Biomedical subjects

Boris Yanovski

Publications and source records attributed to Boris Yanovski.

8 recordsLinked to original sources

PubMed2006

Stroke onset time using sodium MRI in rat focal cerebral ischemia.

BACKGROUND AND PURPOSE: Thrombolytic therapy with intravenous tPA must be administered within 3 hours after stroke onset. However, stroke onset time cannot be established in 20% to 45% of potential patients. We propose that the rate of increase of the brain concentration of sodium ([Na+]br) after stroke, monitored using sodium MRI in a rat model of cortical ischemia, is linear in each individual animal, can locate the ischemic region, and can be used to estimate onset time. METHODS: After induction of focal cortical ischemia in rats under isoflurane anesthesia, [Na+]br time course maps were acquired continuously on a 3 T whole body scanner from 2 to 7 hours after occlusion followed by T2-weighted proton images. Microtubule-associated protein-2 immunostained brain sections were used to verify the location of the infarct. RESULTS: The ischemic region identified with microtubule-associated protein-2 corresponded to the region of maximum [Na+]br increase (P<0.001; n=5), and all of the animals demonstrated high linearity. [Na+]br increased at a mean rate of 25+/-4.7%/h in ischemic tissue (P=0.013) but not in normal cortex (1.0+/-1.1%/h; P=0.42). The mean onset time error was 1+/-4 minutes (n=4). CONCLUSIONS: These results of sodium MRI show that the region of maximum [Na+]br increase corresponds to the ischemic region. Although [Na+]br increases at a different rate in each animal, the increase is linear, and, therefore, onset time can be estimated. These findings suggest that this method can be used as a ticking clock to estimate time elapsed after vascular occlusion.

Animals↗

PubMed2006

Delayed ventricular fibrillation following blunt chest trauma in a 4-year-old child.

A 4-year-old boy who was involved in a motor vehicle accident as a pedestrian and suffered blunt chest trauma was admitted to the emergency room. Unpredictable delayed ventricular fibrillation was diagnosed and treated successfully 2 h later. This case cannot be classified as commotio cordis as the ventricular fibrillation (VF) developed so long after the sustained chest injury. At the same time, other possible etiologies of VF such as cardiac pathology or electrolyte and metabolic disorders had been ruled out. Thus, an etiological link between the chest trauma and the subsequent VF could not be ruled out and is in fact plausible despite the late onset.

Accidents, Traffic↗

PubMed2006

A comparison between the PLA Cobra and the Laryngeal Mask Airway Unique during spontaneous ventilation: a randomized prospective study.

The Laryngeal Mask (LMA) Unique and the Cobra Perilaryngeal Airway (PLA) are single-use supraglottic devices. There are no published studies comparing these devices during spontaneous ventilation. We compared the LMA Unique and the Cobra PLA with respect to 1) ventilatory variables during spontaneous ventilation, 2) time to achieve an effective airway, 3) airway intervention requirements, 4) cuff seal pressures, 5) fiberoptic score, and 6) perioperative adverse events. Eighty adult ASA physical status I-II patients undergoing general anesthesia for minor routine surgery were randomly allocated to LMA Unique or PLA Cobra for airway management. No statistically significant differences were found between the devices with respect to inspiratory tidal volume, expiratory tidal volume, end-tidal CO2 concentration, respiratory rate, number and type of airway interventions required with placement, the fiberoptic score, and the incidence of perioperative adverse events. The oropharyngeal leak (seal) pressure was higher for the CobraPLA (27 +/- 7 versus 21 +/- 4 cm H2O; P < 0.001). The oxygen saturation was higher (98.1% +/- 1% versus 97.3% +/- 2%; P = 0.02) in the LMA group. Time of insertion was shorter for LMA (23.7 +/- 2 s versus 26.6 +/- 7 s; P = 0.02) and insertion difficulty was less for LMA (P = 0.03). As these differences were not judged to be clinically important, both devices appear to be effective in establishing an adequate airway in patients who are spontaneously breathing under general anesthesia.

Anesthesia, General↗

PubMed2005

The esophageal-tracheal combitube resistance and ventilatory pressures.

STUDY OBJECTIVE: To measure resistance of the Combitube, a supraglottic ventilatory device used in the management of the patients with difficult airways, and its influence on delivered ventilatory pressures. DESIGN: Prospective study. SETTING: University-affiliated hospital. PATIENTS: A total of 20 patients with ASA status I or II who were scheduled for elective knee arthroscopy. INTERVENTIONS: (Part 2 of the study) After induction of general anesthesia and insertion of the Combitube, mechanical ventilation was initiated. Airway pressures were measured using fluid-filled pressure lines at the Y-piece (P(Y-piece)) of the breathing system and in the oropharynx (P(oropharynx)) at a position 2 cm beyond the second proximal anterior hole of the Combitube. These pressures were simultaneously recorded and the pressure curves were compared. MEASUREMENTS: (Part 1 of the study) Resistance of the esophageal and the tracheal lumen of the 37-F Combitube and standard endotracheal tubes (with internal diameters of 6, 7, and 8 mm) was compared ex vivo with a Datex AS/3 monitor. Ventilation conditions were kept constant at a tidal volume of 0.5 L, frequency of 10 breaths per minute, and ramp flow waveform and peak flow of 1 L/s. MAIN RESULTS: Resistance of standard endotracheal tubes was inversely proportional to their diameters (16, 11, and 7 cm H(2)O/L per second for the tubes with internal diameters of 6, 7, and 8 mm, respectively). The resistance of the Combitube's tracheal lumen was 12 cm H(2)O/L per second. There was a significant difference in peak respiratory pressures between P(Y-piece) and P(oropharynx) (40 +/- 5 and 23 +/- 5 cm H(2)O, respectively). CONCLUSIONS: The Combitube has significant airflow resistance that should be considered when patients are mechanically ventilated because the delivered oropharyngeal pressure is significantly lower than the pressure measured at the anesthesia breathing system.

