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Objective: The prognostic impact of thrombocytopenia in patients supported by extracorporeal membrane oxygenation after cardiac surgery is uncertain. We investigated whether thrombocytopenia is independently predictive of poor outcome and describe the incidence and time course of thrombocytopenia in extracorporeal membrane oxygenation patients., Design: Retrospective analysis of prospectively collected data., Setting: Cardiosurgical ICU at a tertiary referral center., Patients: Three hundred adult patients supported with venoarterial extracorporeal membrane oxygenation for more than 24 hours because of refractory cardiogenic shock after heart surgery between January 2001 and December 2014., Interventions: None., Measurements and Main Results: Two-way analysis of variance was used to compare the time course of platelet count changes between survivors and nonsurvivors. Using multiple Cox regression with time-dependent covariates, we investigated the impact of platelet count on 90-day mortality. In nonsurvivors, the daily incidence of moderate (< 100 - 50 × 10/L), severe (49 - 20 × 10/L), and very severe (< 20 × 10/L) thrombocytopenia was 50%, 54%, and 7%, respectively. Platelet count had a biphasic temporal pattern with an initial decrease until day 4-5 after the initiation of extracorporeal membrane oxygenation. Although a significant recovery of the platelet count was observed in survivors, a recovery did not occur in nonsurvivors (p = 0.0001). After adjusting for suspected confounders, moderate, severe, and very severe thrombocytopenia were independently associated with 90-day mortality. The highest risk was associated with severe (hazard ratio, 5.9 [2.7-12.6]; p < 0.0001) and very severe thrombocytopenia (hazard ratio, 25.9 [10.7-62.9], p < 0.0001)., Conclusion: Thrombocytopenia is an independent risk factor for poor outcome in extracorporeal membrane oxygenation patients after cardiac surgery, with persistent severe thrombocytopenia likely reflecting a high degree of physiologic imbalance.

Objectives: Extracorporeal membrane oxygenation represents a valuable and rapidly evolving therapeutic option in patients with severe heart or lung failure following cardiovascular surgery. However, survival remains poor and accurate risk stratification challenging. Therefore, we evaluated the predictive value of urinary output within 24 hours after extracorporeal membrane oxygenation initiation on mortality in patients undergoing venoarterial extracorporeal membrane oxygenation support following cardiovascular surgery and aimed to improve established risk prediction models., Design: Single-center, observational registry., Setting: University-affiliated tertiary care center., Patients: We included 205 patients undergoing veno-arterial extracorporeal membrane oxygenation therapy following cardiovascular surgery at a university-affiliated tertiary-care center into our single-centre registry., Interventions: None., Measurements and Main Results: During a median follow-up time of 35 months (interquartile range, 19-69), 64% of patients died. Twenty-four-hour urinary output was the strongest predictor of outcome among renal function variables with an adjusted hazard ratio per 1 SD of 0.55 (95% CI, 0.40-0.76; p < 0.001) for 30-day mortality and of 0.65 (95% CI, 0.53-0.86; p = 0.002) for 2-year long-term mortality. Most remarkably, 24-hour urinary output showed additional prognostic value beyond that achievable with the simplified acute physiology score-3 and sequential organ failure assessment score indicated by improvements in the category-free net reclassification index for 30-day mortality (simplified acute physiology score-3: 36%, p = 0.015; sequential organ failure assessment score: 36%, p = 0.02), as well as for 2-year mortality (simplified acute physiology score-3: 33%, p = 0.02; sequential organ failure assessment score: 43%, p = 0.005)., Conclusions: We identified 24-hour urinary output as a strong and easily available predictor of mortality in patients undergoing extracorporeal membrane oxygenation therapy following cardiovascular surgery. Implementation of 24-hour urinary output leads to a substantial improvement of established risk prediction models in this vulnerable patient population. These results are particularly compelling because measurement of urinary output is inexpensive and routinely performed in all critical care units.

