Search

Background: In 2013, the Centers for Disease Control and Prevention (CDC) issued the concept of the ventilator-associated events (VAEs) as a quality indicator (QI) in the intensive care unit (ICU). A number of studies have been conducted in the United States and other Western countries to evaluate its practicality. However, information on VAEs in non-Western countries is scarce. The purpose of this preliminary study was to illuminate the incidence and associated mortality rate of VAEs in Japan, as a first step in the effort to determine its practicality. Methods: We conducted a multi-center, retrospective review of patient medical record using VAEs surveillance algorithm. We analyzed 785 patients with ≥2 days of mechanical ventilator (MV), admitted to the ICU at seven urban hospital in Japan. The prevalence of VAEs, including its three subtypes, and in-ICU mortality were researched. Results: Forty-nine VAEs were identified, affecting 5.7% of patients requiring MV for ≥2 days and 6.4 per 1,000 MV days. Mortality in those who developed VAEs was 42.9%, significantly higher than the rest of the cohort ( vs . 15.4%, P Conclusions: The prevalence of VAEs appears low in Japanese ICUs. Nonetheless, mortality was substantially higher in patients who developed VAEs. Although some potential indices of VAEs are suggested to serve as QIs, additional studies to elaborate its practicality would further be required.

To investigate whether steroid replacement therapy improved hemodynamics in infants after surgery for congenital heart disease only when they develop adrenal insufficiency. The authors retrospectively investigated adrenal function and evaluated hemodynamic responses to steroid replacement therapy in infants after surgery for congenital heart disease.Retrospective, cohort study.Intensive care unit in the National Cerebral and Cardiovascular Center Hospital in Japan.Thirty-two neonates and infants3 months old who underwent cardiovascular surgery.The patients were divided into 2 groups based on corticotropin stimulation test results: group AI with adrenal insufficiency (baseline cortisol15 µg/dL or incremental increase after testing of9 µg/dL, with baseline cortisol of 15-34 µg/dL); and group N with normal adrenal function. The corticotropin stimulation test was performed by injecting 3.5 µg/kg of tetracosactide acetate. Hydrocortisone (1 mg/kg) was administered every 6 hours, and hemodynamics were compared before and after steroid administration between the groups.Seven patients were classified into group AI, and demonstrated a mean blood pressure increase from 53±8 mmHg before treatment to 68±9 mmHg 18 hours after steroid administration (p0.01). Urine output also increased, from 2.7±1.0 mL/kg/h to 4.8±1.9 mL/kg/h (p0.05). In group N, neither mean blood pressure nor urine output increased after steroid administration.After surgery for congenital heart disease, one-fifth of infants developed adrenal insufficiency. Steroid replacement therapy improved hemodynamics only in the subgroup with adrenal insufficiency.

Dexmedetomidine is thought to activate an endogenous pathway that naturally promotes non-rapid eye movement (NREM) sleep. Dexmedetomidine may induce restorative sleep, that is, NREM stage 3 and 4 (slow wave sleep; SWS) or sleep continuity in mechanically ventilated patients. Few data have been published, however, on the sleep characteristics of mechanically ventilated patients during dexmedetomidine infusion.We recorded polysomnography (PSG) for 24 h in mechanically ventilated patients sedated with dexmedetomidine. Dexmedetomidine (0.2-0.7 μg/kg/h) was administered intravenously to maintain the Richmond Agitation-Sedation Scale between -1 and -4 only during the nighttime (9:00 p.m. to 6:00 a.m.). During the daytime, we interrupted the sedatives and analgesics unless the patient complained of discomfort. When this occurred midazolam or opioids were administered intermittently. Sleep stages and the frequency of arousal/awakening during the nighttime were analyzed using Rechtschaffen and Kales criteria.For the ten mechanically ventilated adult patients recruited into the study, the median total sleep time (TST) during the night was 4.7 h (IQR, 4.2-8.1 h), and 78 % of sleep occurred during the night (median 78 %, IQR: 69-88 %). Sleep architecture was exclusively NREM sleep stage 1 (median 28.9 % of TST) and stage 2 (median 71.2 % of TST). Neither SWS (median 0 % of TST) nor rapid eye movement (REM) sleep (median 0 % of TST) was observed. Median frequency of arousals/awakenings was 9.3/h (IQR, 3-19.5/h).In mechanically ventilated patients, nighttime infusion of dexmedetomidine preserved the day-night cycle of sleep but induced severely disturbed sleep architecture without evidence of SWS or REM sleep.

BACKGROUND: Endotracheal tubes (ETTs) impose a substantial respiratory work load on mechanically ventilated patients. Automatic tube compensation (ATC) should overcome this flow-dependent resistive work load; however, ETT resistance can be increased by tracheal secretions or ETT deformities. Our bench study investigated whether ATC provides effective respiratory work load relief in used ETTs. METHODS: We enrolled 20 critically ill patients requiring mechanical ventilation for longer than 48 hours. After extubation, we collected the used ETTs and measured the pressure-time products (PTPs) by using a bellows-in-a-box lung model that simulated spontaneous breathing, at a respiratory rate of 10 breaths/min, inspiratory time of 1.0 s, and tidal volumes (VT) of 300 mL, 500 mL, and 700 mL. The ventilator was set at ATC 100% with PEEP of 5 cm H2O and FIO2 of 0.21. The flow and airway pressure at the proximal (Paw) and distal (Ptr) ends of the ETT were recorded, and the PTP integrated from Ptr analyzed. RESULTS: PTP values increased with VT during ATC. Even at 100% ATC the ventilator did not completely compensate for the PTP imposed by the ETT. In used ETTs, peak flow and peak Paw were lower and PTP values were greater than in new ETTs. As VT increased, the percentage difference in the PTP values between the new and used ETTs increased. CONCLUSIONS: ATC does not necessarily compensate for an ETT-imposed respiratory work load. ETT configuration changes and tracheal secretions can increase ETT resistance and decrease the ability of ATC to compensate for the increased respiratory work load.

