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Biomedical subjects

Anis Baraka

Publications and source records attributed to Anis Baraka.

At least 19 recordsLinked to original sources
PubMed2006

Correlation between cerebral and mixed venous oxygen saturation during moderate versus tepid hypothermic hemodiluted cardiopulmonary bypass.

OBJECTIVE: This study was undertaken to compare cerebral oxygen saturation (RsO(2)) and mixed venous oxygen saturation (SvO(2)) in patients undergoing moderate and tepid hypothermic hemodiluted cardiopulmonary bypass (CPB). DESIGN: Prospective study. SETTINGS: University hospital operating room. PARTICIPANTS: Fourteen patients undergoing elective coronary artery bypass graft surgery using hypothermic hemodiluted CPB. INTERVENTIONS: During moderate (28 degrees -30 degrees C) and tepid hypothermic (33 degrees -34 degrees C) hemodiluted CPB, RsO(2) and SvO(2) were continuously monitored with a cerebral oximeter via a surface electrode placed on the patient's forehead and with the mixed venous oximeter integrated in the CPB machine, respectively. MEASUREMENTS AND MAIN RESULTS: Mean +/- standard deviation of RsO(2), SvO(2), PaCO(2), and hematocrit were determined prebypass and during moderate and tepid hypothermic phases of CPB while maintaining pump flow at 2.4 L/min/m(2) and mean arterial pressure in the 60- to 70-mmHg range. Compared with a prebypass value of 76.0% +/- 9.6%, RsO(2) was significantly decreased during moderate hypothermia to 58.9% +/- 6.4% and increased to 66.4% +/- 6.7% after slow rewarming to tepid hypothermia. In contrast, compared with a prebypass value of 78.6% +/- 3.3%, SvO(2) significantly increased to 84.9% +/- 3.6% during moderate hypothermia and decreased to 74.1% +/- 5.6% during tepid hypothermia. During moderate hypothermia, there was poor agreement between RsO(2) and SvO(2) with a gradient of 26%; however, during tepid hypothermia, there was a strong agreement between RsO(2) and SvO(2) with a gradient of 6%. The temperature-uncorrected PaCO(2) was maintained at the normocapnic level throughout the study, whereas the temperature-corrected PaCO(2) was significantly lower during the moderate hypothermic phase (26.8 +/- 3.1 mmHg) compared with the tepid hypothermic phase (38.9 +/- 3.7 mmHg) of CPB. There was a significant and positive correlation between RsO(2) and temperature-corrected PaCO(2) during hypothermia. CONCLUSIONS: During moderate hypothermic hemodiluted CPB, there was a significant increase of SvO(2) associated with a paradoxic decrease of RsO(2) that was attributed to the low temperature-corrected PaCO(2) values. During tepid CPB after slow rewarming, regional cerebral oxygen saturation was increased in association with an increase with the temperature-corrected PaCO(2) values. The results show that during hypothermic hemodiluted CPB using the alpha-stat strategy for carbon dioxide homeostasis, cerebral oxygen saturation is significantly higher during tepid than moderate hypothermia.

Blood Pressure↗
PubMed2006

Cisatracurium or rocuronium versus rocuronium-cisatracurium combination.

The present report evaluates the incidence of pain on intravenous injection and the condition of tracheal intubation at one minute following the administration of cisatracurium or rocuronium versus rocuronium-cisatracurium combination. We studied 60 patients, ASA 1, aged 18-60 years, undergoing elective surgical procedures. The patients were randomly assigned to 3 groups who received intravenously either 0.15 mg/kg cisatracurium [2ED95], 0,6 mg rocuronium [2ED95] or a combination of 0.075 mg/kg cisatracurium [1ED95], plus 0.3 mg rocuronium [1ED95]. In the awake patients, the pain on injection of muscle relaxant was assessed on a four point scale (none, mild, moderate, severe). Administration of the relaxant was followed by 1-2 mg/kg of lidocaine and 2 mg/kg propofol. Orotracheal intubation was performed 60 seconds following the administration of the relaxant. The intubating conditions were assessed and rated as excellent, good, fair or poor. The administration of 2ED95 cisatracurium resulted in poor intubating conditions at 60s, without pain on injection. In contrast, the administration of 2ED95 rocuronium resulted in excellent or good intubating conditions at 60s associated with high incidence of pain on injection in most of the patients. However, the combination of 1ED95 cisatracurium with 1ED95 rocuronium provided similar intubating conditions to the 2ED95 rocuronium alone, associated with a significantly less pain on injection.

