Hypoxemia during procedural sedation in adult patients: a retrospective observational study.

PURPOSE: Since 2010, new guidelines for procedural sedation and the Helsinki Declaration on Patient Safety have increased patient safety, comfort, and acceptance considerably. Nevertheless, the administration of sedatives and opioids during sedation procedures may put the patient at risk of hypoxemia. However, data on hypoxemia during procedural sedation are scarce. Here, we studied the incidence and severity of hypoxemia during procedural sedations in our hospital. METHODS: A historical, single-centre cohort study was performed at the University Medical Centre Utrecht (UMCU), a tertiary centre in the Netherlands. Data from procedural sedation in our hospital between 1 January 2011 and 31 December 2018 (3,459 males and 2,534 females; total, 5,993) were extracted from our Anesthesia Information Management System. Hypoxemia was defined as peripheral oxygen saturation < 90% lasting at least two consecutive minutes. The severity of hypoxemia was calculated as area under the curve. The relationship between the severity of hypoxemia and body mass index (BMI), American Society of Anesthesiologists (ASA) Physical Status classification, and duration of the procedure was investigated. The primary outcome was the incidence of hypoxemia. RESULTS: Twenty-nine percent of moderately to deeply sedated patients developed hypoxemia. A high incidence of hypoxemia was found in patients undergoing procedures in the heart catheterization room (54%) and in patients undergoing bronchoscopy procedures (56%). Hypoxemia primarily occurred in longer lasting procedures (> 120 min) and especially in the latter phases of the procedures. There was no relationship between severity of hypoxemia and BMI or ASA Physical Status. CONCLUSIONS: This study showed that a considerable number of patients are at risk of hypoxemia during procedural sedation with a positive correlation shown with increasing duration of medical procedures. Additional prospective research is needed to investigate the clinical consequences of this cumulative hypoxemia.

RéSUMé: OBJECTIF: Depuis 2010, les nouvelles lignes directrices pour la sédation procédurale et la Déclaration d'Helsinki concernant la sécurité des patients ont considérablement augmenté la sécurité, le confort et l'acceptation des patients. L'administration de sédatifs et d'opioïdes pendant les interventions sous sédation peut toutefois mettre le patient à risque d'hypoxémie. Cependant, les données concernant l'hypoxémie pendant une sédation procédurale sont rares. Ici, nous avons étudié l'incidence et la sévérité de l'hypoxémie pendant la sédation procédurale dans notre hôpital. MéTHODE: Une étude de cohorte historique monocentrique a été réalisée au Centre médical universitaire d'Utrecht (UMCU), un centre tertiaire aux Pays-Bas. Les données des sédations procédurales réalisées dans notre hôpital entre le 1er janvier 2011 et le 31 décembre 2018 (3459 hommes et 2534 femmes; au total, 5993 patients) ont été extraites de notre système de gestion de l'information en anesthésie. L'hypoxémie a été définie comme une saturation périphérique en oxygène < 90 % durant au moins deux minutes consécutives. La sévérité de l'hypoxémie a été calculée en tant que surface sous la courbe. Les relations entre la sévérité de l'hypoxémie et l'indice de masse corporelle (IMC), la classification du statut physique selon l'American Society of Anesthesiologists (ASA) et la durée de l'intervention ont été étudiées. Le critère d'évaluation principal était l'incidence d'hypoxémie. RéSULTATS: Vingt-neuf pour cent des patients sous sédation modérée à profonde ont développé une hypoxémie. Une incidence élevée d'hypoxémie a été observée chez les patients subissant des interventions en salle d'hémodynamie (54 %) et chez les patients subissant des bronchoscopies (56 %). L'hypoxémie est principalement survenue lors d'interventions plus longues (> 120 min) et particulièrement dans les phases plus tardives des interventions. Aucune relation n'a été observée entre la sévérité de l'hypoxémie et l'IMC ou le statut physique ASA. CONCLUSION: Cette étude a démontré qu'un nombre considérable de patients sont à risque d'hypoxémie pendant la sédation procédurale, une corrélation positive ayant été démontrée avec une durée prolongée des interventions médicales. D'autres recherches prospectives sont nécessaires pour étudier les conséquences cliniques de cette hypoxémie cumulée.

First clinical experience with a dedicated MRI-guided high-intensity focused ultrasound system for breast cancer ablation.

OBJECTIVES: To assess the safety and feasibility of MRI-guided high-intensity focused ultrasound (MR-HIFU) ablation in breast cancer patients using a dedicated breast platform. METHODS: Patients with early-stage invasive breast cancer underwent partial tumour ablation prior to surgical resection. MR-HIFU ablation was performed using proton resonance frequency shift MR thermometry and an MR-HIFU system specifically designed for breast tumour ablation. The presence and extent of tumour necrosis was assessed by histopathological analysis of the surgical specimen. Pearson correlation coefficients were calculated to assess the relationship between sonication parameters, temperature increase and size of tumour necrosis at histopathology. RESULTS: Ten female patients underwent MR-HIFU treatment. No skin redness or burns were observed in any of the patients. No correlation was found between the applied energy and the temperature increase. In six patients, tumour necrosis was observed with a maximum diameter of 3-11 mm. In these patients, the number of targeted locations was equal to the number of areas with tumour necrosis. A good correlation was found between the applied energy and the size of tumour necrosis at histopathology (Pearson = 0.76, p = 0.002). CONCLUSIONS: Our results show that MR-HIFU ablation with the dedicated breast system is safe and results in histopathologically proven tumour necrosis. KEY POINTS: • MR-HIFU ablation with the dedicated breast system is safe and feasible • In none of the patients was skin redness or burns observed • No correlation was found between the applied energy and the temperature increase • The correlation between applied energy and size of tumour necrosis was good.