Treatment of spinal anaesthesia-induced hypotension with cafedrine/theodrenaline versus ephedrine during caesarean section: Results from HYPOTENS, a national, multicentre, prospective, noninterventional study.

BACKGROUND: In Germany, hypotension induced by spinal anaesthesia is commonly treated with a combination of cafedrine hydrochloride (C, 200 mg) and theodrenaline hydrochloride (T, 10 mg) in 2 ml. We compared the effectiveness of C/T with ephedrine. OBJECTIVES: The primary objectives were to assess the speed of onset and the ability to restore blood pressure without an increase in heart rate. Secondary objectives were to evaluate maternal/foetal outcomes and the number of required additional boluses or other additional measures. DESIGN: HYPOTENS was a national, multicentre, prospective, open-label, two-armed, noninterventional study comparing C/T with ephedrine in two prospectively defined cohorts. This study relates to the cohort of patients receiving spinal anaesthesia for caesarean section. SETTING: German hospitals using either C/T or ephedrine in their routine clinical practice. PATIENTS: Women aged at least 18 years receiving spinal anaesthesia for caesarean section. INTERVENTIONS: Bolus administration of C/T or ephedrine at the discretion of the attending anaesthesiologist. MAIN OUTCOME MEASURES: Endpoints within 15 min after initial administration of C/T or ephedrine were area under the curve between the observed SBP and the minimum target SBP; and incidence of newly occurring heart rate of at least 100 beats min-1. RESULTS: Although effective blood pressure stabilisation was achieved with both treatments, this effect was faster and more pronounced with C/T (P < 0.0001). The incidence of tachycardia and changes in heart rate were higher with ephedrine (P < 0.01). Fewer additional boluses (P < 0.01) were required with C/T. Although favourable neonatal outcomes were reported in both groups, base deficit and lactate values were greater with ephedrine (P < 0.01). Physician satisfaction was higher with C/T. CONCLUSIONS: After C/T, tachycardia was not a problem, providing an advantage over ephedrine. Fewer additional boluses were required with C/T, suggesting greater effectiveness. An increased base deficit with ephedrine suggests reduced oxygen supply or increased demands in foetal circulation. TRIALS REGISTRATION: Clinicaltrials.gov: NCT02893241, German Clinical Trials Register: DRKS00010740.

Adrenal gland blood flow and noradrenaline plasma concentration during CPR in pigs.

AIM OF THE STUDY: In comparison to adrenaline, administration of vasopressin increases adrenal gland perfusion, but decreases catecholamine plasma concentrations when compared to saline placebo. We directly compared the effects of adrenaline with different doses of vasopressin on adrenal gland perfusion, and noradrenaline plasma concentrations during CPR. METHODS: Twenty-one pigs received either 0.2 mg kg(-1) adrenaline (n = 7), 0.2 U kg(-1) vasopressin (n = 7), or 0.8 U kg(-1) vasopressin (n = 7) after 4 min of cardiac arrest and 3 min of CPR. Adrenal gland perfusion was determined using radiolabeled microspheres, noradrenaline plasma concentration was measured by high pressure liquid chromatography. RESULTS: Before administration of vasopressor drugs during CPR, adrenal gland perfusion, and noradrenaline plasma concentrations were not different between groups. Ninety seconds and 5 min after drug administration, adrenal gland perfusion was significantly higher with both doses of vasopressin when compared with adrenaline, but was not different between the vasopressin groups. Noradrenaline plasma concentrations were 23684 ± 5036 pg ml(-1) with adrenaline, 11455 ± 2450 pg ml(-1) with 0.2 U kg(-1) vasopressin, and 12119 ± 2921 pg ml(-1) with 0.8 U kg(-1) vasopressin at 90 s after administration of vasopressors (p < .05 for both doses of vasopressin vs adrenaline). Five of seven animals in the adrenaline group, five of seven animals in the 0.2 U kg(-1) vasopressin group, and six of seven animals in the 0.8 U kg(-1) vasopressin group were successfully defibrillated. CONCLUSIONS: Vasopressin enhances adrenal gland perfusion, but decreases noradrenaline plasma concentration when compared to adrenaline during CPR. Neither adrenal gland perfusion nor noradrenaline plasma concentration affect survival in this pig model of cardiac arrest.

Laryngeal mask airway or endotracheal tube for percutaneous dilatational tracheostomy: a comparison of visibility of intratracheal structures.

PURPOSE: Some severe complications during percutaneous dilatational tracheostomy (PDT) may be related to poor visualization of tracheal structures. Subjectively, the bronchoscopical view obtained via a laryngeal mask airway (LMA) seems to be better than that obtained with an endotracheal tube (ETT). In this prospective, randomized study, we compared LMA and ETT as the ventilatory device during PDT mainly with respect to visualization of tracheal structures. The quality of ventilation and airway-related complications are also reported. METHODS: In this prospective, randomized study, PDT was performed using an LMA (n = 33) or an ETT (n = 30). Quality of ventilation and visualization of tracheal structures (thyroid, cricoid, and tracheal cartilages) were rated as follows: very good (1), good (2), difficult (3), and not possible (4) with LMA/ETT. A rating of 4 required the alternate airway. Groups were compared using the chi(2) test. RESULTS: Visualization of tracheal structures was better with the LMA: ratings were 1 or 2 in 94% of patients with an LMA, compared with 66% of patients with an ETT (P <0.05). Visual control during puncturing the trachea was 1 or 2 in 97% of patients using an LMA and 77% of patients for an ETT (P < 0.05). A rating of 4 was assigned to 1 patient with an LMA and to 3 patients with an ETT. Hemodynamic variables were similar in both groups. Blood gas analysis during PDT showed decreased Pao(2) in both groups, and increased Paco(2), which was more pronounced with an ETT compared with an LMA (59 +/- 14 mm Hg and 51 +/- 11 mm Hg [P < 0.05]). In the ETT group, 2 patients were extubated accidentally, and in another patient, the bronchoscope was damaged because of insufficient visualization of the tracheal puncture site. CONCLUSION: The LMA technique showed definite advantages regarding visualization of relevant tracheal structures and the dilation process compared with an ETT. This may be especially relevant in the hands of inexperienced intensivists and in cases of difficult patient anatomy where improved structural visualization optimizes operating conditions.