Background. While heat and moisture exchangers (HMEs) have been increasingly used for humidification during mechanical ventilation, the efficacy of pediatric HMEs has not yet been fully evaluated.Methods. We tested ten pediatric HMEs when mechanically ventilating a model lung at respiratory rates of 20 and 30 breaths/min and pressure control of 10, 15, and 20 cmH2O. The expiratory gas passed through a heated humidifier. We created two rates of leakage: 3.2 L/min (small) and 5.1 L/min (large) when pressure was 10 cmH2O. We measured absolute humidity (AH) at the Y-piece.Results. Without leakage, eight of ten HMEs maintained AH at more than 30 mg/L. With the small leak, AH decreased below 30 mg/L (26.6 to 29.5 mg/L), decreasing further (19.7 to 27.3 mg/L) with the large leak. Respiratory rate and pressure control level did not affect AH values.Conclusions. Pediatric HMEs provide adequate humidification performance when leakage is absent.

Background Catheter hub contamination has been recognized as a source of catheter-related bloodstream infections. We have investigated the efficacy of a protection cap for a needleless injection device in preventing intraluminal catheter contamination, compared with a conventional 3-way stopcock. Methods Adult patients requiring an intravascular catheter placement for at least 48 hours in an intensive care unit were randomly assigned to receive either the needleless injection device with protection cap (test group, n=31, number of devices=151) or with a conventional 3-way stopcock (comparator group, n=33, number of devices=179). To evaluate intraluminal contamination, we examined the bacteria isolated in the inline bacterial filters, which were attached downstream of the injection ports. Results The incidence of bacterial contamination was significantly different between the groups (test group 2/151 (1.3%) vs comparator group 11/179 (6.2%), P = .04). There was no correlation between the microbial contamination rate and the in situ time of catheter or numbers of injections. Conclusion The protection cap for needleless injection devices decreased microbial transfer from the injection port to the intraluminal fluid pathway and lowered the risk of catheter-related bloodstream infections.

肺動脈カテーテルは心拍出量や循環動態のモニターに広く用いられてきた．しかしその使用によって死亡率は改善せず合併症が増えることが報告され，肺動脈カテーテルに替わって非侵襲的に心拍出量などを測定する手技が開発されてきた．Fick原理を呼気ガス二酸化炭素に応用し心拍出量を計算する部分的CO2再呼吸法，動脈圧波形を解析し一回拍出量をモニターするpulse contour法などである．分時換気量が一定な場合，部分的CO2再呼吸法で求めた心拍出量は信頼できる．Pulse contour法を用いると輸液反応性を予測することができる．

Purpose Post-pyloric feeding tube placement is often difficult, and special equipment or peristalsis agents are used to aid insertion. Although several reports have described blind techniques for post-pyloric feeding-tube placement, no general consensus about method preference has been achieved. Materials and Methods The technique is performed as follows: via the nostril, a stylet-tipped feeding tube is advanced about 70 cm; to confirm tip location to the right of the epigastric area, towards the right hypochondriac region, 5 mL shots of air are injected to enable touch detection of bubbling; finally, the tube is advanced to a length of 100 cm, during which the strength of bubbling seems to diminish under palpation. Results We prospectively enrolled consecutive patients whose oral intake was expected to be difficult for 48 hours in the intensive care unit. Forty-one patients were enrolled and the rate of successful placement at first attempt was 95.1%. Mean duration for successful placement was 15 minutes. Conclusions With a novel technique, from the bedside, without special tools or drugs, we successfully placed post-pyloric feeding tubes. Essential points when inserting the tube are confirmation of the location of the tube tip by palpation of injected air, and to avoid deflection and looping.

Delayed discharge from ICU to the general ward can exert an adverse effect. We researched whether patients are discharged smoothly from our ICU to the general ward.We defined that patients were eligible for discharge if they are without administration of catecholamine, being assisted by mechanical ventilation and having blood purification therapy.Average time from actual discharge to the time patient was considered eligible for discharge was fifteen hours. This study was retrospective.We need to investigate further the reasons why delayed discharge occurred. It is im portant that patients are discharged from the ICU to the general ward properly. Delayed discharge can delay the recovery and expose the patient to multi-resistant microorganisms. We studied whether patients are discharged smoothly from the ICU to the general ward.

A 79-y-old man with generalized tetanus was admitted to the ICU. A left-forearm wound was surgically debrided, and the wound was closed. On postoperative day 1, after the patient experienced opisthotonos and convulsions, endotracheal intubation was performed. Propofol and diazepam were infused but failed to stop the convulsions. Morphine, midazolam, dantrolene, and rocuronium were used to ameliorate the muscle spasms. Magnesium sulfate was also infused. On postoperative day 15, patient-ventilator asynchrony was apparent. The patient showed recurrent tachypnea and bradypnea, which seemed typical of Cheyne-Stokes respiration. A neurally adjusted ventilatory assist (NAVA) catheter was inserted transnasally, and electrical activity of the diaphragm (Edi) was monitored. Readings showed regular attempts to breathe at 40-50 breaths/min with periodic changes in Edi amplitude. NAVA mode improved patient-ventilator synchrony. Periodic breathing continued for 2 weeks. We stopped monitoring Edi on postoperative day 39. He began respiratory rehabilitation and was transferred to a hospital for rehabilitation on postoperative day 80. We encountered periodic respiration in a patient with tetanus. Edi monitoring revealed periodic amplitude change. The cause of the periodic breathing pattern in this patient could not be determined but may be attributable to side effects of the pharmacologic interventions or the natural history of the disease itself. NAVA mode improved patient-ventilator synchrony.

