Jacques E. Chelly

A Department-of-Anesthesiology-based management protocol for perioperative corneal abrasions.

Introduction Corneal abrasions (CAs) are the most prevalent ocular injuries in the perioperative period. Previously, patients at our community hospital would wait for an ophthalmologist to be available to manage these minor injuries. To decrease this waiting period – and thereby increase patient satisfaction – we developed an anesthesiology-based protocol to manage minor CAs arising in the recovery room. The current study sought to assess this protocol’s efficacy as well as further establish the incidence and some risk factors of CA. Methods This was a hospital-based, observational study. As per protocol, anesthesiologists saw and diagnosed any patient exhibiting symptoms of CA, after which they initiated a preestablished treatment regimen. To examine the efficacy of this protocol between March 2007 and December 2011, the number of CAs anesthesiologists managed and time to treatment were recorded. Additionally, the frequency of CAs was established along with some of their risk factors. Results Throughout the study period, there were 91,064 surgical cases, with 118 CAs (0.13% incidence). Anesthesiology alone managed 110 (93.22%) of these cases. The median time between the end of anesthesia to the time of prescribed ophthalmic medication was 156 minutes (first–third interquartile range: 108–219). All patients experienced resolution of symptoms by the morning following their complaint. Compared to the general surgical population, CA patients were older (P<0.01) and underwent longer surgeries (P<0.01). Conclusion Minor CAs can be safely and effectively managed using an anesthesiology-based approach. Advanced age and longer surgery are confirmed as risk factors for these injuries.

Effects of Sevoflurane and Isoflurane on Cardiac and Coronary Dynamics in Chronically Instrumented Dogs

To assess the hemodynamic properties of the new inhalational anesthetic sevoflurane, 22 dogs were chronically instrumented for measurement of heart rate, aortic, left ventricular and left atrial pressures, cardiac output, and coronary blood flow. Dogs were randomly assigned to two groups, receiving either 1.2 and 2 MAC of sevoflurane (n = 11) or isoflurane (n = 11). At 1.2 and 2 MAC, sevoflurane produced an increase in heart rate (+60 +/- 12% and +54 +/- 9%, respectively), dose-dependent aortic hypotension (-22 +/- 4% and -38 +/- 4%, respectively), systemic vasodilation (-22 +/- 5% and -19 +/- 5%, respectively), dose-dependent decrease in stroke volume (-31 +/- 6% and -48 +/- 4%, respectively), and left ventricular dP/dt (-40 +/- 4% and -61 +/- 10%, respectively). Cardiac output decreased only at 2 MAC (-17 +/- 6%). Finally, coronary blood flow increased at 1.2 MAC of sevoflurane (+29 +/- 8%). Except for heart rate, sevoflurane and isoflurane produced similar effects. At 1.2 MAC, sevoflurane produced a greater increase in heart rate than isoflurane (+60 +/- 12% vs. +33 +/- 9%). The authors conclude that, except for heart rate, the effects of sevoflurane on cardiac function and coronary blood flow are almost identical to those induced by isoflurane in the chronically instrumented dog.

The safety and efficacy of a fentanyl patient-controlled transdermal system for acute postoperative analgesia: A multicenter, placebo-controlled trial

A noninvasive method of delivery of parenteral opioids for management of acute pain may offer logistic advantages for patients and nursing staff. A patient-controlled transdermal system (PCTS) under development consists of a preprogrammed, self-contained drug-delivery system that uses electrotransport technology (E-TRANS®, ALZA Corp, Mountain View, CA) to deliver 40 &mgr;g of fentanyl HCl over 10 min per on-demand dose for patient-controlled analgesia (PCA). In this randomized, double-blinded, placebo-controlled trial we compared the efficacy and safety of on-demand fentanyl HCl PCTS 40 &mgr;g against placebo for postoperative pain up to 24 h after major abdominal, orthopedic, or thoracic surgery in 205 patients. The primary efficacy measurement was the percentage of patients withdrawn from the study because of inadequate analgesia after completing at least 3 h of treatment. Secondary efficacy measures included mean pain intensity (using visual analog scales), patient global assessments, and investigator global assessments. Of 189 patients considered evaluable for efficacy, 25% of patients in the fentanyl HCl PCTS 40 &mgr;g group withdrew because of inadequate analgesia, compared with 40.4% of the placebo group (P < 0.05). Use of fentanyl HCl PCTS 40 &mgr;g was associated with lower VAS scores and higher mean patient and investigator global assessment scores compared with placebo. No patient experienced clinically relevant respiratory depression. This study showed that a fentanyl HCl PCTS 40 &mgr;g for PCA was superior to placebo and well tolerated for the control of moderate to severe postoperative pain for up to 24 h after major surgery.

