Ventilation time and prognosis after stroke thrombectomy: the shorter, the better!

BACKGROUND AND PURPOSE: The aim was to investigate the clinical impact of the duration of artificial ventilation in stroke patients receiving mechanical thrombectomy (MT) under general anaesthesia. METHODS: All consecutive ischaemic stroke patients who had been treated at our centre with MT for anterior circulation large vessel occlusion under general anaesthesia were identified over an 8-year period. Ventilation time was analysed as a continuous variable and patients were grouped into extubation within 6 h ('early'), 6-24 h ('delayed') and >24 h ('late'). Favourable outcome was defined as modified Rankin Scale scores of 0-2 at 3 months post-stroke. Pneumonia rate and reasons for prolonged ventilation were also assessed. RESULTS: Amongst 447 MT patients (mean age 69.1 ± 13.3 years, 50.1% female), the median ventilation time was 3 h. 188 (42.6%) patients had a favourable 3-month outcome, which correlated with shorter ventilation time (Spearman's rho 0.39, P < 0.001). In patients extubated within 24 h, early compared to delayed extubation was associated with improved outcome (odds ratio 2.40, 95% confidence interval 1.53-3.76, P < 0.001). This was confirmed in multivariable analysis (P = 0.01). A longer ventilation time was associated with a higher rate of pneumonia during neurointensive care unit/stroke unit stay (early/delayed/late extubation: 9.6%/20.6%/27.7%, P < 0.01). Whilst stroke-associated complications represented the most common reasons for late extubation (>24 h), delayed extubation (6-24 h) was associated with admission outside of core working hours (P < 0.001). CONCLUSIONS: Prolonged ventilation time after stroke thrombectomy independently predicts unfavourable outcome at 3 months and is associated with increased pneumonia rates. Therefore, extubation should be performed as early as safely possible.

[Perioperative bleeding in a Jehovah's Witness]. / Perioperative Blutung bei einem Zeugen Jehovas.

Perioperative bleeding in Jehovah's Witnesses leaves physicians with difficult medical and ethical decisions. We report the case of a 45-year-old man, who refused to accept red blood cell concentrates by a patient directive. A postoperative bleeding occurred after removal of a transplanted kidney. Despite critically low hemoglobin (3.1 g/dl) and hematocrit (9.5%) levels, the case was managed without red blood cell transfusions. The patient showed an amazingly quick recovery and was discharged from hospital after 24 days without any sequelae.

Diabetic neuropathy increases stimulation threshold during popliteal sciatic nerve block.

BACKGROUND: Peripheral nerve stimulation is commonly used for nerve localization in regional anaesthesia, but recommended stimulation currents of 0.3-0.5 mA do not reliably produce motor activity in the absence of intraneural needle placement. As this may be particularly true in patients with diabetic neuropathy, we examined the stimulation threshold in patients with and without diabetes. METHODS: Preoperative evaluation included a neurological exam and electroneurography. During ultrasound-guided popliteal sciatic nerve block, we measured the current required to produce motor activity for the tibial and common peroneal nerve in diabetic and non-diabetic patients. Proximity to the nerve was evaluated post-hoc using ultrasound imaging. RESULTS: Average stimulation currents did not differ between diabetic (n=55) and non-diabetic patients (n=52). Although the planned number of patients was not reached, the power goal for the mean stimulation current was met. Subjects with diminished pressure perception showed increased thresholds for the common peroneal nerve (median 1.30 vs. 0.57 mA in subjects with normal perception, P=0.042), as did subjects with decreased pain sensation (1.60 vs. 0.50 mA in subjects with normal sensation, P=0.038). Slowed ulnar nerve conduction velocity predicted elevated mean stimulation current (r=-0.35, P=0.002). Finally, 15 diabetic patients required more than 0.5 mA to evoke a motor response, despite intraneural needle placement (n=4), or required currents ≥2 mA despite needle-nerve contact, vs three such patients (1 intraneural, 2 with ≥2 mA) among non-diabetic patients (P=0.003). CONCLUSIONS: These findings suggest that stimulation thresholds of 0.3-0.5 mA may not reliably determine close needle-nerve contact during popliteal sciatic nerve block, particularly in patients with diabetic neuropathy. CLINICAL TRIAL REGISTRATION: NCT01488474.

[Perioperative care of patients with diastolic heart failure. Interface to anesthesia]. / Perioperative Betreuung von Patienten mit diastolischer Herzinsuffizienz. Schnittstelle zur Anästhesie.

Diastolic heart failure leads to an increase in perioperative morbidity and mortality. The prevalence of this disease is rising and multiple risk factors have already been identified. Besides higher age and female gender, arterial hypertension, diabetes mellitus and coronary artery disease in particular have to be considered. Clinical examination and laboratory analyses are important for preoperative evaluation; however, echocardiography plays the most important role in the diagnostics of diastolic heart failure. The transmitral flow profile can be used to differentiate the grades of diastolic dysfunction using the ratio between early passive ventricular filling (E) and late active filling due to atrial contraction (A). Data concerning the ideal anesthesia technique are for the most part lacking; however, the application of thoracic epidural anesthesia seems to be beneficial. A great deal of attention has to be paid to the intraoperative volume status of patients with diastolic dysfunction as hypovolemia and hypervolemia can both have detrimental effects. Arrhythmias and major changes in blood pressure put this special group of patients at additional risks.