We review the outcome of surgery for chronic thromboembolic pulmonary hypertension (CTEPH).Between 1995 and 2004, 88 patients underwent surgery for CTEPH. Mean pulmonary artery pressure and pulmonary vascular resistance were 46 mm Hg (range, 23 to 70 mm Hg) and 986 dynes.sec(-1).cm(-5) (298 to 2,231 dynes.sec(-1).cm(-5)). The pulmonary artery lesion was proximally located in 51 patients, subsegmental in 34 patients, and peripheral in 3 patients. Pulmonary endarterectomy was performed using cycles of 15-minute intermittent circulatory arrest followed by 10-minute reperfusion at 16 degrees C to 18 degrees C.The median durations of circulatory arrest, cardiopulmonary bypass, and surgery were 58, 217, and 355 minutes, respectively. Percutaneous extracorporeal membrane oxygenation was used in 8 patients (9.1%) who had difficulty being weaning from cardiopulmonary bypass. Three recent patients for whom this was performed promptly were weaned and survived. There were 7 hospital deaths (8.0%, including 6 30-day deaths) from pulmonary bleeding in 2 patients, residual pulmonary hypertension in 3, rupture of bulla in 1, and empyema in 1. In the 81 survivors, mean pulmonary artery pressure and pulmonary vascular resistance fell significantly after surgery (p0.0001, each case). Age more than 60 years was a risk factor for hospital mortality on multivariate analysis. Although distal pulmonary artery disease including subsegmental and peripheral lesions was not a significant risk factor for mortality, it did influence patient recovery: the frequency of percutaneous extracorporeal membrane oxygenation was higher and hemodynamic improvement less pronounced in patients with distal disease. The actuarial survival rate was 90.7% at 3 years and 86.4% at 5 years. None of the patients have suffered recurrence. The event-free rate was 97.1% at 3 years and 93.5% at 5 years. Of the 68 patients surviving for more than 1 year after surgery, 67.6% were successfully weaned from home oxygen therapy and 13.2% required only occasional use of oxygen.Pulmonary endarterectomy can be safely performed with relatively low mortality and favorable prognosis with long-term survival, although it should be performed carefully for patients with distal disease.

OBJECTIVES To investigate the effects of a recruitment maneuver and high positive end-expiratory pressure (PEEP) on oxygenation and hemodynamics in hypoxemic patients with pulmonary hypertension after pulmonary thromboendarterectomy for chronic pulmonary thromboembolism. DESIGN Prospective, observational, clinical study. SETTING A surgical intensive care unit in a national heart institute. PATIENTS Fourteen consecutively admitted patients who developed acute lung injury (Pa(O2) 25 mm Hg) after pulmonary thromboendarterectomy for chronic pulmonary thromboembolism. INTERVENTIONS The recruitment maneuver was an increase of PEEP to 30 cm H2O in one step for 1 min at F(IO2) 1.0. The level of pressure control ventilation during the recruitment maneuver was the same as before the maneuver. Subsequently, PEEP was decreased in 15-min intervals from 15 to 10, 5, and 0 cm H2O. MEASUREMENTS AND MAIN RESULTS Hemodynamics and respiratory variables were analyzed before and during the recruitment maneuver and at each PEEP level. At F(IO2) 1.0, Pa(O2) increased from 240 +/- 62 torr to 470 +/- 83 torr at 15 cm H2O of PEEP and 469 +/- 75 torr at 10 cm H2O of PEEP after the recruitment maneuver (p < .001). At 15 cm H2O of PEEP, cardiac index decreased (from 2.7 +/- 0.6 at baseline to 2.2 +/- 0.3 L.min(-1).m(-2), p < .01) and mean blood pressure decreased (from 86 +/- 8 at baseline to 74 +/- 11 mm Hg, p < .05), but they returned to the baseline levels at 10 cm H2O of PEEP (2.5 +/- 0.4 L.min(-1).m(-2) and 83 +/- 9 mm Hg). There were no differences in mean pulmonary artery pressure at different levels of PEEP. CONCLUSIONS In hypoxemic patients with pulmonary hypertension after pulmonary thromboendarterectomy for chronic pulmonary thromboembolism, oxygenation was improved by the recruitment maneuver followed by high PEEP. However, hemodynamics were transiently suppressed and overall oxygen delivery did not change.

症例は61歳,男性.腹部大動脈瘤(AAA)破裂のため,自宅で心肺停止となった.ドクターカーの救命医によってただちに心肺蘇生(CPR)が行われ一時は心拍が再開したが搬送中に再度心肺停止となった.来院時,意識はJapan Coma Scale 300,徐脈で血圧測定不能であった.超音波検査でAAAと後腹膜血腫を認めたため,AAA破裂と診断し緊急手術となった.左上腕動脈から大動脈閉塞バルーンを挿入して出血をコントロールし血行動態が安定したのち,腹部正中切開にて開腹した.破裂を伴う6cm径のAAAと,多量の後腹膜血腫を認め,Y字人工血管置換術を施行した.術後5時間で,下行結腸からS状結腸の壊死が判明し,左半結腸切除,人工肛門造設術を行った.急性腎不全のほか,肝機能障害,虚血性脳障害,左後頭葉および頭頂葉の脳梗塞を合併したが,持続鎮静下の全身管理によって肝腎機能が正常に復し,血液透析および呼吸器からの離脱に成功した.脳梗塞による右半盲,感覚性失語の症状はあるものの,意思疎通は可能で,介助なしでの経口摂取,歩行器による歩行ができるまでに回復した.院外で心肺停止に陥ったAAA破裂の1例に約40分間に及ぶCPRののちに手術を施行した.術後に腸管壊死,多臓器不全を合併したが,重篤な後遺症なく救命できた症例を経験したので報告する.

