Magister Scientiae - MSc / The purpose of this research project was to assess the safety and efficacy of a combination of drugs for conscious sedation in patients undergoing office-based plastic and reconstructive surgery. A pilot study was done to determine the safety of the co-administration of the drugs used in the sedation technique. / South Africa

Magister Scientiae Dentium - MSc(Dent) / This study was done to show that sedation is a safe and a viable option in young children. Dental procedures were done on children aged two to ten years. Two hundred children were included in the study. In all of these children the procedures were completed. Only two children were excluded, because an intravenous line could not be placed on the one child, and the other child was unmanageable under sedation. The safety of sedation was evaluated looking at the incidence of adverse events and complications. No serious adverse effects or complications occurred. The complications that occurred were all corrected with minimal or non-invasive interventions. Only six of the two hundred children required oxygen to correct a drop in oxygen saturation.

Magister Scientiae Dentium - MSc(Dent) / In this case study research project I have determined that multidrug sedation in children younger than eight years are possible.Conscious sedation [or sedation where verbal contact with the patient is possible] can be used successfully to decrease anxiety and fear for unpleasant experiences, like dental procedures. Behaviour therapy in conjunction with one or more drugs can be used to depress the central nervous system in order to decrease the patient’s awareness of unpleasant stimuli. This enables treatment to be carried out without patient interference. Extensive literature surveys were done to determine the ideal drugs as well as the ideal route for conscious sedation in dental treatment for children. In this study project drugs like midazolam, propofol, alfentanyl and ketamine were titrated intravenously to achieve conscious sedation. / South Africa

Univerzita Karlova 1. lékařská fakulta Studijní program: Biomedicína Studijní obor: Preventivní medicína MUDr. Karolína Hronová Polymorfismus genů účastnících se v metabolismu léčiv jako potenciální cíl prevence závažných komplikací léčby u novorozenců a dětí Polymorphism of drug metabolizing enzymes as a potential target of prevention of serious treatment complications in neonates and infants Disertační práce- ABSTRAKT V ANGLICKÉM JAZYCE Školitel: prof. MUDr. Ondřej Slanař, Ph.D. Konzultant: MUDr. Pavla Pokorná, PhD. Praha, 2018 Abstract Background and aims: The safety of analgosedative drugs includes drug interactions, adverse effects, withdrawal syndrome and drug dependence are factors that significantly affect morbidity and mortality. Its prevention is critical for quality improvement of care in paediatric patients. The aim of the thesis was to evaluate the prediction of efficacy and safety of analgosedative drugs sufentanil, midazolam, tramadol and valproic acid in neonates and children based on the occurrence of selected pharmacogenetic biomarkers. The incidence of drug interactions of phenobarbital with other analgosedative drugs has also been evaluated. Methodology: The thesis is based on two studies conducted on Intensive and Resuscitation Care Unit of the Clinic of Paediatric and Adolescent...

Made available in DSpace on 2015-04-14T13:32:55Z (GMT). No. of bitstreams: 1 436763.pdf: 467410 bytes, checksum: f234f7135286713fce26da90200be9a5 (MD5) Previous issue date: 2011-12-21 / Objective : compare the therapeutic efficacy of intramuscular midazolam (IM-MDZ) and intravenous diazepam (IV-DZP) to 529treat seizures in children.Methods : Randomized controlled study enrolling children (2months-14years) presenting seizures admitted to the Pediatric Emergency Department of the Hospital Universit?rio de Santa Maria between August 2010-August 2011; being randomized to receive IV-DZP or IM-MDZ as initial treatment. The groups were compared regarding the length of time to start medication, to interrupt seizures after being medicated and the total length of time to achieve the seizures interruption.Results : Venous access was not obtained in 4 minutes in 4 patients (20%) assigned to the IV-DZP. 32 children completed the study (16 in each group). IV-DZP compared to the IM-MDZ, presented the longest interval to cease