
Assuntos
Anestesia Geral/métodos , Período Perioperatório , Complicações Pós-Operatórias/epidemiologia , Transtornos Respiratórios/epidemiologia , Criança , Humanos , Período Pós-Operatório , Respiração , Sistema Respiratório , Apneia Obstrutiva do Sono/complicações , Poluição por Fumaça de Tabaco/efeitos adversosRESUMO
A large tongue is recognised as a factor that increases the collapsibility of the upper airway in obstructive sleep apnoea (OSA) patients. We hypothesised that the propensity to develop severe OSA could be minimised if the dental arches were enlarged in obese OSA people who are thought to have a large tongue. We therefore compared the size of the dental arches in obese and non-obese OSA patients. Using a lateral cephalogram and study models, we compared the sizes of the tongue and dental arches in 23 obese and 23 non-obese Japanese male OSA patients, who were matched for age, apnoea hypopnea index (AHI) and maxillomandibular size. The median age (years) and AHI (events per hour) for the obese and non-obese groups were 36·5 and 39·0, and 13·4 and 14·3, respectively. The maxillomandibular size was matched with regard to SNA, SNB and lower face cage obtained from cephalometric measurements. The parameters that were measured for the study model included dental arch width, dental arch length, overjet and overbite. Tongue size (P < 0·05) and both upper (P < 0·01) and lower (P < 0·05) dental arch widths were significantly larger in obese than in non-obese OSA patients, and there was no difference in the severity of OSA between the two groups. These findings suggest that the tongue was larger and dental arches were enlarged in obese patients compared with non-obese patients under the same disease severity. Wider dental arches in obese OSA patients may help to offset the impact of the enlarged tongue on upper airway patency.
Assuntos
Arco Dental/patologia , Obesidade/fisiopatologia , Apneia Obstrutiva do Sono/fisiopatologia , Língua/patologia , Análise de Variância , Índice de Massa Corporal , Estudos de Casos e Controles , Cefalometria , Arco Dental/anatomia & histologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/patologia , Apneia Obstrutiva do Sono/patologia , Língua/anatomia & histologiaRESUMO
We highlight the areas we think important for future development of the subspeciality. The ultimate goal is to improve patient care and safety and to do this, we need to identify how and where episodes of harm arise. Simply continuing with current practice does not represent the best path towards our ultimate goal; objective evidence is needed to inform changes in practice.
Assuntos
Manuseio das Vias Aéreas/tendências , Pesquisa , Manuseio das Vias Aéreas/instrumentação , Obstrução das Vias Respiratórias/etiologia , Anestesia , Anestesiologia/educação , Medicina Baseada em Evidências , Humanos , Complicações Pós-Operatórias/terapiaRESUMO
Complete paralysis under general anesthesia allowed separating anatomic factors from neural factors which influence pharyngeal patency. We compared static mechanical properties of the passive pharynx in normals and sleep apneics. The passive pharynx was narrower and more collapsible in sleep apneics than normal controls indicating significance of anatomic factors in the pathogenesis of obstructive sleep apnea.
Assuntos
Faringe/fisiopatologia , Síndromes da Apneia do Sono/fisiopatologia , Eletroencefalografia , Endoscopia , Humanos , Ventilação Pulmonar , Sono REM , VigíliaRESUMO
STUDY OBJECTIVES: To examine dose-dependent effects of mandibular advancement on collapsibility of the passive pharynx and sleep-disordered breathing (SDB). DESIGN: Prospective, randomized study. SETTING: University hospital. PATIENTS: Thirty-seven adult patients with SDB. INTERVENTIONS: Oral appliances with 2-, 4-, and 6-mm advancement of the mandible. MEASUREMENTS AND RESULTS: Overnight oximetry was performed with and without oral appliances. Each 2-mm mandibular advancement coincided with approximately 20% improvement in number and severity of nocturnal desaturations. Percentages of patients producing a > 50% improvement rate of the number of desaturations were 25%, 48%, and 65% with use of oral appliances with 2-, 4-, and 6-mm mandibular advancement, respectively. Static pharyngeal mechanics were evaluated in six completely paralyzed patients with SDB under general anesthesia with and without the oral appliances. Advancement of mandibular position was found to produce dose-dependent closing pressure reduction of all pharyngeal segments. Normalization of nocturnal oxygenation was associated with negative closing pressure, especially at the velopharynx. CONCLUSIONS: We conclude that improvement of both nocturnal oxygenation and pharyngeal collapsibility significantly depends on the mandibular position.
