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Background: The circadian rhythm of myocardial infarction (MI) in patients with obstructive sleep apnea (OSA) remains disputable and no studies have directly evaluated the relationship between nocturnal hypoxemia and the circadian rhythm of MI. The aim of the current study was to evaluate the association of OSA and nocturnal hypoxemia with MI onset during the night., Methods: Patients with MI in the OSA-acute coronary syndrome (ACS) project (NCT03362385) were recruited. The time of MI onset was identified by patient's report of the chest pain that prompted hospital admission. All patients underwent an overnight sleep study using a type III portable sleep monitoring device after clinical stabilization during hospitalization. The difference in circadian variation of MI onset was evaluated between patients with moderate/severe OSA and non/mild OSA and those with or without nocturnal hypoxemia. Nocturnal hypoxemia was evaluated using 3 variables, including oxygen desaturation index, minimum oxygen saturation, and total sleep time with saturation <90%., Results: Among 713 patients enrolled, 398 (55.8%) had moderate/severe OSA (apnea-hypopnea index ≥15 events·h - 1). Compared with the non/mild OSA group, the MI onset was significantly increased in the moderate/severe OSA group between midnight to 5:59 am in 6-hour epochs analysis (26.9% versus 18.4%, P =0.008). Only in patients with both moderate/severe OSA and nocturnal hypoxemia, including oxygen desaturation index ≥15, minimum oxygen saturation ≤86%, and total sleep time with saturation <90% ≥2%, the incidence of MI onset between midnight to 5:59 am was significantly increased. Moderate/severe OSA (adjusted odds ratio 1.66 [95% CI, 1.13-2.43]; P =0.01) and nocturnal hypoxemia (oxygen desaturation index ≥15 model, adjusted odds ratio 1.80, [95% CI, 1.21-2.66]; minimum oxygen saturation ≤86% model, adjusted odds ratio 1.70 [95% CI, 1.16-2.47]; P =0.006; total sleep time with saturation <90% ≥2% model, adjusted odds ratio 1.54 [95% CI, 1.04-2.27]; P =0.03) significantly predicted MI occurrence from midnight to 6:00 am., Conclusions: A peak of incident MI onset between midnight to 5:59 am was observed in patients with moderate/severe OSA, especially in those presenting with nocturnal hypoxemia.

Objectives: To assess labour characteristics in relation to the occurrence of Composite Adverse neonatal Outcome (CAO) within a cohort of fetuses with metabolic acidaemia., Design: Retrospective cohort study., Setting: Three Italian tertiary maternity units., Population: 431 neonates born with acidaemia ≥36 weeks., Methods: Intrapartum CTG traces were assigned to one of these four types of labour hypoxia: acute, subacute, gradually evolving and chronic hypoxia. The presence of CAO was defined by the occurrence of at least one of the following: Sarnat Score grade ≥2, seizures, hypothermia and death <7 days from birth., Main Outcome Measures: To compare the type of hypoxia on the intrapartum CTG traces among the acidaemic neonates with and without CAO., Results: The occurrence of a CAO was recorded in 15.1% of neonates. At logistic regression analysis, the duration of the hypoxia was the only parameter associated with CAO in the case of an acute or subacute pattern (odds ratio [OR] 1.3; 95% CI 1.02-1.6 and OR 1.04; 95% CI 1.0-1.1, respectively), whereas both the duration of the hypoxic insult and the time from PROM to delivery were associated with CAO in those with a gradually evolving pattern (OR 1.13; 95% CI 1.01-1.3 and OR 1.04; 95% CI 1.0-1.7, respectively). The incidence of CAO was higher in fetuses with chronic antepartum hypoxia than in those showing CTG features of intrapartum hypoxia (64.7 vs. 13.0%; P < 0.001)., Conclusions: The frequency of CAO seems related to the duration and the type of the hypoxic injury, being higher in fetuses showing CTG features of antepartum chronic hypoxia., Tweetable Abstract: This study demonstrates that in a large population of neonates with metabolic acidaemia at birth, the overall incidence of short-term adverse outcome is around 15%. Such risk seems closely correlated to the duration and the type of hypoxic injury, being higher in fetuses admitted in labour with antepartum chronic hypoxia than those experiencing intrapartum hypoxia., (© 2022 The Authors. BJOG: An International Journal of Obstetrics and Gynaecology published by John Wiley & Sons Ltd.)

