Candida colonization in mechanically ventilated patients

The diagnosis of pulmonary candidosis is controversial. We undertook a prospective study on 50 mechanically ventilated (>48 h) patients who were hospitalized (>72 h) in the intensive care unit (ICU) with the aim of assessing the incidence of the isolation of Candida species from endotracheal aspirates (EA). Patients were categorized as individuals already colonized with Candida spp. on admission, individuals becoming colonized during hospitalization, or patients with no colonization. Patients in the ICU were hospitalized for a mean of 23 days. The percentage of patients already colonized with Candida was low (six of 50; 12%), the incidence of Candida isolation from EA in critically ill, mechanically ventilated patients in ICU was also low (six of 50; 12%). Age, duration of hospitalization, pre-treatment with antimicrobials or immunosuppressive agents and occurrence of underlying disease were not risk factors in our study. Both antifungal usage and neutropenia were more common in already colonized patients. No risk factors were determined for patients colonized during hospitalization. As all the isolates identified were C. albicans. It appears that at present, colonization and/or infection by more resistant Candida species is not a problem in our unit.     

Anxiety and agitation in mechanically ventilated patients

During an ethnography conducted in an intensive care unit (ICU), we found that anxiety and agitation occurred frequently and were important considerations in the care of 30 patients weaning from prolonged mechanical ventilation. We conducted a secondary analysis to (a) describe characteristics of anxiety and agitation experienced by mechanically ventilated patients, (b) explore how clinicians recognized and interpreted anxiety and agitation, and (c) describe strategies and interventions used to manage anxiety and agitation with mechanically ventilated patients. We constructed the Anxiety/Agitation in Mechanical Ventilation Model to illustrate the multidimensional features of symptom recognition and management. Patients' ability to interact with the environment served as a basis for identification and management of anxiety or agitation. Clinicians' attributions about anxiety or agitation, and "knowing the patient," contributed to their assessment of patient responses. Clinicians chose strategies to overcome either the stimulus or the patient's appraisal of risk of the stimulus. This article contributes to the body of knowledge about symptom recognition and management in the ICU by providing a comprehensive model to guide future research and practice.     

24-hour indirect calorimetry in mechanically ventilated critically ill patients.

BACKGROUND: Energy imbalance in critically ill, mechanically ventilated patients may lead to medical complications. The nutrition care team needs accurate, noninvasive, rapid methods to estimate energy requirements. We investigated whether brief measurements of indirect calorimetry at any time of the day would give valid estimates of 24-hour energy expenditure (EE). METHODS: EE of 12 mechanically ventilated critically ill patients (6 men, 6 women, mean +/- SD age 67 +/- 18 years, weight 70.2 +/- 8.8 kg) was recorded every minute during 24 hours by indirect calorimetry. All patients were continuously fed enteral nutrition. RESULTS: Mean +/- SD EE was 1658 +/- 279 kcal/d (6941 +/- 1167 kJ/d). Within patients, EE during the day fluctuated by 234 kcal in the most constant patient to 1190 kcal in the least constant patient, with a mean fluctuation of 521 kcal (12 patients). No statistically significant difference (p = .53) in mean EE between morning (6-12 hours, 1676 kcal), afternoon (12-18 hours, 1642 kcal), evening (18-24 hours, 1658 kcal), and night (0-6 hours, 1655 kcal) was found. A 2-hour instead of a 24-hour measurement resulted in a maximal error of 128 kcal (536 kJ), which was <10% of the average EE. The maximal error decreased with longer time intervals. CONCLUSIONS: In mechanically ventilated critically ill patients, 24-hour indirect calorimetry measurements can be replaced by shorter (>/=2 hours) measurements. Time of day did not affect EE.     

