John Papanikolaou

Real-time ultrasound-guided subclavian vein cannulation versus the landmark method in critical care patients: A prospective randomized study*

Objective:Subclavian vein catheterization may cause various complications. We compared the real-time ultrasound-guided subclavian vein cannulation vs. the landmark method in critical care patients. Design:Prospective randomized study. Setting:Medical intensive care unit of a tertiary medical center. Patients:Four hundred sixty-three mechanically ventilated patients enrolled in a randomized controlled ISRCTN-registered trial (ISRCTN-61258470). Interventions:We compared the ultrasound-guided subclavian vein cannulation (200 patients) vs. the landmark method (201 patients) using an infraclavicular needle insertion point in all cases. Catheterization was performed under nonemergency conditions in the intensive care unit. Randomization was performed by means of a computer-generated random-numbers table and patients were stratified with regard to age, gender, and body mass index. Measurements and Main Results:No significant differences in the presence of risk factors for difficult cannulation between the two groups of patients were recorded. Subclavian vein cannulation was achieved in 100% of patients in the ultrasound group as compared with 87.5% in the landmark one (p < .05). Average access time and number of attempts were significantly reduced in the ultrasound group of patients compared with the landmark group (p < .05). In the landmark group, artery puncture and hematoma occurred in 5.4% of patients, respectively, hemothorax in 4.4%, pneumothorax in 4.9%, brachial plexus injury in 2.9%, phrenic nerve injury in 1.5%, and cardiac tamponade in 0.5%, which were all increased compared with the ultrasound group (p < .05). Catheter misplacements did not differ between groups. In this study, the real-time ultrasound method was rated on a semiquantitative scale as technically difficult by the participating physicians. Conclusions:The present data suggested that ultrasound-guided cannulation of the subclavian vein in critical care patients is superior to the landmark method and should be the method of choice in these patients.

New insights into the mechanisms involved in B-type natriuretic peptide elevation and its prognostic value in septic patients

IntroductionElevated plasma B-type natriuretic peptide (BNP) levels in patients with critical sepsis (severe sepsis and septic shock) may indicate septic cardiomyopathy. However, multiple heterogeneous conditions may also be involved in increased BNP level. In addition, the prognostic value of BNP in sepsis remains debatable. In this study, we sought to discover potential independent determinants of BNP elevation in critical sepsis. The prognostic value of BNP was also evaluated.MethodsIn this observational study, we enrolled mechanically ventilated, critically septic patients requiring hemodynamic monitoring through a pulmonary artery catheter. All clinical, laboratory and survival data were prospectively collected. Plasma BNP concentrations were measured daily for five consecutive days. Septic cardiomyopathy was assessed on day 1 on the basis of left and right ventricular ejection fractions (EF) derived from echocardiography and thermodilution, respectively. Mortality was recorded at day 28.ResultsA total of 42 patients with severe sepsis (N = 12) and septic shock (N = 30) were ultimately enrolled. Daily BNP levels were significantly elevated in septic shock patients compared with those with severe sepsis (P ≤0.002). Critical illness severity (assessed by Acute Physiology and Chronic Health Evaluation II and maximum Sequential Organ Failure Assessment scores), and peak noradrenaline dose on day 1 were independent determinants of BNP elevation (P <0.05). Biventricular EFs were inversely correlated with longitudinal BNP measurements (P <0.05), but not independently. Pulmonary capillary wedge pressures (PCWP) and volume expansion showed no correlation with BNP. In septic shock, increased central venous pressure (CVP) and CVP/PCWP ratio were independently associated with early BNP values (P <0.05).Twenty-eight-day mortality was 47.6% (20 of 42 patients). Daily BNP values poorly predicted outcome; BNP on day 1 > 800 pg/ml (the best cutoff point) fairly predicted mortality, with a sensitivity%, specificity% and area under the curve values of 65, 64 and 0.70, respectively (95% confidence interval = 0.54 to 0.86; P = 0.03). Plasma BNP levels declined faster in survivors than in nonsurvivors in both critical sepsis and septic shock (P ≤0.002). In septic shock, a BNP/CVP ratio >126 pg/mmHg/ml on day 2 and inability to reduce BNP <500 pg/ml implied increased mortality (P ≤0.036).ConclusionsThe severity of critical illness, rather than septic cardiomyopathy, is probably the major determinant of BNP elevation in patients with critical sepsis. Daily BNP values are of limited prognostic value in predicting 28-day mortality; however, fast BNP decline over time and a decrease in BNP <500 pg/ml may imply a favorable outcome.

Sepsis-associated takotsubo cardiomyopathy can be reversed with levosimendan.

