Low tissue oxygen saturation at the end of early goal-directed therapy is associated with worse outcome in critically ill patients

INTRODUCTION: The prognostic value of continuous monitoring of tissue oxygen saturation (StO2) during early goal-directed therapy of critically ill patients has not been investigated. We conducted this prospective study to test the hypothesis that the persistence of low StO2 levels following intensive care admission is related to adverse outcome. METHODS: We followed 22 critically ill patients admitted with increased lactate levels (>3 mmol/l). Near-infrared spectroscopy (NIRS) was used to measure the thenar eminence StO2 and the rate of StO2 increase (RincStO2) after a vascular occlusion test. NIRS dynamic measurements were recorded at intensive care admission and each 2-hour interval during 8 hours of resuscitation. All repeated StO2 measurements were further compared with Sequential Organ Failure Assessment (SOFA), Acute Physiology and Chronic Health Evaluation (APACHE) II and hemodynamic physiological variables: heart rate (HR), mean arterial pressure (MAP), central venous oxygen saturation (ScvO2) and parameters of peripheral circulation (physical examination and peripheral flow index (PFI)). RESULTS: Twelve patients were admitted with low StO2 levels (StO2 <70%). The mean scores for SOFA and APACHE II scores were significantly higher in patients who persisted with low StO2 levels (n = 10) than in those who exhibited normal StO2 levels (n = 12) at 8 hours after the resuscitation period (P < 0.05; median (interquartile range): SOFA, 8 (7 to 11) vs. 5 (3 to 8); APACHE II, 32(24 to 33) vs. 19 (15 to 25)). There was no significant relationship between StO2 and mean global hemodynamic variables (HR, P = 0.26; MAP, P = 0.51; ScvO2, P = 0.11). However, there was a strong association between StO2 with clinical abnormalities of peripheral perfusion (P = 0.004), PFI (P = 0.005) and RincStO2 (P = 0.002). The persistence of low StO2 values was associated with a low percentage of lactate decrease (P < 0.05; median (interquartile range): 33% (12 to 43%) vs. 43% (30 to 54%)). CONCLUSIONS: We found that patients who consistently exhibited low StO2 levels following an initial resuscitation had significantly worse organ failure than did patients with normal StO2 values, and found that StO2 changes had no relationship with global hemodynamic variable

End-expiratory lung volume during mechanical ventilation: a comparison with reference values and the effect of positive end-expiratory pressure in intensive care unit patients with different lung conditions

Introduction: Functional residual capacity (FRC) reference values are obtained from spontaneous breathing patients, and are measured in the sitting or standing position. During mechanical ventilation FRC is determined by the level of positive end-expiratory pressure (PEEP), and it is therefore better to speak of end-expiratory lung volume. Application of higher levels of PEEP leads to increased end-expiratory lung volume as a result of recruitment or further distention of already ventilated alveoli. The aim of this study was to measure end-expiratory lung volume in mechanically ventilated intensive care unit (ICU) patients with different types of lung pathology at different PEEP levels, and to compare them with predicted sitting FRC values, arterial oxygenation, and compliance values. Methods: End-expiratory lung volume measurements were performed at PEEP levels reduced sequentially (15, 10 and then 5 cmH2O) in 45 mechanically ventilated patients divided into three groups according to pulmonary condition: normal lungs (group N), primary lung disorder (group P), and secondary lung disorder (group S). Results: In all three groups, end-expiratory lung volume decreased significantly (P < 0.001) while PEEP decreased from 15 to 5 cmH2O, whereas the ratio of arterial oxygen tension to inspired oxygen fraction did not change. At 5 cmH2O PEEP, end-expiratory lung volume was 31, 20, and 17 ml/kg predicted body weight in groups N, P, and S, respectively. These measured values were only 66%, 42%, and 34% of the predicted sitting FRC. A correlation between change in end-expiratory lung volume and change in dynamic compliance was found in group S (P < 0.001; R2 = 0.52), but not in the other groups. Conclusions: End-expiratory lung volume measured at 5 cmH2O PEEP was markedly lower than predicted sitting FRC values in all groups. Only in patients with secondary lung disorders were PEEP-induced changes in end-expiratory lung volume the result of derecruitment. In combination with compliance, end-expiratory lung volume can provide additional information to optimize the ventilator settings

