Changes in mandibular position during midface distraction in patients with syndromic craniosynostosis.

The purpose of this study was to evaluate changes in mandibular position during midface distraction. Midface distraction was performed in patients with syndromic craniosynostosis to increase upper airway volume. Although this treatment resulted in changes in occlusion, the concomitant changes in mandibular position were poorly understood. In this retrospective study, three-dimensional (3D) cephalograms were obtained before and after midface distraction in 15 patients with syndromic craniosynostosis. Perioperative polysomnography scores and changes in maxillary and mandibular position, mandibular volume, and upper airway volume were analyzed. Results showed a significant improvement in apnea-hypopnea index (AHI) (from 20.6 ± 21.3 to 6.9 ± 5.1, p < 0.05) and upper airway volume (from 2951.65 ± 2286.38 to 5218.04 ± 3150.05 mm3, p < 0.001). When the lowest point of the sella turcica was set as the reference point, the mandible moved significantly in an anterior direction (from 47.9 ± 11.5 to 51.9 ± 9.8 mm, p < 0.05). Mandibular volume did not change significantly perioperatively (from 32530.19 ± 10726.01 to 35590.50 ± 14879.21 mm3, p = 0.10). There were positive correlations between the rates of improvement in AHI and the amount of mandibular movement in the anterior and inferior directions (both p < 0.05). Within the limitations of the study, it seems that the mandible moved in the anterior-inferior direction after midface distraction, and the amount of movement correlated with improvement in respiratory function. Therefore, it is important to consider the position of the mandible when determining the direction of midface distraction, as it may influence the therapeutic effect.

Preoperative sleep-disordered breathing and craniofacial abnormalities are risk factors for postoperative sleep-disordered breathing in patients undergoing skin-flap oropharyngeal reconstruction surgery for oral cavity cancer: a prospective case-control study.

PURPOSE: After oropharyngeal reconstruction surgery, excessive flap volume within the oral cavity may increase the risk of pharyngeal obstruction during sleep. This prospective observational study aimed to test a hypothesis that the skin-flap oropharyngeal reconstructive surgery increases nocturnal apnea-hypopnea index (nAHI, primary variable) after surgery. METHODS: Adult patients undergoing oropharyngeal reconstruction surgery participated in this study. The hypothesis was tested by comparing the results of portable type 4 sleep study and craniofacial assessments with lateral head and neck computed tomography scout image before and after surgery. Multiple linear regression analyses were performed to identify predictors for nAHI increase after the surgery. RESULTS: In 15 patients, a postoperative sleep study was performed at 41 (27, 59) (median (IQR)) days after the surgery. nAHI did not increase after the surgery (mean (95% CI), 13.0 (7.2 to 18.7) to 18.4 (10.2 to 26.6) events.hour-1, p = 0.277), while apnea index significantly increased after the surgery (p = 0.026). Use of the pedicle flap for the oropharyngeal reconstruction (p = 0.051), small mandible (p = 0.008), longer lower face (0.005), and larger tongue size (p = 0.008) were independent predictors for worsening of nAHI after surgery. Hospital stay was significantly longer in patients with the pedicle flap (n = 8) than in those with the free flap (n = 7) (p = 0.014), and the period of hospital stay was directly associated with increase of nAHI after surgery (r = 0.788, p < 0.001, n = 15). CONCLUSIONS: Oropharyngeal reconstruction surgery worsens sleep-disordered breathing in some patients with craniofacial and surgical risk factors. TRIAL REGISTRATION: UMIN Clinical Trial Registry (UMIN000036260, March 22, 2019), https://rctportal.niph.go.jp/s/detail/um?trial_id=UMIN000036260.

Assessments of perioperative respiratory pattern with non-contact vital sign monitor in children undergoing minor surgery: a prospective observational study.

