Pre-hospital and intrahospital workflow optimization for patients with suspected ischemic stroke due to large vessel occlusion - findings from a tertiary care facility.

BACKGROUND: The efficacy of recanalization treatment in patients with ischemic stroke due to large vessel occlusion (LVO) is highly time dependent. We aimed to investigate the effects of an optimization of prehospital and intrahospital pathways on time metrics and efficacy of endovascular treatment in ischemic stroke due to LVO. METHODS: Patients treated with mechanical thrombectomy (MT) at the Hospital of St. John of God Vienna, Austria, between 2013 and 2020 were extracted from the Austrian Stroke Unit Registry. Study endpoints including time metrics, early neurological improvement and functional outcome measured by modified Rankin Scale (mRS) at 3 months were compared before and after optimization of prehospital and intrahospital pathways. RESULTS: Two hundred ninety-nine patients were treated with MT during the study period, 94 before and 205 after the workflow optimization. Workflow optimization was significantly associated with time metrics improvement (door to groin puncture time 45 versus 31 min; p < 0.001), rates of neurological improvement (NIHSS ≥ 8: 30 (35%) vs. 70 (47%), p = 0.04) and radiological outcome (TICI ≥ 2b: 71 (75%) versus 153 (87%); p = 0.013). Functional outcome (mRS 0-2: 17 (18%) versus 57 (28%); p = 0.067) and mortality (34 (37%) versus 54 (32%); p = 0.450) at 3 months showed a non-significant trend in the later time period group. CONCLUSION: The implementation of workflow optimization was associated a significant reduction of intrahospital time delays and improvement of neurological and radiological outcomes.

Resistive-polymer versus forced-air warming: comparable efficacy in orthopedic patients.

BACKGROUND: Several adverse consequences are caused by mild perioperative hypothermia. Maintaining normothermia with patient warming systems, today mostly with forced air (FA), has thus become a standard procedure during anesthesia. Recently, a polymer-based resistive patient warming system was developed. We compared the efficacy of a widely distributed FA system with the resistive-polymer (RP) system in a prospective, randomized clinical study. METHODS: Eighty patients scheduled for orthopedic surgery were randomized to either FA warming (Bair Hugger warming blanket #522 and blower #750, Arizant, Eden Prairie, MN) or RP warming (Hot Dog Multi-Position Blanket and Hot Dog controller, Augustine Biomedical, Eden Prairie, MN). Core temperature, skin temperature (head, upper and lower arm, chest, abdomen, back, thigh, and calf), and room temperature (general and near the patient) were recorded continuously. RESULTS: After an initial decrease, core temperatures increased in both groups at comparable rates (FA: 0.33 degrees C/h +/- 0.34 degrees C/h; RP: 0.29 degrees C/h +/- 0.35 degrees C/h; P = 0.6). There was also no difference in the course of mean skin and mean body (core) temperature. FA warming increased the environment close to the patient (the workplace of anesthesiologists and surgeons) more than RP warming (24.4 degrees C +/- 5.2 degrees C for FA vs 22.6 degrees C +/- 1.9 degrees C for RP at 30 minutes; P(AUC) <0.01). CONCLUSION: RP warming performed as efficiently as FA warming in patients undergoing orthopedic surgery.

Topical lidocaine reduces the risk of perioperative airway complications in children with upper respiratory tract infections.

PURPOSE: To determine the effect of topically applied lidocaine on perioperative airway complications when using a laryngeal mask airway device (LMAD) in children either with or without a history of recent or ongoing upper respiratory tract infection (URI). METHODS: In a randomized controlled double-blind trial, 34 children with a history of recent or ongoing URI and 32 non-URI children- all of whom were younger than age ten and scheduled to undergo minor surgical procedures-were randomly assigned to either a lidocaine or a placebo group. In the lidocaine group, an LMAD was lubricated with lidocaine gel before insertion, and a clear lubricating gel was used in the placebo group. The following data were recorded after standardized anesthesia induction and airway management: postoperative complications, such as coughing, desaturation, laryngospasm, and increased oral secretions, as well as length of stay in the postanesthetic recovery unit. RESULTS: Children with URI had a lower overall perioperative complication rate if they received a lidocaine gel (35%) rather than placebo (94%) (P < 0.01). Also, the incidence of postoperative coughing was less (12% vs 53%; P = 0.03). In non-URI patients, lidocaine did not significantly reduce the rate of airway complications compared with placebo (17% vs 24%, respectively). CONCLUSION: Lubrication of the LMAD with lidocaine gel reduces the incidence of airway complications in children with an upper respiratory tract infection.

Median effective local anesthetic doses of plain bupivacaine and ropivacaine for spinal anesthesia administered via a spinal catheter for brachytherapy of the lower abdomen.