seizures (10.6 x 7.3min; p=0.006). Two children of each group (12.5%) the seizures did not stop after 10 minutes, being 3 children transferred to the PICU after tracheal intubation: 1 belonging to the IM-MDZ (6.25%0 and 2 in the IV-DZP group (12.5%). There were not differences regarding adverse effects between the groups (p=0.171): one child in the IM-MDZ presented hypotension (6.3%) and 5 (31%) presented hyperactivity or vomit after receiving IV-DZP.Conclusion : Intramuscular midazolam presented lower interval to cease seizures than IV diazepam. Intrauscular midazolam demonstrate be ans excellent o treat seizures in children as a result of its efficacy, facility and fast administration. / Objetivo : Comparar a efic?cia terap?utica da administra??o de Midazolam Intramuscular (MZ-IM) e do Diazepam Endovenoso (DZP-EV) em crian?as com crise convulsiva.M?todo : Estudo randomizado e controlado, envolvendo crian?as com crise convulsiva (2 meses a 14 anos) admitidas ao servi?o de Emerg?ncia do Hospital Universit?rio de Santa Maria no per?odo de agosto de 2010 a agosto 2011, sendo randomizadas a receber DZP-EV ou MZ-IM como tratamento inicial para convuls?es. Os grupos foram comparados em rela??o ao tempos necess?rio para iniciar a medica??o, para ceder a crise ap?s a administra??o do f?rmaco e o tempo total para ceder a crise.Resultados : N?o foi obtido acesso venoso aos 4 minutos em 4 pacientes (20%) assinalados ao grupo DZP-EV. Resultaram 32 crian?as que completaram o estudo (16 em cada grupo). O DZP-EV apresentou tempo total maior para ceder ? crise convulsiva quando comparado ao MZ-IM (10,6 x 7,3 min; p=0,006). Em 2 crian?as de cada grupo (12,5%) a crise n?o cedeu ap?s 10 minutos de tratamento, 3 crian?as foram transferidos para a UTI pedi?trica, ap?s serem intubadas: 1 (6,25%) do grupo MDZ-IM e 2 (12,5%) do DZP-EV. N?o houve diferen?a quanto a efeitos adversos entre os grupos (p=0,171): uma crian?a (6,3%) apresentou (hipotens?o) ap?s receber MDZ-IM e outras cinco crian?as (31%) apresentaram (hiperatividade ou vomito) ap?s receberem DZP-EV.Conclus?o : Midazolam intramuscular apresentou menor tempo total para ceder a crise convulsiva que o diazepam endovenoso. Midazolam intramuscular mostrou ser excelente op??o no tratamento de crises convulsivas na inf?ncia pela efic?cia, facilidade e rapidez de aplica??o.

Submitted by VINICIUS DIAS KUMPEL null (vinicius.biotec.assis@gmail.com) on 2016-05-10T13:33:15Z No. of bitstreams: 1 Dissertação_Repositório Institucional Unesp.pdf: 6874433 bytes, checksum: 343f11878b45b778f98411f90032c73f (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-05-13T11:50:11Z (GMT) No. of bitstreams: 1 kumpel_vd_me_assis.pdf: 6874433 bytes, checksum: 343f11878b45b778f98411f90032c73f (MD5) / Made available in DSpace on 2016-05-13T11:50:11Z (GMT). No. of bitstreams: 1 kumpel_vd_me_assis.pdf: 6874433 bytes, checksum: 343f11878b45b778f98411f90032c73f (MD5) Previous issue date: 2016-03-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Ainda pouco se conhece a respeito da atividade serotonérgica sobre receptores 5-HT1A no hipocampo ventral na regulação de diferentes tipos de ansiedade. O Labirinto em T elevado (LTE) é um teste que avalia separadamente dois subtipos de ansiedade: a ansiedade generalizada e o pânico, respectivamente através da avaliação dos comportamentos defensivos de esquivas inibitórias e das fugas. Assim, este estudo teve por objetivo investigar o envolvimento de receptores 5-HT1A no HV sobre a manifestação dos transtornos de ansiedade generalizada (TAG) e pânico (TP) no LTE, tendo como parâmetro a ativação de receptores gabaérgicos (GABAA) nessa área do hipocampo. Foram conduzidos dois experimentos em ratos Wistar: o Experimento 1, visando avaliar o efeito do midazolam (10, 20 ou 40nmol) - um benzodiazepínico que potencializa a ação do GABA em receptores GABAA; e o Experimento 2, para avaliar o efeito de 8-OH-DPAT (0,6, 3 ou 15nmol) – um agonista de receptores 5-HT1A. Animais dos grupos controles nos dois experimentos foram tratados com salina. Dez minutos após as microinjeções foram submetidos ao LTE para avaliação das latências (em segundos) para esquivas e fugas. Imediatamente após, os animais foram colocados no centro da arena para avaliação da atividade motora (número de quadrados percorridos). Os resultados apontaram que a maior dose de midazolam microinjetada no hipocampo ventral causou