Adolescent↗
PubMed2005

Propofol is superior to thiopental for intubation without muscle relaxants.

PURPOSE: To compare intubating conditions and cardiovascular changes following induction of anesthesia and tracheal intubation in patients receiving either lidocaine-remifentanil-propofol or lidocaine-remifentanil-thiopental prior to induction. METHODS: In a randomized, double-blind study 76 healthy adult patients were assigned to one of two groups: lidocaine 1.5 mg.kg(-1), remifentanil 2 mug.kg(-1) and propofol 2 mg.kg(-1) (Group P) or lidocaine 1.5 mg.kg(-1), remifentanil 2 mug.kg(-1) and thiopental 5 mg.kg(-1) (Group T). Ninety seconds after the administration of the hypnotic agent, laryngoscopy and tracheal intubation were attempted. Intubating conditions were assessed as excellent, good or poor on the basis of ease of ventilation, jaw relaxation, position of the vocal cords, and patient's response to intubation and slow inflation of the tracheal cuff. The mean arterial pressure (MAP) and heart rate (HR) were measured 45 sec after hypnotic agent administration, immediately after tracheal intubation, two and five minutes after intubation. RESULTS: Excellent intubating conditions were obtained in 84% of Group P patients and 50% of Group T patients (P < 0.05). The percentage decrease from baseline MAP was significantly higher in Group P than in Group T postinduction (27.4% +/- 11.6 vs 21.8% +/- 10.0) and immediately postintubation (19.0% +/- 16.7 vs 11.2% +/- 14.9). The percentage change from baseline HR was significantly higher in Group P than in Group T postinduction (13.8% +/- 9.7 vs 0.5% +/- 12.4), immediately postintubation (8.7% +/- 13.7 vs 2.1% +/- 13.1), and two minutes postintubation (7.04% +/- 14.3 vs 3.5% +/- 14.3). CONCLUSION: Lidocaine-remifentanil-propofol is superior to lidocaine-remifentanil-thiopental for tracheal intubation without muscle relaxants. However, it induces more hypotension and bradycardia.

Adolescent↗
PubMed2005

Oxygenator exhaust capnography for prediction of arterial carbon dioxide tension during hypothermic cardiopulmonary bypass.

Continuous monitoring and control of arterial carbon dioxide tension (P(a)CO2) during cardiopulmonary bypass (CPB) is essential. A reliable, accurate, and inexpensive system is not currently available. This study was undertaken to assess whether the continuous monitoring of oxygenator exhaust carbon dioxide tension (PexCO2) can be used to reflect P(a)CO2 during CPB. A total of 33 patients undergoing CPB for cardiac surgery were included in the study. During normothermia (37 degrees C) and stable hypothermia (31 degrees C), the values of PexCO2 from the oxygenator exhaust outlet were monitored and compared simultaneously with the P(a)CO2 values. Regression and agreement analysis were performed between PexCO2 and temperature corrected-P(a)CO2 and temperature uncorrected-P(a)CO2. At normothermia, a significant correlation was obtained between PexCO2 and P(a)CO2 (r = 0.79; p < 0.05); there was also a strong agreement between PexCO2 and P(a)CO2 with a gradient of 3.4 +/- 1.9 mmHg. During stable hypothermia, a significant correlation was obtained between PexCO2 and the temperature corrected-P(a)CO2 (r = 0.78; p < 0.05); also, there was a strong agreement between PexCO2 and temperature corrected-P(a)CO2 with a gradient of 2.8 +/- 2.0 mmHg. During stable hypothermia, a significant correlation was obtained between PexCO2 and the temperature uncorrected-P(a)CO2 (r = 0.61; p < 0.05); however, there was a poor agreement between PexCO2 and the temperature uncorrected-P(a)CO2 with a gradient of 13.2 +/- 3.8 mmHg. Oxygenator exhaust capnography could be used as a mean for continuously monitoring P(a)CO2 during normothermic phase of cardiopulmonary bypass as well as the temperature-corrected P(a)CO2 during the stable hypothermic phase of CPB.

