Prevalence of malignant hyperthermia diagnosis in obstetric patients in the United States, 2003 to 2014

Background The cost-benefit of stocking dantrolene in maternity units for treating malignant hyperthermia (MH) has been recently questioned because of the low incidence of MH crisis in the general population and the low utilization of general anesthesia in obstetrics. However, no study has examined the prevalence of MH susceptibility in obstetrics. This study aimed to assess the prevalence of MH diagnosis and associated factors in obstetric patients. Methods Data for this study came from the National Inpatient Sample from 2003 to 2014, a 20% nationally representative sample of discharge records from community hospitals. A diagnosis of MH due to anesthesia was identified using the International Classification of Diseases, Ninth Revision, Clinical Modification code 995.86. MH prevalence was estimated according to the delivery mode and patient and hospital characteristics. Results During the 12-year study period, 47,178,322 delivery-related discharges [including 15,175,127 (32.2%) cesarean deliveries] were identified. Of them, 215 recorded a diagnosis of MH, yielding a prevalence of 0.46 per 100,000 [95% confidence interval (CI), 0.40 to 0.52]. The prevalence of MH diagnosis in cesarean deliveries was 0.81 per 100,000 (95% CI, 0.67 to 0.97), compared with 0.29 per 100,000 (95% CI, 0.23 to 0.35) in vaginal deliveries (P <  0.001). Multivariable logistic regression revealed that cesarean delivery was associated with a significantly increased risk of MH diagnosis [adjusted rate ratio (aOR) 2.88; 95% CI, 2.19 to 3.80]. Prevalence of MH diagnosis was lower in Hispanics than in non-Hispanic whites (aOR 0.47; 95% CI, 0.29 to 0.76) and higher in the South than in the Northeast census regions (aOR 2.44; 95% CI, 1.50 to 3.96). Conclusion The prevalence of MH-susceptibility is about 1 in 125,000 in cesarean deliveries, similar to the prevalence reported in non-obstetrical surgery inpatients. The findings of this study suggest that stocking dantrolene in maternity units is justified

Assessment of pain during labor with pupillometry: a prospective observational study.: Pupillometry and labor pain

International audienceBACKGROUND: Pain intensity is usually self-rated by patients with a numeric rating scale (NRS) but this scale cannot be used for noncommunicating patients. In anesthetized patients, experimental noxious stimulus increases pupillary diameter (PD) and pupillary light reflex amplitude (PLRA), the difference between PD before and after light stimulation. Labor pain is an intense acute nonexperimental stimulus, effectively relieved by epidural analgesia. In this prospective observational study, we therefore describe the effects of labor pain and pain relief with epidural analgesia on PD and PLRA, determine their association with pain intensity and determine the ability of a single measurement of PD or PLRA to assess pain. METHODS: In the first stage, pain (11-point NRS), PD, and PLRA were measured in 4 conditions in 26 laboring women: before and after epidural analgesia and in the presence and absence of a uterine contraction. Pupillometry values among the 4 conditions were compared, and the strength of the association between absolute values of pain and PD or PLRA and between pain and changes in PD or PLRA brought about by uterine contraction was assessed with r(2). In the second stage, 1 measurement was performed in 104 laboring women. The strength of the association between pain and PD or PLRA was assessed with r(2). The ability of PD or PLRA to discriminate pain (NRS > 4) was also assessed. RESULTS: In the first stage, a statistically significant increase in pain, PD, and PLRA was observed during a contraction, and this change was abolished after epidural analgesia. The r(2) for the association between pain and changes in PD (r(2) = 0.25 [95% confidence interval, 0.07-0.46] or PLRA (r(2) = 0.34 [0.14-0.56]) brought about by a uterine contraction was higher than the r(2) for the association between pain and absolute values of PD (r(2) = 0.14 [0.04-0.28]) or PLRA (r(2) = 0.22 [0.10-0.37]) suggesting a stronger association for changes than for absolute values. In the second stage, r(2) was 0.23 [0.10-0.38] for PD and 0.26 [0.11-0.40] for PLRA and the area under the receiver operating characteristics curve was 0.82 [0.73-0.91] and 0.80 [0.71-0.89], respectively. CONCLUSIONS: Changes in PD and PLRA brought about by a uterine contraction may be used as a tool to assess analgesia in noncommunicating patients