Spontaneous breathing trials are commonly used in adults to enable smooth weaning from mechanical ventilation. However, few investigations have examined spontaneous breathing tests in infants. We investigated how respiratory patterns of infants changed during continuous positive airway pressure (CPAP) and whether successful extubation followed CPAP.Fifty-one consecutive post-cardiac surgery infants satisfied the following weaning criteria: stable hemodynamics, pH7.30, tidal volume5 ml.kg(-1), and respiratory rate50 breaths.min(-1) with pressure control of 10-16 cm H(2)O. We applied CPAP of 3 cm H(2)O for 30 min to these 51 infants. During CPAP, tidal volume, respiratory rate, and arterial blood gases were measured. CPAP was terminated if the patient showed a sustained increase or decrease in heart rate or blood pressure (20%), a decrease in arterial oxygen saturation (5%), agitation, or diaphoresis. After the completion of CPAP, tracheal extubation was performed. We considered extubation successful if no reintubation was required in the ensuing 48 h.Although hemodynamic and ventilatory variables were unstable for the first 5 min, they stabilized after 10 min of CPAP. Fifty infants completed the CPAP trial safely. Of these, 46 (92%) underwent successful extubation after the CPAP trial. The failure group (4 infants) showed lower pH, higher arterial carbon dioxide tension, and more rapid shallow breathing during CPAP than the success group.After cardiac surgery, when infants recovered stable hemodynamics and spontaneous breathing, the ventilatory pattern and hemodynamics became stable after 10 min of CPAP. Ninety-two percent of the patients were successfully extubated following a 30-min CPAP trial.

BACKGROUND: ABO-mismatched transfusions caused by human error are among the most serious problems in transfusion therapy. The major cause is misidentification of a recipient or a blood component at the bedside. STUDY DESIGN AND METHODS: A network computer-assisted transfusion-management system has been developed with bar coding as a fail-safe/fool-proof system for accurate component–recipient identification at the bedside, which allows us to monitor the usage of blood components in real time. The efficacy of this system was evaluated to prevent human errors by monitoring the transfusion process via the network and analyzing voluntary and mandatory reports with regard to transfusion errors over a 3-year period. The crossmatch-to-transfusion ratio for operations and outdate rate of RBCs were calculated to assess economic benefit. RESULTS: More than 60,000 blood components have been transfused perfectly to the intended recipients via the network, and one human error was prevented by the system. After establishment of the network system, the crossmatch-to-transfusion ratio for operations and outdate rate of RBCs have been gradually reduced from around 2.5 to 1.8 and from 3.9 to 0.32 percent, respectively. CONCLUSION: The network computer-assisted management system greatly contributes to safe and efficient transfusion therapy.

Background Although evaluation of cardiac output by the partial carbon dioxide rebreathing technique is as accurate as thermodilution techniques under controlled mechanical ventilation, it is less accurate at low tidal volume. It is not clear whether reduced accuracy is due to low tidal volume or low minute ventilation. The effect of spontaneous breathing on the accuracy of partial carbon dioxide rebreathing measurement has not been fully investigated. The objectives of the current study were to investigate whether tidal volume or minute ventilation is the dominant factor for the accuracy, and the accuracy of the technique when spontaneous breathing effort is present. Methods The authors enrolled 25 post-cardiac surgery patients in two serial protocols. First, the authors applied three settings of controlled mechanical ventilation in random order: large tidal volume (12 ml/kg), the same minute ventilation with a small tidal volume (6 ml/kg), and 50% decreased minute ventilation with a small tidal volume (6 ml/kg). Second, when the patient recovered spontaneous breathing, the authors applied three conditions of partial ventilatory support in random order: synchronized intermittent mandatory ventilation-pressure support ventilation, pressure support ventilation with an appropriately adjusted rebreathing loop, and pressure support ventilation with the shortest available loop. After establishing steady state conditions, the authors measured cardiac output using both partial carbon dioxide rebreathing and thermodilution methods. The correlation between the data yielded by the two methods was determined by Bland-Altman analysis and linear regression. Results Cardiac output with the carbon dioxide rebreathing technique correlated moderately with that measured by thermodilution when minute ventilation was set to maintain normocapnia, regardless of tidal volumes. However, when minute ventilation was set low, the carbon dioxide rebreathing technique underreported cardiac output (y = 0.70x; correlation coefficient, 0.34; bias, -1.73 l/min; precision, 1.27 l/min; limits of agreement, -4.27 to +0.81 l/min). When there was spontaneous breathing, the correlation between the two cardiac output measurements became worse. Carbon dioxide rebreathing increased spontaneous tidal volume and respiratory rate (20% and 30%, respectively, during pressure support ventilation) when the rebreathing loop was adjusted for large tidal volume. Conclusions During controlled mechanical ventilation, minute ventilation rather than tidal volume affected the accuracy of cardiac output measurement using the partial carbon dioxide rebreathing technique. When spontaneous breathing is present, the carbon dioxide rebreathing technique is less accurate and increases spontaneous tidal volume and respiratory rate.

OBJECTIVES We sought to assess the impact of diabetic retinopathy on long-term outcome among patients with diabetes and multivessel coronary artery disease (MVD) following coronary artery bypass graft surgery (CABG). BACKGROUND For diabetics, CABG is the preferred revascularization strategy. Diabetic retinopathy is a major microvascular complication of diabetes, and its severity is directly related to total glycemic exposure. METHODS We identified 223 consecutive diabetics with MVD whose retinae were evaluated within one year prior to CABG. The most recent ophthalmologic records up until the time of CABG were used to evaluate the severity of retinopathy. The median follow-up after CABG was 11.6 years. RESULTS Diabetic retinopathy was a strong independent predictor of overall mortality (relative risk [RR], 4.0), and repeat revascularization (RR, 3.0). In separate analyses of diabetics with retinopathy and without retinopathy, predictors of mortality differed significantly between the two groups. Among diabetics with retinopathy, the presence of either preoperative renal (RR, 2.5) or ventricular (RR, 2.0) dysfunction had unfavorable effects on mortality, but the survival curves did not differ significantly according to the presence or absence of internal thoracic artery (ITA) grafting. In comparison, among diabetics without retinopathy, ITA grafting (RR, 0.34) had a beneficial effect on mortality, and the survival curves varied somewhat according to the presence or absence of renal or ventricular dysfunction. CONCLUSIONS Diabetics with retinopathy had a distinct post-CABG course with a worse long-term prognosis, as compared with diabetics without retinopathy. Retina evaluation is useful for prediction of long-term prognosis and management of diabetics who need CABG.

