Girish P. Joshi

Titration of volatile anesthetics using bispectral index facilitates recovery after ambulatory anesthesia.

Background: The bispectral (BIS) index has previously been shown to be a quantifiable measure of the sedative and hypnotic effects of anesthetic drugs. This study was designed to assess the effect of BIS monitoring on the utilization of volatile anesthetics and their recovery profiles after ambulatory surgery. Methods: Sixty consenting women undergoing outpatient laparoscopic tubal ligation procedures were randomly assigned to one of four treatment groups. After a standardized induction, anesthesia was maintained with either desflurane (Groups I and II) or sevoflurane (Groups III and IV) in combination with nitrous oxide, 65%, and fentanyl. In the control groups (Groups I and III), the anesthesiologists were blinded to the BIS value, and the volatile anesthetics were administered according to standard clinical practice. In Groups II and IV, the volatile anesthetics were titrated to maintain the BIS value at 60. The volatile anesthetic usage and the times from discontinuation of anesthesia to verbal response, orientation, and home‐readiness were recorded. Results: During the maintenance period, the BIS values were significantly lower in the control groups (mean, 42) compared with the BIS‐titrated groups (mean, 60). The volatile anesthetic usage in the BIS‐titrated groups was 30–38% lower (P < 0.05) compared with the control groups. Similarly, the times to verbal responsiveness were 30–55% shorter in the BIS‐titrated (vs. control) groups. Conclusions: Titrating desflurane and sevoflurane using the BIS monitor decreased their utilization and contributed to a faster emergence from anesthesia in outpatients undergoing laparoscopic tubal ligation procedures.

A Systematic Review of Randomized Trials Evaluating Regional Techniques for Postthoracotomy Analgesia

BACKGROUND:Thoracotomy induces severe postoperative pain and impairment of pulmonary function, and therefore regional analgesia has been intensively studied in this procedure. Thoracic epidural analgesia is commonly considered the “gold standard” in this setting; however, evaluation of the evidence is needed to assess the comparative benefits of alternative techniques, guide clinical practice and identify areas requiring further research. METHODS:In this systematic review of randomized trials we evaluated thoracic epidural, paravertebral, intrathecal, intercostal, and interpleural analgesic techniques, compared to each other and to systemic opioid analgesia, in adult thoracotomy. Postoperative pain, analgesic use, and complications were analyzed. RESULTS:Continuous paravertebral block was as effective as thoracic epidural analgesia with local anesthetic (LA) but was associated with a reduced incidence of hypotension. Paravertebral block reduced the incidence of pulmonary complications compared with systemic analgesia, whereas thoracic epidural analgesia did not. Thoracic epidural analgesia was superior to intrathecal and intercostal techniques, although these were superior to systemic analgesia; interpleural analgesia was inadequate. CONCLUSIONS:Either thoracic epidural analgesia with LA plus opioid or continuous paravertebral block with LA can be recommended. Where these techniques are not possible, or are contraindicated, intrathecal opioid or intercostal nerve block are recommended despite insufficient duration of analgesia, which requires the use of supplementary systemic analgesia. Quantitative meta-analyses were limited by heterogeneity in study design, and subject numbers were small. Further well designed studies are required to investigate the optimum components of the epidural solution and to rigorously evaluate the risks/benefits of continuous infusion paravertebral and intercostal techniques compared with thoracic epidural analgesia.

A procedure-specific systematic review and consensus recommendations for postoperative analgesia following total knee arthroplasty

The PROSPECT Working Group, a collaboration of anaesthetists and surgeons, conducts systematic reviews of postoperative pain management for different surgical procedures (http://www.postoppain.org). Evidence‐based consensus recommendations for the effective management of postoperative pain are then developed from these systematic reviews, incorporating clinical practice observations, and transferable evidence from other relevant procedures. We present the results of a systematic review of pain and other outcomes following analgesic, anaesthetic and surgical interventions for total knee arthroplasty (TKA). The evidence from this review supports the use of general anaesthesia combined with a femoral nerve block for surgery and postoperative analgesia, or alternatively spinal anaesthesia with local anaesthetic plus spinal morphine. The primary technique, together with cooling and compression techniques, should be supplemented with paracetamol and conventional non‐steroidal anti‐inflammatory drugs or COX‐2‐selective inhibitors, plus intravenous strong opioids (high‐intensity pain) or weak opioids (moderate‐ to low‐intensity pain).