ansiólise, comprovada pela diminuição na latência das esquivas em relação aos animais controles e àqueles tratados com 10nmol do mesmo fármaco. Resultado semelhante foi constatado nas três doses de 8-OH-DPAT. Não se observou qualquer alteração nas fugas, e nem na atividade motora dos animais tratados com qualquer um dos fármacos testados. Essas evidências comportamentais indicam que a ativação de receptores 5-HT1A no HV diminuiu o comportamento de esquiva dos animais, sem afetar as respostas de fugas, semelhantemente ao que se observou em decorrência da ação do midazolam sobre receptores GABAA. Esses resultados indicam um envolvimento desses receptores na regulação do TAG, mas não do TP. / The little is known about the serotoninergic activity on 5-HT1A receptors in the ventral hippocampus in the regulation of different types of anxiety. The Elevated T Maze (ETM) is a test that evaluates separately two subtypes of anxiety: generalized anxiety and panic, respectively by evaluating the defensive behaviors of inhibitory avoidance and escapes. Therefore this study aimed to investigate the involvement of 5-HT1A receptors in VH on the manifestation of generalized anxiety disorder (GAD) and Panic (PD) in ETM, having as parameter the activation of gabaergic receptors (GABAA) in that area of the hippocampus. Two experiments were conducted in rats: Experiment 1, to evaluate the effect of midazolam (10, 20 or 40nmol) – a benzodiazepine that potentiates the action of the GABA on GABAA receptors; and Experiment 2 to evaluate the effect of 8-OH-DPAT (0.6, 3 or 15nmol) - an agonist of 5-HT1A receptors. Animal control groups in both experiments were treated with saline. Ten minutes after microinjection, the animals were submitted for evaluation to the ETM latencies (in seconds) for avoidances and escapes. Immediately after, the animals were placed in the center of the arena to eavaluation of motor activity (number of covered squares). The results showed that the highest dose of midazolam microinjected in the ventral hippocampus caused anxiolysis, evidenced by the decrease in latency of avoidances compared to controls and those treated animals 10nmol of the same drug. A similar result was observed at all three doses of 8-OH-DPAT. There was no change in the escapes, nor the motor activity of animals treated with any of the drugs tested. These behavioral evidence indicates that activation of 5-HT1A receptors in VH decreases the behavior of avoidance of the animals without affecting the escape response, similar to what was observed due to the action of midazolam on the GABAA receptors. These results indicate an involvement of these receptors in the regulation of GAD, but not of PD.

Made available in DSpace on 2014-06-11T19:33:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-30Bitstream added on 2014-06-13T21:05:39Z : No. of bitstreams: 1 menezes_tec_dr_araca.pdf: 231708 bytes, checksum: 9b342af7faf18025f1ee1db5e5205661 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste estudo foi observar resultados de procedimentos odontológicos realizados em pessoas com deficiência, sob sedação consciente com Midazolam, via endovenosa, realizados no Centro de Assistência Odontológica à Pessoa com Deficiência, da Faculdade de Odontologia de Araçatuba – UNESP. Acompanhou-se 460 procedimentos, independente do gênero, idade ou deficiência dos pacientes, que não permitiram a realização de tratamento odontológico previamente. Os resultados foram classificados como sucesso (quando realizados sem problemas, ainda que necessária contenção auxiliar suave, ou houve algum problema contornável, mas os procedimentos planejados puderam ser realizados) e insucesso (quando não foi possível a realização do tratamento planejado). Registrou-se, ainda, o uso de medicamentos pelos pacientes e as prováveis causas de insucesso. A pressão arterial, freqüência cardíaca, saturação de oxigênio e temperatura corporal foram monitorados antes, durante e após o procedimento. As dosagens de Midazolam administradas foram entre 05 a 60mg, de acordo com o peso corporal do paciente. Na maioria dos casos, foi possível a realização do tratamento planejado, sem danos aos pacientes nem à equipe odontológica e os sinais vitais se mantiveram dentro de valores normais. A sedação consciente com Midazolam, via endovenosa, pode ser considerada uma alternativa eficaz para o tratamento odontológico em pessoas com deficiência não colaboradores / The objective of this study was to observe the results of dental procedures performed in disable persons under conscious sedation with Midazolam, intravenously, assisted at the Dental Care Center for Patients with Special Needs, School of Dentistry of Araçatuba - UNESP. 