Excessive supplemental oxygen causes injurious hyperoxemia. Before establishing the best P(aO2) targets for mechanically ventilated patients, it is important to understand the incidence of hyperoxemia and related factors. We investigated oxygenation in mechanically ventilated subjects in our ICU and evaluated factors related to hyperoxemia (P(aO2)120 mm Hg) at 48 h after initiation of mechanical ventilation.We retrospectively reviewed the medical records of patients admitted to our ICU from January 2010 to May 2013. Inclusion criteria were 15 y of age or older and administration of mechanical ventilation for48 h. Patients at risk of imminent death on admission or who had received noninvasive ventilation were excluded. We collected subject demographics, reasons for mechanical ventilation, and during mechanical ventilation, we collected arterial blood gas data and ventilator settings on the first day of intubation (T1), 48 h after initiation of mechanical ventilation (T2), and on the day of extubation (T3). Multivariable logistic regression analysis was performed to clarify independent variables related to hyperoxemia at T2.For the study period, data for 328 subjects were analyzed. P(aO2) statistically significantly increased over time to 90 (interquartile range of 74-109) mm Hg at T1, 105 (89-120) mm Hg at T2, and 103 (91-119) mm Hg at T3 (P.001), coincident with decreases in F(IO2) of 0.4 (0.3-0.5) at T1, 0.3 (0.3-0.4) at T2, and 0.3 (0.3-0.35) at T3 (P.001). Hyperoxemia occurred in 15.6% (T1), 25.3% (T2), and 22.4% (T3) of subjects. Multivariable logistic regression analysis revealed that hyperoxemia was independently associated with age of40 y (odds ratio 2.6, 95% CI 1.1-6.0), Acute Physiology and Chronic Health Evaluation II scores of ≥ 30 (odds ratio 0.53, 95% CI 0.3-1.0), and decompensated heart failure (odds ratio 1.9, 95% CI 1.1 to 3.5).During mechanical ventilation of critically ill subjects, P(aO2) increased, and F(IO2) decreased. One in 4 subjects were hyperoxemic at T2, and hyperoxemia persisted until T3.

Introduction: Although continuous or frequent stimuli in tracheostomized patients may cause tracheal granulomas, little is known about management of patients with translaryngeal intubation. Case presentation: A 1-month-old Japanese boy, weighing 3.5kg, was admitted to our hospital owing to cardiac failure caused by an atrial septal defect and intractable arrhythmia. To treat his unstable cardiovascular status, surgery was performed to close his atrial septal defect. After the operation, stenosis was detected by auscultation and flow limitation worsened. A bronchoscopy revealed granulomas completely obstructing his right bronchus and partially obstructing his left bronchus. Dexamethasone infusion partially reduced the mass, after which removal by yttrium aluminium garnet laser was tried. The airway obstruction was not resolved, however, because of granuloma reproliferation. Budesonide (aerosol liquid) inhalation was started, and tissue was reduced using an yttrium aluminium garnet laser and physically removed using forceps. After continued budesonide inhalation, he was successfully liberated from the ventilator. Conclusions: Life-threatening airway obstruction by granulomas developed in a translaryngeally intubated paediatric patient. The granuloma was detected after a couple of weeks of intubation. A bronchial granuloma is rare in paediatric patients. It should be suspected with evidence of bronchial obstruction. Treatment with corticosteroids and surgery using a laser maybe indicated.

Background Synchronized intermittent mandatory ventilation (SIMV) is commonly used in infants and adults. However, few investigations have examined how SIMV reduces respiratory workload in infants. The authors evaluated how infants' changing respiratory patterns when reducing SIMV rate increased respiratory load. The authors also investigated whether SIMV reduces infant respiratory workload in proportion to the rate of mandatory breaths and which rate of SIMV provides respiratory workloads similar to those after tracheal extubation. Methods When 11 post-cardiac surgery infants aged 2-11 months were to be weaned with SIMV, the authors randomly applied five levels of mandatory breathing: 0, 5, 10, 15, and 20 breaths/min. All patients underwent ventilation with SIMV mode: pressure control ventilation, 16 cm H2O; inspiratory time, 0.8 s; triggering sensitivity, 0.6 l/min; and positive endexpiratory pressure, 3 cm H2O. After establishing steady-state conditions at each SIMV rate, arterial blood gases were analyzed, and esophageal pressure, airway pressure, and airflow were measured. Inspiratory work of breathing, pressure-time products, and the negative deflection of esophageal pressure were calculated separately for assisted breaths, for spontaneous breaths, and for total breaths per minute. Measurements were repeated after extubation. Results As the SIMV rate decreased, although minute ventilation and arterial carbon dioxide tension were maintained at constant values, spontaneous breathing rate and tidal volume increased. Work of breathing, pressure-time products, and negative deflection of esophageal pressure increased as the SIMV rate decreased. Work of breathing and pressure-time products after extubation were intermediate between those at a SIMV rate of 5 breaths/min and those at 0 breaths/min. Conclusion When the load to breathing was increased progressively by decreasing the SIMV rate in post-cardiac surgery infants, tidal volume and spontaneous respiratory rate both increased. In addition, work of breathing and pressure-time products were increased depending on the SIMV rate.