Assuntos
Avanço Mandibular , Oxigenoterapia , Faringe/fisiopatologia , Síndromes da Apneia do Sono/fisiopatologia , Adulto , Idoso , Fenômenos Biomecânicos , Ritmo Circadiano , Hospitais Universitários , Humanos , Pessoa de Meia-Idade , Oximetria , Estudos Prospectivos , Síndromes da Apneia do Sono/sangue , Síndromes da Apneia do Sono/terapia , Resultado do TratamentoRESUMO
The velopharynx is the most common site of obstruction in patients with obstructive sleep apnea (OSA). Advancement of the mandible effectively reverses the pharyngeal obstruction. Accordingly, we hypothesized that mandibular advancement increases cross-sectional area of several segments of the upper airway, including the velopharynx and the oropharynx. We examined the pressure-area properties of the pharyngeal airway in 13 patients with OSA. Under general anesthesia and total muscle paralysis, the pharynx was visualized with an endoscope connected to a video-recording system. During an experimentally induced apnea, we manipulated the nasal pressure from 20 cmH2O to the point of total closure at the velopharynx. The procedure was repeated after maximal forward displacement of the mandible. Measurements of the cross-sectional area at different levels of nasal pressure allowed construction of a static pressure-area relationship of the "passive pharynx," where active neuromuscular factors are suppressed. In 12 of 13 patients with OSA, advancement of the mandible stabilized the airway by reducing the closing pressure and increasing the area at any airway pressure. Thus the maneuver shifted the static pressure-area curve of the velopharynx and the oropharynx upward in these patients. We conclude that anterior movement of the mandible widens the retropalatal airway as well as that at the base of the tongue in the passive pharynx of OSA patients.
Assuntos
Mandíbula/fisiopatologia , Faringe/fisiopatologia , Síndromes da Apneia do Sono/fisiopatologia , Adulto , Resistência das Vias Respiratórias , Endoscopia , Humanos , Pessoa de Meia-IdadeRESUMO
Previous studies have shown that, when the pharyngeal muscles are relaxed, the velopharynx is a highly compliant segment of the pharynx. Thus, under these circumstances, cross-sectional area of the velopharynx (AVP), driving pressure across the velopharynx (DeltaP), and inspiratory airflow (VI) will be mutually interdependent variables. The purpose of the present investigation was to describe the interrelation among these three variables during inspiration. We studied 15 sleeping patients with obstructive sleep apnea/hypopnea when the pharyngeal muscles were rendered hypotonic by applying continuous positive airway pressure to the nasal airway. AVP, determined by endoscopic imaging, was significantly greater at onset of VI limitation than at minimum oropharyngeal pressure (P < 0. 01). Snoring was never observed during VI limitation. In a subgroup of six patients, values for DeltaP, VI, and AVP were obtained at 0. 1-s intervals at various levels of mask pressure. For these six patients, the mathematical expression VI = 0.657(AVP/Amax) . DeltaP0. 332, where Amax is maximal AVP, described the relationship among the three variables (R2 = 0.962) for flow-limited and non-flow-limited inspirations. The impedance of the passive velopharynx, defined as DeltaP0.33/V, was inversely related to AVP and increased dramatically when AVP was <0.3 cm2. In summary, we observed a progressive decrease in AVP during flow-limited inspiration in patients with obstructive sleep apnea. This constriction of the velopharynx contributes to an increase in velopharyngeal impedance that, in turn, counterbalances the increase in DeltaP during flow limitation.