Background: Post-operative hypoxemia is prevalent in hospitalized patients and may adversely affect recovery. However, little data exist on the post-discharge phase or details on duration, severity and potential risk factors. Thus, we investigated the incidence and risk factors for severe desaturation during the first post-operative week after THA/TKA by continuous nocturnal oxygen saturation monitoring., Methods: The study was a secondary analysis of a prospective cohort study of 112 patients undergoing fast-track THA/TKA. Patients with known sleep apnoea were excluded. Oxygen saturation and heart rate were recorded by a wireless wrist-worn pulse oximeter 2 nights before and 7 nights after surgery. Data on demographics, opioid consumption and cognitive function were collected from medical charts, patient diaries and clinical testing respectively. The primary outcome was occurrence of severe desaturation defined as periods with saturation <85% lasting ≥10 minutes. Secondary outcomes included description of various saturation levels and relevant risk factors., Results: Severe oxygen desaturation occurred in 35% of the patients during the first post-operative week. Duration and severity of hypoxemic episodes increased after the first post-operative day. Pre-operative episodes of hypoxemia significantly increased the risk of post-operative hypoxemic events (OR 2.4-4.4, CI 0.4-46), while pre- and post-operative opioid use, age, gender, ASA classification, type of surgery or anaesthesia were significantly related to the development of post-operative hypoxemia., Conclusions: One third of the patients suffered from increased and prolonged episodes of severe nocturnal hypoxemia during the first week after THA/TKA discharge. Increased risk for severe hypoxemic episodes was related to pre-operative hypoxemia., (© 2020 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Background Although sleep characteristics have been linked to cardiovascular disease and cardiovascular risk factors, the association between sleep characteristics measured by polysomnography and cardiovascular health ( CVH ) remains unknown. Methods and Results In a population-based sample (n=1826), sleep characteristics were assessed by both sleep questionnaires and polysomnography. Global, behavioral, and biological CVH were defined according to the American Heart Association. Multinomial logistic regressions were performed to estimate relative risk ratios and 95% CI . Strong dose-response associations were found between all oxygen saturation-related variables (oxygen desaturation index, mean oxygen saturation, and percentage of total sleep time spent under 90% oxygen saturation) and obstructive sleep apnea (severity categories and apnea/hypopnea index) and global, behavioral, and biological CVH . Mean oxygen saturation had the strongest positive association (relative risk ratios 1.31 [ CI 1.22-1.41]; 1.78 [ CI 1.55-2.04] for intermediate relative to ideal CVH ), and oxygen desaturation index had the strongest negative association (relative risk ratios 0.71 [ CI 0.65-0.78]; 0.45 [ CI 0.34-0.58] for intermediate relative to ideal CVH ) with global CVH , and these associations were also the most robust in sensitivity analyses. The impacts of sleep architecture and sleep fragmentation were less consistent. Conclusions Mean oxygen saturation, oxygen desaturation index, and apnea/hypopnea index were associated with CVH . Conversely, most variables related to sleep architecture and sleep fragmentation were not consistently related to CVH . Sleep-disordered breathing and the associated oxygen (de)saturation were associated with CVH more strongly than with sleep fragmentation.

Acute respiratory distress syndrome (ARDS) is an acute inflammatory process that impairs the ability of the lungs to oxygenate and ultimately leads to respiratory failure. Patients who develop ARDS often have prolonged and complicated hospital courses putting them at risk for intensive care unit (ICU) delirium. Patients with ICU delirium often need chemical sedation, mechanical ventilation, prolonged duration of ICU and hospital stays, and they experience long-term cognitive impairment and increased mortality. In a patient with ARDS, ICU delirium further complicates the hospital course and increases the risk of morbidity and mortality. Antipsychotics are prescribed to decrease the severity and duration of ICU delirium, thus potentially decreasing their risk of morbidity and mortality. However, antipsychotics are associated with many adverse effects including respiratory failure. Given the long-term sequelae associated with the development of ICU delirium and the risks associated with antipsychotic use, clinicians must weigh the risks and benefits of antipsychotic use. This review investigates the interrelationship between ARDS, delirium, and antipsychotic use. In addition to discussing relevant studies evaluating antipsychotics for the prevention and treatment of delirium, we investigate safety concerns with the use of antipsychotics, especially as they relate to ARDS. Using the data compiled in this review, clinicians can make an informed decision about the use of antipsychotics for the prevention or treatment of delirium, with special consideration for their patients with ARDS. Future studies are needed to critically evaluate antipsychotic timing, dose, and duration for the prevention and treatment of ICU delirium and specifically evaluate the impact in special populations, particularly patients with ARDS., (© 2018 Pharmacotherapy Publications, Inc.)