Identification, évaluation et utilité clinique de marqueurs non invasifs de la douleur et du stress en anesthésie obstétricale

Les techniques d'anesthésie, péridurale ou rachianesthésie, utilisées lors de l' accouchement peuvent être associées à une hypotension artérielle liée au stress maternel, à une analgésie insuffisante et à des difficultés de réalisation. L'utilisation de marqueurs non invasifs de ces 3 événements permettrait d'instaurer des mesures correctrices en temps réel L'amylase salivaire (AS) est un marqueur de stress, sécrétée en réponse à une stimulation sympathique. L'identification d'une réponse au stress par une augmentation de TAS nécessite de définir sa variabilité. Nous avons calculé chez 18 volontaires un référence change value (RCV) de TAS ou différence biologiquement significative entre 2 mesures de 76% à partir de la variabilité liée à la mesure biologique et de la variabilité liée au patient. Nous avons mis en évidence une augmentation de TAS supérieure au RCV chez 13 patientes parmi 15 bénéficiant d'une césarienne programmée lors de leur transfert au bloc opératoire. La douleur est autoévaluée par une échelle verbale numérique (EVN) non utilisable en cas de barrière de communication. Une augmentation du diamètre pupillaire (PD) et de l'amplitude du réflexe photomoteur (PLRA), différence entre PD avant et après une stimulation lumineuse, est observée lors d'une douleur expérimentale mais n'a pas été étudiée pendant une douleur spontanée comme celle du travail obstétrical. Chez 28 patientes en travail, nous avons montré une association entre l'EVN, PD et PLRA. Nous avons évalué ces marqueurs chez 104 patientes et déterminé une valeur seuil et son intervalle de confiance basée sur un compromis entre sensibilité et spécificité et une technique de minimisation de coût. L'utilité clinique de ces marqueurs a été évaluée par les courbes de décision. L'identification des facteurs de risque (FDR) de péridurale difficile n'a pas été réalisée en obstétrique. Sur une cohorte prospective de 330 patientes, nous avons identifié 3 FDR de péridurale difficile qui ont permis de construire un score de prédiction et de définir 3 groupes de risque (faible, intermédiaire et élevé). Une règle de décision clinique ( utiliser une technique d'aide à la réalisation de la péridurale dans le groupe à haut risque ) est proposée et son utilité clinique évaluée par courbes de décision. L'utilisation en pratique clinique des 3 marqueurs étudiés pourrait permettre d'améliorer la qualité des soin anesthésiques. Ces 3 études de preuve de concept doivent être complétées par des études d'impact.Neuraxial techniques used in obstetric anesthesia (i.e. epidural or spinal techniques) can be associated with hypotension related to maternal stress, inadequate analgesia or procedural technical difficulty. The use of markers predicting these 3 events could help implement real-time corrective measures. Salivary amylase (SA) is a stress marker, secreted in response to sympathetic stimulation. However, identification of a stress response based on SA increase requires to determine SA variability. We have calculated in 18 volunteers the reference change value (RCV) for SA or biologically significant difference between two measurements of 76%. In 13 out of 15 patients undergoing planned cesarean section, we have observed an increase in SA greater than the RCV during transfer from the ward to the operating room. Pain is self-rated by patients with numeric rating scale (NRS) but cannot be used in case of communication barrier. Increase in pupiliary diameter (PD) and in pupillary light reflex amplitude (PLRA), the difference in PD after and before a retinal flashlight stimulation, is observed during an experimental noxious stimulation. Nevertheless, PD and PLRA have not been assessed during a natural noxious stimulation such as labor pain. In 28 laboring women, we have observed an association between NRS and PD or PLRA. We have assessed PD and PLRA in 104 laboring women and calculated a threshold value with its 95% confidence interval to diagnose pain based on a balance between sensitivity and specificity or a cost-minimization technique. The clinical usefulness of these markers has been assessed with decision curves. Identification of risk factors for difficult epidural placement (DEP) has not been performed in obstetrics. We have prospectively identified in a cohort of 330 laboring women 3 risk factors for DEP and built a prediction score defining 3 risk groups of DEP (low-, intermediate- and high-risk groups). A clinical decision rule ("intervene in high-risk group patients") has been suggested and its clinical usefulness assessed with decision curves. Use in clinical practice of these 3 markers may improve anesthetic care. However, these 3 proof-of-concept studies should be confirmed with impact studies.PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Les hyponatrémies post-opératoires précoces repondent-elles à un mécanisme de translocation ou de dilution