Assuntos
Pressão do Ar , Faringe/anatomia & histologia , Faringe/fisiopatologia , Mecânica Respiratória/fisiologia , Síndromes da Apneia do Sono/fisiopatologia , Adulto , Endoscopia , Humanos , Músculos Faríngeos/patologia , Músculos Faríngeos/fisiopatologia , Síndromes da Apneia do Sono/patologiaRESUMO
Anatomic abnormalities of the pharynx are thought to play a role in the pathogenesis of obstructive sleep apnea (OSA), but their contribution has never been conclusively proven. The present study tested this anatomic hypothesis by comparing the mechanics of the paralyzed pharynx in OSA patients and in normal subjects. According to evaluation of sleep-disordered breathing (SDB) by nocturnal oximetry, subjects were divided into three groups: normal group (n = 17), SDB-1 (n = 18), and SDB-2 (n = 22). The static pressure-area relationship of the passive pharynx was quantified under general anesthesia with complete paralysis. Age and body mass index were matched among the three groups. The site of the primary closure was the velopharynx in 49 subjects and the oropharynx in only 8 subjects. Distribution of the location of the primary closure did not differ among the groups. Closing pressure (PC) of the velopharynx for SDB-1 and SDB-2 groups (0.90 +/- 1.34 and 2.78 +/- 2.78 cmH2O, respectively) was significantly higher than that for the normal group (-3.77 +/- 3.44 cmH2O; P < 0.01). Maximal velopharyngeal area for the normal group (2.10 +/- 0.85 cm2) was significantly greater than for SDB-1 and SDB-2 groups (1.15 +/- 0.46 and 1.06 +/- 0.75 cm2, respectively). The shape of the pressure-area curve for the velopharynx differed between normal subjects and patients with SDB, being steeper in slope near Pc in patients with SDB. Multivariate analysis of mechanical parameters and oxygen desaturation index (ODI) revealed that velopharyngeal Pc was the only variable highly correlated with ODI. Velopharyngeal Pc was associated with oropharyngeal Pc, suggesting mechanical interdependence of these segments. We conclude that the passive pharynx is more narrow and collapsible in sleep-apneic patients than in matched controls and that velopharyngeal Pc is the principal correlate of the frequency of nocturnal desaturations.
Assuntos
Faringe/patologia , Síndromes da Apneia do Sono/patologia , Adulto , Pressão do Ar , Anestesia Geral , Índice de Massa Corporal , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Laringoscopia , Masculino , Pessoa de Meia-Idade , Orofaringe/patologia , Oximetria , Análise de RegressãoRESUMO
The static mechanics of the hypotonic pharynx were endoscopically evaluated in nine sleeping patients with obstructive sleep apnea, having a primary narrowing only at the velopharynx. The velopharynx closed completely at a mean pressure of 0.18 +/- 1.21 cmH2O, and the mean half-dilation pressure was 1.93 cmH2O above closing pressure. The dependence of area on pressure was distinctly curvilinear, being steep near closing pressure and asymptotically approaching maximum area (mean = 1.32 cm2). The data for each patient were satisfactorily fitted by an exponential function (mean R2 = 0.98), and a single exponential relationship usefully represented the dependence of relative area on pressure above closing pressure for the population (R2 = 0.85). During the test inspiration, flow limitation was consistently observed when mask pressure exceeded closing pressure by 0.5-3.0 cmH2O. In summary, the static mechanics of the hypotonic velopharynx of patients with obstructive sleep apnea can be described by an exponential pressure-area relationship, with a closing pressure near atmospheric pressure and a high compliance in the range of airway pressure 0-3 cmH2O above closing pressure.
Assuntos
Orofaringe/fisiopatologia , Palato Mole/fisiopatologia , Síndromes da Apneia do Sono/fisiopatologia , Adulto , Pressão do Ar , Diazepam/farmacologia , Eletrocardiografia/efeitos dos fármacos , Eletroencefalografia/efeitos dos fármacos , Eletromiografia , Eletroculografia/efeitos dos fármacos , Feminino , Humanos , Complacência Pulmonar/fisiologia , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio/efeitos dos fármacos , Consumo de Oxigênio/fisiologia , Músculos Faríngeos/fisiologia , Respiração com Pressão PositivaRESUMO
OBJECTIVES/HYPOTHESIS: Although uvulopalatopharyngoplasty (UPPP) is an attractive surgical treatment for obstructive sleep apnea (OSA), the unpredictable outcome limits application of the procedure. Since UPPP corrects only retropalatal airway (RP) patency, we hypothesized that response to UPPP is determined by collapsibility of the retroglossal airway (RG), where UPPP does not correct. METHODS: We estimated closing pressure (Pclose) for each pharyngeal segment by endoscopically obtaining the static pressure/area relationship of the passive pharynx in completely paralyzed and anesthetized patients with sleep-disordered breathing (n = 41) before UPPP. Preferable response to UPPP was defined as the number of oxygen dips (ODI), obtained by nocturnal oximetry, less than 10 h(-1) after UPPP. RESULTS: Patients with negative Pclose at RG responded to UPPP significantly better than those with positive Pclose at RG (22/30 [73%] vs. 3/11 [27%], P<.05). ODI after UPPP was significantly correlated with age, Pclose at RP, and Pclose at RG. CONCLUSIONS: Endoscopic assessment of anatomic abnormality of the pharynx in paralyzed patients with sleep-disordered breathing under general anesthesia has clinical value for the improvement of UPPP outcome.