Traditional conscious sedation for endobronchial ultrasound procedures places patients at risk of desaturation, and high-flow nasal oxygen may reduce the risk. We designed a parallel-group randomised controlled trial of high-flow nasal oxygen at a flow rate of 30-70 l.min -1 via nasal cannulae, compared with standard oxygen therapy at 10 l.min -1 via a bite block in adults planned for conscious sedation for endobronchial ultrasound. The primary outcome was the proportion of patients experiencing desaturation (defined as SpO 2 < 90%). Secondary outcomes included oxygen saturation after pre-oxygenation, lowest oxygen saturation during procedure, number of hypoxic episodes, duration of hypoxia, end-procedure end-tidal CO 2 , satisfaction scores and complications. Thirty participants were allocated to each group. Baseline patient characteristics, procedure time and anaesthetic agents used were similar between the groups. Desaturation occurred in 4 out of 30 patients allocated to the high-flow nasal oxygen group, compared with 10 out of 30 allocated to the standard oxygenation group, a non-significant difference (p = 0.07) with intention to treat analysis. The difference was significant (p = 0.047) when using a per-protocol analysis. Oxygen saturation after pre-oxygenation and the lowest oxygen saturation during procedure were significantly higher in the high-flow nasal oxygen group compared with the standard oxygenation group; median (IQR [range] 100 (99-100 [93-100]) vs. 98 (97-99 [94-100]), p = 0.0001 and 97.5 (94-99 [77-100]) vs. 92 (88-95 [79-98]), p < 0.001, respectively. There were no differences in other secondary outcomes. Although high-flow nasal oxygen may prevent desaturation due to some causes, it does not protect against hypoxaemia in all circumstances., (© 2017 The Association of Anaesthetists of Great Britain and Ireland.)

Pulse oximetry is an essential monitor for safe anaesthesia but is often not available in low-income countries. The aim of this study was to determine whether the introduction of pulse oximetry with training was feasible and could reduce the incidence of oxygen desaturation during anaesthesia in a low-income country. Pulse oximeters were donated, with training, to 83 non-physician anaesthetists in Malawi. Knowledge was tested immediately before and after training and at follow-up. Providers were asked to record the lowest peripheral oxygen saturation (SpO 2 ) for the first 100 cases anaesthetised after training. The primary clinical outcome was the proportion of cases with an oxygen desaturation event (SpO 2 < 90%). Seventy-seven of 83 (93%) participants completed all pre- and post-training tests. Pulse oximetry knowledge improved after training from a median (IQR [range]) score of 39 (37-42 [28-48]) to 44 (42-46 [35-50]) and this knowledge was maintained for 8 months (p < 0.001). Oxygen saturation data and provider responses were recorded for 4772 cases. The proportion of oxygen desaturation episodes decreased from 17.2% to 6.5%, representing a 36% reduction in the odds of an oxygen desaturation event in the second 50 cases compared with the first 50 (OR 0.64, 95%CI 0.50-0.82, p < 0.001). We conclude that donation of pulse oximeters, with training, in Malawi was feasible, improved knowledge and reduced the incidence of oxygen desaturation events., (© 2017 The Association of Anaesthetists of Great Britain and Ireland.)