PURPOSE: Nurses routinely assess respiration of hospitalized children; however, respiratory rate measurements are technically difficult due to rapid and small chest wall movements. The aim of this study is to reveal the respiratory status of small children undergoing minor surgery with load cells placed under the bed legs, and to test the hypothesis that respiratory rate (primary variable) is slower immediately after arrival to the ward and recovers in 2 h. METHODS: Continuous recordings of the load cell signals were performed and stable respiratory waves within the 10 discriminative perioperative timepoints were used for respiratory rate measurements. Apnea frequencies were calculated at pre and postoperative nights and 2 h immediately after returning to the ward after surgery. RESULTS: Continuous recordings of the load cell signals were successfully performed in 18 children (13 to 119 months). Respiratory waves were appraisable for more than 70% of nighttime period and 40% of immediate postoperative period. There were no statistically significant differences of respiratory rate in any timepoint comparisons (p = 0.448), thereby not supporting the study hypothesis. Respiratory rates changed more than 5 breaths per minute postoperatively in 5 out of 18 children (28%) while doses of fentanyl alone did not explain the changes. Apnea frequencies significantly decreased 2 h immediately after returning to the ward and during the operative night compared to the preoperative night. CONCLUSION: Respiratory signal extracted from load cell sensors under the bed legs successfully revealed various postoperative respiratory pattern change in small children undergoing minor surgery. CLINICAL TRAIL REGISTRATION: UMIN (University Hospital Information Network) Clinical Registry: UMIN000045579 ( https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000052039 ).

Continuous monitoring of activity and vital signs with load cells under the bed legs in advanced cancer patients: a prospective exploratory observational study-can it represent performance status?

BACKGROUND: Activity levels of patients often scaled as performance status (PS) is the most important scale in oncology populations for treatment decisions and prognosis prediction. However, it is usually subjective and open to bias. The need for more objective and reliable assessment tools is mandatory for safe and effective oncology practice. To investigate the reliability of continuous vital and activity evaluation monitored by bed sensor systems in advanced cancer patients, we conducted a cohort pilot study in hospitalized cancer patients under several PS conditions. METHODS: Adult patients, either admitted in the oncology department or palliative care unit, were enrolled in the study after written informed consent. Continuous monitoring for 48 hours from the first night of admission was performed without any restrictions on the patients. Calculated acceleration of movement [activity index (ACI)], % time on bed and number of bed leave in an 8-hour period, as well as other vital signs were monitored. Analysis focused on change of PS to 3, a standard cut-off for curative cancer treatment and PS4, vital for prognosis assessment. RESULTS: Nineteen patients' data were analyzed. In PS4 palliative care patients, ACI was significantly low and % time on bed was high from PS3 palliative care patients. Instabilities of respiratory rate, respiratory tidal weight and heart rate were significantly higher in palliative care patients (PS3, PS4) compared with oncology patients (PS1, PS2). CONCLUSIONS: This result, though in need of larger trials, shows possibilities for continuous objective monitoring of patients in bed for PS assessment in advanced cancer patients.

Dynamic vocal cord behavior and stridor during emergence from general anesthesia in small children with supraglottic airway.

PURPOSE: Stridor during emergence from anesthesia is not rare in children managed with supraglottic airway (SGA). However, we know little about the mechanisms of stridor and behavior of the vocal cords (VC). This study aimed to clarify patterns of VC movement and laryngeal airway maintenance function during recovery from anesthesia in children with SGA. METHODS: This is a secondary analysis of data collected from an observational study involving 27 anesthetized children. Using a multi-panel recording system, endoscopic VC image, vital sign monitor, multi-channel tracings of respiratory variables and respiratory sound and patient's view were simultaneously captured in one monitor. Inspiratory and expiratory VC angles formed by lines connecting anterior and posterior commissures were measured at the first spontaneous breath and the breath one minute after the first breath. VC narrowing and dilation were assessed by differences of VC angles. RESULTS: Inspiratory VC narrowing (median (IQR): 5.3 (2.7, 9.1) degree at the first breath) and dilation (- 2.7 (- 3.8, - 1.7) degree at the first breath) were observed in 15 and 12 out of 27 children, respectively. The former group achieved greater tidal volume compared to the latter in one minute. Five children (19%) temporarily developed stridor-like sound from outside with inspiratory VC narrowing. The stridor-like sound was captured by microphones attached to the neck and anesthesia circuit, but was not evident from the chest. CONCLUSION: Laryngeal narrowing occurs in half of the children with SGA during emergence from anesthesia, and temporal stridor-like sound is relatively common. CLINICAL TRIAL REGISTRATION: UMIN (University Hospital Information Network) Clinical Registry: UMIN000025058 ( https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000028697 ).

Contact-free assessments of respiratory rate and volume with load cells under the bed legs in ventilated patients: a prospective exploratory observational study.