Assuntos
Faringe/fisiopatologia , Síndromes da Apneia do Sono/fisiopatologia , Síndromes da Apneia do Sono/cirurgia , Úvula/cirurgia , Adulto , Idoso , Endoscopia , Humanos , Pessoa de Meia-Idade , Pressão , Prognóstico , Resultado do TratamentoRESUMO
Three cases of Charcot spinal arthropathy in long-standing (greater than 20 years) paraplegia are presented. In this group of patients with other known chronic infections, the differential diagnosis strongly favored osteomyelitis. Scanning techniques including technetium 99, indium 111, and computed tomography (CT) were used in the extensive work-up and were helpful, although not diagnostic. Closed needle and, in two cases, open biopsies eventually confirmed the diagnosis. The possible occurrence of this neuroarthropathy long after the onset of nonprogressive paraplegia should be kept in mind by those treating spinal cord injured patients.
Assuntos
Artropatia Neurogênica/etiologia , Paraplegia/complicações , Doenças da Coluna Vertebral/etiologia , Idoso , Artropatia Neurogênica/diagnóstico , Diagnóstico Diferencial , Humanos , Masculino , Pessoa de Meia-Idade , Doenças da Coluna Vertebral/diagnóstico , Fatores de Tempo , Tomografia Computadorizada por Raios XRESUMO
Cytologic findings of aspiration smears from 146 histologically confirmed mammary were analyzed in this paper. High cellularity, dispersal of cells in the smears and enlarged nuclei of more than 20 mu in major axis were considered to be useful key points to distinguish carcinoma from benign lesions. Irregular piling, variable nuclear shape, cellular fusion and cytoplasmic inclusions were other common findings in cancer specimens and were scarcely noticed in benign cases. However, in some papillotubular carcinomas the above mentioned characteristics were not so dominant. Scirrhous carcinomas sometimes presented small nuclei in the smears. In some fibroadenomas, the smears were occasionally very cellular and revealed dipersal of cells.
Assuntos
Doenças Mamárias/patologia , Neoplasias da Mama/patologia , Adenocarcinoma Mucinoso/patologia , Adenocarcinoma Esquirroso/patologia , Adenofibroma/patologia , Biópsia por Agulha , Carcinoma/patologia , Núcleo Celular/patologia , Feminino , Humanos , Mastite/patologia , Gravidez , Sarcoma/patologiaRESUMO
Cytologic studies based on the observation of 32 atypical epithelial growths from 31 patients revealed the following characteristics: (1) The nuclei were usually elongated. The mean size of the major axis of the nuclei was most frequently distributed in the range of from 14 to 17mu while the mean size of the minor axis was between 6 and 10mu. (2) The chromatins of the nuclei were fine and showed even to somewhat dense distribution. The nucleolus was inconspicuous. (3) The cells were heaped together. A cellular aggregation was clearly composed of smaller groups of cells in which the polarity of nuclear arrangement was well preserved. Some cells at the periphery of a cellular aggregation were arranged radially toward the outside. The cells were usually cohesive, but in severe grade of atypism, they sometimes showed a scattering tendency. (4) The cells of atypical epithelium seemed to be very insensitive to radiation, compared with carcinoma cells of the stomach.
Assuntos
Mucosa Gástrica/patologia , Gastropatias/patologia , Neoplasias Gástricas/patologia , Adenocarcinoma/patologia , Núcleo Celular/ultraestrutura , Células Epiteliais , Epitélio/ultraestrutura , HumanosRESUMO
The rpIU and rpmA genes that encode ribosomal proteins (r-proteins) L21 and L27 of Escherichia coli K-12 have been isolated from the ordered clone bank of this bacterium. They were found to be located at coordinates 3,351.7-3,352.3 kb on the physical map of E. coli. The nucleotide sequence of the cloned genes and their flanking regions indicated that the two r-protein genes compose an operon. Upstream of the two genes there is an open reading frame (ORF) in the opposite direction. The deduced polypeptide encoded by this ORF has a molecular weight of 35,215 and shows a significant degree of sequence similarity to the enzyme that is involved in the carotenoid biosynthesis and encoded by the crtE gene of carotenogenic bacteria and to prenyltransferases found in various organisms.