BACKGROUND AND OBJECTIVES: Continuous spinal anesthesia via a spinal catheter allows adjusting the duration and extent of anesthesia to surgical needs, maintenance of hemodynamic stability, and good postoperative analgesia. This study was designed to determine the median effective local anesthetic dose of plain ropivacaine and bupivacaine administered intrathecally for interstitial brachytherapy of the lower abdomen using the Dixon up-and-down method. METHODS: Forty patients were randomly allocated to receive either intrathecal bupivacaine 5 mg per mL or ropivacaine 10 mg per mL via a 24-gauge spinal catheter at the L3-4 interspace. The initial dose was 10 mg of bupivacaine or 20 mg of ropivacaine; the dosing intervals were 1 mg and 2 mg, respectively. Doses for subsequent patients were determined by the response of the previous patient in that group. Successful anesthesia was defined as a loss of sensation to a cold stimulus at the T6 level and full motor blockade within 20 minutes after administration of the local anesthetic. RESULTS: The median effective local anesthetic dose for intrathecal bupivacaine was 11.2 mg (95% confidence interval [CI], 10.3-12.1) and 22.6 mg for ropivacaine (95% CI, 20.5-24.6). A relative analgesic potency ratio of 0.50 (95% CI, 0.44-0.56) was calculated between the median effective local anesthetic dose of intrathecal bupivacaine and ropivacaine. CONCLUSIONS: Bupivacaine and ropivacaine are appropriate for continuous spinal anesthesia for interstitial radiation therapy procedures of the lower abdomen. In the dose-ranges investigated, intrathecal ropivacaine is approximately half as potent as bupivacaine.

Airborne bacterial contamination during orthopedic surgery: A randomized controlled pilot trial.

STUDY OBJECTIVE: Several factors such as lack of unidirectional, turbulent free laminar airflow, duration of surgery, patient warming system, or the number of health professionals in the OR have been shown or suspected to increase the number of airborne bacteria. The objective of this study was to perform a multivariate analysis of bacterial counts in the OR in patients during minor orthopedic surgery. DESIGN: Prospective, randomized pilot study. SETTING: Medical University of Vienna, Austria. PATIENTS: Eighty patients undergoing minor orthopedic surgery were included in the study. INTERVENTIONS: Surgery took place in ORs with and without a unidirectional turbulent free laminar airflow system, patients were randomized to warming with a forced air or an electric warming system. MEASUREMENT: The number of airborne bacteria was measured using sedimentation agar plates and nitrocellulose membranes at 6 standardized locations in the OR. MAIN RESULTS: The results of the multivariate analysis showed, that the absence of unidirectional turbulent free laminar airflow and longer duration of surgery increased bacterial counts significantly. The type of patient warming system and the number of health professionals had no significant influence on bacterial counts on any sampling site. CONCLUSION: ORs with unidirectional turbulent free laminar airflow, and a reduction of surgery time decreased the number of viable airborne bacteria. These factors may be particularly important in critical patients with a high risk for the development of surgical site infections.

Influence of different oxygenator types on changing frequency, infection incidence, and mortality in ARDS patients on veno-venous ECMO.

PURPOSE: Veno-venous extracorporeal membrane oxygenation (vv-ECMO) is pivotal in the treatment of patients suffering from acute respiratory distress syndrome (ARDS). Comparative data with different oxygenator models have not yet been reported. The aim of this retrospective investigation was therefore to assess whether different oxygenator types might influence changing frequency, infection incidence, and mortality in patients on vv-ECMO. METHODS: 42 patients undergoing vv-ECMO between 1998 and 2009 were identified. In 20 out of these patients, a polypropylene (PP) microporous hollow fiber membrane oxygenator, and in 22 patients a nonmicroporous polymethylpentene (PMP) diffusion membrane oxygenator was used. Infection incidence, changing frequency, and mortality were documented. RESULTS: In the PMP group, an oxygenator change was necessary less often than in the PP group (p<0.001). The incidence of bacterial, viral, or fungal growth was similar in the groups, thus independent of the frequency of oxygenator change. Irrespective of the groups, the occurrence of Candida sp. tended to correlate with death (p = 0.06). In general, there was a trend towards a higher infection incidence in the subgroup with pulmonary ARDS (p = 0.07). Moreover, infection incidence was associated with a longer ICU stay (p = 0.03) and longer ECMO therapy (p = 0.03). ICU mortality was lower in the PMP group than in the PP group, although not statistically significant (p = 0.10). CONCLUSIONS: The PMP oxygenator membranes showed benefits with regards to changing frequency, but not infection incidence, length of ICU stay, and length of ECMO therapy. There was a trend towards a lower ICU mortality in patients with PMP oxygenators.