Development of reliable noncontact unrestrained respiratory monitoring is capable of augmenting the safety of hospitalized patients in the recovery phase. We previously discovered respiratory-related centroid shifts along the long axis of the bed with load cells under the bed legs [bed sensor system (BSS)]. This prospective exploratory observational study examined whether noncontact measurements of respiratory-related tidal centroid shift amplitude (TA-BSS; primary variable) and respiratory rate (RR-BSS; secondary variable) were correlated with tidal volume (TV-PN) and respiratory rate (RR-PN), respectively, measured by pneumotachograph in 14 ICU patients under mechanical ventilation. Among the 10-min average data automatically obtained for a 48-h period, 14 data samples were randomly selected from each patient. Successfully and evenly selected 196 data points for each variable were used for the purpose of this study. A good agreement between TA-BSS and TV-PN (Pearson's r = 0.669) and an excellent agreement between RR-BSS and RR-PN (r = 0.982) were observed. Estimated minute ventilatory volume [3.86 · TA-BSS · RR-BSS (MV-BSS)] was found to be in very good agreement with true minute volume (MV-PN) (r = 0.836). Although Bland-Altman analysis evidenced accuracy of MV-BSS by a small insignificant fixed bias (-0.02 L/min), a significant proportional bias of MV-BSS (r = -0.664) appeared to produce larger precision (1.9 L/min) of MV-BSS. We conclude that contact-free unconstrained respiratory monitoring with load cells under the bed legs may serve as a new clinical monitoring system, when improved.NEW & NOTEWORTHY We previously discovered that four load cells placed under the bed legs capture a centroid shift during respiration in bedridden human subjects. In 14 ICU patients under mechanical ventilation, this study evidenced that contact-free measurements of respiratory rate, tidal volume, and minute ventilation with the load cells correlated well with those measured by pneumotachograph. Possible clinical usefulness of this approach as a new clinical respiratory monitor is indicated.

Postoperative pain and quality of life after lung cancer surgery: a prospective observational study.

BACKGROUND: We aimed to identify the factors associated with postoperative pain, quality of life, and development of chronic pain after lung cancer surgery, including pain sensation threshold, fentanyl sensitivity, and surgical procedures. METHODS: We conducted a single-center prospective observational study involving lung cancer patients. Brief pain inventory, including nine items concerning pain and quality of life, was investigated at 1 week, 1 month, and 3 months postoperatively. Pain sensation threshold and fentanyl sensitivity were assessed preoperatively. RESULTS: Of the 146 patients who were enrolled, 100 who met our criteria were analyzed. Thoracoscopic surgery was performed in 42 patients and minimally invasive thoracotomy in 58 patients. Pain sensation threshold and fentanyl sensitivity were normally distributed among the patients and were not significantly associated with brief pain inventory scores at each postoperative time-point. The average pain score 1 week after the operation was significantly higher in the thoracotomy group than in the thoracoscopic surgery group (P<0.050). The worst pain scores did not differ between the groups at all the examination periods. Pain sensation threshold, fentanyl sensitivity, and surgical procedures were not related to the incidence of post-thoracotomy pain syndrome. CONCLUSIONS: Individual pain sensation threshold and fentanyl sensitivity were not associated with subjective postoperative pain score, quality of life score, or development of post-thoracotomy pain syndrome.

Phase II study comparing nasal pressure monitoring with capnography during invasive endoscopic procedures: a single-center, single-arm trial.

Nasal pressure signal is commonly used to evaluate obstructive sleep apnea. This study aimed to assess its safety for respiratory monitoring during sedation. A total of 45 adult patients undergoing sedation with propofol and fentanyl for invasive endoscopic procedures were enrolled. While both nasal pressure and capnograph signals were continuously recorded, only the nasal pressure signal was displayed. The primary outcome was the incidence of oxygen desaturation below 90%. The secondary outcomes were the ability to predict the desaturation and incidence of harmful events and false alarms, defined as an apnea waveform lasting more than 3 min without desaturation. Of the 45 participants, 43 completed the study. At least one desaturation event occurred in 12 patients (27.9%; 95% confidence interval 15.3-43.7%). In these 12 patients, more than half of the desaturation events were predictable in 9 patients by capnography and 11 patients by nasal pressure monitoring (p = 0.59). In the 43 patients, false alarms were detected in 7 patients with capnography and 11 patients with nasal pressure monitoring (p = 0.427). Harmful events unrelated to nasal pressure monitoring occurred in 2 patients. Nasal pressure monitoring is safe and possibly useful for respiratory monitoring despite false alarms during sedation.

