UNLABELLED Tramadol is a synthetic, centrally acting analgesic agent with 2 distinct, synergistic mechanisms of action, acting as both a weak opioid agonist and an inhibitor of monoamine neurotransmitter reuptake. The 2 enantiomers of racemic tramadol function in a complementary manner to enhance the analgesic efficacy and improve the tolerability profile of tramadol. In several comparative, well designed studies, oral and parenteral tramadol effectively relieved moderate to severe postoperative pain associated with surgery. Its overall analgesic efficacy was similar to that of morphine or alfentanil and superior to that of pentazocine. Tramadol provided effective analgesia in children and in adults for both inpatient and day surgery. Tramadol was generally well tolerated in clinical trials. The most common adverse events (incidence of 1.6 to 6.1%) were nausea, dizziness, drowsiness, sweating, vomiting and dry mouth. Importantly, unlike other opioids, tramadol has no clinically relevant effects on respiratory or cardiovascular parameters at recommended doses in adults or children. Tramadol also has a low potential for abuse or dependence. CONCLUSIONS The efficacy of tramadol for the management of moderate to severe postoperative pain has been demonstrated in both inpatients and day surgery patients. Most importantly, unlike other opioids, tramadol has no clinically relevant effects on respiratory or cardiovascular parameters. Tramadol may prove particularly useful in patients with poor cardiopulmonary function, including the elderly, the obese and smokers, in patients with impaired hepatic or renal function, and in patients in whom nonsteroidal anti-inflammatory drugs are not recommended or need to be used with caution. Parenteral or oral tramadol has proved to be an effective and well tolerated analgesic agent in the perioperative setting.

Tramadol: a review of its use in perioperative pain.

Background: Emergence delirium has been investigated in several clinical trials. However, no reliable and valid rating scale exists to measure this phenomenon in children. Therefore, the authors developed and evaluated the Pediatric Anesthesia Emergence Delirium (PAED) scale to measure emergence delirium in children. Methods: A list of scale items that were statements describing the emergence behavior of children was compiled, and the items were evaluated for content validity and statistical significance. Items that satisfied these evaluations comprised the PAED scale. Each item was scored from 1 to 4 (with reverse scoring where applicable), and the scores were summed to obtain a total scale score. The degree of emergence delirium varied directly with the total score. Fifty children were enrolled to determine the reliability and validity of the PAED scale. Scale validity was evaluated using five hypotheses: The PAED scale scores correlated negatively with age and time to awakening and positively with clinical judgment scores and Post Hospital Behavior Questionnaire scores, and were greater after sevoflurane than after halothane. The sensitivity of the scale was also determined. Results: Five of 27 items that satisfied the content validity and statistical analysis became the PAED scale: (1) The child makes eye contact with the caregiver, (2) the child’s actions are purposeful, (3) the child is aware of his/her surroundings, (4) the child is restless, and (5) the child is inconsolable. The internal consistency of the PAED scale was 0.89, and the reliability was 0.84 (95% confidence interval, 0.76 ‐ 0.90). Three hypotheses supported the validity of the scale: The scores correlated negatively with age (r 0.31, P < 0.04) and time to awakening (r 0.5, P < 0.001) and were greater after sevoflurane anesthesia than halothane (P < 0.008). The sensitivity was 0.64. Conclusions: These results support the reliability and validity of the PAED scale.

Development and psychometric evaluation of the pediatric anesthesia emergence delirium scale.

Observational (behavioral) scales of pain for children aged 3 to 18 years were systematically reviewed to identify those recommended as outcome measures in clinical trials. This review was commissioned by the Pediatric Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (www.immpact.org). In an extensive literature search, 20 observational pain scales were identified for review including behavior checklists, behavior rating scales, and global rating scales. These scales varied in their reliance on time sampling and inclusion of physiological items, facial and postural items, as well as their inclusion of multiple dimensions of assessment (e.g., pain and distress). Each measure was evaluated based on its reported psychometric properties and clinical utility. Scales were judged to be indicated for use in specific acute pain contexts rather than for general use. Two scales were recommended for assessing pain intensity associated with medical procedures and other brief painful events. Two scales were recommended for post-operative pain assessment, one for use in hospital and the other at home. Another scale was recommended for use in critical care. Finally, two scales were recommended for assessing pain-related distress or fear. No observational measures were recommended for assessing chronic or recurrent pain because the overt behavioral signs of chronic pain tend to habituate or dissipate as time passes, making them difficult to observe reliably. In conclusion, no single observational measure is broadly recommended for pain assessment across all contexts. Directions for further research and scale development are offered.

http://www.immpact.org/static/publications/von%20Baeyer%20and%20Spagrud,%202007.pdf

Systematic review of observational (behavioral) measures of pain for children and adolescents aged 3 to 18 years.