460 procedures were observed, regardless of gender, age or disability of the patients, which did not allow their dental treatment realization. The results were classified as success (when carried out without problems, even it was necessary restraint gentle help, or there was some manageable problem, but the planned procedures could be performed) and failure (when it was not possible to perform the planned treatment). It was also recorded, the use of medicines by patients and the probable causes of failure results. Blood pressure, heart rate, oxygen saturation and body temperature were monitored before, during and after the procedure. The doses of Midazolam were administered between 05 to 60mg, according to the patient's body weight. In most cases it was possible to perform the planned treatment without problems to the patients or to the dental staff and their vital signs remained within normal values. The conscious sedation with Midazolam, intravenously, can be considered an effective alternative for dental treatment to disable persons not employees

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2014-11-20T13:17:10Z No. of bitstreams: 2 Dissertação - Sarah Barboza Martins - 2013.pdf: 2809487 bytes, checksum: bf21b99c3be3beb9a86f860a74b72247 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-11-20T14:32:05Z (GMT) No. of bitstreams: 2 Dissertação - Sarah Barboza Martins - 2013.pdf: 2809487 bytes, checksum: bf21b99c3be3beb9a86f860a74b72247 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-11-20T14:32:05Z (GMT). No. of bitstreams: 2 Dissertação - Sarah Barboza Martins - 2013.pdf: 2809487 bytes, checksum: bf21b99c3be3beb9a86f860a74b72247 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-08-15 / The availability of blood products for cats is low, with one of the determining factors the requirement of sedation or anesthesia for blood collection. The blood pressure measurement is routine in clinical and anesthesiology, and may be used either the indirect methods, with easy implementation and low risk to the animals, or the direct method, more reliable. This study evaluated the safety of two anesthetic protocols and accuracy of two methods of indirect blood pressure measurement for blood collection in cats. We used five animals weighing 4.3 ± 0.5 kg submitted to two different anesthetic protocols at intervals of 30 days. For the femoral artery and jugular vein catheterization, the animals were anesthetized with isoflurane. Thirty minutes after end of instrumentation, anesthesia was again induced and maintained either with isoflurane (GI) or ketamine (10 mg/kg) and midazolam (0.2 mg / kg) (GCM) IM. After that we collected the whole blood (53mL) and replaced volume with ringer's lactate solution (20 mL / kg), and then allowed the anesthetic recovery. We analyzed the cardiac (FR) and respiratory (f) rate, the systolic (PAS), diastolic (PAD) and mean (PAM) arterial pressure with direct and oscillometric method, and PAS with Doppler ultrasound; oxyhemoglobin saturation ( SpO2) and central venous pressure (PVC). It were also collected arterial blood samples for analysis of blood gases and electrolytes. Animals were evaluated before induction to blood collection (T0), immediately after induction (Tind), immediately after blood collection (Tcol) and after volume replacement (Trep). Tha PAS, PAD and PAM obtained by oscillometric and Doppler methods were compared to invasive method in GCM when animals were awake (CONS), anesthetized (ANEST) and after collection of blood (HIPOV). All animals had PAS, PAD and PAM decreased at Tcol. There was no statistical difference between the groups in any variable evaluated. Both indirect methods of blodd pressure measurement underestimated the blood pressure at CONS e ANEST, although the Doppler method had better correlation with the direct method. We conclude that isoflurane and ketamine/midazolam anesthesia are safe and efficient for blood collection in cats. Between the two indirect methods of blood pressure evaluated, the Doppler method had the best accuracy for measurement of PAS