Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2003
Randomized Controlled Trial Comparative Study Clinical TrialPropofol-nitrous oxide anesthesia enhances the heart rate response to intravenous isoproterenol infusion.
Heart rate (HR) response to IV atropine is attenuated during propofol-nitrous oxide (N(2)O) anesthesia. We studied the effects of propofol-N(2)O anesthesia on isoproterenol-induced HR changes. The control group (n = 15) received no propofol and no N(2)O. Patients in the propofol-N(2)O group (n = 21) received IV propofol 2.5 mg/kg over 1 min followed by a continuous infusion of propofol 10 mg x kg(-1) x h(-1). After tracheal intubation, anesthesia was maintained with propofol 5 mg. kg(-1) x h(-1) and 67% N(2)O in oxygen. All patients in both groups received IV isoproterenol at incremental infusion rates (2.5, 5, 7.5, 10, 12.5, 15, and 17.5 ng x kg(-1) x min(-1) for 2 min at each dose) until HR increased more than 20 bpm from baseline values. At the end of each infusion period, hemodynamic data were collected. The HR response to isoproterenol 7.5 ng. kg(-1) x min(-1) was increased more in the propofol group than in the control group (20 +/- 5 versus 14 +/- 4 bpm; P < 0.05). During the isoproterenol infusion at 10 ng. kg(-1) x min(-1), HR increased by more than 20 bpm in all patients in the propofol group but in only 31% of patients in the control group (P < 0.0001). These results suggest that continuous isoproterenol infusion might be useful when a large dose of atropine is ineffective in restoring normal HR during propofol-N(2)O anesthesia. ⋯ We demonstrated that the heart rate response to IV isoproterenol infusion is enhanced during propofol-nitrous oxide anesthesia. This suggests that continuous isoproterenol infusion may be useful when a large dose of atropine is ineffective for restoration of normal heart rate in patients receiving propofol-nitrous oxide anesthesia.
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Anesthesia and analgesia · Jan 2003
Randomized Controlled Trial Clinical TrialSupplemental oxygen does not reduce the incidence of postoperative nausea and vomiting after ambulatory gynecologic laparoscopy.
Supplemental 80% oxygen administration halves the incidence of postoperative nausea and vomiting (PONV) in inpatients. Whether it prevents PONV after ambulatory surgery is unknown. We tested the efficacy of supplemental 80% oxygen in decreasing the incidence of PONV after ambulatory gynecologic laparoscopy. One hundred patients were given a standardized sevoflurane anesthetic. They were randomly assigned to two groups: routine oxygen administration with 30% oxygen, balance nitrogen (Group A); and supplemental oxygen with 80% oxygen, balance nitrogen (Group B). Oxygen was administered during surgery and up to 1 h after surgery. The incidence of nausea and vomiting and the need for rescue antiemetics did not differ between the groups in the postanesthesia care unit, in the Phase II unit, or during the 24-h follow-up. The overall incidence of nausea and vomiting during the first postoperative 24 h was 62% in Group A and 55% in Group B (P = 0.486). There were no differences in the recovery profiles and patient satisfaction between the groups. In this study, supplemental oxygen did not prevent PONV in patients undergoing ambulatory gynecologic laparoscopy. ⋯ Supplemental 80% oxygen administration during surgery and until 1 h after surgery compared with 30% oxygen administration did not prevent postoperative nausea and vomiting after ambulatory gynecologic laparoscopy.
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Anesthesia and analgesia · Jan 2003
Clinical TrialAn intervention study to enhance postoperative pain management.
This study, conducted before and after the implementation of an acute pain service (APS) in a 1000-bed hospital, describes the process of the implementation of an APS. The nursing, anesthesia, and surgery departments were involved. In this study we sought to evaluate the results of a continuous quality improvement program by defining quality indicators and using quality tools. A quality program in accordance with current standards of acute pain treatment (multimodal) was worked out to enhance pain relief for all surgical inpatients. A survey of nurses' knowledge with regard to postoperative pain was conducted, and a visual analog scale (VAS) was introduced to assess pain intensity. Both nurses and physicians became familiar with evidence-based guidelines concerning postoperative pain. The entire process was monitored in three consecutive surveys and enrolled 2383 surgical inpatients. Pain indicators based on VAS and analgesic consumption were recorded during the first 72 postoperative hours. After a baseline survey about current practices of pain treatment, a nurse-based, anesthesiologist-supervised APS was implemented. The improvement in pain relief, expressed as VAS scores, was assessed in two further surveys. A quality manual was written and implemented. A major improvement in pain scores was observed after the APS inception (P < 0.001). ⋯ The implementation of an acute pain service, including pain assessment by a visual analog scale, standard multimodal pain treatment, and continuous quality evaluation, improved postoperative pain relief. Establishing teams of surgeons, anesthesiologists, and nurses is the prerequisite for this improvement.