Comparison of the effects of isoflurane and desflurane on cardiovascular dynamics and regional blood flow in the chronically instrumented dog

Seven mongrel dogs were chronically instrumented for the measurement of aortic and left ventricular blood pressures, cardiac output, left ventricular wall thickening, left ventricular dP/dt, and circumflex coronary, renal, hepatic and portal blood flows under the influence of desflurane (D) and isoflurane (I). Administration of the two anesthetics, was randomized, as was the order of the concentrations administered. Each dog was studied awake and at 1.2, 1.4, 1.75, and 2.0 MAC of each anesthetic on different days. Both anesthetics decreased mean arterial pressure, stroke volume, systemic vascular resistance, left ventricular dP/dt, and wall thickness. The decreases were dose-dependent for mean arterial pressure (percent of awake values: D 78, I 85 at 1.2 MAC, and D 67, I 69 at 2.0 MAC); stroke volume (D 66, I 72 at 1.2 MAC, and D 52, I 57 at 2.0 MAC); dP/dt (D 61, I 64 at 1.2 MAC, and D 46, I 49 at 2.0 MAC); and WT (D 68, I 70 at 1.2 MAC, and D 47, I 60 at 2.0 MAC). Systemic vascular resistance decreased approximately the same at 1.2 MAC (D 71, I 87%) as at 2.0 MAC (D 71, I 79%). Heart rate increased but also not in a dose-dependent fashion (percent of awake values: D 177, I 145 at 1.2 MAC, and D 176, I 155 at 2.0 MAC). Coronary blood flow was increased by both anesthetics at all concentrations (percent of awake values: I 136 at 1.2 MAC and 161 at 2.0 MAC of awake, and D 131 at 1.2 MAC and 138 at 2.0 MAC.(ABSTRACT TRUNCATED AT 250 WORDS)

A randomized, double-blind comparison of the NK1 antagonist, aprepitant, versus ondansetron for the prevention of postoperative nausea and vomiting

BACKGROUND: Antiemetics currently in use are not totally effective. Neurokinin-1 receptor antagonists are a new class of antiemetic that have shown promise for chemotherapy-induced nausea and vomiting. This is the first study evaluating the efficacy and tolerability of the neurokinin-1 receptor antagonist, aprepitant, for the prevention of postoperative nausea and vomiting. METHODS: In this multicenter, double-blind trial, we randomly assigned 805 patients receiving general anesthesia for open abdominal surgery to a preoperative dose of aprepitant 40 mg orally, aprepitant 125 mg orally, or ondansetron 4 mg IV. Vomiting, nausea, and use of rescue therapy were assessed over 48 h after surgery. Treatments were compared using logistic regression. RESULTS: Incidence rates for the primary end point (complete response [no vomiting and no use of rescue] over 0–24 h after surgery, tested for superiority of aprepitant) were not different across groups (45% with aprepitant 40 mg, 43% with aprepitant 125 mg, and 42% with ondansetron). The incidence of no vomiting (0–24 h) was higher with aprepitant 40 mg (90%) and aprepitant 125 mg (95%) versus ondansetron (74%) (P < 0.001 for both comparisons), although between-treatment use of rescue and nausea control was not different. Both aprepitant doses also had higher incidences of no vomiting over 0–48 h (P < 0.001). No statistically significant differences were seen among the side effect profiles of the treatments. CONCLUSIONS: Aprepitant was superior to ondansetron for prevention of vomiting in the first 24 and 48 h, but no significant differences were observed between aprepitant and ondansetron for nausea control, use of rescue, or complete response.

Economics of nerve block pain management after anterior cruciate ligament reconstruction: potential hospital cost savings via associated postanesthesia care unit bypass and same-day discharge.