Background: Patients with heart failure (HF) presenting to the emergency department (ED) can be admitted to care settings of different intensity, where the intensive care unit (ICU) is the highest intensity, ward admission is intermediate intensity, and those discharged home are of lowest intensity. Despite the costs associated with higher-intensity care, little is known about disposition decisions and outcomes of HF patients treated in different care settings., Methods and Results: We identified predictors of ICU or ward admission and determined whether survival differs in patients admitted to higher-intensity versus lower-intensity care settings (ie, ICU vs ward, or ward vs ED-discharged). Among 9054 patients (median, 78 years; 51% men) presenting to an ED in Ontario, Canada, 1163 were ICU-admitted, 5240 ward-admitted, and 2651 were ED-discharged. Predictors of ICU (vs ward) admission included: use of noninvasive positive pressure ventilation (adjusted odds ratio [OR], 2.01; 95% CI, 1.36-2.98), higher respiratory rate (OR, 1.10 per 5 breaths/min; 95% CI, 1.05-1.15), and lower oxygen saturation (OR, 0.90 per 5%; 95% CI, 0.86-0.94; all P<0.001). Predictors of ward-admitted versus ED-discharged were similar. Propensity-matched analysis comparing lower-risk ICU to ward-admitted patients demonstrated a nonsignificant trend at 100 days (relative risk [RR], 0.69; 95% CI, 0.43-1.10; P=0.148). At 1 year, however, survival was higher among those initially admitted to ICU (RR, 0.68; 95% CI, 0.49-0.94; P=0.022). There was no survival difference among low-risk ward-admitted versus ED-discharged patients., Conclusions: Respiratory factors were associated with admission to higher-intensity settings. There was no difference in early survival between some lower-risk patients admitted to higher-intensity units compared to those treated in lower-intensity settings., (© 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.)

Background: Pre-hospital tracheal intubation (TI) is an important but difficult procedure with the potential to produce hypoxaemia. The aim of this study was to determine the incidence of desaturation episodes during out-of-hospital rapid sequence induction (RSI) and TI by the medical team of a German Helicopter Emergency Medical Service (HEMS)., Methods: We performed a prospective study at HEMS 'CHRISTOPH 22'. TI was performed as RSI according to a standard protocol. Desaturation was defined as a reduction in SpO(2) below 90% or a reduction of more than 10% from baseline SpO(2) when initial values were less than 90%., Results: The RSI/TI manoeuvre was attempted in 150 patients [107 male (71.3%); median age 40 years (IQR 21-61); overall success rate 100%]. The incidence of desaturation episodes was 13.3% with a median duration of 50 sec. (IQR 30-92) and a median SpO(2) decrease of 24 ± 10%. Upon hospital admission, all patients had SpO(2) values ≥ 96%. In the desaturation group the duration of successful TI was significantly longer [median 85 sec. (IQR 60-119) vs. median 63 sec. (IQR 48-70); P < 0.01], and the number of patients with a baseline SpO(2) ≥ 90% was significantly lower (65.0% vs. 88.5%; P < 0.01). Among patients with difficult to manage airway, those with desaturation were significantly younger, and technical problems were significantly more frequent., Conclusion: The incidence of episodes of desaturation during pre-hospital RSI/TI at HEMS Ulm is relatively low, and the duration of such episodes is short., (© 2012 The Authors. Acta Anaesthesiologica Scandinavica © 2012 The Acta Anaesthesiologica Scandinavica Foundation.)

Background: Post-anaesthesia care unit (PACU) admission must be well founded and the stay as short as possible without compromising patient safety. However, within the concept of fast-track surgery, studies are limited in addressing the question: why are patients staying in the PACU?, Methods: All patients operated with primary unilateral total hip or knee arthroplasty (THA or TKA) under spinal anaesthesia were included in this hypothesis-generating, prospective, observational cohort study during a 4-month period. Surgical technique, analgesia, and perioperative care were standardized. Well-defined PACU discharge criteria that had to be met on two successive assessments were evaluated every 15 min until discharge. The primary outcome was time to meet PACU discharge criteria. Secondary outcomes were actual discharge time from the PACU, specific factors detaining patients in the PACU, and potential complications at the surgical ward at follow-up 24 h post-operatively., Results: One hundred sixty-three patients were included in the final analysis (69 THA and 94 TKA). Time to meet PACU discharge criteria was [median (interquartile range)(95% confidence interval)]: 15 min (15-15)(15-116) for THA and 15 min (15-15)(15-75) for TKA. Actual discharge time from PACU was: 25 min (20-35)(16-198) for THA and 25 min (20-31)(15-107) for TKA. Reasons for not meeting PACU discharge criteria in 15 min were mainly low oxygen saturation and pain. The short stay in the PACU did not impose complications at the surgical ward., Conclusion: The vast majority of patients (> 85%) operated with THA and TKA under low-dose spinal anaesthesia may achieve pre-defined PACU discharge criteria in 15 min. Large-scale studies should be performed to evaluate safety aspects after short PACU stay., (© 2012 The Authors. Acta Anaesthesiologica Scandinavica © 2012 The Acta Anaesthesiologica Scandinavica Foundation.)

