Anesthesia and analgesia
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Anesthesia and analgesia · Aug 2001
A new, safety-oriented, integrated drug administration and automated anesthesia record system.
Medication errors are an important cause of patient morbidity and mortality and excessive costs, including in anesthesia. Conventional methods of injectable drug administration in anesthesia make little use of technology to support manual checking and are idiosyncratic and relatively error prone. Similarly, conventional anesthesia records are handwritten, time-consuming to make, and often unreliable. There are automated record systems, but they do not provide support for checking drugs. Therefore, by using a multifaceted approach based on established principles of systems design and human factors psychology, we have developed a system that includes trays that promote a well-organized anesthetic workspace, color- and bar-coded labeling of syringes, and automatic visual and auditory verification of the syringe labels by computer just before each drug administration. In addition, documentation of drugs administered and a traditional anesthetic case record are generated automatically. The system has been successfully deployed for 25 mo and has been used by 35 anesthesiologists in 1148 diverse cases, including cardiopulmonary bypass procedures, heart and lung transplants, and orthopedic and otorhinolaryngologic operations. It is in daily use in a tertiary teaching center and in a private hospital. ⋯ Traditional methods of drug administration and record keeping in anesthesia are relatively error prone. By using sound principles of systems design and human factors psychology, we have designed and deployed a system with the aim of improving patient safety by facilitating correct drug administration and accurate anesthesia record making.
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Anesthesia and analgesia · Aug 2001
Randomized Controlled Trial Comparative Study Clinical TrialColloids versus crystalloids and tissue oxygen tension in patients undergoing major abdominal surgery.
The effects of intravascular volume replacement regimens on tissue oxygen tension (ptiO(2)) are not definitely known. Forty-two consecutive patients scheduled for elective major abdominal surgery were prospectively randomized to receive either 6% hydroxyethyl starch (HES) (mean molecular weight 130 kd, degree of substitution 0.4, n = 21) or lactated Ringer's solution (RL, n = 21) for intravascular volume replacement. Fluids were administered perioperatively and continued for 24 h on the intensive care unit to keep central venous pressure between 8 and 12 mm Hg. The ptiO(2) was measured continuously in the left deltoid muscle by using microsensoric implantable partial pressure of oxygen catheters after the induction of anesthesia (baseline, T0), 60 min (T1) and 120 min thereafter (T2), at the end of surgery (T3), and on the morning of the first postoperative day on the intensive care unit (T4). HES 130/0.4 2920 +/- 360 mL and 11,740 +/- 2,630 mL of RL were given to the patients within the study period. Systemic hemodynamics and oxygenation (PaO(2), PaCO(2)) did not differ significantly between the two volume groups throughout the study. From similar baseline values, ptiO(2) increased significantly in the HES-treated patients (a maximum of 59% at T4), whereas it decreased in the RL group (a maximum of -23% at T4, P < 0.05). The largest differences of ptiO(2) were measured on the morning of the first postoperative day. We conclude that intravascular volume replacement with 6% HES 130/0.4 improved tissue oxygenation during and after major surgical procedures compared with a crystalloid-based volume replacement strategy. Improved microperfusion and less endothelial swelling may be responsible for the increase in ptiO(2) in the HES 130/0.4-treated patients. ⋯ In patients undergoing major abdominal surgery, a colloid-based (with hydroxyethyl starch [HES] 130/0.4) and a crystalloid-based (with lactated Ringer's solution [RL]) volume replacement regimen was compared regarding tissue oxygen tension (ptiO(2)) measured continuously by microsensoric implantable catheters. The ptiO(2) increased in the HES-treated (+59%) but decreased in the RL-treated (-23%) patients. Improved microcirculation may be the mechanism for the better ptiO(2) in the HES group.
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Anesthesia and analgesia · Aug 2001
Randomized Controlled Trial Clinical TrialMore epidural than intravenous sufentanil is required to provide comparable postoperative pain relief.
The extent to which epidurally administered sufentanil acts directly on spinal opioid receptors remains controversial. We tested the hypothesis that small-dose boluses of sufentanil, given epidurally or IV, provide comparable analgesia at similar plasma sufentanil concentrations. The lipophilicity of sufentanil makes it likely to be absorbed into fat surrounding the epidural space. We therefore also tested the hypothesis that more epidural than IV sufentanil is required to produce comparable analgesia. Analgesia and plasma sufentanil concentrations were evaluated in 20 postoperative patients randomly assigned to patient-controlled epidural or IV sufentanil. Pain was evaluated with visual analog scales by blinded observers. Sufentanil doses and plasma concentrations were measured. Analgesia was similar with epidural and IV sufentanil administration. Plasma sufentanil concentrations were virtually identical in the two groups. However, significantly larger sufentanil doses were required with epidural administration: 238 +/- 50 microg vs 160 +/- 32 microg (P < 0.01). The primary mechanism by which small-dose boluses of epidurally-administered sufentanil produce analgesia seems to be systemic absorption of the drug with subsequent recirculation to the supraspinal opioid receptors. This study demonstrates that the cumulative dose of sufentanil, when administered as a small epidural bolus, is approximately 50% more than that administered IV to provide comparable analgesia. This indicates that the bioavailability of epidurally-administered sufentanil is reduced and suggests that a large proportion of the drug may be absorbed into the epidural fat. ⋯ More epidural than IV sufentanil was required to provide comparable postoperative pain relief and similar plasma sufentanil concentrations. These data suggest that when sufentanil is administered in small-dose boluses, much of the drug is absorbed into the epidural fat and that the primary mechanism by which epidurally administered sufentanil produces analgesia is via systemic absorption.
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Anesthesia and analgesia · Aug 2001
Randomized Controlled Trial Clinical TrialIpsilateral shoulder pain after thoracotomy with epidural analgesia: the influence of phrenic nerve infiltration with lidocaine.
Patients receiving effective thoracic epidural analgesia for postthoracotomy pain may still complain of severe ipsilateral shoulder pain. The etiology of this pain is unclear. In this randomized, double-blinded, placebo-controlled study, we investigated the effect of phrenic nerve infiltration with lidocaine or saline on postoperative shoulder pain in 48 patients. After completion of a lung resection, patients received either 10 mL of 1% lidocaine or 10 mL of 0.9% saline infiltrated into the periphrenic fat pad at the level of the diaphragm. Shoulder pain was experienced by 33% of patients receiving lidocaine, compared with 85% of patients receiving saline (P < 0.008). Overall pain scores were lower with lidocaine (P < 0.05). PaCO(2) values were not significantly higher with lidocaine in the first 2 h. We conclude that pain transmitted via the phrenic nerve and referred to the shoulder is the most likely explanation for the ipsilateral shoulder pain experienced by patients receiving epidural analgesia for postthoracotomy pain. ⋯ Ipsilateral shoulder pain after thoracotomy is common and may be severe, even in the presence of a functioning thoracic epidural. We have shown that infiltration of the phrenic nerve with local anesthetic significantly and safely reduces this shoulder pain, potentially allowing the ideal goal of a pain-free thoracotomy.
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Anesthesia and analgesia · Aug 2001
Intraoperative monitoring of the recurrent laryngeal nerve in 151 consecutive patients undergoing thyroid surgery.
We present a technique of intraoperative monitoring of the recurrent laryngeal nerve using a surface electrode attached to a routine endotracheal tube. The technique proved noninvasive, easy to use, and reliable in 151 prospective consecutive patients for preventing permanent laryngeal nerve damage in thyroid surgery.