Ana Lucia Pappas

The effect of preoperative dexamethasone on the immediate and delayed postoperative morbidity in children undergoing adenotonsillectomy.

In this prospective, randomized, double-blind, placebo-controlled study, we examined the effect of preoperative dexamethasone on postoperative nausea and vomiting (PONV) and 24-h recovery in children undergoing tonsillectomy. One hundred thirty children, 2-12 yr of age, ASA physical status I or II, completed the study. All children received oral midazolam 0.5-0.6 mg/kg preoperatively. Anesthesia was induced with halothane and nitrous oxide in 60% oxygen and maintained with nitrous oxide and isoflurane. Intubation was facilitated by mivacurium 0.2 mg/kg. Each child received fentanyl 1 [micro sign]g/kg IV before initiation of surgery, as well as dexamethasone 1 mg/kg (maximal dose 25 mg) (steroid group) or an equal volume of saline (control group). Intraoperative fluids were standardized to 25-30 mL/kg lactated Ringers solution. All tonsillectomies were performed under the supervision of one attending surgeon using an electrodissection technique. Postoperatively, fentanyl and acetaminophen with codeine elixir were administered as needed for pain. Rescue antiemetics were administered when a child experienced two episodes of retching and/or vomiting. Before home discharge, the incidence of PONV, need for rescue antiemetics, quality of oral intake, and analgesic requirements did not differ between groups. However, during the 24 h after discharge, more patients in the control group experienced PONV (62% vs 24% in the steroid group) and complained of poor oral intake. Additionally, more children in the control group (8% vs 0% in the steroid group) returned to the hospital for the management of PONV and/or poor oral intake. The preoperative administration of dexamethasone significantly decreased the incidence of PONV over the 24 h after home discharge in these children. Implications: In this double blind, placebo-controlled study, we examined the efficacy of a single large dose (1 mg/kg; maximal dose 25 mg) of preoperative dexamethasone on posttonsillectomy postoperative nausea and vomiting (PONV) in children 2-12 yr of age undergoing tonsillectomy. Compared with placebo, dexamethasone significantly decreased the incidence of PONV in the 24 h after discharge, improved oral intake, decreased the frequency of parental phone calls, and resulted in no hospital returns for the management of PONV and/or poor oral intake. (Anesth Analg 1998;87:57-61)

Propofol versus propofol-ketamine sedation for retrobulbar nerve block: comparison of sedation quality, intraocular pressure changes, and recovery profiles.

UNLABELLED We compared sedation quality, intraocular pressure (IOP) changes, and recovery profiles in patients who received propofol or propofol-ketamine sedation during placement of the retrobulbar nerve block (RBB). Seventy elderly patients undergoing cataract extraction according to a prospective, randomized, double-blinded protocol were preoperatively evaluated with a Mini-Mental State examination and baseline IOP. A hypnotic dose was provided with either propofol (Group P) or a propofol-ketamine (Group PK) combination. The IOP measurement was repeated, and the surgeon initiated the RBB. Supplemental study drug was given if needed. The level of sedation was considered acceptable if the patient exhibited minimal or no movement and grimacing with needle insertion. Patients were evaluated in terms of quality of sedation, cardiopulmonary stability, and recovery profile. Compared with patients in Group P, patients in Group PK had a significantly faster onset of acceptable sedation (Group P 235 +/- 137 s versus Group PK 164 +/- 67 s) and required significantly less supplemental sedation (Group P 1.1 +/- 1.9 mL versus Group PK 0.15 +/- 0.3 mL). Additionally, none of the Group PK patients required ventilatory assistance, but two patients in Group P required assisted mask ventilation. In conclusion, the addition of ketamine (13.2 +/- 3.3 mg) to propofol (44 +/- 11 mg) decreased the hypnotic requirement and improved the quality of sedation without prolonging recovery. IMPLICATIONS Anesthesiologists frequently perform retrobulbar blocks while simultaneously providing sedation. Using ketamine to supplement propofol sedation provided a faster onset and improved the quality of sedation during the retrobulbar block procedure.