[EEG-Monitoring to avoid awareness during anaesthesia - benefit or luxury?]. / EEG-Messung zur Awareness-Vermeidung - Nutzen oder Luxus?

The intraoperative perception of pain, anxiety and helplessness is a serious complication of anaesthesia, the frequency is now 0,1-0,2 %. Post-operative memories can cause posttraumatic stress disorder (PTSD), but this will require a consolidation of conscious awareness in the long-term memory. Memory formation is promoted by high emotional contents and a longer duration of awareness. There are defined risk factors for awareness, including patient factors, surgery and anaesthesia technique. In patients with high risk of awareness EEG monitoring can decrease the incidence. Because of lack of evidence, its use in every anaesthesia cases is an option but not a must.

Effects of combined administration of vasopressin, epinephrine, and norepinephrine during cardiopulmonary resuscitation in pigs.

OBJECTIVE: Synergistic effects of epinephrine and vasopressin may be of benefit during cardiopulmonary resuscitation. However, cerebral perfusion was decreased when epinephrine was combined with vasopressin compared with vasopressin alone. Although a combined infusion of norepinephrine and vasopressin improves hemodynamic variables compared with norepinephrine alone during sepsis, it is unknown whether norepinephrine in addition to vasopressin and epinephrine changes vital organ perfusion during cardiopulmonary resuscitation. DESIGN: Prospective, randomized animal study. SETTING: : University hospital research laboratory. SUBJECTS: Twenty-one domestic pigs. INTERVENTIONS: After 4 mins of ventricular fibrillation and 3 mins of basic life support, the pigs were randomly assigned to receive either 200 microg/kg epinephrine, 0.4 units/kg vasopressin alone, or 45 microg/kg norepinephrine plus 45 microg/kg epinephrine plus 0.4 units/kg vasopressin before defibrillation. MEASUREMENTS AND MAIN RESULTS: Organ perfusion was determined by radiolabeled microspheres. Myocardial blood flow (mean +/- sem) before and 90 secs and 5 mins after drug administration was 8 +/- 2, 25 +/- 6, and 7 +/- 1 mL/min/100 g after high-dose epinephrine, 12 +/- 1, 75 +/- 7, and 60 +/- 10 mL/min/100 g after vasopressin, and 9 +/- 2, 95 +/- 26, and 46 +/- 15 mL/min/100 g after vasopressin/epinephrine/norepinephrine, respectively (p < .05 at 90 secs and 5 mins vasopressin vs. epinephrine and vasopressin/epinephrine/norepinephrine vs. epinephrine). At the same time points, cerebral blood flow was 8 +/- 2, 23 +/- 3, and 17 +/- 3 mL/min/100 g after epinephrine, 11 +/- 3, 55 +/- 7, and 52 +/- 7 mL/min/100 g after vasopressin, and 11 +/- 4, 67 +/- 13, and 53 +/- 12 mL/min/100 g after vasopressin/epinephrine/norepinephrine, respectively (p < .05 at 90 secs and 5 mins vasopressin vs. epinephrine and vasopressin/epinephrine/norepinephrine vs. epinephrine). Two of seven animals in the epinephrine group, four of seven animals in the vasopressin/epinephrine/norepinephrine group, and seven of seven animals in the vasopressin group could be successfully resuscitated (p < .05 vasopressin vs. epinephrine). CONCLUSIONS: Vasopressin with or without epinephrine and norepinephrine resulted in higher myocardial and cerebral perfusion than epinephrine alone, but there was no benefit in adding norepinephrine to vasopressin and epinephrine with regard to cardiac and cerebral blood flow during cardiopulmonary resuscitation.

Vibrography during tumor neurosurgery.

OBJECTIVE: The aim of this study was to determine whether elastography, a sonographically based real-time strain imaging method for registering the elastic properties of tissue, can be used in brain tumor surgery. METHODS: A modification of classic elastography called vibrography was applied in these measurements with static compression replaced by low-frequency axial vibration. Twenty patients were examined with this technique during brain tumor surgery. A conventional sonographic system with a custom-designed radio frequency (RF) interface was used. The RF data were digitized with a 50-MHz, 12-bit peripheral component interconnect analog/digital converter for real-time or offline processing. Sonographic RF data were acquired with a 6.5-MHz endocavity curved array. A special applicator equipped with a stepping motor moved the ultrasonic probe and produced a low-frequency mechanical vibration of approximately 5 to 10 Hz with a vibration amplitude of 0.3 mm. RESULTS: Detection of tumors was possible in 18 of 20 cases. Brain tissue was normally color coded orange or red. Three major groups of tumors with different elastic properties relative to brain tissue could be differentiated. In 3 cases, the stiffness of the tumor was identical to that of brain tissue, but the tumors were surrounded by a thin yellow border. Six tumors displayed higher strain than brain, whereas 7 tumors exhibited lower strain than the surrounding cerebrum. Two patients could not be assigned clearly to either of these groups. CONCLUSIONS: These findings indicate that vibrography is a feasible imaging method for brain tumor surgery and may have numerous potential applications in neurosurgery if further improvements are made.