Rocuronium versus saline for effective facemask ventilation during anesthesia induction: a double-blinded randomized placebo-controlled trial.

BACKGROUND: Mask ventilation progressively improves after loss of consciousness during anesthesia induction possibly due to progression of muscle paralysis. This double-blinded randomized placebo-controlled study aimed to test a hypothesis that muscle paralysis improves mask ventilation during anesthesia induction. METHODS: Forty-four adults patients including moderate to severe obstructive sleep apnea undergoing scheduled surgeries under elective general anesthesia participated in this study. Randomly-determined test drug either rocuronium or saline was blinded to the patient and anesthesia provider. One-handed mask ventilation with an anesthesia ventilator providing a constant driving pressure and respiratory rate (15 breaths per minute) was performed during anesthesia induction, and changes of capnogram waveform and tidal volume were assessed for one minute. The needed breaths for achieving plateaued-capnogram (primary variable) within 15 consecutive breaths were compared between the test drugs. RESULTS: Measurements were successful in 38 participants. Twenty-one and seventeen patients were allocated into saline and rocuronium respectively. The number of breaths achieving plateaued capnogram did not differ between the saline (95% C.I.: 6.2 to 12.8 breaths) and rocuronium groups (95% C.I.: 5.6 to 12.7 breaths) (p = 0.779). Mean tidal volume changes from breath 1 was significantly greater in rocuronium group than saline group (95% C.I.: 0.56 to 0.99 versus 3.51 to 4.53 ml kg-IBW-1, p = 0.006). Significantly more patients in rocuronium group (94%) achieved tidal volume greater than 5 mg kg-ideal body weight-1 within one minute than those in saline group (62%) (p = 0.026). Presence of obstructive sleep apnea did not affect effectiveness of rocuronium for improvement of tidal volume during one-handed mask ventilation. CONCLUSIONS: Use of rocuronium facilitates tidal volume improvement during one-handed mask ventilation even in patients with moderate to severe obstructive sleep apnea. TRIAL REGISTRATION: The clinical trial was registered at (05/12/2013, UMIN000012495): https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000014515.

Long-term body weight change assessed by non-contact load cells under the bed in older people with and without eating assistance: a preliminary study.

Utilizing automatic daily body weight (BW) measurements may be helpful for assessing nutritional status and detecting underlying diseases particularly in older people who require nursing care. This preliminary study aimed to verify effectiveness of eating assistance for maintaining BW in older people using a contact-free load cells under the bed (Bed Sensor System: BSS). BW was measured every night for 3 months in eight nursing home older people with severe cognitive and physical dysfunctions. Body composition of the subject's trunk and each limb was measured using a segmented multi-frequency bioelectrical impedance analyzer (BIA). A monthly BW loss was estimated as a slope of linear regression of the daily BW plot. BSS successfully measured daily BW for the study period in all participants. The 4 residents with eating assistance gained slightly more weight, while the 4 residents without eating assistance lost weight. There was a significant difference between the two groups in the monthly BW change (- 0.79 ± 0.51 kg/month versus 0.20 ± 0.49 kg/month, P = 0.030). None of the BIA-derived parameters was associated with the monthly BW change. BSS revealed effectiveness of eating assistance to maintain BW in nursing home residents with severe cognitive and physical dysfunctions.

Combination Therapy of High-flow Nasal Cannula and Upper-body Elevation for Postoperative Sleep-disordered Breathing: Randomized Crossover Trial.