Background: Optimal dosing strategies have not been established for rabbit antithymocyte globulin (rATG) after heart transplantation, and there is currently wide variability in rATG regimens with respect to both dose and duration., Methods: In a retrospective, single-center analysis, 523 patients undergoing heart transplantation during 1996 to 2009 were stratified by cumulative rATG dose: less than 4.5 mg/kg (group A), 4.5 to 7.5 mg/kg (group B) or greater than 7.5 mg/kg (group C)., Results: Survival at 1 year after transplantation was 80% in group A, 90% in group B, and 88% in group C (P = 0.062). Incidence of acute rejection per 1000 patient-years was significantly higher in group A (hazards ratio [HR], 54.8; 95% confidence interval [95% CI], 33.9-83.8) compared to groups B (19.6; 95% CI, 11.4-31.4) and C (23.6; 95% CI, 17.5-31.3). Incidence of severe infection 10 years after transplantation was higher in group C (45%) than groups A (37%) or B (23%) (P < 0.001); cytomegalovirus infection rates were 35%, 20% and 23%, respectively (P = 0.009). Multivariable Cox regression showed an HR of 0.51 (95% CI, 0.25-1.02) for acute rejection with group B versus group A, and 0.54 (95% CI, 0.33-0.88; P = 0.013) for severe infection. The rate of malignancy per 1000 patient-years was higher in groups B (13.85) and C (14.95) than group A (7.83)., Conclusions: These retrospective data suggest that a cumulative rATG dose of 4.5 to 7.5 mg/kg may offer a better risk-benefit ratio than lower or higher doses, with acceptable rates of infection and posttransplant malignancy. Prospective trials are needed.

Objective: To determine the impact of brief periods of cardiac arrest (CA) on regional cerebral oxygen saturation (rSO2) in patients with low left ventricular ejection fraction (LVEF <30%)., Design: Prospective observational study., Setting: Cardiac surgery room at a university hospital., Patients: Seventy-seven consecutive patients undergoing elective implantation of a cardioverter/defibrillator in monitored anesthesia care. According to preoperative assessments, left ventricular function was classified as normal (LVEF >50%), moderately impaired (LVEF 30%-50%), or severely reduced (LVEF <30%)., Interventions: None., Measurements and Main Results: rSO2 was determined during threshold testing with concomitant induction of CA. In patients with LVEF <30%, mean baseline rSO2 (59%) was already below the lower range of normal despite normal arterial blood pressure, heart rate, and arterial oxygen saturation. rSO2 increased by 6% after 6 L/min oxygen insufflation (p < 0.05) and dropped again in each group after CA, reaching a nadir after successful defibrillation. Patients with LVEF <30% and baseline rSO2 <63% exhibited the lowest values. They also showed the highest incidence (11%) of critical cerebral desaturations (i.e., >20% drop from baseline or rSO2 value <50%). rSO2 in patients with LVEF <30% was always below that determined in patients with LVEF >30% (p < 0.05). There was a strong correlation between rSO2 values before CA and rSO2 nadir (p < 0.05). The drop in rSO2 was only moderately related to the brief CAs (p < 0.05)., Conclusion: These findings demonstrate that severely compromised left ventricular pump function is associated with diminished rSO2. As these patients seem to be more susceptible to critical desaturations, they may be prone to severe tissue hypoxemia unless adequate oxygen delivery is reestablished rapidly. This may contribute to the poor neurologic outcome after successful resuscitation in patients with LVEF <30%.