机械通气患者静息能量消耗测定

目的探讨机械通气治疗患者能量消耗与疾病严重程度的相关性,比较间接能量消耗测定仪测定的能量消耗与Harris—Benedict公式推导的能量消耗差异。方法以24例采用机械通气治疗的普外科重症监护病房患者为研究对象,收集采用机械通气72h时的相关数据计算急性生理与既往健康状况评分Ⅱ（APACHEⅡ）和MarshaⅡ评分。机械通气72h时,采用MedGraphicsCCM／DSystem能量测定系统测定静息能耗值（MREE）;采用Harris—Benedict公式计算基础能耗值,再乘以相应应激系数得出预测静息能耗值（PREE）。结果机械通气72h时,所有患者的平均APACHEⅡ评分和MarshaⅡ评分分别为（14±5）和（6±3）分,MREE和PREE分别为（6793．64±1197．15）和（8041．02±1971．54）kJ／d。MREE与PREE间无相关性（r^2=0．28,P=0．07）,差异有统计学意义（t=7．62,P=0．04）。MREE与APACHEⅡ评分（r^2=0．14,P=0．08）和MarshaⅡ评分（r^2=0．08,P=0．63）间、PREE与APACHEⅡ评分（r^2=0．05,P=0．65）和MarshaⅡ评分（r^2=0．03,P=0．87）间均无显著相关性。结论机械通气患者能量消耗与疾病严重程度无相关性。采用校正Harris—Benedict公式推导的PREE过高估计了机械通气患者的能耗水平。     

Pleural empyema in mechanically ventilated patients with pneumonia

Two males aged 41 and 32 years developed pneumonia which responded inadequately to antibiotic treatment and necessitated mechanical ventilation. It was only after surgical and digital opening, drainage of pus pockets and daily pleural lavage that the clinical picture improved. The microorganisms cultured from both patients included Streptococcus milleri, probably acquired by aspiration. Thoracic empyema as a complication of pneumonia is clinically recognised by lack of response to antimicrobial agents. For the diagnosis, ultrasonographic and CT imaging, followed by pleural puncture are used. Simple parapneumonic effusions are managed by drainage with or without rinsing with normal saline, while in advanced empyema, instillations with fibrinolytic agents have proved safe and effective. Sometimes, video-assisted thoracoscopic or conventional surgery is necessary to clear the pleural space, while in complicated cases, extensive surgical procedures are warranted.     

Variation in enteral nutrition delivery in mechanically ventilated patients

OBJECTIVE: We determined the variability in enteral feeding practices in mechanically ventilated patients in four adult intensive care units of a tertiary-care, referral hospital. METHODS: Patients who had been mechanically ventilated for at least 48 h and received enteral nutrition were prospectively followed. RESULTS: Fifty-five of 101 consecutive mechanically ventilated patients received enteral nutrition; in 93% of patients, feedings were infused into the stomach. Patients who were cared for in the medical intensive care unit, where a nutritional protocol was operational, received enteral nutrition earlier in their ventilatory course (P=0.004) and feedings were advanced to target rates faster (P=0.043) than those who received care in other units. The number (P=0.243) and duration (P=0.668) of interruptions in feeding did not differ by patient location. On average, patients received only 50% to 70% of their targeted caloric goals during the first 6 days of enteral nutrition. Most feeding discontinuations (41%) were secondary to procedures. Gastrointestinal intolerances, including vomiting, aspiration, abdominal distention, and increased gastric residuals, were uncommon despite allowing gastric residuals up to 300 mL. CONCLUSIONS: The practice of providing enteral feeds to mechanically ventilated patients varies widely, even within one hospital. A protocol enhanced early initiation of enteral feeds and advancement to target feeding rates but did not alter the number or duration of interruptions in enteral feedings. Procedures represented the most common reason for stopping enteral feeds, and gastrointestinal intolerances (vomiting, aspiration, and increased gastric residuals) caused few feeding interruptions. The gastric route was safe and well tolerated for early enteral feeding in most mechanically ventilated patients.     

Assessment of resting energy expenditure in mechanically ventilated patients

BACKGROUND: Usual equations for predicting resting energy expenditure (REE) are not appropriate for critically ill patients, and indirect calorimetry criteria render its routine use difficult. OBJECTIVE: Variables that might influence the REE of mechanically ventilated patients were evaluated to establish a predictive relation between these variables and REE. DESIGN: The REE of 70 metabolically stable, mechanically ventilated patients was prospectively measured by indirect calorimetry and calculated with the use of standard predictive models (Harris and Benedict's equations corrected for hypermetabolism factors). Patient data that might influence REE were assessed, and multivariate analysis was conducted to determine the relations between measured REE and these data. Measured and calculated REE were compared by using the Bland-Altman method. RESULTS: Multivariate analysis retained 4 independent variables defining REE: body weight (r(2) = 0.14, P < 0.0001), height (r(2) = 0.11, P = 0.0002), minute ventilation (r(2) = 0.04, P = 0.01), and body temperature (r(2) = 0.07, P = 0.002): REE (kcal/d) = 8 x body weight + 14 x height + 32 x minute ventilation + 94 x body temperature - 4834. REE calculated with this equation was well correlated with measured REE (r(2) = 0.61, P < 0.0001). Bland-Altman plots showed a mean bias approaching zero, and the limits of agreement between measured and predicted REE were clinically acceptable. CONCLUSION: Our results suggest that REE estimated on the basis of body weight, height, minute ventilation, and body temperature is clinically more relevant than are the usual predictive equations for metabolically stable, mechanically ventilated patients.     