BACKGROUND: The low acceptance rate of continuous positive airway pressure therapy in postoperative patients with untreated obstructive sleep apnea (OSA) indicates the necessity for development of an alternative postoperative airway management strategy. The authors considered whether the combination of high-flow nasal cannula and upper-body elevation could improve postoperative OSA. METHODS: This nonblinded randomized crossover study performed at a single university hospital investigated the effect on a modified apnea hypopnea index, based exclusively on the airflow signal without arterial oxygen saturation criteria (flow-based apnea hypopnea index, primary outcome), of high-flow nasal cannula (20 l · min-1 with 40% oxygen concentration) with and without upper-body elevation in patients with moderate to severe OSA. Preoperative sleep studies were performed at home (control, no head-of-bed elevation) and in hospital (30-degree head-of-bed elevation). On the first and second postoperative nights, high-flow nasal cannula was applied with or without 30-degree head-of-bed elevation, assigned in random order to 23 eligible participants. RESULTS: Twenty-two of the 23 (96%) accepted high-flow nasal cannula. Four participants resigned from the study. Control flow-based apnea hypopnea index (mean ± SD, 60 ± 12 events · h-1; n = 19) was reduced by 15 (95% CI, 6 to 30) events · h-1 with head-of-bed elevation alone (P = 0.002), 10.9 (95% CI, 1 to 21) events · h-1 with high-flow nasal cannula alone (P = 0.028), and 23 (95% CI, 13 to 32) events · h-1 with combined head-of-bed elevation and high-flow nasal cannula (P < 0.001). Compared to sole high-flow nasal cannula, additional intervention with head-of-bed elevation significantly decreased flow-based apnea hypopnea index by 12 events · h-1 (95% CI, 2 to 21; P = 0.022). High-flow nasal cannula, alone or in combination with head-of-bed elevation, also improved overnight oxygenation. No harmful events were observed. CONCLUSIONS: The combination of high-flow nasal cannula and upper-body elevation reduced OSA severity and nocturnal hypoxemia, suggesting a role for it as an alternate postoperative airway management strategy.

Impact of perioperative antithrombotic strategies on clinical events in non-cardiac surgery.

Antithrombotic therapy including antiplatelet agents and anticoagulants are prescribed for secondary prevention in patients with established cardiovascular disease. Although antithrombotic therapy is often interrupted before non-cardiac surgery with or without perioperative bridging anticoagulation, the impact on thrombotic and bleeding events remains uncertain. A total of 360 patients chronically treated with antithrombotic therapy for secondary prevention underwent elective non-cardiac surgery under general anesthesia, with the complete interruption of antithrombotic agents. The study endpoints included all-cause death, thrombotic events, and major bleeding complications after surgical procedures. Of 360 patients, 190 (52.8%) and 200 (55.6%) received antiplatelet and anticoagulation perioperatively. Atrial fibrillation (32.8%) and coronary artery disease (22.5%) were the major indications for antithrombotic regimens. Antithrombotic therapy was interrupted from 5 [2, 7] days before the surgery to 4 [2, 7] days postoperatively. Perioperative bridging therapy with unfractionated heparin was employed in 113 (31.4%) patients. During the hospitalization, one (0.3%) patient died due to non-cardiovascular causes. Thrombotic events and major bleeding occurred in two (0.6%) and eight (2.2%) patients. Bridging therapy with heparin was significantly associated with an increased risk of bleeding events (5.3% vs. 0.8%, p = 0.02). Pre-operative bridging therapy with heparin and operative duration were significantly associated with bleeding complications. In the present study, complete interruption of antithrombotic therapy resulted in a few thrombotic events in patients undergoing elective non-cardiac surgery. Bridging therapy with heparin and longer operative duration were significantly associated with post-operative bleeding complications.

Changes in breathing pattern during severe hypothermia and autoresuscitation from hypothermic respiratory arrest in anesthetized mice.

Some evidence suggests that both hypothermia and anesthesia can exert similar effects on metabolism and ventilation. This study examined the synergistic effects of anesthesia and hypothermia on ventilation in spontaneously breathing adult mice under three different conditions, that is, (1) pentobarbital group (n = 7) in which mice were anesthetized with intraperitoneal pentobarbital of 80 mg/kg, (2) sevoflurane-continued group (n = 7) in which mice were anesthetized with 1 MAC sevoflurane, and (3) sevoflurane-discontinued group (n = 7) in which sevoflurane was discontinued at a body temperature below 22˚C. We cooled mice in each group until breathing ceased and followed this with artificial rewarming while measuring changes in respiratory variables and heart rate. We found that the body temperature at which respiration arrested is much lower in the sevoflurane-discontinued group (13.8 ± 2.0˚C) than that in the sevoflurane-continued group (16.7 ± 1.2˚C) and the pentobarbital group (17.0 ± 1.4˚C). Upon rewarming, all animals in all three groups spontaneously recovered from respiratory arrest. There was a considerable difference in breathing patterns between sevoflurane-anesthetized mice and pentobarbital-anesthetized mice during progressive hypothermia in terms of changes in tidal volume and respiratory frequency. The changes in the respiratory pattern during rewarming are nearly mirrored images of the changes observed during cooling in all three groups. These observations indicate that adult mice are capable of autoresuscitation from hypothermic respiratory arrest and that anesthesia and hypothermia exert synergistic effects on the occurrence of respiratory arrest while the type of anesthetic affects the breathing pattern that occurs during progressive hypothermia leading to respiratory arrest.