Objective: To investigate whether transtracheal open ventilation (TOV), pressure control ventilation (PCV) through a minitracheotomy tube (internal diameter 4 mm), is an effective method of inspiratory assistance under high upper airway resistance in postextubation patients; to compare, in a lung model study, TOV with other methods. Design: Clinical study: A prospective, controlled, crossover study. Lung model study: A prospective laboratory trial. Setting: Clinical study: A six-bed general intensive care unit in a teaching hospital. Lung model study: Animal research laboratory. Patients: Clinical study: Eleven postextubation patients, who had undergone minitracheotomy for sputum retention between January 1997 and December 1997. Subject: Lung model study: Two-bellows-in-a-box lung model, which included ordinary and high levels of upper airway resistance. Interventions: Clinical study: Ventilatory settings were: assist/control (A/C) mode, 2 breaths/min of AIC back-up rate, 35-40 cm H 2 O of PCV, 0.6-0.8 secs of inspiratory time, and 0 cm H 2 O of positive end-expiratory pressure. The ventilatory parameters of TOV were compared with those of spontaneous breathing (SB). Lung model study: Effect of TOV on inspiratory assistance was compared with those of SB, open minitracheotomy, 5 Umin of transtracheal gas insufflation, and 5 and 10 cm H 2 O of pressure support ventilation (PSV), which simulated noninvasive positive ventilation. TOV ventilatory settings were: A/C mode; 30, 40, and 50 cm H 2 O of PCV, 0.9 secs of inspiratory time, and 0 cm H 2 O of positive end-expiratory pressure. At each ventilatory setting, we adjusted the inspiratory effort of the model to give a tidal volume of 0.5 L. Measurements and Main Results: Clinical study: TOV was performed for 76.6 ± 38.6 hrs (mean ± SD) over 5.6 ± 2.6 days without major complication. Peak tracheal pressure, which was measured distal to the minitracheotomy tube in six patients by a catheter pressure transducer, was 4.33 ± 0.59 cm H 2 O. Inspiratory tidal volume delivered by the ventilator was 0.51 ± 0.06 L. Respiratory rate during TOV was lower than during SB. According to esophageal pressure and respiratory inductive plethysmography, TOV reduced the patient's inspiratory work and improved the breathing pattern. Lung model study: Mean tracheal pressure during TOV and 10 cm H 2 O of PSV were positive values and they had larger inspiratory assistance according to the pressure-time product of pleural pressure. Although high upper airway resistance reduced the inspiratory assistance of PSV, it did not change the effects of TOV. Conclusions: TOV effectively reduced patient's inspiratory work and was more useful than open minitracheotomy and transtracheal gas insufflation. TOV also improved the breathing pattern. TOV may be useful for resolving some postextubation respiratory problems and avoiding the need for reintubation.

Objective: To investigate, in a rat model, the role of the Mac1/ICAM-1 pathway and the anti-inflammatory activity of steroid in ventilator-induced lung injury. Design: Prospective, randomized controlled study. Setting: Animal investigation using Wistar rats. Intervention: Rats in three randomly assigned groups of 18, a total of 54 animals, were subject to the following: Two groups received high peak inspiratory pressure (35 cm H 2 O) ventilation after pretreatment with methylprednisolone (high-methylprednisolone group) or pretreatment with methylprednisolone vehicle (high-vehicle group). The third group of animals received low peak inspiratory pressure (7 cm H 2 O) ventilation after pretreatment with methylprednisolone vehicle (low-vehicle group). Except for animals previously killed to establish baseline values, after 40 mins of mechanical ventilation, the animals in each group were killed. Some animals provided histological samples, and the rest received total lung lavage. Measurement: We measured flow cytometry of lavage fluid, cell counts of tissue samples, and pressure-volume curves before and after mechanical ventilation. Results: In the groups that received high peak inspiratory pressure ventilation, both the number of neutrophils that infiltrated the lungs and the expression of Mac-1 and ICAM-1 on neutrophils and macrophages increased significantly more than in the low-vehicle group. Static lung compliance was reduced in the high peak inspiratory pressure groups. In the high peak inspiratory pressure groups, there were significantly fewer neutrophils in samples from the high-methylprednisolone group (0.412 ± 0.1 x 10 5 ) than from the high-vehicle group (1.10 ± 0.1 x 10 5 ; p

Activated neutrophils contribute to the development of ventilator-induced lung injury (VILI) caused by high-pressure mechanical ventilation. However, exact cellular and molecular mechanisms have not been conclusively studied. Our investigation aimed to examine expression of adhesion molecules by both neutrophils and macrophages in lung lavage fluids of rats with VILI. Further, involvement of proinflammatory (tumor necrosis factor-alpha) and profibrogenetic (transforming growth factor-beta 1) mediators was analyzed at mRNA level in lung tissue. Wistar rats were ventilated by high pressure (45 cm H(2)O of peak inspiratory pressure, n = 23) or low pressure (7 cm H(2)O, n = 13) with 0 positive end-expiratory pressure. After 40 min of comparative ventilation, lung lavage was performed in 20 rats from the experimental group and 10 from the control for immunofluorescence analysis with anti-Mac-1 and anti-ICAM-1 monoclonal antibodies. The lung tissues from remaining rats were subjected to pathological and reverse transcription-polymerase chain reaction examinations. Although there was no significant change of PaO(2) in the low-pressure group, PaO(2) was decreased in the high-pressure group. The high-pressure group also had greater neutrophil infiltration into alveolar spaces, upregulation of CD54 and CD11b on alveolar macrophages, and more transforming growth factor-beta 1 mRNA in lung tissues. Tumor necrosis factor-alpha was not involved in the pathogenesis of the severe VILI observed. Histologic findings also demonstrated more infiltrating neutrophils, destructive change of the alveolar wall, and deposition of matrix in the high-pressure group. These results suggest that a series of proinflammatory reactions and profibrogenetic process may be involved in the course of VILI.