Medical information on the Internet: Quality assessment of lumbar puncture and neuroaxial block techniques on YouTube.

BACKGROUND: The Internet has become the largest, most up-to-date source for medical information. Besides enhancing patients' knowledge, the freely accessible audio-visual files have an impact on medical education. However little is known about their characteristics. In this manuscript the quality of lumbar puncture (LP) and spinal anaesthesia (SA) videos available on YouTube is assessed. METHODS: This retrospective analysis was based on a search for LP and SA on YouTube. Videos were evaluated using essential key points (5 in SA, 4 in LP) and 3 safety indicators. Furthermore, violation of sterile working techniques and a rating whether the video must be regarded as dangerously misleading was performed. RESULTS: From 2321 hits matching the keywords, 38 videos were eligible for evaluation. In LP videos, 14% contained information on all, 4.5% on 3 and 4.5% on 2 key points, 59% on 1 and 18% on no key point. Regarding SA, no video contained information on all 5 key points, 56% on 2-4 and 25% on 1 key point, 19% did not contain any essential information. A sterility violation occurred in 11%, and 13% were classified as dangerously misleading. CONCLUSIONS: Even though high quality videos are available, the quality of video clips is generally low. The fraction of videos that were not performed in an aseptic manner is low, but these pose a substantial risk to patients. Consequently, more high-quality, institutional medical learning videos must be made available in the light of the increased utilization on the Internet.

A comparison of paediatric airway anatomy with the SimBaby high-fidelity patient simulator.

BACKGROUND: The SimBaby high-fidelity patient simulator is a widely used paediatric simulator for the training of standard and critical airway management scenarios. Furthermore this simulator is frequently used for the evaluation of different airway devices and techniques. However, the anatomic structures of the SimBaby have not been compared to actual patients' anatomy. METHODS: The CT radiographic measures of the upper airway anatomy of two SimBaby simulators were compared to MRI images of the upper airway of 20 children aged 1-11 months who underwent routine MRI scans under sedation for diagnostic purposes. Various distances of the tongue, soft palate and pharynx, cross sectional areas and volumes of anatomic structures of the upper airway including the retroglossal airspace were compared. RESULTS: The SimBaby's retroglossal airspace volume greatly differed from the measurements in patients (SimBaby 5.3±0.4 vs. 1.9±0.8 cm(3) in infants, p<0.01). Furthermore the distance from the alveolar process of the mandible to the posterior pharyngeal wall was larger in the SimBaby than in infants (5.8±0.1 vs. 4.5±0.5 cm, p<0.001) and dimensions of the epiglottis and pharynx were larger in the Simbaby. CONCLUSION: The anatomic features of the SimBaby do not adequately simulate the upper airway anatomy of infants. These results imply inadequate realism of this simulator for airway training and compromise the validity of comparative trials of different airway devices with the SimBaby as airway model.

The anxiolytic effect of pregabalin in outpatients undergoing minor orthopaedic surgery.

Preoperative anxiety can increase postoperative pain and is therefore important to avoid. Different approaches have already been tested for preoperative anxiolysis. Gabapentinoids might be a useful alternative to benzodiazepines. Pregabalin is used for treating generalized anxiety disorders and shows a favourable pharmacokinetic profile after oral administration; however, its anxiolytic effect preoperatively in healthy outpatients is still unclear. In this randomised, double-blind, placebo-controlled trial the anxiolytic effect of pregabalin in 40 outpatients undergoing standardised general anaesthesia and postoperative pain therapy for minor orthopaedic surgery was analysed. Patients received preoperatively either 300 mg pregabalin or placebo orally. The primary outcome was anxiety before anaesthesia induction, the secondary outcome the postoperative pain, both assessed using a visual analogue scale from 0 to 100. Without any side effects pregabalin reduced preoperative anxiety compared with the control group (23 ± 10 vs. 38 ± 17; p = 0.003). Pain scores did not differ between groups; however, need of piritramide in the postanaesthesia care unit was reduced to half by pregabalin compared with the control group. A single preoperative dose of 300 mg pregabalin reduces anxiety in patients undergoing minor orthopaedic surgery without any side effects like dizziness or persisting sedation resulting in a prolonged stay in the postanaesthesia care unit.

Determination of enoxaparin with rotational thrombelastometry using the prothrombinase-induced clotting time reagent.