Recovery of lower oesophageal barrier function: a pilot study comparing a mixture of atropine and neostigmine and sugammadex: A randomised controlled pilot study.

BACKGROUND: The lower oesophageal sphincter (LOS) barrier serves to prevent regurgitation of gastric contents. Although general anaesthesia depresses its function, its recovery process during emergence from anaesthesia has not been systematically examined. OBJECTIVE: To explore whether recovery of lower oesophageal barrier function differed between patients receiving a mixture of 1 mg atropine and 2 mg neostigmine and those receiving 2 mg kg-1 sugammadex during emergence from anaesthesia. DESIGN: An unblinded randomised controlled pilot study. SETTING: A single university hospital from January 2016 to December 2018. PATIENTS: A total of 20 non-obese adult females undergoing minor surgery. INTERVENTION: The patients were randomly assigned to a group either receiving atropine and neostigmine or sugammadex for reversal of rocuronium. MAIN OUTCOME MEASURES: Through use of the high-resolution manometry technique, the lower oesophageal barrier pressure (PBAR: primary variable) defined as a pressure difference between pressures at the LOS and the stomach was measured at five distinguishable time points during emergence from total intravenous anaesthesia. A mixed effects model for repeated measures was used to test the hypothesis. RESULTS: In all patients baseline PBAR values were positive even under muscle paralysis and general anaesthesia before administration of reversal agents, and did not differ between the groups (P = 0.299). During recovery from muscle paralysis and general anaesthesia, PBAR (mean ±â€ŠSD) significantly increased (P = 0.004) from 17.0 ±â€Š2.9 to 21.0 ±â€Š5.0 mmHg in the atropine and neostigmine group (n = 8) and from 19.1 ±â€Š9.0 to 24.5 ±â€Š12.7 mmHg in the sugammadex group (n = 11). PBAR significantly increased immediately after return of consciousness in both groups, whereas return of muscle tone, lightening of anaesthesia and tracheal extubation did not change it. CONCLUSION: Recovery of the lower oesophageal barrier function does not differ between patients receiving either atropine and neostigmine or sugammadex and is completed after recovery of consciousness from general anaesthesia. TRIAL REGISTRATION: UMIN Clinical Trials Registry: UMIN000020500: https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=brows&action=brows&recptno=R000023594&type=summary&language=E.

Hypercapnia versus normocapnia for emergence from desflurane anaesthesia: Single-blinded randomised controlled study.

BACKGROUND: Rapid emergence from general anaesthesia is desirable only if safety is not sacrificed. Mechanical hyperventilation during hypercapnia produced by carbon dioxide infusion into the inspired gas mixture or by rebreathing was reported to shorten emergence time from inhalation anaesthesia. OBJECTIVES: To test the hypothesis that hypercapnia produced by hypoventilation before desflurane cessation shortens emergence time from general anaesthesia (primary hypothesis) and reduces undesirable cardiorespiratory events. DESIGN: A single-blinded randomised controlled study. SETTING: A single university hospital. PATIENTS: Fifty adult patients undergoing elective abdominal surgery under general anaesthesia using desflurane inhalation and intra-operative epidural anaesthesia. INTERVENTION: The patients were randomly assigned to either the normocapnia or hypercapnia group. MAIN OUTCOME MEASURES: Emergence time from desflurane anaesthesia and comparison of the incidence of 11 predefined undesirable cardiorespiratory events during and after emergence from anaesthesia between the groups. RESULTS: Forty-six patients were included in the analysis. End-tidal carbon dioxide concentrations at cessation of desflurane were 35 ±â€Š6 mmHg (mean ±â€ŠSD) and 52 ±â€Š6 mmHg in normocapnia (n = 23) and hypercapnia groups (n = 23), respectively. Emergence time was significantly faster in the hypercapnia group than the normocapnia group: 9.4 ±â€Š2.4 min, hypercapnia: 5.5 ±â€Š2.6 min, (P < 0.001) with a difference of 3.8 min on average (95% CI: 2.4 to 5.3). Spontaneous breathing established before recovery of consciousness was more evident in hypercapnia patients (normocapnia: 13%, hypercapnia: 96%, P < 0.001). Hypercapnia patients had more episodes of bradypnoea and apnoea before emergence of consciousness. In contrast, after tracheal extubation, incidences of bradypnoea and hypopnoea were more common in the normocapnia group. Undesirable cardiovascular events were not common, and no group differences were observed during emergence and postextubation periods. CONCLUSION: Hypoventilation-induced hypercapnia before desflurane cessation shortens the emergence time without causing additional clinically significant undesirable events. TRIAL REGISTRATION: UMIN Clinical Trials Registry (UMIN000020143) https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=brows&recptno=R000023266&language=E.