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Anesthesia and analgesia · Jan 2003
Comparative Study Clinical Trial Controlled Clinical TrialLidocaine sprayed down the endotracheal tube attenuates the airway-circulatory reflexes by local anesthesia during emergence and extubation.
To determine whether lidocaine sprayed down the endotracheal tube (ETT) would attenuate airway-circulatory reflexes during emergence, we compared the reflex responses after endotracheal or IV lidocaine (IVL) in 75 patients receiving a standardized anesthetic protocol. At the end of surgery, the patients were divided into 3 groups (n = 25 for each group) and given no drug (Group 1), given 1 mg/kg of 2% lidocaine sprayed down the ETT 5 min before (Group 2), or given the same dose of IVL 3 min before extubation (Group 3). Blood pressure and heart rate were recorded at predetermined time points from 5 min (baseline) before until 5 min after extubation. The number of coughs per patient was continuously monitored during this period. The number (mean +/- SD) of coughs was decreased in Group 2 (4.5 +/- 3.7) compared with the control (10.2 +/- 6.0) (P < 0.01) with no difference for the control versus Group 3 (7.8 +/- 4.6). The increase in blood pressure was only attenuated immediately before extubation (P < 0.05), whereas the increase in heart rate was attenuated (P < 0.05) at all (except baseline) time points (P < 0.05) in Group 2 compared with the control with no difference for the control versus Group 3. The results indicate that lidocaine sprayed down the ETT suppresses the reflexes whereas using the same dose IVL does not, which is probably attributable to the mucosa-anesthetizing effect of lidocaine. ⋯ Lidocaine sprayed down the endotracheal tube suppresses the airway-circulatory reflex responses whereas using the same dose IV lidocaine does not. This effect seems to be from the direct local anesthesia rather than from systemic absorption from the airway.
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Anesthesia and analgesia · Jan 2003
Comparative StudyAgreements between the prothrombin times of blood treated In Vitro with heparinase during cardiopulmonary bypass (CPB) and blood sampled after CPB and systemic protamine.
The prothrombin time (PT) is useful for identifying coagulation factor deficits after cardiopulmonary bypass (CPB). However, long processing times and the need for fresh frozen plasma (FFP) to be thawed cause delays in factor replacement. We hypothesized that, by treating with heparinase, blood sampled toward the end of CPB can provide PT results that help to determine the requirement for FFP after CPB. Laboratory delays can be eliminated with point-of-care monitors. We studied 158 adults undergoing nonemergent cardiac surgery. Blood taken before separation from CPB was mixed with heparinase, and PT was measured in the laboratory with a HemoTec timer. Agreements between these results and laboratory measurements of blood taken after systemic protamine were compared by using Bland and Altman plots with the threshold of +/-1.0 s. We found that the laboratory PT measurements during CPB versus after CPB were compara-ble, but the limits of agreement exceeded these thresholds. Similarly, there was unsatisfactory agreement between the HemoTec and laboratory PT results measured before, during, and after CPB. For each PT measured during CPB, the corresponding confidence interval for the postprotamine PT was calculated. During CPB, a laboratory PT of < or =16 s or > or =18 s suggests a > or =83% or > or =93% probability of not requiring or potentially requiring, respectively, FFP after CPB. We conclude that the majority of PT measurements obtained from blood taken before weaning from CPB and treated in vitro with heparinase was associated with a high probability of whether or not FFP would be needed after CPB. ⋯ Coagulation dysfunction after cardiopulmonary bypass may contribute to bleeding. Obtaining coagulation tests and fresh frozen plasma requires time and delays treatment in patients who need fresh frozen plasma. We have devised a technique to provide early estimation of postbypass coagulation status.