Pain management following the Nuss procedure: a survey of practice and review.

BACKGROUND: Pectus excavatum is the most common congenital chest wall deformity. The Nuss procedure is frequently used for surgical correction and this technique has been associated with severe and prolonged post-operative pain. At the present time, the optimal analgesic strategy for managing patients following this procedure has not been determined. METHODS: A web-based survey was sent to representatives from 108 primarily pediatric hospitals in North America, Europe, Asia and Australia. One individual per institution was contacted to complete the survey on behalf of their department. RESULTS: Survey response rate was 54% and 55 institutions reported using the Nuss procedure for correction of pectus excavatum. Annual case volume is less than or equal to 25 cases in 57% of institutions, and the most common age of patients is 14 to 17 years old. A clinical protocol for patient post-operative pain management is used in 45% of institutions. Thoracic epidural is utilized as a primary analgesic modality by 91% of institutions. Concomitant use of intravenous patient-controlled analgesia is reported by 27% of institutions. Nine respondents (16%) reported that they had recently stopped performing epidurals because of surgeon preference. Referral of one or more patients annually for chronic pain management was reported in 22% of surveys. CONCLUSIONS: Post-operative pain management following the Nuss procedure is variable and poorly characterized. Clinical trials or large observational registries comparing the safety and efficacy of primary modalities and long-term outcomes are needed to enable evidence-based decision-making for the management of these patients.

Population pharmacokinetics of epsilon-aminocaproic acid in infants undergoing craniofacial reconstruction surgery.

BACKGROUND: Understanding the clinical pharmacology of the antifibrinolytic epsilon-aminocaproic acid (EACA) is necessary for rational drug administration in children. The aim of this study is to determine the pharmacokinetics (PKs) of EACA in infants aged 6-24 months undergoing craniofacial reconstruction surgery. METHODS: Cohorts of six infants were enrolled sequentially to one of the three escalating loading dose-continuous i.v. infusion (CIVI) regimens: 25 mg kg(-1), 10 mg kg(-1) h(-1); 50 mg kg(-1), 20 mg kg(-1) h(-1); 100 mg kg(-1), 40 mg kg(-1) h(-1). Plasma EACA concentrations were determined using a validated high-performance liquid chromatography-tandem mass spectrometry assay. A population non-linear mixed effects modelling approach was used to characterize EACA PKs. RESULTS: Population PK parameters of EACA were estimated using a two-compartment disposition model with weight expressed as an allometric covariate and an age effect. The typical patient in this study had an age of 38.71 weeks and a weight of 8.82 kg. PK parameters for this typical patient were: pre-/postoperative plasma drug clearance of 32 ml min(-1) (3.6 ml kg(-1) min(-1)), inter-compartmental clearance of 42.4 ml min(-1) (4.8 ml min(-1) kg(-1)), central volume of distribution of 1.27 litre (0.14 litre kg(-1)), and peripheral volume of distribution of 2.53 litre (0.29 litre kg(-1)). Intra-operative clearance and central volume of distribution were 89% and 80% of the pre-/postoperative value, respectively. CONCLUSIONS: EACA clearance increased with weight and age. The dependence of clearance on body weight supports weight-based dosing. Based on this study, a loading dose of 100 mg kg(-1) followed by a CIVI of 40 mg kg(-1) h(-1) is appropriate to maintain target plasma EACA concentrations in children aged 6-24 months undergoing these procedures.

Prospective randomized observer-blinded study comparing the analgesic efficacy of ultrasound-guided rectus sheath block and local anaesthetic infiltration for umbilical hernia repair.

BACKGROUND: Umbilical hernia repair, a common day-surgery procedure in children, is associated with considerable postoperative discomfort. Possible modes of postoperative analgesia for umbilical hernia repair are rectus sheath block (RSB) and local anaesthetic infiltration of the surgical site (LAI). METHODS: We undertook an observer-blinded, randomized, prospective, observational study to compare the efficacy of ultrasound-guided RSB and LAI in providing postoperative analgesia for umbilical hernia repair. Our primary objective was to compare the use of opioid medication between patients who receive RSB and those who receive LAI. Our secondary objectives were to compare the duration of analgesia based on time to first rescue analgesic, to compare the quality of analgesia based on revised FACES scale, and to determine the incidence of side-effects. RESULTS: Fifty-two patients (26 in each group) completed the study. There was a statistically significant difference in the perioperative opioid medication consumption between the LAI group [mean: 0.13 mg kg(-1), confidence interval (0.09-0.17 mg kg⁻¹)] and the RSB group [mean: 0.07 mg kg⁻¹, confidence interval (0.05-0.09 mg kg⁻¹)] (P=0.008). When we compared the postoperative opioid consumption between the LAI group [mean: 0.1 mg kg⁻¹, 95% confidence interval (0.07-0.13 mg kg⁻¹)] and the RSB group [mean: 0.07 mg kg(-1), 95% confidence interval (0.05-0.09 mg kg⁻¹)] (P=0.09), there was a trend towards statistical significance between the two groups. The difference in time to rescue analgesic administration between the RSB group [49.7 (36.9) min] and the LAI group [32.4 (29.4) min] was not statistically significant (P=0.11). CONCLUSIONS: This study demonstrates that ultrasound-guided RSB provides superior analgesia in the perioperative period compared with infiltration of the surgical site after umbilical hernia repair. In comparing only the postoperative period, analgesia provided by an ultrasound-guided RSB showed a trend towards statistically significant improvement compared with infiltration of the surgical site.