during the blood collection process in cats. Knowing the underestimation of the blood pressure obtained, it is recommended to consider not just the values obtained, but also the clinical signs like pulse quality and membrane mucosa color, to detection of hypotension with indirect methods. / A disponibilidade de derivados sanguíneos em felinos é baixa, sendo um dos fatores determinantes a obrigatoriedade de sedação ou anestesia para a colheita de sangue. A aferição da pressão arterial é rotineira na clínica e na anestesiologia, podendo ser utilizados os métodos indiretos, de fácil execução e baixo risco para os animais, ou o método direto, mais fidedigno. Neste estudo foi avaliada a segurança de dois protocolos anestésicos e a acurácia de dois métodos indiretos de aferição da pressão arterial comparados ao método direto, para colheita de sangue em gatos. Foram utilizados cinco animais pesando 4,3±0,5 kg submetidos a dois protocolos anestésicos diferentes com intervalo de 30 dias. Para a cateterização da artéria femoral e da veia jugular, os animais foram anestesiados com isofluorano e ao final foi permitida a recuperação anestésica. Trinta minutos após o final da instrumentação, a anestesia foi induzida e mantida novamente com isofluorano (GI) ou com cetamina (10mg/kg) e midazolam (0,2mg/kg) via IM (GCM). Em seguida, realizou-se colheita de sangue total (53mL) e reposição volêmica com solução de Ringer com lactato (20 mL/kg), para então permitir a recuperação anestésica. Foram avaliadas as frequências cardíaca (FC) e respiratória (f); as pressões arteriais sistólica (PAS), diastólica (PAD) e média (PAM), pelos métodos invasivo e oscilométrico e a PAS pelo uso de Doppler vascular; a saturação periférica da oxihemoglobina (SpO2) e a pressão venosa central (PVC). Foram ainda colhidas amostras de sangue arterial para análise dos gases sanguíneos e dos eletrólitos. Os animais foram avaliados antes da indução para colheita (T0), imediatamente após a indução (Tind), imediatamente após a colheita (Tcol) e depois da reposição volêmica (Trep). A PAS, PAD e PAM obtidas pelo método oscilométrico e a PAS obtida pelo Doppler vascular foram comparadas às obtidas pelo método invasivo nos animais do GCM quando acordados (CONS), anestesiados (ANEST) e após a colheita do sangue (HIPOV). Todos os animais apresentaram diminuição da PAS, PAD e PAM em Tcol. Não houve diferença estatística entre os grupos em nenhuma variável avaliada. Os dois métodos indiretos subestimaram a pressão arterial no momento CONS e ANEST, contudo o método Doppler Vascular apresentou melhor correlação com o método direto. Concluiu-se que a anestesia com isofluorano ou cetamina-midazolam é segura e eficiente para colheita de sangue em gatos. Dos métodos indiretos avaliados o Doppler foi mais acurado para aferição da PAS durante o processo de colheita de sangue em gatos. Tendo em vista a subestimação dos valores, deve-se por tanto considerar, além do valor obtido, as variáveis clinicas como qualidade de pulso e coloração das mucosas para detecção de hipotensão pelos métodos indiretos.

Dental caries is a preventable multifactorial infectious disease which results from the overall impact of biological, behavioural and psychosocial factors. The environment of every individual plays a role in its aetiology, too. The content and form of the diet, regularly performed oral hygiene, fluoride intake and continuous dental care act as an unquestionable part in the prevention of dental caries. "Quality of life" or "well-being" is nowadays an emphasized aspect in most of the studies. There is one factor linked to the well-being of a child discussed on a field of paediatric dentistry - the dental fear. The four following studies presented in this dissertation describe the above mentioned topic. The first surveys the dentist's relationship with the child patients and looks for the reasoning why the children were referred to the faculties and specialists. The second pursues the environmental factors which influence the perception of dental environments in pre-schoolers and the fear of even the most common dental procedures. The third performs an evaluation of the dental fear level in a sample of preschool children in the Czech Republic, with correlation to their dental status and geographic location. This study also deals with a possible use of colours as another tool for dental fear evaluation...