Drug monitoring of low molecular weight heparin is generally not recommended, but could be reasonable in critically ill patients, whose risk for bleeding or thrombosis shows a high interpatient variability. Anti-Xa assays are not available around the clock even in central hospitals, whereas rotational thrombelastometry (ROTEM) becomes increasingly used at the bedside. Prothrombinase-induced clotting time (PiCT) reagent allows determination of factor Xa-inhibition in plasma. The aim of our study was to evaluate enoxaparin determination in whole blood with the ROTEM using specific test modifications, including PiCT. After ethics committee's approval, citrated whole blood obtained from overall 16 healthy volunteers was incubated with enoxaparin at 16 different anti-Xa concentrations. Main endpoint was the clotting time (CT) in ROTEM representing initial activation of clot formation. CT was determined in the new PiCT-ROTEM test, in a low-tissue factor-activated modification (LowTF-ROTEM) as well as in the commercially available heparin-sensitive ROTEM assays (HEPTEM and INTEM). In the absence of enoxaparin, CT values were 168.6 +/- 6.1 s (PiCT-ROTEM), 247.3 +/- 18.6 s (LowTF-ROTEM), and -6.2 +/- 7.9 s (INTEM-HEPTEM). A linear dependency (P < 0.01) between anti-Xa concentration and CT was found for PiCT-ROTEM, LowTF-ROTEM, and for INTEM-HEPTEM with correlation coefficients of 0.93 for PiCT-ROTEM, 0.94 for LowTF-ROTEM, and 0.81 for INTEM-HEPTEM. This in-vitro experiment demonstrates a strong correlation between enoxaparin anti-Xa concentrations and specific ROTEM tests. These promising assays should be further evaluated for monitoring anticoagulation in high-risk patients in clinical studies.

Supplemental postoperative oxygen and tissue oxygen tension in morbidly obese patients.

BACKGROUND: Subcutaneous tissue oxygen tension (PsqO(2)) is a major predictor for wound healing and the occurrence of wound infections. Perioperative subcutaneous wound and tissue oxygen tension is significantly reduced in morbidly obese patients. Even during intraoperative supplemental oxygen administration, PsqO(2) remains low. Tissue hypoxia is pronounced during surgery and might explain the substantial increase in infection risk in obese patients. It remains unknown whether long-term supplemental postoperative oxygen augments tissue oxygen tension. Consequently, we tested the hypothesis that 80% inspired oxygen administration during 12-18 postoperative hours significantly increases PsqO(2) compared to 30% inspired oxygen fraction. METHODS: After IRB approval and informed consent, 42 patients undergoing laparoscopic bariatric surgery were randomly assigned to receive either 80% inspired oxygen via a PULMANEX Hi-Ox Mask (Viasys MedSystems, Wheeling, IL) (10 L/min) or 30% oxygen via nasal cannula (2 L/min) after surgery until the next morning. PsqO(2) was measured with a temperature-corrected Clark-type electrode in the subcutaneous tissue of the upper arm and adjacent to the wound. RESULTS: Postoperative subcutaneous tissue oxygen tension was significantly increased in the Hi-Ox group: 58 (47.7, 74.1) mmHg vs. 43 (38.7, 55.2) mmHg, P = 0.002. Also, wound tissue oxygen tension was improved during supplemental oxygen administration: 75.2 (69.8, 95.5) mmHg vs. 52.4 (46.3, 66.1) mmHg, P < 0.001. CONCLUSION: Subcutaneous tissue oxygen tension was significantly increased by supplemental postoperative oxygen administration. Whether there is an effect on the incidence of wound infection in morbidly obese patients is matter of further research.

Intrathecal clonidine for postoperative analgesia in elderly patients: the influence of baricity on hemodynamic and analgesic effects.

Intrathecal (IT) clonidine is an effective analgesic, but it also produces hemodynamic depression and sedation which are likely to be related to IT clonidine's cephalad spread within the cerebrospinal fluid. We hypothesized that IT clonidine's side effects could be reduced without compromising the duration and quality of analgesia by injecting clonidine IT in a hyperbaric solution and elevating the patient's trunk. We prospectively randomized 30 elderly patients to receive IT 150 microg of either isobaric (ISO) or hyperbaric (HYPER) clonidine for postoperative analgesia after surgical repair of traumatic hip fracture. Hemodynamics, IV fluid administration, visual analog pain scores, sedation scores, and clonidine cerebrospinal fluid levels were recorded at fixed intervals. Patients in the ISO group required significantly more crystalloid fluid administration (median, 2500 mL; range, 1500-3000 mL) than those in the HYPER group (median, 1500; range, 500-3000 mL) to maintain adequate arterial blood pressure (P < 0.01). Also, the decrease in heart rate was significantly more pronounced in the ISO than in the HYPER group (P < 0.01). The duration of analgesia was significantly larger in the ISO (median, 400 min; range, 115-400 min) than in the HYPER (median, 265 min; range, 205-400 min) group (P < 0.05). Sedation scores did not differ between groups. We conclude that increasing the baricity of IT clonidine solution in the conditions of our experiment reduces hemodynamic side effects but also analgesia from IT administered clonidine.