Ensuring safety of patients receiving sedation for procedures: evaluation of clinical practice guidelines.

BACKGROUND: In 1995 The Johns Hopkins Hospital in Baltimore convened an interdisciplinary task force to evaluate sedation practices, create a comprehensive set of sedation guidelines, and evaluate patient safety outcomes following guideline implementation. METHODOLOGY: Baseline data were collected on all procedures in which sedation was administered by a nonanesthesiologist for a 6-month period, using scanning technology to automate data entry. Sedation practices were reviewed, and four critical events were examined: unresponsiveness, obstructed airway, airway placement, and cardiopulmonary resuscitation (CPR). In 1998 data collection procedures were repeated to evaluate the impact of the guidelines on sedation practices and patient safety outcomes. RESULTS: In 1995 sedation practices varied, and one or more critical events occurred in 45 (1.4%) of 3,255 procedures. Steps taken included development and dissemination of a clinical sedation guideline, including monitoring criteria to guide nonanesthesiologists, and evaluation planning. In 1998 sedation practices were more consistent. One or more critical events occurred in 50 (1.6%) of 3,134 procedures, representing a small increase in critical events from 1995. More events of unresponsiveness were identified, and no event required CPR. Although not statistically significant, this trend suggests that critical events were being identified earlier, preventing patients from progressing to a more serious event requiring CPR. Steps taken included further refinement of clinical practice guidelines and establishment of ongoing monitoring. CONCLUSIONS: Standardization of sedation practices is a complex and resource-intensive activity, requiring ongoing oversight and monitoring. Commitment from medical staff, nursing staff, and administration is essential to successful implementation of sedation guidelines.

Perioperative management issues in pediatric patients.

Recent developments in perioperative practice, emphasizing issues that are of greatest concern in pediatric patients, are reviewed in this article. Many areas bear further evaluation in the evolving field of perioperative medicine: Effective techniques of psychologic preparation for children and their parents in an era in which the family rarely encounters the hospital environment before the day of surgery Application of newer intraoperative anesthetics, such as new narcotics and muscle relaxants, to shorten PACU and pediatric ICU stay while maintaining safety and comfort Critical evaluation of current methods of pain management to optimize comfort, while minimizing cost of such management in an increasingly cost-conscious health care environment The recent advent of a process for credentialing pediatric anesthesia fellowship programs, which requires a research component, bodes well for the prospect of finding answers to some of these questions.

The management of pain in sickle cell disease.

The pain of vaso-occlusive crisis in patients with sickle cell disease is excruciating, incapacitating, and sometimes refractory to even the most advanced analgesic treatments. A comprehensive, multimodal approach to therapy that includes education, cognitive therapies, anti-inflammatory drugs, opioids, and psychostimulant adjuvant drugs has been presented. Until a cure for the underlying disease is found, these are the best approaches available. The authors hope that future research will find even better modalities of analgesic care.

Polysomnography after adenotonsillectomy in mild pediatric obstructive sleep apnea.

OBJECTIVES: a) To determine the need for intensive monitoring on the first operative night of surgery in children undergoing adenotonsillectomy for mild obstructive sleep apnea; b) to examine the effect of narcotics on postoperative obstructive sleep apnea. DESIGN: Randomized, prospective study. SETTING: University hospital. PATIENTS: Children, ranging in age between 1 and 18 yrs, presented to the Pediatric Otolaryngology Clinic for adenotonsillectomy for mild obstructive sleep apnea defined as from one to 15 obstructive apnea events per hour on preoperative polysomnogram. INTERVENTIONS: Patients were assigned to receive either a narcotic- or a halothane-based anesthetic for adenotonsillectomy. A postoperative polysomnogram was performed in the pediatric intensive care unit on the first operative night. MEASUREMENTS AND MAIN RESULTS: Eighteen patients were recruited, 15 of whom met inclusion criteria: nine patients received a halothane-based anesthetic and six patients received a fentanyl-based anesthetic. When the data were analyzed by pooling both groups, the differences between pre- and postoperative sleep studies demonstrated a reduction in the number of obstructive events and less severe oxygen desaturations on the operative night. Total sleep time between the two sleep studies decreased from 371 +/- 13 to 304 +/- 14 mins. The number of obstructive apnea events/hr decreased as well. The lowest oxygen saturation measured during rapid eye movement sleep was 78 +/- 5% preoperatively and 92 +/- 1% postoperatively. CONCLUSIONS: Our data suggest that children without underlying medical conditions, neuromotor diseases, or carniofacial abnormalities, 1 to 18 yrs of age, who suffer from mild obstructive sleep apnea, have improvements documented by polysomnography on the night of surgery following adenotonsillectomy and do not necessarily need to be monitored intensively. These findings were not significantly affected by the choice of intraoperative anesthetic.