Objective/hypothesis: The Hunsaker Mon-Jet tube (HMJT) (Xomed, Jacksonville, FL) has been used effectively for subglottic ventilation. We previously reported a series of 552 patients over a 10-year period with no major complications. This is a continuation of that series with an additional 5 years of cases., Study Design: Retrospective consecutive case series., Methods: Patients who were ventilated with the HMJT for microlaryngeal surgery at the University of Washington Medical Center over a 15-year period (1995-2010) were identified from the Voice Disorders database. Charts were reviewed for demographic data, laryngeal diagnosis, and anesthetic parameters. Main outcome measure was the rate of complications., Results: Fifty-seven complications occurred in 49 cases out of 839 cases (5.8% complication rate). In descending order, the complications were hypoxia (SpO(2) <90%, n = 30, 3.6%), hypercarbia (end tidal CO(2) of >60 mm Hg, n = 17, 2.0%), airway obstruction (n = 4, 0.5%), barotrauma (n = 2, 0.2%), seeding of blood into trachea (n = 2, 0.2%), submucosal injection of air (n = 1, 0.1%), and mucosal damage (n = 1, 0.1%). Factors associated with complications included high body mass index (P = .04), American Society of Anesthesiology class III or IV (P = .01), history of heart disease (P = .02), history of previous laryngeal surgery (P = .02), longer duration of case (P = .006), and laser use (P = .005)., Conclusions: Although subglottic ventilation via an HMJT is a safe alternative to traditional endotracheal intubation in an appropriately selected population, practitioners should remain vigilant about the known complications., (Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.)

Hypoxic hepatitis (HH), an acute liver injury also known as 'ischaemic hepatitis' or 'shock liver', is frequently observed in intensive care units. HH is heralded by a massive but transient rise in serum aminotransferase activities caused by anoxic necrosis of centrilobular liver cells. Cardiac failure, respiratory failure and toxic-septic shock are the main underlying conditions accounting for more than 90% of cases, but HH may also occur in other circumstances. Until recently, liver ischaemia, i.e. a drop in hepatic blood flow, was considered the leading, and even the sole, hemodynamic mechanism responsible for HH, and it was generally held that a shock state was required. In reality, other hemodynamic mechanisms of hypoxia, such as passive congestion of the liver, arterial hypoxaemia and dysoxia, play an important role while a shock state is observed in only 50% of cases. Accordingly, 'ischaemic hepatitis' and 'shock liver' are misnomers. Therapy of HH depends primarily on the nature of the underlying condition. The prognosis is poor, with more than half of patients dying during the hospital stay., (© 2011 John Wiley & Sons A/S.)

Background: propofol is an excellent sedative agent for use in patients undergoing bronchoscopy. The addition of an opioid to propofol can be advantageous because of the antitussive effect of the opioid and the possible improvement in sedation quality. However, it may increase the risk of hypoxaemia. To investigate the effect of the addition of alfentanil to propofol, we performed a prospective study to compare propofol-only sedation with propofol-alfentanil combination sedation in patients undergoing bronchoscopy., Methods: patients were randomly assigned either to the propofol-only (group P, n=32) or to the propofol-alfentanil combination group (group PA, n=32). The average peripheral oxygen saturation (SpO(2) ) and the lowest SpO(2) during the sedation were compared. Patient and bronchoscopist satisfaction as well as the degree of coughing were compared using a 100 mm visual analogue scale, where 0 indicated the least and 100 indicated the most satisfied., Results: group P had the higher average SpO(2) (%) during the procedure than group PA (97.8 ± 1.6 and 96.4 ± 1.1, P<0.01) as well as the lowest SpO(2) (%) (95.4 ± 2.7 and 94.0 ± 2.4, P<0.05). Patient satisfaction (92.2 ± 13.5 and 92.3 ± 18.2), bronchoscopist satisfaction (76.6 ± 18.1 and 72.8 ± 19.1), and degree of cough (73.4 ± 22.7 and 72.2 ± 18.5; group P and group PA, respectively) were not different between the groups., Conclusions: the combination of propofol and alfentanil resulted in a greater respiratory depression than propofol alone; furthermore, the addition of an opioid did not improve the quality of sedation. In conclusion, we do not recommend sedation with propofol and alfentanil during bronchoscopy., (2010 The Acta Anaesthesiologica Scandinavica Foundation.)