Effects of opioids on respiration assessed by a contact-free unconstraint respiratory monitor with load cells under the bed in patients with advanced cancer.

Nocturnal periodic breathing of chronic opioid users has been predominantly documented by the use of polysomnography. No previous studies have assessed the opioid effects of respiratory rhythms throughout the day without the use of physical restraint. We recently developed a contact-free unconstraint vital sign monitoring system with four load cells placed under the bed legs, which allows continuous measurements of respiratory change at the center of gravity on the bed. We aimed to reveal details of the patient's 24-h respiratory status under a monitoring system and to test the hypothesis that respiratory rhythm abnormalities are opioid dose-dependent and worsen during the night time. Continuous 48-h respiratory measurements were successfully performed in 51 patients with advanced cancer (12 opioid-free patients and 39 opioid-receiving patients). Medians of respiratory variables with minimal body movement artifacts were calculated for each 8-h split time period. Compared with opioid-free patients, opioid-receiving patients had slower respiratory rate with higher respiratory rate irregularity without changing tidal centroid shift regardless of the time period. Irregular ataxic breathing was only identified in opioid-receiving patients (33%, P = 0.023) whereas incidence rate of periodic breathing did not differ between the groups. Multivariate regression analyses revealed that opioid dose was an independent risk factor for occurrence of irregular breathing [odds ratio 1.81 (95% CI: 1.39-2.36), P < 0.001], and ataxic breathing [odds ratio 2.08 (95% CI: 1.60-2.71), P < 0.001]. Females developed the ataxic breathing at lower opioid dose compared with males. We conclude that respiratory rhythm irregularity is a predominant specific feature of opioid dose-dependent respiratory depression particularly in female patients with advanced cancer.NEW & NOTEWORTHY Through usage of a novel contact-free unconstraint vital sign monitoring system with four load cells placed under the bed legs allowing continuous measurements of respiratory changes of center of gravity on the bed, this study is the first to assess detailed respiratory characteristics throughout day and night periods without interference of daily activities in patients with advanced cancer receiving opioids. Respiratory rhythm irregularity is a predominant specific feature of opioid dose-dependent respiratory depression particularly in female patients with advanced cancer.

Risk factors including preoperative echocardiographic parameters for post-induction hypotension in general anesthesia.

BACKGROUND: Severe hypotension immediately after induction of general anesthesia (post-induction hypotension) is a common complication and is associated with a poor postoperative outcome. We hypothesized that post-induction hypotension results from cardiac dysfunction which can be assessed by preoperative echocardiography. METHODS: We retrospectively enrolled 200 patients who had undergone elective surgery within 6 months after preoperative transthoracic echocardiography. The incidence of post-induction hypotension identified from anesthesia records was defined as a decrease in mean blood pressure to ≤50 mmHg after injection of induction anesthetics prior to surgery. Logistic regression analysis of patient characteristics and echocardiographic variables was used to identify the independent factors for post-induction hypotension. RESULTS: Post-induction hypotension was found in 63 of the 200 cases (incidence 32%). Independent risk factors for post-induction hypotension were the presence of a regional wall motion abnormality (RWMA) [odds ratio (OR), 6.65.; 95% confidence interval (CI), 1.76 - 25.10], an elevated E/e' (OR, 1.13; 95% CI, 1.00 - 1.28), female gender (OR, 3.61; 95% CI, 1.37 - 9.56), and the use of an angiotensin II receptor blocker (OR, 3.17; 95% CI, 1.12 - 8.96). CONCLUSIONS: Assessment of RWMA and E/e' with preoperative transthoracic echocardiography might be helpful for stratification of patients at a risk of post-induction hypotension in general anesthesia.