Recovery after propofol with and without intraoperative fentanyl in patients undergoing ambulatory gynecologic laparoscopy.

This prospective, randomized double-blind study was conducted to examine the effect of intraoperative opioid (fentanyl) supplementation on postoperative analgesia, emesis, and recovery in ambulatory patients receiving propofol-nitrous oxide anesthesia. Eighty patients undergoing ambulatory gynecologic laparoscopy participated. Confounding variables that could influence the incidence of postoperative emesis were controlled. Patients received either fentanyl 100 micro g (Group I) or ketorolac 60 mg (Group II) intravenously (IV) at the time of anesthetic induction. No further analgesic supplements were given intraoperatively. Anesthesia was induced with propofol and maintained with propofol-nitrous oxide. Atracurium was used for muscle relaxation and reversed with neostigmine and glycopyrrolate. Postoperative pain during early recovery was treated with IV fentanyl 25-50 micro g (Group I) or IV ketorolac 15-30 mg (Group II). Subsequent breakthrough pain in both groups was treated with IV fentanyl 25 micro g increments as needed (rescue analgesia). Eighty-four percent of patients in Group I required analgesics during early recovery versus 56% of patients in Group II (P < 0.05). Maintenance dose of propofol was significantly lower in Group I (129 +/- 35 micro g [centered dot] kg-1 [centered dot] min-1) than in Group II (170 +/- 63 micro g [centered dot] kg-1 [centered dot] min-1). Immediate recovery (emergence) in the two groups was comparable, despite different propofol requirements. Although the incidence of emetic sequelae in the postanesthesia care unit was not significantly different between the two treatment groups, a significantly larger number of patients in Group I (fentanyl group) had emetic sequelae that required therapeutic intervention (Group I 29% versus Group II 10%). Patients in Group I also took a significantly longer time to ambulate and meet criteria for home discharge. These results indicate that, in patients undergoing ambulatory gynecologic laparoscopy, the practice of administering a small dose of fentanyl at the time of anesthetic induction reduces maintenance propofol requirement, but fails to provide effective postoperative analgesia. Fentanyl administration at anesthetic induction increased the need for rescue antiemetics. The relative severity of emetic sequelae could have contributed to delay in ambulation and discharge. (Anesth Analg 1996;83:975-81)

Severity of airway hyperreactivity associated with laryngeal Mask airway removal : Correlation with volatile anesthetic choice and Depth of anesthesia

STUDY OBJECTIVE To compare the influence of anesthetic depth and choice of volatile anesthetic drug on the incidence and severity of airway hyperreactivity associated with Laryngeal Mask Airway (LMA) removal. DESIGN Randomized observer-blinded study. SETTING Ambulatory Surgical Center at a University Medical Center. PATIENTS 123 ASA physical status I and II children undergoing infraumbilical procedures. INTERVENTIONS Patients were randomly assigned to one of four treatment groups: Group 1 = anesthetic induction with halothane, maintenance with isoflurane, nitrous oxide (N(2)O), and oxygen (O(2)), LMA removed when child awakened; Group 2 =anesthetic induction and maintenance as in Group 1, LMA removed while child anesthetized with age adjusted 2 minimum alveolar concentration (MAC) end-tidal concentration of isoflurane; Group 3 = anesthetic induction and maintenance with sevoflurane, N(2)O, and O(2), LMA removed when child awakened; Group 4 = anesthetic induction and maintenance as in Group 3, but LMA removed while child anesthetized with age-adjusted 2 MAC end-tidal concentration of sevoflurane. MEASUREMENTS AND MAIN RESULTS Severity of airway hyperreactivity was graded as mild, moderate, or severe. A significant difference was not found amongst the four groups with respect to mild and moderate airway hyperreactivity. Severe airway hyperreactivity leading to a critical event [partial or complete laryngospasm with oxygen saturation (SPO(2)) < 85%] was only encountered in Group 1 patients (incidence 13%). Adverse airway events (SPO(2) < 90%, vomiting and bronchospasm) were also significantly higher in Group 1 (p < 0.05). Isoflurane use was independently associated with significantly higher airway hyperreactivity when compared with sevoflurane (p < 0.05). CONCLUSIONS Depth of anesthesia during LMA removal does not appear to affect the incidence or severity of airway hyperreactivity when sevoflurane is the maintenance anesthetic. However, awake LMA removal during isoflurane anesthesia results in a higher incidence of adverse airway events and carries the risk of severe airway hyperreactivity.