Sepsis is a stressful physical condition, and at the acute phase, overstimulation of the sympathetic nervous system may occur; these events have the potential to induce cardiomyopathy. Takotsubo cardiomyopathy (TTC) is a form of catecholamine-induced cardiomyopathy, which occurs very rarely in sepsis. However, TTC management in critically ill patients with sepsis may be challenging because the use of exogenous catecholamines for circulatory support might augment further TTC. Herein, we report a rare case of TTC after urosepsis; and we point out that cardiac function may improve after catecholamine withdrawal and the application of calcium channel sensitizer levosimendan.

Cardiac and central vascular functional alterations in the acute phase of aneurysmal subarachnoid hemorrhage

Objectives:To investigate aortic functional alterations in the acute phase of aneurysmal subarachnoid hemorrhage and to evaluate the relationship between potential cardiovascular alterations and delayed cerebral infarctions or poor Glasgow Outcome Scale score at discharge from critical care unit. Design:Prospective observational study. Setting:Critical Care Departments of two tertiary centers. Patients:Thirty-seven patients with aneurysmal subarachnoid hemorrhage. Interventions:Patients were evaluated at two time points: on admission (acute aneurysmal subarachnoid hemorrhage phase) and at least 21 days later (stable aneurysmal subarachnoid hemorrhage state). At baseline, the severity of aneurysmal subarachnoid hemorrhage was assessed clinically (Hunt and Hess scale) and radiologically (brain computed tomography Fisher grading). Aortic elasticity was evaluated by Doppler-derived pulse-wave velocity and left ventricular function by echocardiography. Serum B-type natriuretic peptide and troponin I were also assessed at the same time points. Measurements and Main Results:At the acute phase, 23 patients (62%) were found to present supranormal pulse-wave velocity and 14 patients (38%) presented left ventricular systolic dysfunction; there were significant associations between pulse-wave velocity values and left ventricular ejection fraction (p < .001). Left ventricular ejection fraction and pulse-wave velocity were both associated with Hunt and Hess (p ⩽ .004) and Fisher grading (p ⩽ .03). Left ventricular ejection fraction and pulse-wave velocity were improved between acute aneurysmal subarachnoid hemorrhage and stable state (p ⩽ .005); changes (&Dgr;%) were greater in patients who initially had regional wall motion abnormalities compared to patients who had not (28.7% ± 10.2% vs. 2.4% ± 1.8% [p = .002] and −17.9% ± 3.7% vs. −3.5% ± 4.7% [p = .045], respectively). Pulse-wave velocity/left ventricular ejection fraction ratio was the only independent predictor for delayed cerebral infarctions. Left ventricular ejection fraction, B-type natriuretic peptide, pulse-wave velocity, and pulse-wave velocity/left ventricular ejection fraction showed significant diagnostic performance for predicting delayed cerebral infarctions or poor Glasgow Outcome Scale score (1–3). Conclusions:Our findings suggest that significant cardiovascular alterations in left ventricular function and in aortic stiffness occur during the early phase of aneurysmal subarachnoid hemorrhage. These phenomena were associated with adverse outcomes in this study and their role in the pathogenesis of delayed neurologic complications warrants further investigation.

Transesophageal echocardiography and vascular ultrasound in the diagnosis of catheter-related persistent left superior vena cava thrombosis

We refer to a very rare case of catheter-related thrombosis in a trauma patient with persistent left and absent right superior vena cava. The role of ultrasound examination in the early diagnosis and treatment of thrombosis in the setting of intensive care unit (ICU) is thoroughly discussed. A 30-year-old man was admitted to the ICU due to multiple trauma. Six days after right internal jugular vein (IJV) catheter insertion, and during a vascular ultrasound examination, an IJV catheter-related thrombosis was diagnosed. Hence, the catheter was removed, and a follow-up ultrasound examination revealed thrombus remnant in the IJV extended into brachiocephalic vein. Subsequently, to exclude a possible extension of the thrombus in the superior vena cava, a transesophageal echocardiography (TEE) examination was performed. The latter revealed a distended coronary sinus and the presence of persistent left superior vena cava (PLSVC). Additionally, TEE examination disclosed thrombus remnant within the PLSVC that was also confirmed with CT venography. Anticoagulant therapy was started thus preventing major complications such as coronary sinus obstruction. This case underlines the role of cardiovascular ultrasound examination as an important tool in performing variety of monitoring in the setting of the ICU.