Intraoperative Fluid Restriction Improves Outcome After Major Elective Gastrointestinal Surgery

Fluid therapy is one of the most controversial topics in perioperative management. There is continuing debate with regard to the quantity and the type of fluid resuscitation during elective major surgery. However, there are increasing reports of perioperative excessive intravascular volume leading to increased postoperative morbidity and mortality. Recent evidence suggests that judicious perioperative fluid therapy improves outcome after major elective gastrointestinal surgery. The observed benefits may not be solely attributable to crystalloid restriction but also to the use of colloids instead. Some clinically useful guidelines based on the studies discussed in this review include avoidance of deep general anesthesia and elimination of preload for patients who receive epidural analgesia. A balanced approach to fluid management is recommended, with colloids administered to provide hemodynamic stability and maintain urine output of 0.5 mL · kg−1 · h−1 and crystalloids administered only for maintenance. In addition, blood loss may be replaced with colloid on a volume-to-volume basis. Furthermore, predetermined algorithms that suggest replacement of third space losses and losses through diuresis are unnecessary. Significant reduction in crystalloid volume can be achieved without encountering intraoperative hemodynamic instability or reduced (i.e., < 0.5 mL · kg−1 · h−1) urinary output just by avoiding replacement of third space losses and preloading. Finally, there is a need for well-controlled studies in a well-defined patient population using clear criteria or end-points for perioperative fluid therapy.

Society for Ambulatory Anesthesia consensus statement on preoperative selection of adult patients with obstructive sleep apnea scheduled for ambulatory surgery.

The suitability of ambulatory surgery for a patient with obstructive sleep apnea (OSA) remains controversial because of concerns of increased perioperative complications including postdischarge death. Therefore, a Society for Ambulatory Anesthesia task force on practice guidelines developed a consensus statement for the selection of patients with OSA scheduled for ambulatory surgery. A systematic review of the literature was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Although the studies evaluating perioperative outcome in OSA patients undergoing ambulatory surgery are sparse and of limited quality, they do provide useful information that can guide clinical practice. Patients with a known diagnosis of OSA and optimized comorbid medical conditions can be considered for ambulatory surgery, if they are able to use a continuous positive airway pressure device in the postoperative period. Patients with a presumed diagnosis of OSA, based on screening tools such as the STOP–Bang questionnaire, and with optimized comorbid conditions, can be considered for ambulatory surgery, if postoperative pain can be managed predominantly with nonopioid analgesic techniques. On the other hand, OSA patients with nonoptimized comorbid medical conditions may not be good candidates for ambulatory surgery. What other guidelines are available on this topic? The American Society of Anesthesiologists (ASA) practice guidelines for management of surgical patients with OSA published in 2006. Why was this guideline developed? The ASA guidelines are outdated because several recent studies provide new information such as validated screening tools for clinical diagnosis of OSA and safety of ambulatory laparoscopic bariatric surgery in OSA patients. Therefore, an update on the selection of patients with OSA undergoing ambulatory surgery is warranted. How does this guideline differ from existing guidelines? Unlike the ASA guidelines, this consensus statement recommends the use of the STOP–Bang criteria for preoperative OSA screening and considers patients’ comorbid conditions in the patient selection process. Also, current literature does not support the ASA recommendations that upper abdominal procedures are not appropriate for ambulatory surgery. Why does this guideline differ from existing guidelines? This consensus statement differs from existing ASA guidelines because of the availability of new evidence.

Perioperative Management of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is the most common breathing disorder, with a high prevalence in both the general and surgical populations. OSA is frequently undiagnosed, and the initial recognition often occurs during medical evaluation undertaken to prepare for surgery. Adverse respiratory and cardiovascular outcomes are associated with OSA in the perioperative period; therefore, it is imperative to identify and treat patients at high risk for the disease. In this review, we discuss the epidemiology of OSA in the surgical population and examine the available data on perioperative outcomes. We also review the identification of high-risk patients using clinical screening tools and suggest intraoperative and postoperative treatment regimens. Additionally, the role of continuous positive airway pressure in perioperative management of OSA and a brief discussion of ambulatory surgery in patients with OSA is provided. Finally, an algorithm to guide perioperative management is suggested.

Society for Ambulatory Anesthesia consensus statement on perioperative blood glucose management in diabetic patients undergoing ambulatory surgery.

Optimal evidence-based perioperative blood glucose control in patients undergoing ambulatory surgical procedures remains controversial. Therefore, the Society for Ambulatory Anesthesia has developed a consensus statement on perioperative glycemic management in patients undergoing ambulatory surgery. A systematic review of the literature was conducted according the protocol recommended by the Cochrane Collaboration. The consensus panel used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system for providing suggestions. It was revealed that there is insufficient evidence to provide strong recommendations for the posed clinical questions. In the absence of high-quality evidence, recommendations were based on general principles of blood glucose control in diabetics, drug pharmacology, and data from inpatient surgical population, as well as clinical experience and judgment. In addition, areas of further research were also identified.