Background: Before clinical treatment and during transportation, the analgesic therapy offered to patients with painful knee trauma may be quite insufficient. We hypothesize that a femoral nerve blockade for analgesia can be administered in a preclinical setting at the injury site and provides better pain relief than intravenous metamizole, whose analgesic effect is comparable with that of opioids., Methods: After an initial clinical investigation, 52 patients were randomized according to computer-generated codes; 26 patients received a femoral nerve blockade and 26 received metamizole. The treatment was started at the injury site and the level of pain on the 100-mm visual analog scale was assessed at the beginning and the end of treatment., Results: Pain and anxiety scores were significantly reduced by half in the femoral nerve blockade group; peripheral vasoconstriction was noted in 26 patients at the injury site and dropped to six at the time of arrival at the hospital. Two of 26 patients in the blockade group did not benefit from the treatment. In the metamizole group, pain and anxiety did not decrease significantly; vasoconstriction persisted in all patients., Conclusion: Patients with painful knee trauma benefited from femoral nerve blockade administered before hospitalization. The treatment can be administered safely in the preclinical setting and provides effective analgesia.

Background: Analgesia at the location of the accident and on transport for femoral trauma is often delayed or insufficient. In this prospective, randomized, controlled study, we evaluated the preclinical use of femoral nerve blockade for reducing pain and anxiety compared with IV analgesia using metamizol., Methods: Patients with painful femoral trauma, such as fracture or severe contusion, were randomized to receive at the site of the accident a femoral nerve blockade (n = 31) or IV analgesia with metamizol (n = 31). A visual analog scale (VAS) was used to assess pain and anxiety. Variables were assessed at baseline, during transport and upon arrival at the hospital., Results: In patients receiving the femoral nerve blockade, pain values decreased by half from VAS 86 +/- 6 mm at the site of the accident to VAS 41 +/- 15 mm during transport. Anxiety decreased by half from VAS 84 +/- 11 mm to VAS 39 +/- 14 mm. Heart rate decreased by 20 +/- 5 bpm. In the metamizol group, pain, anxiety, and heart rate did not decrease (P < 0.001). Time of treatment was 7.4 +/- 3.5 min longer in the femoral nerve blockade group., Conclusion: Preclinically administered femoral nerve blockade effectively decreases pain, anxiety, and heart rate after femoral trauma. Regional blockade is an option for out-of-hospital analgesia administered by a trained physician.

Background: Accurate monitoring of the peripheral arterial oxygen saturation has become an important tool in the prehospital emergency medicine. This monitoring requires an adequate plethysmographic pulsation. Signal quality is diminished by cold ambient temperature due to vasoconstriction. Blockade of the stellate ganglion can improve peripheral vascular perfusion and can be achieved by direct injection or transcutaneous electrical nerve stimulation (TENS) stimulation. We evaluated whether TENS on the stellate ganglion would reduce vasoconstriction and thereby improve signal detection quality of peripheral pulse oximetry., Methods: In our study, 53 patients with minor trauma who required transport to the hospital were enrolled. We recorded vital signs, including core and skin temperature before and after transport to the hospital. Pulse oximetry sensors were attached to the patient's second finger on both hands. TENS of the stellate ganglion was started on one side after the beginning of the transport. Pulse oximeter alerts, due to poor signal detection, were recorded for each side separately., Results: On the hand treated with TENS we detected a significant reduction of alerts compared to the other side (mean alerts TENS 3.1 [1-15] versus control side 8.8 [1-28] P < 0.05). The duration of dropouts was shorter as well (mean duration TENS 77 [16-239] s versus control side 333 [78-1002] s)., Conclusion: The data indicate that blockade of the stellate ganglion with TENS improves signal quality of pulse oximeters in the prehospital setting.