BackgroundAnterior cruciate ligament reconstruction is a complex outpatient surgical procedure often associated with pain. Traditionally, the procedure is performed under general anesthesia and often requires the use of the PACU. Refractory pain and/or nausea/vomiting occasionally leads to an unplanned hospital admission. In this study, the authors examine the associations of nerve block analgesia for these patients and its associated reductions in PACU use, hospital admission, and hospital costs. MethodsThis was an observational, nonrandomized study in which existing data regarding patients’ day-of-surgery outcomes were merged with hospital cost data. We reviewed a consecutive sample of 948 men and women who were in good health and underwent anterior cruciate ligament reconstruction in an outpatient surgery unit between July 1995 and June 1999. ResultsThe use of nerve block analgesia was associated with reduced PACU admissions to 18% and decreased unplanned hospital admission rates from 17% to 4%. Multivariate linear regression analysis showed that patients bypassing the PACU had an associated hospital cost reduction of 12% (P = 0.0001), whereas patients who needed hospital admission had an associated hospital cost increase of 11% (P = 0.0003). ConclusionsThe use of nerve blocks for acute pain management in patients undergoing anterior cruciate ligament reconstruction is associated with PACU bypass and reliable same-day discharge. Although the cost savings for this one procedure are unlikely to generate sufficient cost savings via staffing reductions, extrapolating these results to a large volume of all types of invasive outpatient orthopedic procedures may have the potential to create significant hospital cost savings.

Effects of sevoflurane and isoflurane on hepatic circulation in the chronically instrumented dog

To compare the effects of sevoflurane and isoflurane on hepatic circulation, eighteen dogs were chronically instrumented for measurements of mean aortic blood pressure and cardiac output and for simultaneous measurements of hepatic and portal blood flows. Each animal was studied while awake and during 1.2 and 2 MAC of either isoflurane or sevoflurane. Both anesthetics induced tachycardia and a dose-dependent decrease in mean aortic blood pressure (isoflurane -27% and -39%; sevoflurane -22% and -37%). Cardiac output decreased only at the highest concentration (isoflurane -10%; sevoflurane -21%). During sevoflurane, portal blood flow decreased at both 1.2 and 2 MAC (-14 and -33%, respectively), whereas an increase in hepatic arterial blood flow was recorded at 2 MAC (+33%). During isoflurane, the only significant change was a decrease in portal blood flow (-16%) at 1.2 MAC. Neither anesthetic significantly changed renal blood flow. Therefore, both anesthetics led to similar systemic and hepatic vasodilation.

Continuous lumbar plexus block for postoperative pain control after total hip arthroplasty. A randomized controlled trial.

BACKGROUND Continuous femoral or lumbar plexus blocks have been demonstrated to provide effective postoperative analgesia of the lower extremity following total joint arthroplasty. The purpose of this study was to compare these two techniques when used with intravenous patient-controlled analgesia and the use of patient-controlled analgesia alone for postoperative pain management following unilateral primary hip arthroplasty. METHODS Two hundred and twenty-five patients undergoing unilateral total hip arthroplasty for a diagnosis of osteoarthritis were randomly allocated into one of three postoperative treatment groups: continuous lumbar plexus block with patient-controlled analgesia, continuous femoral block with patient-controlled analgesia, and patient-controlled analgesia alone. Scores on a visual analog pain scale administered during physiotherapy twenty-four hours postoperatively were used as the primary outcome measured. Secondary outcomes included scores on a visual analog pain scale at rest, hydromorphone consumption, opioid-related side effects, complications, sensory and motor blockade, and patient satisfaction. RESULTS Continuous lumbar plexus block significantly reduced pain scores during physiotherapy on postoperative day 1 (p < 0.0001) and day 2 (p < 0.0001) compared with either continuous femoral block or patient-controlled analgesia alone. There were no significant differences for pain at rest between the two regional analgesic techniques. Both regional anesthesia techniques significantly reduced total hydromorphone consumption (p < 0.05) and delirium (disorientation to time and/or place) compared with patient-controlled analgesia alone (p < 0.023). In addition, the use of continuous lumbar plexus block was associated with fewer patients with opioid-related side effects (p < 0.05), greater distances walked (p < 0.05), and enhanced patient satisfaction (p < 0.05) compared with the use of a continuous femoral nerve block with patient-controlled analgesia or with patient-controlled analgesia alone. CONCLUSIONS Continuous lumbar plexus and femoral blocks significantly reduce the need for opioids and decrease related side effects. Continuous lumbar plexus block is a more effective analgesic modality than is a continuous femoral block or patient-controlled intravenous administration of hydromorphone alone during physical therapy following primary unilateral total hip arthroplasty.