Contrast-Induced Nephropathy in Aged Critically Ill Patients

Background. Aging is associated with renal structural changes and functional decline. The attributable risk for renal dysfunction from radiocontrast agents in critically ill older patients has not been well established. Methods. In this prospective study, we assessed the incidence of contrast-induced nephropathy (CIN) in critically ill patients with stable renal function who underwent computed tomography with intravenous contrast media. Patients were categorized into two age groups: <65 (YG) or ≥65 years old (OG). CIN was defined as 25% or greater increase from baseline of serum creatinine or as an absolute increase by 0.5 mg/dL until the 5th day after the infusion of contrast agent. We also evaluated the alterations in oxidative stress by assessing serum 8-isoprostane. Results. CIN occurred in 5 of 13 OG patients (38.46%) whereas no YG patient presented CIN (P = 0.015). Serum creatinine kinetics in older patients demonstrated a rise over five days following contrast infusion time while a decline was observed in the YG (P = 0.005). Conclusions. Older critically ill patients are more prone to develop renal dysfunction after the intravenous infusion of contrast agent in relation to their younger counterparts.

Acute effect of sildenafil on central hemodynamics in mechanically ventilated patients with WHO group III pulmonary hypertension and right ventricular failure necessitating administration of dobutamine

BACKGROUND/OBJECTIVES Sildenafil decreases pulmonary vascular resistance index (PVRI), in patients with pulmonary hypertension (PH). We investigated sildenafils effects on central hemodynamics of mechanically ventilated patients with WHO group-III PH and RV failure necessitating dobutamine administration. METHODS Prospective non-controlled study involving 12 (9 males, 59 ± 4 years old), patients with the above characteristics. All patients in phase-1 (days 1-2) received dobutamine (5 μg/kg/min IV). During phase-2 (days 3-6), sildenafil was started via nasogastric tube (80 mg/day) and dobutamine discontinuation was attempted. Patients were designated responders or non-responders based on whether dobutamine could be stopped or not. Phase-3 lasted from day 7 to day of weaning from mechanical ventilation; or if weaning failed, until day 20 following admission (end-of-study). Invasive and echocardiographic parameters were repeatedly recorded throughout the study. RESULTS Significantly changed parameters (P<0.025) from baseline to phase-1, -2 and -3 (%change of mean ratios), in responders (n=7) included among others PVRI (-40%, -51%, -42%), RV stroke work index (RVSWI: 43%, 79%, 41%) and cardiac index (49%, 54%, 48%), which also differed significantly from non-responders (N=5). In phases-1 and -3 non-responders had not significant changes, in phase-2 PVRI (27%) and RVSWI (-22%) changed significantly. In contrast to non-responders, all responders were weaned from mechanical ventilation until the end-of-study (P<0.025). CONCLUSIONS Sildenafil may improve central hemodynamics and RV function indices in ventilated patients with WHO group-III PH and RV failure requiring dobutamine infusion, when they respond favorably to the latter. Accordingly, an adequate RV systolic reserve may be mandatory for sildenafil to exert its actions.

The value of computed tomography perfusion & transcranial Doppler in early diagnosis of cerebral vasospasm in aneurysmal & traumatic subarachnoid hemorrhage

Early detection and diagnosis of cerebral vasospasm in subarachnoid hemorrhage may be challenging both on clinical and radiographic grounds. In this respect we conducted a pilot study in order to assess the feasibility of the technique in the everyday setting of a tertiary hospital and to evaluate the diagnostic performance of different diagnostic computed tomography perfusion aspects in diagnosing the clinical outcome of patients with subarachnoid hemorrhage. Receiver-operating characteristic analysis showed that a cerebral blood flow value of <24.5 presented 67% sensitivity and 100% specificity to diagnose adverse ischemic events at 1 month (p = 0.041). These case series data provide evidence that computed tomography perfusion-derived cerebral blood flow is a measurable index that may detect the degree of cerebral ischemia in a very early stage.

Traumatic dissection of the left circumflex artery after a fall from height.

The authors present the case of a healthy 40-year-old man who developed a myocardial infarction because of traumatic dissection of the left circumflex coronary artery following a fall from height. To our knowledge, this is the first time that a traumatic lesion of the left circumflex artery is being reported after a fall.

Discontinuation of prolonged dual antiplatelet therapy for a dental extraction; A nearly-fatal decision

Stent thrombosis remains one of the most feared complications in patients with multiple stents implanted. In this clinical setting, optimal upfront dual antiplatelet therapy (DAPT) duration still remains controversial. Herein, we wish to report a case of life-threatening very-late stent thrombosis after DAPT temporary discontinuation, highlighting the prolonged increased thrombotic risk of complex angioplasty, even in otherwise low-ischemic risk patients according to recent recommendations. Our data are in line with novel information and might be useful in the pre-operative management of patients with complex percutaneous coronary intervention (PCI).