Anesthesia and analgesia
-
Anesthesia and analgesia · Nov 2001
Multicenter Study Comparative Study Clinical TrialThe recovery of Senegalese African blacks from intravenous anesthesia with propofol and remifentanil is slower than that of Caucasians.
Differences in sensitivity to anesthetic drugs have already been described among races. This study was designed to comparatively investigate the anesthetic requirements of two different ethnic groups: Caucasians and African blacks. Forty-five Caucasians from Italy and 45 African blacks from Senegal, who underwent general IV anesthesia with propofol and remifentanil, were comparatively evaluated for anesthetic depth and time lapsed before recovery. We used an electroencephalographic-derived index of depth of anesthesia, the bispectral index (BIS), and evaluation of clinical variables to assess the depth of anesthesia and the recovery trend. Mean BIS values from Caucasians after propofol discontinuation returned to baseline (92-100) in approximately 8 min, whereas in African blacks BIS values remained <80 for some 30 min. Time to eye opening was 10.6 +/- 4.8 min in Caucasians versus 16.9 +/- 8.8 min in African blacks (P < 0.001). Time to respond to loud verbal commands was 14.8 +/- 9.1 min in African blacks versus 9.1 +/- 4.2 min in Caucasians (P < 0.01). During anesthetic induction, the mean arterial pressure decreased by 20% in Caucasians and by only 10% in African blacks. We conclude that the recovery from general anesthesia with propofol was slower in African blacks compared with Caucasian patients. ⋯ This study demonstrates statistically significant differences between Caucasians and African blacks in the arousal time from IV anesthesia with propofol and remifentanil. The authors conclude that the recovery from general anesthesia was slower in African blacks compared with Caucasian patients.
-
Anesthesia and analgesia · Nov 2001
Randomized Controlled Trial Clinical TrialInflatable pillows as axillary support devices during surgery performed in the lateral decubitus position under epidural anesthesia.
The lateral decubitus position can cause dependent shoulder discomfort or result in traction on the brachial plexus. We measured pressure beneath the dependent shoulder and lateral angulation of the cervical spine in patients positioned in the lateral decubitus position for total hip replacement under epidural anesthesia. Inflatable pillows (Shoulder-Float) beneath the chest wall and head reduced pressure beneath the dependent shoulder from 66 to 12 mm Hg (P < 0.001) and lateral angulation of the cervical spine from 14 degrees to 4 degrees (P < 0.001). In a randomized crossover study of a further 15 patients, the use of inflatable pillows resulted in significantly less pressure beneath the dependent shoulder and chest wall than either a gel-pad or a 1000-mL lactated Ringer's bag. Inflatable pillows placed beneath the chest wall and head in the lateral decubitus position provided lower pressure beneath the dependent shoulder than other support devices and facilitated alignment of the cervical spine. ⋯ When patients lie on their side, this results in pressure beneath the shoulder and tilting of the head and neck to one side. These problems were effectively corrected with an inflatable pillow (Shoulder-Float).
-
Anesthesia and analgesia · Nov 2001
Randomized Controlled Trial Clinical TrialVoluntary hyperventilation before a rapid-sequence induction of anesthesia does not decrease postintubation PaCO2.
To prevent hypercapnia, voluntary hyperventilation is recommended for patients with increased intracranial pressure before the induction of general anesthesia. We sought to determine whether this maneuver results in a lower PaCO2 than breathing 3 min of oxygen 100% by face mask (preoxygenation) after intubation. Thirty patients requiring general anesthesia were randomly assigned to breathe either 3 min of oxygen 100% by face mask (Group P) or 1 min of oxygen 100% followed by 2 min of voluntary hyperventilation with oxygen 100% (Group H). All patients received a standard rapid-sequence induction of anesthesia followed by a 90-s period of apnea. Patients were then tracheally intubated and mechanically ventilated. Five arterial blood gas samples were taken: with room air, after preoxygenation or hyperventilation, after 60 and 90 s of apnea, and after tracheal intubation. Voluntary hyperventilation decreased PaCO2 before rapid-sequence induction (hyperventilation, 30.0 +/- 3.5 mm Hg versus preoxygenation, 37.9 +/- 5.2 mm Hg; P < 0.0001), but after 60 s of apnea, both groups had similar PaCO2 (hyperventilation, 36.1 +/- 3.3 mm Hg versus preoxygenation, 35.6 +/- 3.4 mm Hg; P = 0.673), and no benefit was found after intubation (hyperventilation, 40.5 +/- 3.9 mm Hg versus preoxygenation, 41.4 +/- 2.7 mm Hg; P = 0.603). We conclude that voluntary hyperventilation before rapid-sequence induction does not provide protection against potential hypercapnia during intubation. ⋯ Voluntary hyperventilation before anesthesia induction is recommended for patients with increased intracranial pressure to prevent hypercapnia. This randomized, prospective study demonstrated that this maneuver does not result in a lower postintubation PaCO2 than standard preoxygenation.
-
Anesthesia and analgesia · Nov 2001
Randomized Controlled Trial Clinical TrialThe effect of noise on the bispectral index during propofol sedation.
Because noise in the operating room has been alleged to interfere with the ability to sedate patients before surgery, we evaluated the effect of noise on the Bispectral index (BIS) value during propofol sedation. Thirty unpremedicated patients were studied before the start of surgery while receiving propofol sedation on two separate occasions according to a randomized, crossover protocol design. After achieving a stable baseline BIS value of either 75 or 80 with a target-controlled infusion of propofol, an external sound source administered noise at 50, 80, 110, and 120 dB. The changes in the BIS value were recorded over a 1-min interval at each noise level. In the BIS 75 group, increasing levels of noise did not significantly alter the BIS value. However, in the BIS 80 group, the BIS values at 80, 110, and 120 dB were significantly higher compared to the value at 50 dB. In conclusion, experimental noise increases the BIS and appears to have a greater effect on the BIS value at "lighter" levels of propofol sedation. ⋯ Experimental noise levels can increase the Bispectral index (BIS) values during propofol sedation in the operating room. However, the magnitude of the BIS response is influenced by the depth of sedation.
-
Anesthesia and analgesia · Nov 2001
Randomized Controlled Trial Clinical TrialSevoflurane titration using bispectral index decreases postoperative vomiting in phase II recovery after ambulatory surgery.
We tested the hypothesis that titration of sevoflurane using bispectral index (BIS) of the electroencephalogram decreases postoperative nausea and vomiting and improves recovery after outpatient gynecologic laparoscopy. After propofol induction, anesthesia was maintained in all patients with sevoflurane in 65% nitrous oxide and oxygen. In the BIS-Titrated group (n = 32), sevoflurane was titrated to maintain the BIS between 50 and 60 during surgery. In the Control group (n = 30), sevoflurane was adjusted to keep hemodynamic variables within 25% of control values. The severity of pain, postoperative nausea and vomiting, and recovery variables were recorded. In the Control group, 30% of the patients had BIS <40 during surgery (versus 0 in the BIS-Titrated group). Orientation and ability to drink were achieved earlier in the BIS group (P < 0.05). At 30 min after cessation of nitrous oxide, patients in the BIS group performed better in the psychomotor recovery test (P < 0.01). In Phase II recovery room, these patients had significantly less vomiting than the patients in the Control group (16% versus 40% of the patients, respectively, P < 0.05). No differences were found in times to achieve home readiness. ⋯ In patients undergoing outpatient gynecologic laparoscopy, the monitoring of bispectral index decreases vomiting in Phase II recovery room, but it has no effect on the time to achieve home readiness.