Background: In Central Europe, ambulances for patients suffering from pain caused by nonlife-threatening trauma, such as hip fractures are staffed by medical personnel (medics) without physicians. Thus, there is an urgent need for nonpharmacological interventions that can be applied during the transport by basic life-support (BLS) medical personnel., Methods: In all, 101 patients were screened for participation in this randomized placebo-controlled double-blind study, and randomly assigned to two groups (verum and sham transcutaneous electrical nerve stimulation [TENS]). First, medic A recorded all baseline parameters and measurements, then medic B performed TENS in absence of medic A. At the end of transportation, medic A performed data collection. Each patient was asked to grade his/her pain and anxiety level on visual analog scales (VAS, 0 to 100 mm)., Results: From 101 screened patients fulfilling the entry criteria, 29 declined consent and 9 had to be excluded from the analysis because of their final diagnosis. Therefore, the data from 30 patients (group 1, verum TENS) as well as from 33 patients (group 2 [control], sham TENS) were analyzed. No significant differences in potentially influencing factors were found before treatment. Pain scores upon arrival at the hospital differed significantly between group 1 and group 2 (p < 0.01). In group 1, pain reduction was observed between departure from the site of emergency and arrival at the hospital (VAS: 89 +/- 9 to 59 +/- 6 mm), whereas pain scores remained nearly unchanged in group 2 (VAS: 86 +/- 12 to 79 +/- 11 mm)., Conclusion: Our findings show that TENS is a valuable and fast-acting pain treatment under the difficult circumstances of "out-of-hospital rescue". Because of its lack of side effects, it could also be a valuable tool in the hospital.

To determine the degree of neurocognitive dysfunction after placement of internal cardioverter defibrillators (ICD) and its relationship to the extent of neuronal injury, we studied 42 patients undergoing ICD (n = 21) or pacemaker (PM) insertion (control patients, n = 21). The Mini Mental State Examination, the Trailmaking A test and the forward and backward Digit Span tests were used and P300 latencies were determined preoperatively and postoperatively. Serum neuron-specific enolase (NSE) was determined before and at the end of, as well as 2, 6, and 24 h after surgery. Preoperatively, PM patients scored worse in the Digit Span backward and the Trailmaking tests and showed prolonged P300 latencies. Postoperatively, the Digit Span backward scores declined and NSE levels increased only in the ICD group (P < or = 0.05). The difference between preoperative and postoperative Digit Span backward scores correlated with the increase in serum NSE levels (r2 = 0.3, P < or = 0.05). Moreover, P300 latencies increased in 13 of 17 ICD patients, but decreased in 7 of 10 PM patients (P < or = 0.05). PM patients even improved in the Trailmaking test (P < or = 0.05). Neuronal injury from even brief periods of global brain ischemia seems to be associated with deteriorating neurocognitive function.

Remifentanil, a short-acting opioid, is commonly used in cardiac anesthesia. In this study we sought to demonstrate the feasibility of pain treatment and to determine the remifentanil dose necessary for adequate analgesia in tracheally extubated patients after cardiac surgery. Thirty patients undergoing elective cardiac surgery were included in this study. After surgery, the intraoperatively administered remifentanil was initially continued at 0.05 microg . kg(-1) . min(-1). Before tracheal extubation, a nonsteroidal antiinflammatory drug was administered and remifentanil was reduced to 0.035 microg . kg(-1) . min(-1). Pain assessment using a visual analog scale (VAS) was performed after tracheal extubation, in 2-min intervals for 10 min, every 10 min until the end of the first hour and every 30 min during the ensuing 5 h. A VAS score > or =30 or a respiratory rate <10 breaths/min was followed by an increase or decrease in the remifentanil dose by 0.005 microg . kg(-1) . min(-1), respectively. For rapid dose adaptation during the first 10 min, remifentanil was increased twice by 0.005 microg. kg(-1) . min(-1) and then 3 times by 0.01 microg . kg(-1) . min(-1). With a mean remifentanil dose of 0.051 microg . kg(-1) . min(-1) VAS decreased to 26 +/- 14 after 30 min. Sufficient analgesia was achieved with remifentanil doses ranging from 0.03 to 0.09 microg. kg(-1) . min(-1). A maximum mean remifentanil dose of 0.057microg. kg(-1) . min(-1) was reached after 4 h. The combination of remifentanil with a nonsteroidal antiinflammatory drug provided adequate analgesia in 73% of patients 30 min after tracheal extubation. Rapid dose titration was necessary during the first 10 min in 50% of patients. Increasing the initial remifentanil dose could shorten the titration period but may be associated with respiratory complications.