Femoral-sciatic nerve blocks for complex outpatient knee surgery are associated with less postoperative pain before same-day discharge: a review of 1,200 consecutive cases from the period 1996-1999.

Background Outpatient knee surgery has come to involve increasingly complex procedures. The authors present observational data from a nerve block algorithm designed for the care of outpatients undergoing knee surgery. The aim of this report is to demonstrate differences in pain and unplanned hospital admission associated with surgical complexity and nerve blocks used. Methods Day-of-surgery outcomes were studied for 1,200 consecutive outpatients undergoing routine arthroscopy or one of six complex outpatient knee procedures. Nerve blocks were administered on the basis of anticipated pain from open incisions in the femoral and sciatic nerve distributions. Regression analysis was used to determine factors associated with postoperative pain and unplanned hospital admissions, and patients were categorized as having received femoral and sciatic nerve blocks (FSB), femoral nerve block only (FNB), or no nerve blocks. Results Patients undergoing more complex (vs. less invasive) knee surgery were at greater risk for pain (P ≤ 0.004), whereas the use of FSB (vs. FNB or no block) was associated with less pain (P < 0.01). When no nerve blocks were used, more complex (vs. less invasive) knee surgery was associated with a 10-fold greater risk of hospital admission (P = 0.001). In the regression analyses, more complex surgery (P < 0.001) was associated with increased risk of admission, and the use of FNB or FSB (vs. no block) was associated with a 2.5-fold reduction in unplanned admissions (P = 0.009). Conclusions For complex knee surgery, the use of FSB was associated with less pain; the use of FNB or FSB (vs. no block) was associated with fewer hospital admissions.

Interscalene Brachial Plexus Anesthesia and Analgesia for Open Shoulder Surgery: A Randomized, Double-Blinded Comparison Between Levobupivacaine and Ropivacaine

UNLABELLED We compared the onset time and quality of interscalene brachial plexus block produced with levobupivacaine and ropivacaine in 50 patients undergoing open shoulder surgery randomly allocated to receive 30 mL of 0.5% levobupivacaine (n = 25) or 0.5% ropivacaine (n = 25) injected through a 20-gauge catheter placed into the interscalene sheath using a 18-gauge insulated and stimulating Tuohy introducer. The block was also prolonged after surgery using a patient-controlled interscalene analgesia with 0.125% levobupivacaine or 0.2% ropivacaine, respectively (basal infusion rate, 6 mL/h; bolus, 2 mL; lockout period, 15 min; maximum boluses per hour, three). Three patients (two with levobupivacaine [8%] and one with ropivacaine [4%]) failed to achieve surgical block within 45 min after the injection and were excluded. The onset time of surgical block was 20 min (10-40 min) with levobupivacaine and 20 min (5-45 min) with ropivacaine (P = 0.53). Rescue intraoperative analgesia (0.1 mg of fentanyl IV) was required in eight patients in each group (34%) (P = 0.99). Forty-two patients completed the 24-h postoperative infusion (22 with levobupivacaine and 20 with ropivacaine). Postoperative analgesia was similarly effective in both groups. Total consumption of local anesthetic infused during the first 24 h was 147 mL (144-196 mL) with levobupivacaine and 162 mL (144-248 mL) with ropivacaine (P = 0.019), with a ratio between boluses received and requested of 0.8 (0.4-1.0) and 0.7 (0.4-1.0), respectively (P = 0.004). The degree of motor block of the operated limb was deeper with levobupivacaine than ropivacaine when starting postoperative analgesia; however, no further differences in degree of motor function were observed between the two groups. We conclude that 30 mL of levobupivacaine 0.5% induces an interscalene brachial plexus anesthesia of similar onset and intensity as the one produced by the same volume and concentration of ropivacaine. Postoperative interscalene analgesia with 0.125% levobupivacaine results in similar pain relief and recovery of motor function with less volume of local anesthetic than with 0.2% ropivacaine. IMPLICATIONS This prospective, randomized, double-blinded study demonstrates that 30 mL of 0.5% levobupivacaine produces an interscalene brachial plexus block of similar onset and quality as the one produced by the same volume of 0.5% ropivacaine. When prolonging the block after surgery, 0.125% levobupivacaine provides adequate pain relief and recovery of motor function after open shoulder surgery, with less volume infused during the first 24 h after surgery than 0.2% ropivacaine.