Introdução: A pressão crítica de fechamento da faringe (PCrit) é a pressão nasal em que há colapso da faringe. Conceitualmente a Pcrit reflete a contribuição anatômica na gênese da apnéia obstrutiva do sono (AOS). No entanto, a relação entre a PCrit e a anatomia das vias aéreas superiores (VAS) tem sido pouco estudada. A PCrit determinada durante o sono requer pesquisadores experientes durante a noite. A indução do sono com midazolam é usada na prática clínica para a realização de procedimentos ambulatoriais e poderia ser uma alternativa mais conveniente para se determinar a Pcrit. Porém, o midazolam pode provocar sedação além de simples indução do sono, reduzir a atividade muscular das VAS e aumentar a colapsabilidade quando comparado com o sono normal. Objetivos: 1. validar a determinação da PCrit durante o dia após a indução do sono com midazolam; 2. comparar a arquitetura do sono induzido com baixa dose de midazolam com o sono natural; 3. correlacionar a PCrit com a anatomia das VAS. Métodos: Homens com graus variados de sintomas sugestivos de AOS foram submetidos a polissonografia completa noturna, determinação da PCrit durante o sono natural e após a indução do sono com midazolam bem como tomografia computadorizada de cabeça e pescoço para avaliação das VAS. Resultados: Foram estudados 15 sujeitos com idade (média±DP) de 54 ± 10 anos, índice de massa corporal de 29,9 ± 3,9 kg/m2 e índice de apnéiahipopnéia (IAH) de 38 ± 22 (variação: 8-66 eventos/h). A indução do sono foi obtida em todos os sujeitos, utilizando doses mínimas de midazolam (mediana [intervalo interquartil]) (2,4 [2,0-4,4] mg). A PCrit durante o sono natural e induzido foram semelhantes (-0,82 ± 3,44 e -0,97 ± 3,21 cmH2O, P = 0,663) e se associaram (coeficiente de correlação intraclasse=0,92 (IC 95% 0,78-0,97 P<0,001). A distribuição das fases do sono durante sono natural e induzido foi similar, com excessão da fase 1 (10,5 ± 5,1% vs. 20,6 ± 8,1, respectivamente; P=0,001). A Pcrit determinada durante o sono natural e induzido se correlacionaram com o IAH (r=0,592, P=0,020 e r=0,576, P=0,025, respectivamente). Além disso tanto a Pcrit determinada por sono natural e induzido se correlacionaram com diversas variáveis tomográficas de VAS, incluindo a posição do osso hióide, ângulo da base do crânio e as áreas seccionais da velofaringe e hipofaringe (r variando de 0,577 a 0,686, P<0,05). A regressão linear múltipla revelou que o IAH foi independentemente associado com a Pcrit durante sono induzido, circunferência da cintura e idade (r2 = 0,785, P = 0,001). Conclusão: A PCrit determinada durante o dia com indução do sono é semelhante à determinada durante o sono natural e é um método alternativo promissor para determinar a PCrit. O sono induzido por doses baixas de midazolan promove um sono similar ao sono natural. A Pcrit determinada tanto durante o sono natural e induzido correlaciona-se com várias características anatômicas das VAS / Introduction: The pharyngeal critical closing pressure (Pcrit) is the nasal pressure at which the airway collapses. Pcrit is thought to reflect the anatomical contribution to the genesis of obstructive sleep apnea (OSA). However, the relationship between Pcrit and upper airway anatomy has been poorly investigated. Pcrit determined during sleep requires experienced investigators at night. Sleep induction with midazolam is frequently used in clinical practice during ambulatory procedure and could be a more convenient alternative to assess Pcrit. On the other hand, midazolam could induce sedation rather than sleep, decrease upper airway muscle activity and increase collapsibility compared with natural sleep. Objectives: 1. validate Pcrit determination during the day after sleep induction with midazolam; 2. compare the sleep architecture of induced sleep after low doses of midazolam with natural sleep; 3.correlate Pcrit with upper airway anatomy. Methods: Men with different severity of OSA symptoms underwent baseline full polysomnography, Pcrit determination during natural sleep and after sleep induction with midazolam and head and neck computed tomography. RESULTS: Fifteen men aged (mean±SD) 54±10ys, body mass index=29.9 ± 3.9 Kg/m2 and apnea hypopnea index=38±22, range: 8-66 events/h were studied. Sleep induction was obtained with minimum doses of midazolam (median[interquartile range] (2.4 [2.0-4.4] mg). Sleep phase distribution during natural and induced sleep was similar, except for stage 1 (10.5 ± 5.1% vs. 20.6 ± 8.1, respectively; P=0.001). Natural and induced sleep Pcrit were similar (-0.82 ± 3.44 and -0.97 ± 3.21 cmH2O, P=0.663) and closely associated (intraclass correlation coefficient=0.92 (95%CI 0.78-0.97, P<0.001). Natural and sleep induced Pcrit correlated with AHI (r=0.592, P=0.020; r=0.576, P=0.025, respectively). Pcrit determined both during natural and induced sleep were significantly associated with several tomographic variables, including hyoid position, cranial base angle and cross sectional areas of the velopharynx and hypopharynx (r range: 0.577 to 0.686, P<0.05). Multiple linear regression revealed that AHI was independently associated with induced sleep Pcrit, waist circumference and age (r2=0.785, P=0.001). Conclusion: Pcrit determined during the day with sleep induction is similar to natural sleep and is a promising alternative method to determine Pcrit. Sleep induction with small doses of midazolam promoted sleep similar to natural sleep. Pcrit determined both during natural and induced sleep correlates with several anatomical characteristics of the upper airway