Delivering heated and humidified medical gas at 20-60 L/min, high-flow nasal cannula (HFNC) creates low levels of PEEP and ameliorates respiratory mechanics. It has become a common therapy for patients with respiratory failure. However, independent measurement of heat and humidity during HFNC and comparison of HFNC devices are lacking.We evaluated 2 HFNC (Airvo 2 and Optiflow system) devices. Each HFNC was connected to simulated external nares using the manufacturer's standard circuit. The Airvo 2 outlet-chamber temperature was set at 37°C. The Optiflow system incorporated an O2/air blender and a heated humidifier, which was set at 40°C/3. For both systems, HFNC flow was tested at 20, 40, and 50 L/min. Simulating spontaneous breathing using a mechanical ventilator and TTL test lung, we tested tidal volumes (VT) of 300, 500, and 700 mL, and breathing frequencies of 10 and 20 breaths/min. The TTL was connected to the simulated external nares with a standard ventilator circuit. To prevent condensation, the circuit was placed in an incubator maintained at 37°C. Small, medium, and large nasal prongs were tested. Absolute humidity (AH) of inspired gas was measured at the simulated external nares.At 20, 40, and 50 L/min of flow, respective AH values for the Airvo 2 were 35.3 ± 2.0, 37.1 ± 2.2, and 37.6 ± 2.1 mg/L, and for the Optiflow system, 33.1 ± 1.5, 35.9 ± 1.7, and 36.2 ± 1.8 mg/L. AH was lower at 20 L/min of HFNC flow than at 40 and 50 L/min (P.01). While AH remained constant at 40 and 50 L/min, at 20 L/min of HFNC flow, AH decreased as VT increased for both devices.During bench use of HFNC, AH increased with increasing HFNC flow. When the inspiratory flow of spontaneous breathing exceeded the HFNC flow, AH was influenced by VT. At all experimental settings, AH remained30 mg/L.

Background Patient-triggered ventilation (PTV) is commonly used in adults to avoid dyssynchrony between patient and ventilator. However, few investigations have examined the effects of PTV in infants. Our objective was to determine if pressure-control PTV reduces infants' respiratory workloads in proportion to the level of pressure control. We also explored which level of pressure control provided respiratory workloads similar to those after the extubation of the trachea. Methods When seven post-cardiac surgery infants, aged 1 to 11 months, were to be weaned with the pressure-control PTV, we randomly applied five levels of pressure control: 0, 4, 8, 12, and 16 cm H2O. All patients were ventilated with assist-control mode, triggering sensitivity of 1 l/min, and positive end-expiratory pressure of 3 cm H2O. After establishing steady state conditions at each level of pressure control, arterial blood gases were analyzed and esophageal pressure (Pes), airway pressure, and airflow were measured. Inspiratory work of breathing (WOB) was calculated using a Campbell diagram. A modified pressure-time product (PTPmod) and the negative deflection of Pes were calculated from the Pes tracing below the baseline. The measurement was repeated after extubation. Results Pressure-control PTV supported every spontaneous breath. By decreasing the level of pressure control, respiratory rate increased, tidal volume decreased, and as a result, minute ventilation and arterial carbon dioxide partial pressure were maintained stable. The WOB, PTPmod, and negative deflection of Pes increased as pressure control level was decreased. The WOB and PTPmod at 4 cm H2O pressure control and 0 cm H2O pressure control and after extubation were significantly greater than those at the pressure control of 16, 12, and 8 cm H2O (P < 0.05). The WOB and PTPmod were almost equivalent after extubation and at 4 cm H2O pressure control. Conclusions Work of breathing and PTPmod were changed according to the pressure control level in post-cardiac surgery infants. PTV may be feasible in infants as well as in adults.

Objectives: We noticed that in some patients after cardiac surgery, when flow triggering was used, cardiogenic oscillation might be autotriggering the ventilatory support. In a prospective study, we evaluated the degree of cardiogenic oscillation and the frequency rate of autotriggering. We suspected that autotriggering caused by cardiogenic oscillation was more common than clinically appreciated. Design: Prospective, nonrandomized, clinical study. Setting: Surgical intensive care unit in a national heart institute. Patients: A total of 104 adult patients were enrolled after cardiac surgery. Interventions: During the study period, patients were paralyzed and ventilated with intermittent mandatory ventilation at a rate of 10 breaths/min, pressure support of 10 cm H 2 O, and flow triggering with a sensitivity of 1 Umin. Measurements and Main Results: Because the patients would not be able to breathe spontaneously, we counted pressure-support (PS) breaths as instances of autotriggering. Then, we classified the patients into two groups according to the number of PS breaths: an AT group (PS breaths of >5/min) and a non-AT group (PS breaths of ≤5/min). If autotriggering occurred, we decreased the sensitivity so autotriggering disappeared (threshold triggering sensitivity). The intensity of cardiogenic oscillation was assessed as the flow and airway pressure at the airway opening. A total of 23 patients (22%) demonstrated more than five autotriggered breaths/min. During mechanical ventilation, the inspiratory flow fluctuation caused by cardiogenic oscillation was significantly greater in the AT group than in the non-AT group (4.67 ± 1.26 Umin vs. 2.03 ± 0.86 Umin; p