Intravenous nitroglycerin does not preserve gastric microcirculation during gastric tube reconstruction: a randomized controlled trial

INTRODUCTION: Complications of oesophagectomy and gastric tube reconstruction include leakage and stenosis, which may be due to compromised microvascular blood flow (MBF) in gastric tissue. We recently demonstrated that decreased MBF could be improved perioperatively by topical administration of nitroglycerin. The aim of the present study was to investigate whether nitroglycerin, administered intravenously during gastric tube reconstruction, could preserve tissue blood flow and oxygenation in the gastric fundus, and reduce the incidence of postoperative leakage. METHODS: In this single-centre, prospective, double-blinded study, we randomized 32 patients scheduled for oesophagectomy into two groups. The intervention group received intravenous nitroglycerin during gastric tube reconstruction, and the control group received normal saline. Baseline values for MBF, microvascular haemoglobin oxygen saturation and microvascular haemoglobin concentration were determined at the gastric fundus before and after gastric tube construction and after pulling up the gastric tube to the neck. RESULTS: MBF and microvascular haemoglobin oxygen saturation decreased similarly in both groups during gastric tube reconstruction and were comparable. The oesophageal anastomosis was controlled by contrast radiography before discharge from the hospital; leakage was observed in two patients (13%) in the nitroglycerin group and five patients (31 %) in the control group (not significant). CONCLUSION: Under stable systemic haemodynamic conditions, continuous intravenous administration of nitroglycerin could not prevent deterioration in gastric microvascular perfusion and microvascular haemoglobin saturation during gastric tube reconstruction. (Trial registration number NCT 00335010.

Generating insights in uncharted territories:Real-time learning from data in critically ill patients-an implementer report

Introduction In the current situation, clinical patient data are often siloed in multiple hospital information systems. Especially in the intensive care unit (ICU), large volumes of clinical data are routinely collected through continuous patient monitoring. Although these data often contain useful information for clinical decision making, they are not frequently used to improve quality of care. During, but also after, pressing times, data-driven methods can be used to mine treatment patterns from clinical data to determine the best treatment options from a hospitals own clinical data. Methods In this implementer report, we describe how we implemented a data infrastructure that enabled us to learn in real time from consecutive COVID-19 ICU admissions. In addition, we explain our step-by-step multidisciplinary approach to establish such a data infrastructure. Conclusion By sharing our steps and approach, we aim to inspire others, in and outside ICU walls, to make more efficient use of data at hand, now and in the future

Nutritional intake and gastro-intestinal symptoms in critically ill COVID-19 patients

BACKGROUND & AIMS: Critically ill COVID-19 patients seem hypermetabolic and difficult to feed enterally, due to gastro-intestinal (GI) symptoms such as high gastric residual volumes (GRV) and diarrhea. Our aim was to describe the association of nutritional intake and GI symptoms during first 14 days of ICU admission. METHODS: Observational study including critically ill adult COVID-19 patients. Data on nutritional intake (enteral nutrition (EN) or parenteral nutrition) and GI symptoms were collected during 14 days after ICU admission. Target energy and protein feeding goals were calculated conform ESPEN guidelines. GI symptoms included GRV (ml/d), vomiting, abdominal distension and faeces (ml/d). High GRV’s were classified as ≥2 times ≥150 ml/d and diarrhea as Bristol stool chart ≥6. GI symptoms were defined as mild if at least one symptom occurred and as moderate when ≥2 symptoms occurred. Acute gastrointestinal injury (AGI) grades of III were classified as GI dysfunction and grades of IV were considered as GI failure with severe impact on distant organs. Linear mixed model analysis was performed to explore the development of nutritional intake and GI symptoms over time at day (D) 0,4,10 & 14. RESULTS: 150 patients were included (75% male; median age 64 years [IQR 54-70]). BMI upon admission was 28 kg/m(2) [IQR 25-33], of which 43% obese (BMI>30 kg/m(2)). Most patients received EN during admission (98% D4; 96% D10-14). Mean energy goals increased from 87% at D4 to 93% D10-14 and protein goals (g/kg) were increasingly achieved during admission (84% D4; 93% D10-14). Presence of moderate GI symptoms decreased (10% DO; 6% D4-10; 5% D14), reversely mild GI symptoms increased. Occurrence of GI dysfunction fluctuated (1% D0; 18% D4; 12% D10; 8% D14) and none of patients developed grade IV GI failure. Development of high GRV fluctuated (5% D0; 23% D4; 14% D10; 8% D14) and occurrence of diarrhea slightly increased during admission (5% D0; 22% D4; 25% D10; 27% D14). Linear mixed models showed only an association between AGI grades III and lower protein intake at day 10 (p=0.020). CONCLUSION: Occurrence of GI symptoms was limited and seems no major barrier for EN in our group of critically COVID-19 patients. Nutritional intake was just below requirements during the first 14 days of ICU admission. The effect on nutritional status remains to be studied