Trends and Outcomes of Malignant Hyperthermia in the United States, 2000 to 2005

Background:Malignant hyperthermia (MH) is a potentially fatal pharmacogenetic disorder with an estimated mortality of less than 5%. The purpose of this study was to evaluate the current incidence of MH and the predictors associated with in-hospital mortality in the United States. Methods:The Nationwide Inpatient Sample, which is the largest all-payer inpatient database in the United States, was used to identify patients discharged with a diagnosis of MH during the years 2000–2005. The weighted exact Cochrane-Armitage test and multivariate logistic regression analyses were used to assess trends in the incidence and risk-adjusted mortality from MH, taking into account the complex survey design. Results:From 2000 to 2005, the number of cases of MH increased from 372 to 521 per year. The occurrence of MH increased from 10.2 to 13.3 patients per million hospital discharges (P = 0.001). Mortality rates from MH ranged from 6.5% in 2005 to 16.9% in 2001 (P < 0.0001). The median age of patients with MH was 39 (interquartile range, 23–54 yr). Only 17.8% of the patients were children, who had lower mortality than adults (0.7% vs. 14.1%, P < 0.0001). Logistic regression analyses revealed that risk-adjusted in-hospital mortality was associated with increasing age, female sex, comorbidity burden, source of admission to hospital, and geographic region of the United States. Conclusions:The incidence of MH in the United States has increased in recent years. The in-hospital mortality from MH remains elevated and higher than previously reported. The results of this study should enable the identification of areas requiring increased focus in MH-related education.

Effective treatment of laparoscopic cholecystectomy pain with intravenous followed by oral COX-2 specific inhibitor

In this multicenter, double-blinded, randomized, placebo-controlled study we evaluated the analgesic and opioid-sparing efficacy of a preoperative dose of IV parecoxib followed by oral valdecoxib in treating pain associated with elective laparoscopic cholecystectomy. Patients were randomized to receive a single IV dose of parecoxib 40 mg (n = 134) or placebo (n = 129) 30–45 min before induction of anesthesia. Six to 12 h after the IV dose, the parecoxib group received a single oral dose of valdecoxib 40 mg, followed by valdecoxib 40 mg qd on postoperative days 1–4, then 40 mg qd prn days 5–7. The placebo IV group received oral placebo on an identical schedule. All patients were allowed supplemental IV fentanyl as needed during the first 4 h postoperatively (T0–240 min) followed by hydrocodone 5 mg/acetaminophen 500 mg (Vicodin®; 1–2 tablets orally every 4–6 h as needed). Patients taking parecoxib used 21% less fentanyl than those receiving placebo (P = 0.011). The mean area under the curve of pain intensity (PI) scores over time from T0–240 min was 55.2 for parecoxib and 61.2 for placebo (P = 0.083). At T180 and T240 min, mean PI score was 7.0 and 7.6 points lower in the parecoxib group, respectively (P < 0.02). Fewer patients on valdecoxib required supplemental analgesics (P < 0.05) after discharge. At T240 min and at day 7, Patient’s and Physician’s/Nurse’s Global Evaluations were significantly better in the parecoxib/valdecoxib group (P < 0.05). Incidences of adverse events, adverse events causing withdrawal, and serious adverse events were less for parecoxib/valdecoxib than for placebo. The authors conclude that preoperative parecoxib is a valuable opioid-sparing adjunct to the standard of care for treating pain after laparoscopic cholecystectomy, and subsequent treatment with oral valdecoxib extends this clinical benefit.

Effects of Prophylactic Nalmefene on the Incidence of Morphine-related Side Effects in Patients Receiving Intravenous Patient-controlled Analgesia

BACKGROUND Opioid-related side effects associated with intravenous patient-controlled analgesia can be reduced by a low-dose naloxone infusion. The influence of nalmefene, a pure opioid antagonist with a longer duration of action, on opioid-related side effects has not been evaluated. This study was designed to determine the dose-response relation for nalmefene for the prevention of morphine-related side effects in patients receiving intravenous patient-controlled analgesia. METHODS One hundred twenty women undergoing lower abdominal surgery were enrolled in the study. General anesthesia was induced using thiopental and rocuronium and maintained with desflurane, nitrous oxide, and fentanyl or sufentanil. All patients received neostigmine and glycopyrrolate to reverse residual neuromuscular blockade. No prophylactic antiemetics were administered. At the end of surgery, patients were randomized to receive saline, 15 microg nalmefene, or 25 microg nalmefene intravenously. The need for antiemetic and antipruritic drugs and the total consumption of morphine during the 24-h study were recorded. The incidences of postoperative nausea, vomiting, pruritus, and pain were recorded 30 min after patients were admitted to the postanesthesia care unit. In addition, patient remembrance of these side effects was noted at 24 h after operation. RESULTS The need for antiemetic and antipruritic medications during the 24-h study period was significantly lower in the patients receiving nahmefene compared with those receiving placebo. However, the need to treat side effects was similar in the two nahmefene groups. Prophylactic administration of nalmefene reduced the patients remembrance of nausea and itching as assessed 24 h after operation. Although the total consumption of morphine during the 24-h study period was similar in the three groups, retrospectively patients who received nalmefene characterized their pain as less severe in the previous 24 h. CONCLUSION Compared with placebo, prophylactic administration of nalmefene significantly decreased the need for antiemetics and antipruritic medications in patients receiving intravenous patient-controlled analgesia with morphine.