Ondansetron and dolasetron provide equivalent postoperative vomiting control after ambulatory tonsillectomy in dexamethasone-pretreated children

In this prospective, randomized, double-blinded, placebo-controlled study, we compared the incidence of emesis and 48-h recovery profiles after a single dose of preoperative ondansetron versus dolasetron in dexamethasone-pretreated children undergoing ambulatory tonsillectomy. One-hundred-forty-nine children, 2–12 yr old, ASA physical status I and II, completed the study. All children received standardized perioperative care, including premedication, surgical and anesthetic techniques, IV fluids, analgesics, and rescue antiemetic medications. Patients were randomized to receive ondansetron 0.15 mg/kg, maximum 4 mg (Group 1); dolasetron 0.5 mg/kg, maximum 25 mg (Group 2); or saline placebo (Group 3) IV before the initiation of surgery. In addition, all patients received dexamethasone 1 mg/kg (maximum 25 mg). Rescue antiemetics were administered for two or more episodes of retching/vomiting. The incidence of retching/vomiting before home discharge did not differ between the ondansetron and dolasetron groups and was significantly less frequent compared with the placebo group (10%, Group 1; 8%, Group 2; 30%, Group 3). Similar results were obtained at 24–48 h after discharge (6%, Groups 1 and 2; 18%, Group 3). The need for rescue antiemetics administered after the second retching/vomiting episode was significantly less in Groups 1 (4%) and 2 (6%) compared with Group 3 (22%) before home discharge. The complete response rate, defined as no retching/vomiting and no antiemetic for 48 h, was significantly increased in Groups 1 (76%) and 2 (74%) compared with Group 3 (44%). The antiemetic efficacy of prophylactic ondansetron and dolasetron was comparable in dexamethasone-pretreated children undergoing ambulatory tonsillectomy.

Postoperative Analgesia in Children Undergoing Myringotomy and Placement Equalization Tubes in Ambulatory Surgery

We enrolled 120 children undergoing bilateral myringotomy and tube placement in this prospective, randomized, observer-blinded study. Patients were randomized into one of four groups: Group 1 (control) was plain acetaminophen 10 mg/kg orally, Group 2 was acetaminophen 10 mg/kg with 1 mg/kg of codeine orally, Group 3 was transnasal butorphanol 25 &mgr;g/kg given immediately after the induction of anesthesia, and Group 4 was ketorolac 1 mg/kg given IM immediately after the induction of anesthesia. All children received oral midazolam (0.6 mg/kg) before surgery. A nurse blinded to the analgesic technique used assessed the child’s behavior at the induction of anesthesia and in the postanesthesia care unit using a 4-point scale. Analgesic effectiveness was determined by assessing the child’s pain at 5-min intervals using a modified 10-point objective pain scale. In the postanesthesia care unit, rescue pain medication was administered for an objective pain scale ≥4 or a behavior score ≥3. Our data suggest that IM ketorolac is a promising analgesic to be used in this surgical population. Time to first rescue analgesic was longest in the ketorolac group, and there was no associated postoperative vomiting or nausea. IM ketorolac given during surgery was the best analgesic regimen for these procedures. IMPLICATIONS: We compared four different analgesics in the management of pain after placement of pressure equalization tubes during myringotomy in children and demonstrated that ketorolac or butorphanol provided superior analgesia when compared with acetaminophen with codeine or plain acetaminophen. Children who received ketorolac versus butorphanol had less vomiting in the 24 h after surgery.