Assuntos
Escherichia coli/genética , Genes Bacterianos , Proteínas Ribossômicas/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Códon , DNA Bacteriano , Dados de Sequência Molecular , Fases de Leitura Aberta , Óperon , Mapeamento por Restrição , Homologia de Sequência de AminoácidosRESUMO
The technique of percutaneous transluminal angioplasty (PTA) that was introduced initially by Dotter and Judkins in 1964 has been applied to various arterial stenoses and some occlusive lesions and has advanced dramatically with the development of the Grüntzig catheter in the treatment of peripheral vascular disease. However, the application to occlusive disease in brachiocephalic arteries is still considered to be disputable and has been made only in selective cases, especially in Japan. We report here a case with stenosis of the left subclavian artery successfully treated with PTA. The patient was 66 year-old man, who had been suffering from transient attacks of vertigo, ataxia, visual disturbance and the left arm claudication. Blood pressure was 150/92 mmHg in the right arm and 110 mmHg in systole in the left arm. Diagnostic arteriography identified the right carotid artery occlusion at its origin and significant stenosis in the proximal left subclavian artery. PTA under fluoroscopic control was performed by passing dilating catheter in antegrade fashion by Seldinger method through the left femoral artery. Anatomic correction was achieved without hemorrhagic or embolic complications. Systolic blood pressure gradient measured at the brachial artery level disappeared immediately after PTA and symptomatic relief was obtained completely. One month later, wide patency of the left subclavian artery and sufficient antegrade flow in the vertebral artery were confirmed angiographically. During follow-up period of 4 months, the patient was asymptomatic. We reviewed the literature reporting PTA for occlusive disease in brachiocephalic arteries and discussed its problems and possibilities, especially for the treatment of subclavian artery stenosis.
Assuntos
Angioplastia com Balão , Arteriopatias Oclusivas/terapia , Artéria Subclávia , Idoso , Humanos , Masculino , Síndrome do Roubo Subclávio/etiologiaRESUMO
Proper anesthetic management is necessary to preserve renal function during anesthesia and surgery. Using ultra-sound color Doppler, we examined the influence of sevoflurane on renal medullary blood flow in 20 adult patients without renal dysfunction. After identifying an interlobar artery in the outer medulla, we measured the velocity of the arterial blood flow before induction of anesthesia, and during sevoflurane anesthesia (1 MAC, 1.5 MAC). The minimum velocity of the interlobar arterial blood flow (Vmin) during wakefulness correlated significantly with creatinine clearance measured preoperatively. We did not find any significant change in Vmin after induction of sevoflurane anesthesia, despite significant decreases in mean arterial blood pressure.
Assuntos
Anestésicos Inalatórios/farmacologia , Medula Renal/irrigação sanguínea , Éteres Metílicos/farmacologia , Adulto , Idoso , Velocidade do Fluxo Sanguíneo , Humanos , Medula Renal/diagnóstico por imagem , Pessoa de Meia-Idade , Fluxo Sanguíneo Regional/efeitos dos fármacos , Sevoflurano , Procedimentos Cirúrgicos Operatórios , Ultrassonografia Doppler em CoresRESUMO
Precise determination of the site of obstruction is mandatory for improvement of surgical outcome. The size of the upper airway depends on the balance between the upper airway(UA) muscle activity and intraluminal pressure. Structural property of the UA is considered to be a fulcrum of the balance model. Our final goal is to identify structural abnormalities within the UA. State-dependent and individual variability of the UA muscle activity and luminal pressure makes interpretation of UA size difficult. Measurements of UA size and evaluation of UA collapsibility may be less valuable during wakefulness and sleep without controlling the variability. Two unique approaches to identify the anatomic abnormalities while controlling the UA muscle activity and luminal pressure were reviewed.
Assuntos
Obstrução das Vias Respiratórias/diagnóstico , Apneia Obstrutiva do Sono/complicações , Humanos , Músculo Liso/fisiopatologia , Faringe/patologia , Pressão , Sono/fisiologiaRESUMO
The nocturnal oxygenation of 45 patients with OSAS who had UPPP at our hospital were evaluated by pulse oximetry before and after surgery and at the time more than one year after UPPP. "Successful case" is defined as the case that showed more than 50% reduced oxygen desaturation index(ODI) after UPPP. Twenty seven cases including 15 severe cases(ODI > or = 40) have showed continuously successful ODI for more than one year. We could not get good result in 8 cases, which kept high ODI. Four of them are now using dental appliance. We have recognized the recurrence of sleep apnea in 10 cases that once got successful results just after UPPP. Our report strongly suggests the importance of long-term follow-up after surgery.