Aim: To investigate the incidence, clinical management, mortality and its risk factors, major outcome and costs of acute hypoxemic respiratory failure (AHRF) and acute respiratory distress syndrome (ARDS) in a Chinese network of 26 paediatric intensive care unit (PICU)., Methods: In a consecutive 12-month period, AHRF and ARDS were identified and followed up for 90 days or until death or discharge., Results: From a total of 11 521 critically ill patients, 461 AHRF were identified in which 306 developed ARDS (66.4%), resulting in incidences of 4% and 2.7%, respectively, with pneumonia (75.1%) and sepsis (14.7%) as main underlying diseases and 83% were 5 years and 1 month-old. In-hospital mortality of AHRF was 41.6% (44.8% for ARDS), accounted for 15.5% of all PICU deaths. For those of pneumonia or sepsis with AHRF and ARDS, mortality and its relative risk were significantly higher than those without. Relatively lower tidal volume and total fluid balance, adequate upper limit of PaCO(2) in the early PICU days, and family affordability, tended to result in better outcome., Conclusion: In this prospective study, AHRF had high possibilities to develop ARDS and death risk, as impacted by ventilation settings and fluid intake in the early treatment, as well as socioeconomic factors, which should be considered for implementation of standard of care in respiratory therapy.

Objective: The relationship between the frequency of autonomic dysfunction (AD) and the severity of chronic obstructive pulmonary disease (COPD) has not been exactly known, despite its importance in the pathogenesis of COPD. Therefore, we aimed to evaluate the relationship between the clinical stage severity of the disease and the frequency of AD in COPD patients., Methods: The frequency and type of AD were determined according to the clinical severity of 35 stable COPD patients. The results were compared between the mild and moderate-severe COPD groups. Sympathetic system (SS) was evaluated with sympathetic skin response (SSR), QT and QTc intervals (ms) analyses. Parasympathetic system was evaluated with the heart rate interval variations (RRIV)., Results: For the total group, an AD was detected in 20 patients (57%), a parasympathetic dysfunction (PD) in 14 (40%), a mixed-type dysfunction in five (14%) and a sympathetic dysfunction (SD) in only one patient (3%). For the 12 mildly affected patients, there were cases of isolated SD in only one patient (8.5%), isolated PD in five (42%) and AD in six patients (50%). For the 23 moderate-severe COPD patients, mixed AD was detected in five patients (22%), isolated PD in nine (39%) and AD in 14 patients (61%). There were no significant differences between the two patient groups, neither for isolated parasympathetic and sympathetic, mixed form nor for total AD (P>0.05)., Conclusions: The results suggested that PD was dominant in patients with COPD. However, the frequencies of autonomic parasympathetic and sympathetic dysfunction did not increase significantly with the severity of COPD. The severity of hypoxemia and/or airflow limitation may not be the only unique or definite reason for AD in COPD, as there was not an exact correlation between the presence of AD and the severity of airflow limitation and hypoxemia.

Background: Statistical data of mortality and morbidity related to anesthesia have not been reported in Japan since World War II. The need to comprehensively examine the events of cardiac arrest as well as mortality prompted the first national study in Japan., Methods: Confidential questionnaires were sent to all Japan Society of Anesthesiologists Certified Training Hospitals every year from 1994 through 1998. Collected data were analyzed for incidence of cardiac arrest and other critical events during anesthesia and surgery, and their outcomes within 7 postoperative days. The principal causes of the critical incidents were also analyzed., Results: With an average response rate of 39.9%, a total of 2,363,038 cases were documented over 5 years. The average incidence per year of cardiac arrest during surgery due to all etiologies and that totally attributable to anesthesia was 7.12 [95%CI: 6.30,7.94] and 1.00 [0.88, 1.12]) per 10,000 cases, respectively. The average mortality per year in the operating room or within 7 postoperative days due to all etiologies and that totally attributable to anesthesia was 7.18 [6.22, 8.13] and 0.21 [0.15, 0.27] per 10,000 cases, respectively. The two principal causes of cardiac arrest during anesthesia and surgery due to all etiologies were massive hemorrhage (31.9%) and surgery (30.2%), and those totally attributable to anesthesia were drug overdose or selection error (15.3%) and serious arrhythmia (13.9%). Preventable human errors caused 53.2% of cardiac arrest and 22.2% of deaths in the operating room totally attributable to anesthesia., Conclusions: The rates in Japan of cardiac arrest and death during anesthesia and surgery due to all etiologies as well as those totally attributable to anesthesia are comparable to those of other developed countries.