The objective of this study was to investigate whether nitric oxide (NO) inhalation might be an alternative strategy as a chemical assist for the circulation in patients showing a deterioration in oxygen delivery. Twelve adult patients whose oxygen delivery indices (D O2I) were less than 400 ml/min/m2 after cardiovascular surgery were included in this study. NO was administered via a premixing system or a side stream system at doses between 1 and 10 (5.1 ± 2.4) ppm. Data obtained before and during a 120 min NO inhalation were compared using the paired Student's t-test. The increase in Pa O2/Fi O2 resulting from NO inhalation was significant (from 162 to 251 mm Hg). D O2I increased significantly from 326 to 417 ml/min/m2 concomitantly with significant increases in both arterial oxygen content (Ca O2) and cardiac index (CI) (from 14.1 to 15.4 vol% and from 2.31 to 2.71 L/min/m2, respectively). The increase in S VO2 during NO inhalation was significant (from 55.2 to 62.6%). Among the other hemodynamic parameters, both total pulmonary resistance and systolic pulmonary arterial pressure (SPAP) showed significant decreases during NO inhalation, but right atrial pressure did not change significantly. There was a close relationship between the baseline SPAP level (bSPAP) and the decrease in SPAP during NO inhalation (dSPAP) (r = −0.88). However, negative correlations were observed between bSPAP and percentage increase in CI (%CI) (r = −0.61) and between bSPAP and percentage increase in D O2I (% D O2I) (r = −0.48). Moreover, positive relationships were observed between dSPAP and %CI (r = 0.62) and between dSPAP and %D O2I (r = 0.45). Hemoglobin (Hb) increased significantly from 11.0 to 11.4 g/dl. There were no significant changes in Fi O2, pH, Pa CO2, or base excess (BE) during NO inhalation. The level of methemoglobin measured during the study period remained within the normal range (0.86 ± 0.23%). In conclusion, NO inhalation could be an efficient and alternative assist for the circulation in patients whose oxygen delivery deteriorates after cardiovascular surgery.

We studied the effect of inhaled nitric oxide (NO) on 80 patients who had undergone cardiac surgery in our center. The indications for receiving NO inhalation and the number of patients were as follows: Pp/Ps0.5 for pulmonary hypertension (PH) (n = 32; 21 children and 11 adults), severe PH crisis (n = 9), high pulmonary vascular tone (Glenn pressure more than 18 mm Hg after bidirectional Glenn operation) or arterial oxygen saturation (SaO2) less than 70% despite an FiO2 of 1.0 after Blalock-Taussig shunt (n = 6), mean pulmonary artery pressure (PAP)15 mm Hg and transpulmonary gradient (TPG) (mean PAP - left atrial pressure [LAP])8 mm Hg after Fontan-type operation (n = 18), elevated pulmonary vascular tone (mean PAP30 mm Hg and left ventricular assist system [LVAS] flow rate2.5 L/min/m2) in patients with LVAS (n = 3), and impaired oxygenation (PaO2/FiO2100 under positive end-expiratory pressure [PEEP]5 cm H2O) (n = 12). Low dose inhaled NO (10 ppm) had the following effects. In adult PH patients, it significantly reduced the mean PAP (from 37.3 to 27.0 mm Hg; average values are given) and increased the mean systemic arterial pressure (SAP) (64.7 to 75.3 mm Hg). In infant PH patients, it increased the mean SAP (51.8 to 56.1 mm Hg). In patients with a PH crisis, it significantly reduced the central venous pressure (CVP) (13.3 to 8.8 mm Hg) while increasing both the mean SAP (49.4 to 57.9 mm Hg) and PaO2/FiO2 (135 to 206). In patients after a Fontan-type operation, it significantly reduced the mean PAP (16.8 to 13.8 mm Hg) and TPG (9.5 to 5.8 mm Hg). In patients under LVAS, it reduced the CVP (11.7 to 8.0 mm Hg) and mean PAP (32.0 to 24.7 mm Hg). In impaired oxygenation patients, PaO2/FiO2 was increased (75 to 106). Sixty-five patients were all followed for 2.0-4.3 years (average, 3.1 years). All 65 patients remained free from oxygen requirement, and possible chronic adverse effects including the occurrence of malignant tumors or chronic inflammation in the respiratory tract were not observed.

Study Objective: To evaluate the effectiveness of mild hypothermia in postcardiac surgical patients with severe heart failure in spite of conventional medical therapy and the use of intra-aortic balloon pumping (IABP). Design: Prospective, clinical study. Setting: Teaching hospital. Patients: 10 postcardiac surgical patients with severe heart failure despite the use of IABP with massive doses of catecholamine. Interventions: Patients underwent mild hypothermia produced by surface cooling (to approximately 34.5°C). Hemodynamic criteria for the induction of hypothermia included a cardiac index (CI) of less than 2.2 L/min/m 2 with a pulmonary capillary wedge pressure (PCWP) of up to 18 mmHg despite the use of IABP with massive doses of catecholamine. Measurements and Main Results: After control measurements had been taken at normal core body temperature (37°C), patients were cooled to approximately 34.5°C (using a cooling blanket and gastric lavage with cold water) to decrease tissue oxygen (O 2 ) demand. Patients showed significant improvements in CI (1.9 ± 0.3 to 2.2 ± 0.3 L/min/m 2 ), mixed venous O 2 saturation, (SvO 2 ; 55 ± 7 to 64 ± 6%), and urine output (2.1 ± 1.1 to 3.4 ± 2.2 ml/kg/hr). Patients were rewarmed while SvO 2 was being monitored. The duration of the hypothermia was 38 ± 41 hours. Oxygen delivery increased in 8 of the 10 patients, the mean value (±SD) for the group rising from 309 ± 65 ml/min/m 2 to 358 ± 57 ml/min/m 2 as temperature was reduced from 36.7 ± 0.4°C to 34.7 ± 0.3°C. All patients were successfully weaned from IABP at 140 ± 107 hours after admission to the intensive care unit. Conclusions: Mild hypothermia is a simple and useful procedure for improving the circulation of postcardiac surgical patients with severe heart failure despite the use of IABP.