Les hyponatrémies sont le trouble métabolique le plus fréquent de la période postopératoire et peuvent conduire à des complications graves. Elles résultent à la fois d'une balance en eau sans electrolyse (ESE) positive et d'une libération d'hormone antidiurétique. Pendant la chirurgie, l'augmentation de la perméabilité membranaire serait responsable de la fuite de solutés intracellulaires aboutissant à une augmentation de l'osmolalité extracellulaire, à un transfert d'eau intracellulaire vers le secteur extracellulaire et à une chute de natrémie, concept denommé " Sick cell syndrome ". Cette hyponatrémie de redistribution s'accompagnerait d'une augmentation du trou osmalaire (TO) en raison de la libération de subtances osmotiquement actives dans le sang. L'objectif de ce travail etait de déterminer si les hyponatrémies postopératoires résultaient d'une accumulation de subtances osmotiquement actives ou d'une balance en ESE positive.Il s'agit d'une étude prospective ouverte réalisée à l'Hopital Bichat pendant 5 mois consécutifs. Trente-trois patients devant subir une intervention pour prothèse de hanche programmée sous anesthésie générale ont été inclus. Ils ont été divisé en 2 groupes selon que la natrémie postopératoire diminuait de 2 mmol/L (groupe1) ou 2 mmol/L (groupe 2)...?Les hypotranémies postopératoires précoces semblent résulter d'une accumulation de subtances osmotiquement actives dans le sang (hyponatrémie de translocation) et non d'une balance de l'eau sans électrolyte positive (hypotranémie de dilution).PARIS7-Villemin (751102101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Assessment of salivary amylase as a stress biomarker in pregnant patients.: Salivary alpha-amylase: a stress biomarker in pregnant patients

International audienceBACKGROUND: Chronic stress during pregnancy has been associated with worsened maternal and fetal outcomes. Acute stress immediately before spinal anaesthesia for caesarean section may contribute to hypotension. Therefore objective measures of acute stress may help identify women at risk of adverse outcomes. Salivary alpha-amylase is a stress biomarker that has so far been poorly investigated during pregnancy. The reference change value is the difference between two sequential results that must be exceeded for a change to be considered clinically relevant. Our first aim was to determine if salivary alpha-amylase increased in pregnant patients when subjected to the stress of transfer to the operating room. Our second aim was to determine if changes in salivary alpha-amylase were likely to be clinically significant by measuring reference change value in healthy volunteers. METHODS: In 15 pregnant patients undergoing planned caesarean section under spinal anaesthesia, salivary alpha-amylase, systolic blood pressure, heart rate, and immediate anxiety were measured on the morning of surgery on the ward and again in the operating room. The reference change value was calculated from 18 healthy volunteers. RESULTS: A median 220% increase in salivary alpha-amylase activity (P=0.0015) and a 17% increase in systolic blood pressure (P=0.0006) were observed between the ward and operating room. No changes of immediate anxiety or heart rate were observed. Reference change value was ±76% in volunteers and 13 of the 15 pregnant patients had a salivary alpha-amylase increase greater than the reference change value. CONCLUSION: When pregnant women are taken to the operating room, a clinically and statistically significant increase in salivary alpha-amylase was observed. Further studies are required to define its clinical usefulness

Pain assessment in the postanaesthesia care unit using pupillometry. A cross-sectional study after standard anaesthetic care.