早期肠内营养支持对机械通气患者的辅助治疗作用

目的 观察早期肠内营养（EEN）支持对ICU机械通气患者的辅助治疗作用.方法 机械通气时间大于1周的患者47例,随机分为EEN组（n=24）和对照组（n=23）.EEN组入住ICU后12 ～24 h给予肠内营养（EN）,对照组入住ICU后72h～5 d给予EN,利用双糖试验法（乳果糖/甘露醇,L/M）测定两组患者肠黏膜屏障功能,观察患者体质量指数、体温、L/M比值、血清白蛋白、前白蛋白、脱机时间等临床指标.结果 入住ICU第7天时EEN组L/M为0.036±0.004,而对照组为0.108±0.020,EEN组明显低于对照组（t=2.746,P＜0.01）.EEN组平均体温（38.25±1.20）℃,低于对照组（38.92±1.40）℃（t=2.683,P＜0.05）便秘腹泻不良反应发生率[16.7％（4/23）与27.3％ （6/22）]及2周脱机成功率[90％ （18/20）与80％ （16/20）]好于对照组（x2值分别为5.36、6.08,均P＜0.05）;营养状态血清白蛋白、前白蛋白水平也较对照组有增高趋势.结论 早期应用肠内营养支持对呼吸机辅助通气患者能改善肠黏膜屏障,提高脱机成功率.     

Tube feeding in mechanically ventilated critically ill patients: a prospective clinical audit.

BACKGROUND: When and whether early enteral nutrition (EN) benefits critically ill patients is debatable. This prospective clinical audit aimed to evaluate the feasibility of an early EN protocol and to identify factors that may hinder EN delivery in critically ill patients. METHODS: Thirty-six medical patients with severe respiratory failure under invasive ventilation and scheduled to receive early EN, with a length of ICU stay >72 hours, were included. As asserted by the Society of Critical Care Medicine, 8% of patients were priority 1, 72% priority 2, and 20% priority 3 for intensive therapeutic and vital support interventions. RESULTS: Overall, because of gastrointestinal complications, only 39% of the prescribed EN was administered; only 8 (22%) patients did tolerate EN within the first 48 hours after admission and did achieve their minimum nutritional requirements. The most frequent complication (78%) was high volume of gastric residuals followed by abdominal distention (61%), both associated with hemodynamic instability (HI). Gastrointestinal dysfunction was associated with high Acute Physiologic and Chronic Health Evaluation II score (p = .01), total calorie intake (p = .02), total carbohydrate intake (p = .02), HI (p = .03), malnutrition (p = .04), volume of IV saline (p = .04), and concurrent vasoactive drug administration (p = .05). CONCLUSIONS: This audit in extremely severe intensive care patients identified several factors that impair gastrointestinal function and preclude EN at any stage, namely early EN. Nutrition management must take into account concurrent therapies, given their potential interference with nutrition and organ function.     

Measured versus estimated energy expenditure in mechanically ventilated critically ill patients

Accurate determination of energy expenditure is essential in patients receiving nutritional support to meet metabolic needs. The purpose of this study was to assess and compare the energy expenditure as measured by indirect calorimetry (MEE) and estimated by 5 equations in the mechanically ventilated critically ill patients. Forty-six patients were divided into either enteral nutrition (EN) (n=l2), total parenteral nutrition (TPN) (n=16) or combined (EN plus TPN) (n=l8) groups. Patients' energy expenditure was measured by indirect calorimetry on two occasions. Anthropometric and biochemical measurements, energy expenditure and medical status (APACHE II score) were also assessed in the intensive care unit (ICU) of Taichung Veteran General hospital. No significant difference was found in the MEE among the 3 groups. The type of nutritional support did not affect MEE. Energy expenditure calculated by using Harris- Benedict, Kleiber and Liu equations times the estimated stress factor did not significantly different than the values of MEE in all groups. There were significant correlations (P<0.01) between MEE and patients' sex (r=-0.499), age (r=-0.402), height (r=0.533), knee height (r=0.431), current body weight (r=0.379), usual body weight (r=0.407), ideal body weight (r=0.466) and urinary urea nitrogen (r=0.383) in the pooled group. Results demonstrated that energy expenditure could be estimated in most critically ill patients by using Harris-Benedict, Kleiber and Liu equations if the estimated stress factor is in the reasonable value.     