The effect of propofol/remifentanil rapid-induction technique without muscle relaxants on intraocular pressure

STUDY OBJECTIVE To evaluate the effect of propofol (two mg/kg)/remifentanil (4 μg/kg) on intraocular pressure (IOP) when used for rapid-sequence induction. DESIGN Randomized, double-blinded trial. SETTING Ambulatory surgery center. PATIENTS 47 adult, ASA physical status I and II patients (ages 18-75 yrs), undergoing outpatient, elective, nonophthalmologic surgery. INTERVENTIONS After premedication with midazolam (two mg) and glycopyrrolate (0.2 mg), standard monitors and a bispectral index (BIS) monitor were applied. Patients underwent rapid-sequence induction with intravenous (IV) propofol two mg/kg and either remifentanil 4 μg/kg IV or succinylcholine 1.5 mg/kg IV. An experienced anesthesiologist, blinded to patient group assignment, performed intubation after 60 seconds. MEASUREMENTS IOP, heart rate (HR), blood pressure, BIS scores, intubating conditions, and response to intubation (coughing or moving) were recorded at baseline, immediately after completion of induction, one minute after intubation, and three minutes after intubation. Time to return of spontaneous ventilation was also measured. MAIN RESULTS Remifentanil produced a 39% decrease in IOP immediately after induction, which remained unchanged by laryngoscopy and intubation (P < 0.001). IOP remained below baseline even in patients who coughed or moved in response to intubation. Remifentanil caused a significant decrease in mean arterial pressure of 24% to 31% but no significant change in HR, and it blocked the hemodynamic response to laryngoscopy and intubation while providing intubating conditions comparable to those of succinylcholine. CONCLUSIONS Propofol/remifentanil induction provides adequate intubating conditions, prevents an increase in IOP, and controls the hemodynamic stress response to laryngoscopy and intubation.

The anesthetic and recovery profile of two doses (60 and 80 mg) of plain mepivacaine for ambulatory spinal anesthesia.

Reports of transient neurological symptoms with the use of subarachnoid lidocaine has generated interest in alternate local anesthetics of intermediate duration, such as mepivacaine. This prospective randomized, double-blinded, dose-response study examined the anesthetic and recovery profiles of 60- and 80-mg doses of preservative-free plain mepivacaine for ambulatory spinal anesthesia. Sixty patients undergoing ambulatory anterior cruciate ligament repair of the knee under spinal anesthesia were randomized into two groups; Group 1 (29 patients) received 4 mL of 1.5% (60-mg dose) and Group 2 (31 patients) received 4 mL of 2% (80-mg dose) of plain mepivacaine. All patients received a combined spinal-epidural anesthetic technique. The epidural catheter was used only in the event the surgery outlasted the duration of surgical anesthesia with subarachnoid mepivacaine. Epidural supplementation was administered in three patients (12%) in Group 1 and one patient (3%) in Group 2 when the sensory block regressed to L-1 with surgery expected to last longer than 15 min. The cephalad dermatome level of the block and degree of motor block was comparable in the two groups. Times to two-segment and T-10 regression were comparable in the two groups (112 ± 26 min in Group 1 versus 122 ± 28 min in Group 2). Time to L-1 regression was significantly longer in Group 2 (146 ± 28 min in Group 1 versus 159 ± 19 min in Group 2). All of the ambulatory milestones were significantly faster in Group 1. Side effects, such as hypotension and emesis were negligible, severe bradycardia and urinary retention did not occur, and none of the patients in the two groups reported transient neurological symptoms over 24 h. In conclusion, plain mepivacaine in a 60- or 80-mg dose is a suitable local anesthetic choice for ambulatory spinal anesthesia with respect to anesthetic, as well as recovery profiles. Implications We evaluated the anesthetic and recovery profiles of 60- and 80-mg doses of plain mepivacaine for ambulatory spinal anesthesia. Both doses produced comparable sensory and motor block. Sensory and motor regression and ambulatory milestones were 20–30 min longer with the 80-mg dose. Side effects were negligible and transient neurological symptoms were not reported during a 24-h follow-up.