Pain, nausea and vomiting are frequently listed by patients as their most important perioperative concerns. With the change in emphasis from an inpatient to outpatient hospital and office-based medical/surgical environment, there has been increased interest in the ‘big little problem’ of postoperative nausea and vomiting (PONV). Currently, the overall incidence of PONV is estimated to be 25 to 30%, with severe, intractable PONV estimated to occur in approximately 0.18% of all patients undergoing surgery. PONV can lead to delayed postanaesthesia care unit (PACU) recovery room discharge and unanticipated hospital admission, thereby increasing medical costs. The aetiology and consequences of PONV are complex and multifactorial, with patient-, medical- and surgery-related factors. A thorough understanding of these factors, as well as the neuropharmacology of multiple emetic receptors [dopaminergic, muscarinic, cholinergic, opioid, histamine, serotonin (5-hydroxy-tryptamine; 5-HT)] and physiology [cranial nerves VIII (acoustic-vestibular), IX (glossopharyngeal) and X (vagus), gastrointestinal reflex] relating to PONV are necessary to most effectively manage PONV. Commonly used older, traditional antiemetics for PONV include the anticholinergics (scopolamine), phenothiazines (promethazine), antihistamines (diphenhydramine), butyrophenones (droperidol) and benzamides (metoclopramide). These antiemetics have adverse effects such as dry mouth, sedation, hypotension, extrapyramidal symptoms, dystonic effects and restlessness. The newest class of antiemetics used for the prevention and treatment of PONV are the serotonin receptor antagonists (ondansetron, granisetron, tropisetron, dolasetron). These antiemetics do not have the adverse effects of the older, traditional antiemetics. Headache and dizziness are the main adverse effects of the serotonin receptor antagonists in the dosages used for PONV. The serotonin receptor antagonists have improved antiemetic effectiveness but are not as completely efficacious for PONV as they are for chemotherapy-induced nausea and vomiting. Older, traditional antiemetics (such as droperidol) compare favourably with the serotonin receptor antagonists regarding efficacy for PONV prevention. Combination antiemetic therapy improves efficacy for PONV prevention and treatment. In the difficult-to-treat PONV patient (as in the chemotherapy patient), suppression of numerous emetogenic peripheral stimuli and central neuroemetic receptors may be necessary. This multimodal PONV management approach includes use of: (i) multiple different antiemetic medications (double or triple combination antiemetic therapy acting at different neuroreceptor sites); (ii) less emetogenic anaesthesia techniques; (iii) adequate intravenous hydration; and (iv) adequate pain control.

Prevention and Treatment of Postoperative Nausea and Vomiting

We conducted a case-control study to identify clinical and demographic risk factors for admission to the hospital following ambulatory surgery. Of 9616 adult patients who underwent ambulatory surgery at a university-affiliated hospital between 1984 and 1986, one hundred were admitted. The most common reasons for admission were pain (18), excessive bleeding (18), and intractable vomiting (17). The mean age (±SD) of patients who were admitted was 37±13 years, and 96% had American Society of Anesthesiologists' physical status scores of 1 or 2. Factors that were independently associated with an increased likelihood of admission were general anesthesia (odds ratio, 5.2), postoperative emesis (odds ratio, 3.0), lower abdominal and urologic surgery (odds ratio, 2.9), time in the operating room greater than 1 hour (odds ratio, 2.7), and age (odds ratio, 2.6). Our results indicate that the likelihood of unanticipated admission is related more to the type of anesthesia and surgical procedure rather than to the patient's clinical characteristics. ( JAMA . 1989;262:3008-3010)

Unanticipated admission to the hospital following ambulatory surgery.

Comparison of caudal and ilioinguinal/iliohypogastric nerve blocks for control of post-orchiopexy pain in pediatric ambulatory surgery.

The Antiemetic Effect of Droperidol Following Outpatient Strabismus Surgery in Children Michael Abramowitz;Tae Oh;Burton Epstein;Urs Ruttimann;David Friendly; Anesthesiology

The antiemetic effect of droperidol following outpatient strabismus surgery in children.

Low doses (0.05 mg/kg) of intravenously administered droperidol were given intraoperatively to randomly assigned pediatric strabismus patients in a controlled double-masked paradigm. No difference between control and treatment groups in the severity of vomiting was noted in the postanesthesia recovery room, but such a difference was probably present in the hospital rooms during the interval between room arrival and the meeting of hospital discharge criteria. Administration of the drug did not appear to produce somnolence sufficient to delay postoperative recovery.

Antiemetic effectiveness of intraoperatively administered droperidol in pediatric strabismus outpatient surgery--preliminary report of a controlled study.

Residents' Attitudes Toward Parents' Presence during Anesthesia Induction in ChildrenDoes Experience Make a Difference?

The differential solubilities of gases permit nitrous oxide (N2O) diffusion into air-filled body cavities, increasing their size and/or pressure An air-filled balloon-tipped catheter represents a body cavity that may be affected by the diffusion of N2O, and could account for the authors' clinical observation that more gas was aspirated than injected during insertion of Swan-Ganz (S-G) catheters in patients receiving N2O anesthesia An accompanying increase in balloon diameter could conceivably account for difficulties in floating the tip into the pulmonary outflow tract To help substantiate these observations, balloon volumes of three S-G catheters were measured at 05, 1, 2, 3, 4, 5, 10, 20, and 30 min in various N2O and oxygen mixtures, and the diameters of the balloon were compared with published diameters of pulmonary outflow tracts The volume changes were near maximum between 5-10 min, increasing to 30 to 150 per cent depending on the N2O concentration The increases in balloon diameter, when compared to pediatric pulmonary outflow tract diameters, could account for difficulties in passage of the catheter tip through the pulmonary outflow tract These findings suggest that manipulation of S-G catheters under N2O anesthesia sould be done with intermittent deflation of the balloon every few minutes

Michael D. Abramowitz

Papers

Comparison of caudal and ilioinguinal/iliohypogastric nerve blocks for control of post-orchiopexy pain in pediatric ambulatory surgery.

The antiemetic effect of droperidol following outpatient strabismus surgery in children.

Antiemetic effectiveness of intraoperatively administered droperidol in pediatric strabismus outpatient surgery--preliminary report of a controlled study.

Residents' Attitudes Toward Parents' Presence during Anesthesia Induction in ChildrenDoes Experience Make a Difference?

Nitrous Oxide and Air-filled Balloon-tipped Catheters