A method for increasing confidence in respiratory gas exchange measurements in mechanically ventilated patients.

Measurement of O2 uptake (VO2) and CO2 output (VCO2) with automated instruments can be used to optimize nutritional management of critically ill patients. However, these measurements may be made infrequently because of calibration problems or suspected inaccuracies, especially when the patient is given supplemental oxygen. A simple method is described for periodic testing of automated gas exchange measurements. While a test lung is mechanically ventilated an accurately known mixture of CO2 and nitrogen is introduced into the inspired gas, simulating VO2 by dilution and VCO2 by addition of CO2. The ratio of VCO2:VO2 (respiratory gas exchange ratio, R) in the "expired gas" should be [FGCO2/(1-FGCO2)] x [(1-FIO2)/FIO2], where FGCO2 is the fraction of CO2 in the diluting gas and FIO2 is the fraction of O2 in the inspired gas. R is independent of the flow rate of the diluting gas or the rate of ventilation of the test lung. Using a mixing chamber-mass spectrometer, we found that R calculated from measurement of CO2 and O2 concentrations in the simulated mixed expired gas closely matched the predicted R for FIO2 = 0.21-0.50. On the other hand, when an automated gas exchange measurement device was tested, R was sometimes excessively high, especially for FIO2 greater than 0.35. This method, using a single diluting gas and without precision flowmeters, may be useful for periodic testing of respiratory gas exchange instruments in the intensive care unit. If a discrepancy is found between measured and predicted R, measurements should not be relied upon until further calibration or repairs can be effected.     

Energy expenditure and substrate utilization in mechanically ventilated children.

The objective of the study was to determine the value of indirect calorimetry and nitrogen balance (N balance) in order to evaluate the current feeding protocols of mechanically ventilated children. The study was designed as a cross-sectional prospective study. In 36 mechanically ventilated children energy expenditure was measured by indirect calorimetry, and total urinary nitrogen excretion (TUN) was determined. Substrate utilization and respiratory quotient (RQ) were calculated from the measured values of oxygen consumption (VO2), carbon dioxide production (VCO2), and TUN. The RQ was compared with the RQ of the macronutrients administered (RQmacr) according to the modified criteria of Lusk. In results, the total measured energy expenditure (TMEE) showed a wide variation (range 155-272 kJ.kg-1.d-1). The N balance was positive in 20 and negative in 16 patients. The ratio of caloric intake/TMEE was significantly higher in patients with a positive N balance (1.50 +/- 0.06) as compared with those with a negative N balance (0.8 +/- 0.1, P < 0.001). There was a significant relationship between the difference of RQ-RQmacr versus the ratio caloric intake/TMEE (r = 0.72, P < 0.001). Carbohydrate and fat utilization were not significantly different in patients with a positive or negative N balance. Protein utilization was significantly higher in those patients with a negative N balance. We concluded that measurement of TMEE with indirect calorimetry results in accurate determination of energy needs in critically ill mechanically ventilated children. Feeding according to or in excess of the TMEE is correlated with a positive N balance. A combination of the RQ and the RQmacr can be helpful in differentiating under- or overfeeding.     

Clinical implications of continuous measurement of energy expenditure in mechanically ventilated patients

Energy expenditure was monitored in 20 critically-ill mechanically ventilated patients using the Siemens-Elema Oxygen Consumption Calculator (OCC 980). Energy expenditure was measured continuously over the 24-h period in all patients (altogether, over 2500 patient hours; range 48-288 h). A predicted energy expenditure was calculated for each patient from standard tables for basal metabolic rates modified according to previously published reports on the influence of trauma, infection and elevated body temperature. For all patients combined, the agreement between the predicted and the measured energy expenditure was good. However, in individual patients the measured energy expenditure varied between 48 and 148% of the predicted value. The measured energy expenditure in surviving traumatized and/or septic patients correlated well (95-100%) with the predicted value at the time when weaning off the ventilator could be initiated. On the first day of measurements, the energy expenditure (in % of the predicted value) in the six patients who later died was significantly lower than in surviving patients (84 +/- 6 vs 107 +/- 2%; p < 0.01). Over a 24-h period, energy expenditure, defined as the value noted during a stable 30-40-min period of measurement, varied between 12 and 50% in the individual patients. This study shows that energy expenditure cannot be accurately predicted in the individual patient, that an energy expenditure below predicted values appears to be indicative of a poor prognosis and that short periods of energy expenditure monitoring may fail to reflect 24-h conditions.     