Aged↗
PubMed2005

Muallem endo-tracheal tube introducer: (METTI)--an aid for the difficult airway.

This is a brief report evaluating a new single use endotracheal tube introducer (METTI) which has a soft curved atraumatic tip. The introducer was tried in 44 patients, whose direct laryngoscopic view was simulated to Cormack IIIb score, and in six patients with real Cormack III score. The overall success rate of railroading of the tracheal tube over the introducer was 94% from the first attempt.

Adult↗
PubMed2004

Remifentanil for modulation of hemodynamics in a patient undergoing laparoscopic resection of pheochromocytoma.

The present report monitors the hemodynamic fluctuations in a 63 year-old female patient undergoing laparoscopic resection of right adrenal pheochromocytoma during remifentanil-based anesthesia. Anesthesia was induced with lidocaine 1 mg x kg(-1), propofol 3.5 mg x kg(-1), and cisatracurium 0.2 mg(-1) x kg(-1) and a remifentanil infusion was started at a rate of 1 ug.kg (-1) x min(-1). Anesthesia was then maintained with remifentanil infusion (0.5 microg(-1) x kg(-1) x min), sevoflurane 1-2% (end-tidal) in a mixture of air/oxygen (3:1), and a continuous infusion of cisatracurium. There were no significant changes of BP and HR following tracheal intubation or surgical incision. However, creation of pneumoperitoneum as well as tumor manipulation resulted in a dramatic increase of systolic BP and pulmonary artery pressure, associated with a decrease in cardiac output. These hemodynamic changes were unresponsive to an increase in the remifentanil infusion rate up to 1.5 ug.kg(-1) x min(-1), but were controlled by increasing the concentration of sevoflurane up to 6%, and by a nitroglycerin (NTG) infusion. Ten min after removal of the tumor, and despite discontinuation of the NTG infusion as well as a reduction in the remifentanil infusion and sevoflurane concentration, the BP decreased down to 64/43 mmHg. In conclusion, the present report shows in a patient undergoing laparoscopic resection of adrenal pheochromocytoma that remifentanil does not prevent the severe hypertensive episodes associated with intraperitoneal carbon dioxide insufflation or tumor manipulation. However, it can be titrated to prevent the hemodynamic reflex response to tracheal intubation and surgical stimulation.

Adrenal Gland Neoplasms↗
PubMed2004

Alpha-stat vs. pH-stat strategy during hypothermic cardiopulmonary bypass.

There are two different strategies of acid-base regulation during hypothermis. The alpha-stat strategy of ectotherms maintains the temperature-uncorrected arterial PCO2 and pH at normothermic values (i.e., 40 mmHg and 7.4, respectively), irrespective of the body temperature. In contrast, the pH-stat of hibernators maintains the temperature-corrected pH and PCO2 at the normal values at the different body temperatures. Clinically, it appears that it is more physiological to use the alpha-stat strategy whenever tepid or moderate hypothermic CPB is used in order to maintain intracellular electrochemical neutrality, and to adopt the pH-stat strategy whenever deep hypothermic circulatory arrest is induced, in order to otimize brain protection.

Acid-Base Imbalance↗