Preanesthetic medication of children with midazolam using the Biojector jet injector.

BACKGROUND: A rapid, dependable, and economical technique to atraumatically sedate children before anesthesia that does not prolong postanesthesia care unit time remains elusive. The Biojector jet injection system uses carbon dioxide rather than a needle to deliver an intramuscular injection. The dose-response relationship when midazolam is administered was studied using this jet injector. METHODS: Forty children (2.3 +/- 1.3 yr old) undergoing elective myringotomy and tube placement were randomly assigned to receive 0.05, 0.1, 0.15, 0.2, or 0.3 mg.kg-1 midazolam injected intramuscularly using the Biojector disposable syringe (0.006-inch orifice). Assessment of each child before, during, and 10 min after injection, on application of the anesthesia face mask, and every 15 min for 1 h after arrival to the postanesthesia care unit was made by an observer blinded to drug dosage. RESULTS: Face mask tolerance using doses > or = 0.1 mg.kg-1 midazolam was acceptable and statistically different from 0.05 mg/kg. Crying on injection tended to increase with increasing dose. All children were awake and arousable, meeting discharge criteria, after 30 min from arrival in the postanesthesia care unit. CONCLUSIONS: Midazolam (0.1-0.15 mg.kg-1) administered using jet injection effectively and rapidly produces sedation, in a manner acceptable to parents, without delaying postanesthesia care unit discharge.

Preoperative evaluation of children.

Preoperative evaluation and preparation are directed toward minimizing the intrinsic risks of anesthesia and surgery by having the child in the healthiest possible condition prior to surgery. The pediatrician can contribute to this goal by understanding the effects of general anesthesia on the physiology of children. This knowledge allows an appreciation of the anesthesiologists' concerns regarding underlying diseases, which may seem "stable" (and, therefore, of little present concern to the pediatrician) but which may have grave consequences during anesthesia. The preoperative evaluation is designed to ensure that the child's preoperative needs may be met by providing the anesthesiologist both qualitative and quantitative information regarding the child's state of health and disease. The relationship between the child, parents, and pediatrician places the pediatrician in an ideal position to prepare families for their children's surgical experience.

Disposition and respiratory effects of intrathecal morphine in children.

BACKGROUND: The extent and duration of respiratory depression after opioid administration are poorly defined in infants and children. METHODS: The disposition and respiratory effects of intrathecal morphine were studied in ten patients (ages 4 months-15 yr) after repair of craniofacial defects. Morphine, 0.02 mg/kg, was administered intrathecally before the end of surgery. Postoperatively, we determined the minute ventilation (VE) in response to increasing partial pressure of end-tidal carbon dioxide (PETCO2) during carbon dioxide rebreathing. The slope (VE/PETCO2) and intercept (VE at PETCO2 60 mmHg, VE 60) of the carbon dioxide response curve were calculated at 6, 12, and 18 h after morphine administration. Cerebrospinal fluid (CSF) and blood were analyzed for morphine concentration by radioimmunoassay. RESULTS: Mean VE/PETCO2 decreased from a preoperative value of 35.1 +/- 3.7 to 16.3 +/- 2.8 ml.kg-1 x min-1 x mmHg-1 at 6 h after morphine, and remained depressed to 23.4 +/- 2.9 and 23.5 +/- 3.3 ml.kg-1 x min-1 x mmHg-1 at 12 h and 18 h, respectively, compared to preoperatively). The infants' (n = 3) VE/PETCO2 at 6 h were 21, 4, and 27 ml.kg-1 x min-1 x mmHg-1. Mean VE 60 decreased from 874 +/- 125 to 276 +/- 32 ml x kg-1 x min-1 at 6 h, but then recovered at 12 and 18 h to 491 +/- 68 and 567 +/- 82 ml.kg-1 x min-1, respectively. The infants' VE 60 at 6 h were 350, 142, and 245 ml.kg-1 x min-1. Mean CSF morphine concentration was 2,860 +/- 540 ng/ml at 6 h, and decreased to 640 +/- 220 and 220 +/- 150 ng/ml at 12 and 18 h, respectively. CONCLUSIONS: Intrathecal morphine, 0.02 mg/kg, depressed the ventilatory response to carbon dioxide for up to 18 h concomitant with increased CSF morphine concentrations. Infants (4-12 months of age) did not exhibit greater ventilatory depression than did children (2-15 yr of age).