酸性氧化电位水在机械通气患者口腔护理中的应用

机械通气是救治呼吸衰竭患者的重要措施,而经口-气管插管是机械通气患者初期常用的人工气道建立方式,做好经口-气管插管患者的口腔护理具有重要意义。笔者选择酸性氧化电位水,对经口-气管插管机械通气患者进行口腔护理,现报道如下。     

Enteral access device selection

Enteral tube feedings have once again emerged as the first choice for nutritional support of the patient on the basis of safety, convenience, and economy. In order to provide adequate nutrition, an appropriate route of administration must be identified. Tube selection will depend on an accurate assessment of the patient, including the duration of therapy, history of abdominal procedures, competency of gag reflex, level of debilitation, gastrointestinal function, and discharge plan. Since placement of these tubes may involve several different physicians, a coordinator is necessary. The clinical specialist in nutrition support may be the appropriate health professional to coordinate this care. With an emphasis on shorter hospital stays, more patients may go home with enteral feeding regimens. The clinical specialist will need to be aware of these changes and become more involved in the initial enteral access device decision to insure appropriate selection.     

机械通气患者艰难梭菌感染危险因素及临床预后分析

目的探讨艰难梭菌感染(Clostridium difficile infection,CDI)在机械通气患者发生的危险因素并评估CDI对临床预后的影响。方法选择医院2014年4月-2016年4月收治577例机械通气患者,并根据有无CDI分为CDI感染组(54例)和CDI非感染组(523例),对机械通气患者CDI的危险因素进行分析,并比较两组患者入院30d内生存率的差异。结果 577例机械通气患者中有54例CDI,感染率为9.36%;机械通气患者CDI与性别、基础疾病类型及大多数并存症无显著相关性,患者年龄≥70岁、入ICU时APACHEⅡ评分高、住院时间长、住ICU时间长、机械通气时间长等CDI感染率较高,差异有统计学意义(P<0.05);logistic多因素回归分析发现,CDI危险因素包括年龄,入ICU时APACHEⅡ评分,使用抑酸剂以及机械通气前抗菌药物使用种类(≥3种);机械通气CDI与非感染患者入院30d内生存率差异无统计学意义。结论 CDI在机械通气患者中比较常见,且能明显延长住院时间、ICU住院时间和机械通气时间,熟悉CDI危险因素可能有助于降低CDI的感染率。     

The effect of protein enriched nutrition on diaphragm function in mechanically ventilated patients

ObjectivesOur primary aim was to demonstrate the effect of high protein on diaphragm muscle thickness, our secondary aim was to evaluate the correlation of diaphragm thickness fraction with rectus femoris muscle thickness in high protein patients.Patients and methodsThis study included 49 mechanically ventilated patients who were randomly divided into a standard protein (1.2 g/kg/d) group and high protein group (2.0 g/kg/d). Thickness of rectus femoris, thickness of peak inspiratory diaphragm, thickness of end expiratory diaphragm were measured by ultrasonography. Thickness fraction of diaphragm was calculated.ResultsIn the high protein group, thickness of peak inspiratory diaphragm values were found to be statistically significantly higher on days 3rd, 5th, 7th, and 15th (P < 0.05). Thicknesses of end-expiratory diaphragm values were found to be statistically significantly higher on the 3rd, 5th and 7th days (P < 0.05). Thicknesses fraction of diaphragm values were found to be statistically significantly higher on days 3rd, 5th, 7th and 15th (P < 0.05) in the high protein group. Thicknesses of rectus femoris values were higher in the high protein group compared with standard protein group on the 5th, 7th, and 15th days (P < 0.005). In high protein group, statistically significant correlations were found between thickness of rectus femoris and thickness fraction of diaphragm at the 3rd day (rho = 0.429, P = 0.032).ConclusionThis study showed that diaphragmatic muscle thicknesses were higher in patients who received 2 g/kg/d protein supplement, These findings have shown that muscle atrophy can be prevented with high protein support in the intensive care unit.