International audienceBACKGROUND Patients assess their own pain with a numerical rating scale (NRS). In the postanaesthesia care unit (PACU), NRS helps to determine and monitor analgesic administration, but is useless in patients who are unable to communicate. In non-PACU patients, acute pain increases pupillary diameter and pupillary light reflex amplitude (PLRA), the difference between pupillary diameter before and after light stimulation. OBJECTIVES To study the association between postopera-tive pain (NRS) and pupillary diameter or PLRA in PACU patients after routine anaesthetic care. DESIGN Cross-sectional cohort study. SETTING Bichat-Claude Bernard Hospital, Paris. PATIENTS One hundred and forty-five patients undergoing planned surgery under general anaesthesia. INTERVENTIONS NRS, pupillary diameter and PLRA were measured on arrival in the PACU. When NRS was more than 4, intravenous morphine titration was started and a second measurement performed. MAIN OUTCOME MEASURES Association between NRS and pupillary diameter or PLRA was assessed with Pearson correlation coefficient (r) as was association between changes in these variables after morphine titration. RESULTS Mean NRS was 4.7, and was more than 4 in 79 patients (55%). No statistically significant association was observed between NRS and pupillary diameter (r ¼ 0.10, P ¼ 0.54) or PLRA (r ¼ 0.03, P ¼ 0.72). Twenty-seven patients (19%) received morphine titration with significant decreases in NRS, pupillary diameter and PLRA afterwards. No association was observed between NRS changes and pupillary diameter or PLRA changes. CONCLUSION Acute postoperative pain is not associated with pupillary diameter or PLRA. Further research is required to develop tools to assess pain in the PACU

[Anaesthetic management of patients with bicuspid aortic valve for delivery. About two consecutive cases].

International audienceCardiac diseases are the second cause of non-obstetrical death during pregnancy in France. Bicuspid aortic valve is the most frequent congenital cardiac disease but its characteristics are little known. We report two consecutive cases of pregnant patients with aortic bicuspidy, one with a severe aortic stenosis and one with a severe dilatation of the ascending aorta. We describe the anaesthetic management of delivery for these two cases and summarize the current recommendations for management of this condition during pregnancy

Development and evaluation of a score to predict difficult epidural placement during labor.

International audienceBACKGROUND AND OBJECTIVES: Difficult epidural placement (DEP) during labor may be distressing for the patient and may increase the risk of dural puncture. A score predicting DEP based on the combination of individual risk factors could identify high-risk patients. This study aimed to identify risk factors for DEP and build a prediction score. METHODS: Three hundred thirty patients were prospectively included. Difficult epidural placement was defined as more than 1 skin puncture with a Tuohy needle. Dura puncture occurrence was recorded. The population was randomly split into a training set and a validation set. In the training set, risk factors were identified with logistic regression and used to build a score defining 3 risk groups. Model and score discrimination was assessed with the C-index and clinical usefulness of the score with decision curves. RESULTS: Difficult epidural placement frequency was 30% (95% confidence interval [95% CI], 25%-35%). Dural puncture was more frequent in DEP patients (4% vs 0%, P = 0.007). Three independent risk factors for DEP were identified: difficult interspinous space palpation (odds ratio [OR], 6.1; 95% CI, 2.8-13.9), spinal deformity (OR, 2.4; 95% CI, 1.1-5.3), and inability to flex the back (OR, 3.0; 95% CI, 1.2-7.8). The C-index of the model was 0.81 (95% CI, 0.74-0.88) in the training set and 0.78 (95% CI, 0.70-0.86) in the validation set. A 5-point score was created to define groups with low risk (score 0), intermediate risk (score 1-2), and high risk (score 3-4), with predicted rates of DEP of 9.7%, 30.3%, and 68.9%, respectively. The C-index of the score was 0.79 (95% CI, 0.72-0.86) in the training set and 0.76 (95% CI, 0.69-0.84) in the validation set. Decision curves support the clinical usefulness of the score. CONCLUSIONS: This study confirms risk factors for DEP and proposes a score to predict DEP. The score identifies high-risk patients who may benefit from an intervention to decrease DEP. This hypothesis should be evaluated in an impact study