Anesthetic and recovery profiles of lidocaine versus mepivacaine for spinal anesthesia in patients undergoing outpatient orthopedic arthroscopic procedures

STUDY OBJECTIVE To compare isobaric lidocaine and mepivacaine in outpatient arthroscopic surgery. DESIGN Prospective, randomized, double-blinded study. SETTING Ambulatory surgery center affiliated with an academic tertiary-care hospital. PATIENTS 84 adult, ASA physical status 1, 2, and 3 ambulatory patients, age 18-70 years, undergoing arthroscopic knee surgery. INTERVENTION Patients were randomized to receive a combination spinal-epidural anesthetic using 80 mg of either isobaric 2% mepivacaine or isobaric 2% lidocaine. Patients also received a femoral 3-in-1 block with 0.5% bupivacaine applied to the affected extremity. MEASUREMENTS Demographic data and level and duration of the block were recorded. The use of supplemental epidural anesthesia was noted along with frequency of bradycardia, hypotension, and episodes of nausea and vomiting. Duration of block and times to ambulation and voiding were recorded. Delayed variables, including fatigue, difficulty urinating, back pain, and transient neurologic symptoms (TNS) were obtained. MAIN RESULTS No demographic differences were noted between groups, and surgical duration was similar. Satisfactory anesthesia was achieved in all cases, with no differences noted in hypotension, bradycardia, nausea, or vomiting. Onset of sensory and motor block was similar. Duration of block before epidural supplementation was 94 ± 21 minutes with lidocaine versus 122 ± 23 minutes for mepivacaine (P < 0.011). Times to ambulation and voiding were longer in patients receiving mepivacaine but did not affect PACU stay. Twenty-four and 48-hour recovery was similar with no TNS symptoms reported. CONCLUSION No major differences were noted between lidocaine and mepivacaine spinal anesthesia. Time to ambulation and voiding were longer in patients who received mepivacaine as was time to first dose of epidural catheter. Neither group had TNS symptoms. Lidocaine and mepivacaine are both appropriate spinal anesthetics for ambulatory orthopedic lower extremity procedures.

Is succinylcholine after pretreatment with d-tubocurarine and lidocaine contraindicated for outpatient anesthesia?

Because succinylcholine has obvious advantages for facilitating endotracheal intubation in the ambulatory setting (e.g., low cost, fast onset, and no need for reversal of neuromuscular block), it is important to determine whether this muscle relaxant is indeed associated with an increased incidence of postoperative myalgias, compared with alternative but more expensive nondepolarizing muscle relaxants. We studied 119 outpatients undergoing endoscopic nasal sinus surgery or septoplasty. The anesthetic technique consisted of propofol/lidocaine for induction, followed by isoflurane/nitrous oxide/oxygen for maintenance. Oral tracheal intubation was performed by using a fiberscope. Patients were randomly assigned to one of two muscle relaxant groups. Group 1 patients received d-tubocurarine 3 mg followed by succinylcholine 1.5 mg/kg. Group 2 patients received mivacurium 0.2 mg/kg. After recovery from anesthesia, patients were asked whether they had any muscle pain and/or stiffness. Pain was categorized by location and quantified by using a verbal scale (from 0 to 10). Analgesic usage and myalgias limiting ambulation were recorded. After discharge from the ambulatory surgery unit, patients were contacted by telephone on Postoperative Day 1. If patients complained of myalgias, they were contacted by telephone on Days 2 and 3. Only one patient (in the mivacurium-treated group) reported myalgia as a limiting factor in ambulation or resumption of normal activity. There were no differences between groups with respect to the incidence (21% in the succinylcholine-treated group and 18% in the mivacurium-treated group), location, or severity of myalgia. In conclusion, succinylcholine (preceded by pretreatment with d-tubocurarine and lidocaine) is not associated with an increased incidence of myalgias, compared with mivacurium, when used to facilitate tracheal intubation in patients undergoing ambulatory nasal surgery. Implications The results of this study show that the frequency of muscle pains after surgery in outpatients is approximately 20%, regardless of whether succinylcholine (after precurarization) or mivacurium is used to assist in insertion of the breathing tube.