Rising C-Reactive Protein and Procalcitonin Levels Precede Early Complications After Esophagectomy

BACKGROUND: Elective esophagectomy with gastric tube reconstruction carries a high risk for complications. Early and accurate diagnosis could improve patient management. Increased C-reactive protein (CRP) levels may be associated with any, surgical or infectious, complication and procalcitonin (PCT) specifically with infectious complications. METHODS: We measured CRP and PCT on post-operative days 0, 1, 2, and 3 in 45 consecutive patients. Complications were recorded up to 10 days post-esophagectomy. RESULTS: Twenty-eight patients developed a post-operative complication (5 surgical, 14 infectious, 9 combined surgical/infectious, including anastomotic leakage), presenting on day 3 or later. Elevated days 2 and 3 and a rise in CRP preceded the diagnosis of general or combined surgical/infectious complications (minimum area under the receiver operating characteristics curve (AUROC) 0.75, P = 0.006). Elevated day 3 PCT preceded combined complications (AUROC 0.86, P < 0.001). High day 1 and 3 PCT levels preceded anastomotic leakage (minimum AUROC 0.76, P = 0.005), as did the day 3 CRP levels and their increases (minimum AUROC 0.78, P = 0.002). CONCLUSIONS: This small study suggests that high or increasing CRP levels may precede the clinical diagnosis of general or surgical/infectious complications after esophagectomy. Elevated PCT levels may more specifically and timely precede combined surgical/infectious complications mainly associated with anastomotic leakage

Nitroglycerin reverts clinical manifestations of poor peripheral perfusion in patients with circulatory shock

Introduction: Recent clinical studies have shown a relationship between abnormalities in peripheral perfusion and unfavorable outcome in patients with circulatory shock. Nitroglycerin is effective in restoring alterations in microcirculatory blood flow. The aim of this study was to investigate whether nitroglycerin could correct the parameters of abnormal peripheral circulation in resuscitated circulatory shock patients.Methods: This interventional study recruited patients who had circulatory shock and who persisted with abnormal peripheral perfusion despite normalization of global hemodynamic parameters. Nitroglycerin started at 2 mg/hour and doubled stepwise (4, 8, and 16 mg/hour) each 15 minutes until an improvement in peripheral perfusion was observed. Peripheral circulation parameters included capillary refill time (CRT), skin-temperature gradient (Tskin-diff), perfusion index (PI), and tissue oxygen saturation (StO2) during a reactive hyperemia test (RincStO2). Measurements were performed before, at the maximum dose, and after cessation of nitroglycerin infusion. Data were analyzed by using linear model for repeated measurements and are presented as mean (standard error).Results: Of the 15 patients included, four patients (27%) responded with an initial nitroglycerin dose of 2 mg/hour. In all patients, nitroglycerin infusion resulted in significant changes in CRT, Tskin-diff, and PI toward normal at the maximum dose of nitroglycerin: from 9.4 (0.6) seconds to 4.8 (0.3) seconds (P <0.05), from 3.3°C (0.7°C) to 0.7°C (0.6°C) (P <0.05), and from [log] -0.5% (0.2%) to 0.7% (0.1%) (P <0.05), respectively. Similar changes in StO2 and RincStO2 were observed: from 75% (3.4%) to 84% (2.7%) (P <0.05) and 1.9%/second (0.08%/second) to 2.8%/second (0.05%/second) (P <0.05), respectively. The magnitude of changes in StO2 was more prono