Adult↗

PubMed2004

A randomized controlled trial comparing the ProSeal Laryngeal Mask Airway with the Laryngeal Tube Suction in mechanically ventilated patients.

BACKGROUND: The ProSeal Laryngeal Mask Airway (PLMA) (Laryngeal Mask Company, Henley-on-Thames, United Kingdom) is a new laryngeal mask with a modified cuff designed to improve its seal and a drain tube for gastric tube placement. Similarly, the Laryngeal Tube Suction (LTS) (VBM Medizintechnik Gmbh, Sulz a.N, Germany) is a new laryngeal tube that also has an additional channel for gastric tube placement. This study compared the placement and functions of these two devices. METHODS: One hundred fifty patients undergoing general anesthesia for elective surgery were randomly allocated to the PLMA (n = 75) or LTS (n = 75). Oxygenation and ventilation, ease of insertion, fiberoptic view, oropharyngeal leak pressure, ventilatory data, ease of gastric tube insertion, and postoperative airway morbidity were determined. RESULTS: After successful insertion of the devices in 96% of patients with the PLMA and in 94.4% with the LTS it was possible to maintain oxygenation, ventilation, and respiratory mechanics during the entire duration of surgery. Successful first and second attempt insertion rates were 57 patients (76%) and 15 patients (20%), respectively, for the PLMA and 60 patients (80%) and 11 patients (14.6%), respectively, for the LTS. Airway placement was unsuccessful with the PLMA in three patients and with the LTS in four patients. Time to achieve an effective airway was 36 +/- 24 s with the PLMA versus 34 +/- 25 s with the LTS. Gastric tube insertion was possible in 97.3% of patients with the PLMA and in 96% with the LTS. CONCLUSIONS: With respect to both physiologic and clinical function, the PLMA and LTS are similar and either device can be used to establish a safe and effective airway in mechanically ventilated anesthetized adult patients.

Adult↗

PubMed2003

Postdural puncture headache: an imaging-guided management protocol.

IMPLICATIONS: We propose an imaging-based algorithm for the management of headache caused by the inadvertent puncture of dura that occurs sporadically during epidural analgesia. Its implementation can identify those postdural puncture headache cases that cannot benefit from epidural blood patches, and their unnecessary application can consequently be avoided.

Adult↗

PubMed2003

An evaluation of the Laryngeal Tube during general anesthesia using mechanical ventilation.

UNLABELLED: The Laryngeal Tube is a new supraglottic ventilatory device for airway management. It has been developed to secure a patent airway during either spontaneous or mechanical ventilation. In this study, we sought to determine the effectiveness of the Laryngeal Tube for primary airway management during routine surgery with mechanical ventilation. One-hundred-seventy-five subjects classified as ASA physical status I and II, scheduled for elective surgery, were included in the study. After the induction of general anesthesia and insertion of a Size 4 Laryngeal Tube, measurements of oxygen saturation, end-tidal CO(2) and isoflurane concentration, and breath-by-breath spirometry data were obtained every 5 min throughout surgery. The lungs were ventilated with volume-controlled mechanical ventilation. The number of attempts taken to insert the Laryngeal Tube and the insertion time were recorded. In 96.6% of patients, it was possible to maintain oxygenation, ventilation, and respiratory mechanics by using mechanical ventilation throughout the surgical procedure. The results of this study suggest that the Laryngeal Tube is an effective and safe airway device for airway management in mechanically ventilated patients during elective surgery. IMPLICATIONS: In 96.6% of patients intubated with the Laryngeal Tube, it was possible to maintain oxygenation, ventilation, and respiratory mechanics during mechanical ventilation.

Adolescent↗

PubMed2002

Effect of ilioinguinal nerve block on the catecholamine plasma levels in orchidopexy: comparison with caudal epidural block.

BACKGROUND: Both caudal epidural and ilioinguinal/iliohypogastric nerve blocks have been used to provide effective intra- and postoperative analgesia. Stress response hormone levels can be used as an objective method to assess the analgesic efficacy of the anaesthetic techniques used in infraumbilical surgery in children. In this study, we compared catecholamine blood levels in children undergoing these two different supplementary analgesic/anaesthetic techniques. METHODS: Thirty male paediatric patients undergoing orchidopexy, ASA I, received inhalation general anaesthesia, and were randomly allocated to one of two groups: a caudal group (n = 15) and an ilioinguinal/iliohypogastric nerve block group (n = 15). Plasma epinephrine and norepinephrine concentrations were measured at the induction time, at the end of surgery, and in the postanaesthesia care unit. Postoperative pain score was also assessed in the postanaesthesia care unit. RESULTS: In both groups, there was a substantial decrease in the catecholamine blood levels; however, there were significantly higher levels of epinephrine in the ilioinguinal group at the end of surgery (P = 0.008) and in the recovery room (P = 0.02) and a significant higher level of norpinephrine in the recovery room (P = 0.008). CONCLUSIONS: The result of this study revealed that caudal epidural block was more effective than ilioinguinal block in suppressing the stress response as reflected in epinephrine and norepinephrine blood levels in orchidopexy patients.

Anesthesia, Caudal↗