Predictor of respiratory disturbances during gastric endoscopic submucosal dissection under deep sedation.

BACKGROUND: Sedation is commonly performed for the endoscopic submucosal dissection (ESD) of early gastric cancer. Severe hypoxemia occasionally occurs due to the respiratory depression during sedation. AIM: To establish predictive models for respiratory depression during sedation for ESD. METHODS: Thirty-five adult patients undergoing sedation using propofol and pentazocine for gastric ESDs participated in this prospective observational study. Preoperatively, a portable sleep monitor and STOP questionnaires, which are the established screening tools for sleep apnea syndrome, were utilized. Respiration during sedation was assessed by a standard polysomnography technique including the pulse oximeter, nasal pressure sensor, nasal thermistor sensor, and chest and abdominal respiratory motion sensors. The apnea-hypopnea index (AHI) was obtained using a preoperative portable sleep monitor and polysomnography during ESD. A predictive model for the AHI during sedation was developed using either the preoperative AHI or STOP questionnaire score. RESULTS: All ESDs were completed successfully and without complications. Seventeen patients (49%) had a preoperative AHI greater than 5/h. The intraoperative AHI was significantly greater than the preoperative AHI (12.8 ± 7.6 events/h vs 9.35 ± 11.0 events/h, P = 0.049). Among the potential predictive variables, age, body mass index, STOP questionnaire score, and preoperative AHI were significantly correlated with AHI during sedation. Multiple linear regression analysis determined either STOP questionnaire score or preoperative AHI as independent predictors for intraoperative AHI ≥ 30/h (area under the curve [AUC]: 0.707 and 0.833, respectively) and AHI between 15 and 30/h (AUC: 0.761 and 0.778, respectively). CONCLUSION: The cost-effective STOP questionnaire shows performance for predicting abnormal breathing during sedation for ESD that was equivalent to that of preoperative portable sleep monitoring.

Qualitative measurement of opioid effects on pain and dyspnea: gender difference in the sensitivity.

BACKGROUND: An increasing number of patients come to the operating room in use of opioid analgesics. They have different levels of tolerance to opioid effects which challenge the anesthesiologists in search of safe and effective opioid dosing perioperatively. The tested hypothesis is that simple measures introduced will allow us to measure tolerance qualitatively. Opioid effects on pain (analgesia) and dyspnea sensations (relieving effect) are tested. Patients were allocated to three groups according to pre-operative analgesics: (1) control, without any opioid analgesics, (2) weak opioid, and (3) strong opioid. Pressure pain threshold (PPT) and no-respiratory sensation period (NRSP) were measured at two points: before and 3 min after intravenous fentanyl administration. RESULTS: A total of 58 (43 controls, 9 weak opioids, and 6 strong opioids) patients were enrolled. PPT and NRSP, after iv 2 µg/kg ideal body weight (IBW) fentanyl, were significantly elevated in the control patients (PPT: 6.2 ± 2.1 N to 9.2 ± 3.9 N, p < 0.0001, NRSP: 17.8 ± 10.8 s to 22.8 ± 18.7 s, p < 0.005, paired t test). However, preoperative opioid use, though with tendency, did not show a significant decrease of the opioid effect. Due to an insufficient number of participants, no conclusion could be drawn. Further analysis of the data from control patients showed a significant difference between the two sexes in sensitivity to PPT and NRSP, as well as fentanyl effect on PPT. CONCLUSIONS: Current data showed a simple method of measuring the opioid effect on two dimensions: pain and respiration. Though not able to show a qualitative measurement of tolerance formation in opioid-users, data from control patients showed females to be more sensitive to pain and dyspnea but is less sensitive to the opioid effect. Further studies are necessary to show whether these gender differences serve as clinical relevance. TRIAL REGISTRATION: UMIN, UMIN 000011580. Registered 27 August 2013, https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=brows&action=brows&type=summary&recptno=R000013352&language=J.