This study examines patterns of growth in height and weight among children (< 60 months) of highland and coastal agricultural communities of Ecuador. Highland children are significantly shorter, but not significantly lighter than their coastal peers. Linear growth rates (cm/6 months) are comparable between the two samples. Growth rates for body weight (kg/6 m) are similar in highland and coastal boys, whereas highland girls display larger weight gains than their coastal counterparts. In both regions, linear growth is compromised to a much greater extent than growth in body weight, and growth faltering for both height and weight is most pronounced between birth and 24 months of age. The similarity in growth rates between the highland and coastal samples suggests that high altitude hypoxia plays a relatively small role in shaping growth during the first five years after birth. Rather, it appears that most of the disparity in height between the two samples can be attributed to differences established by 6 months of age. The pattern of growth retardation seen in both regions during the first 24 postnatal months is similar to that observed among impoverished populations throughout the world and is likely associated with the influence of nutritional and disease stressors. After 2 years of age, little or no "catch up" growth is seen in height, whereas improvements in weight gain are more pronounced, especially among highland girls. Ongoing research is investigating the nutritional and socio-economic correlates of growth within each region.

The pathophysiology of cyanotic/apnoeic episodes in preterm infants was investigated using overnight tape recordings of beat-to-beat arterial oxygen saturation (SaO2), plethysmographic waveforms from the oximeter, breathing movements and nasal airflow. Recordings were made in 16 preterm infants with recurrent cyanotic episodes of unknown cause that had received stimulation or resuscitation, and 15 preterm controls, matched for birth weight, post-conceptional and postnatal age. The recordings were analysed for baseline SaO2, the number of hypoxaemic episodes (SaO2 < or = 80% for > or = 4 s) and the breathing patterns associated with each episode. There was a significant difference in the total number of hypoxaemic episodes between patients and controls (520 versus 100; p < 0.01), but no difference was found for mean baseline SaO2 (98.6 versus 99.0%; p > 0.05). The mean duration of each hypoxaemic episode in the patients was 9.5 s compared with 5.8 s in the controls (p < 0.01). Although most hypoxaemic episodes (62 and 76%) were associated with pauses in breathing movements, a proportion (8 and 18%, respectively) occurred despite continuous airflow and breathing movements in both patients (6 of 16) and preterm controls (2 of 15). The rate of decrease in SaO2 was significantly more rapid during these latter hypoxaemic episodes than during episodes associated with isolated apnoeic pauses (8.5 versus 3.2% per second, p = 0.02). Preterm infants with cyanotic episodes have increased numbers of clinically unapparent hypoxaemic episodes, some of which have continued ventilation and rapid desaturation. The pathogenesis of these episodes warrants further investigation.

The frequency and severity of hypoxaemia during induction of anaesthesia in neonates and small infants at the Norfolk and Norwich Hospital, a district general hospital, was compared, using pulse oximetry, with that of the nearest specialist hospital, the Queen Elizabeth Hospital for Sick Children in London. There were differences in staffing and the choice of anaesthetic techniques between the hospitals. One third of the patients in both hospitals experienced desaturation of more than 5% (moderate or severe hypoxaemia) at one or more recordings during induction. The highest incidence of hypoxaemia was associated with awake intubation. There was no statistical difference in the incidence or severity of hypoxaemia between the hospitals. In the district general hospital, moderate or severe hypoxaemia of greater than 30 s duration was more likely if an anaesthetist with a regular paediatric operating list was not present at induction (p < 0.01).