Dominic Cave

Thoracic and lumbar epidural analgesia via the caudal approach using electrical stimulation guidance in pediatric patients: a review of 289 patients.

BackgroundNerve stimulation guidance (Tsui test) has been reported to be an effective alternative to radiographic imaging for proper catheter placement. The purpose of this study was to examine the success rate and complications of continuous caudal epidural analgesia since the implementation of routine use of the Tsui test at the authors’ institution. MethodsThe authors examined prospectively collected data in their pediatric pain service database from 289 children who had attempted caudal placement of a lumbar or thoracic catheter between 1999 and 2002. ResultsIn five patients (aged 5 months–1.6 yr), the catheter did not thread to the desired level and was abandoned in the operating room (technical success rate, 98.2%). Of the remaining 284 patients, the overall analgesic success rate of all caudal route epidural analgesia procedures was 84.9%. There was no significant difference in adequate pain control (success) in infants (aged 1 day–1 yr) versus older children (aged younger than 1 yr). The most common adverse effects were pruritus (26.1%) and nausea and vomiting (16.9%). Of the patients in our study, 57.7% had urinary catheters in situ; of those who did not have a catheter placed, 20.8% experienced urinary retention. The incidence of respiratory depression was 4.2%, but the administration of naloxone for severe respiratory depression was never necessary. Three percent of catheters were removed because of suspected contamination, but no epidural abscesses or systemic infection were noted. ConclusionsThe results of this study suggest that epidural catheter placement via the caudal approach using the Tsui test is an effective and reasonable alternative to direct lumbar and thoracic epidural analgesia in pediatric patients.

Intraoperative renal support during liver transplantation

Acute kidney injury (AKI) is common in liver failure prior to orthotopic liver transplantation (OLT) and may complicate the intraoperative course. We describe the logistics of intraoperative continuous renal replacement therapy (CRRT) during OLT and the associated clinical outcomes. We performed a retrospective review of adult patients (age > 18 years) receiving intraoperative CRRT during OLT at the University of Alberta Hospital between January 1, 1996 and December 31, 2005. Demographic, detailed clinical, and perioperative data, physiologic and laboratory measures, details of renal replacement therapy (RRT) provided, and data on renal recovery and survival were ascertained. Of 636 OLTs, 41 (6.4%) received intraoperative CRRT. The most common indications for OLT in these patients were hepatitis C (34.2%) and alcoholic (29.3%) cirrhosis. The median [interquartile range (IQR)] Model for End‐Stage Liver Disease score was 38 (31‐43), and 90.2% were classified as Child‐Pugh class C. Preoperatively, 70% were in the intensive care unit, 58.5% were mechanically ventilated, and 48.7% required vasopressor support. The median (IQR) duration of intraoperative CRRT was 258 (189‐390) minutes, representing 57% of the total operative time. Filter circuit clotting occurred in 40% but was not associated with a shorter CRRT duration (P = 0.41). No other complications were described. CRRT allowed an even or negative intraoperative fluid balance in 92.7%. CRRT was continued in 78% after OLT for a median (IQR) of 5 (3‐11) days. Of these, 24 (75%) were transitioned to intermittent hemodialysis for a median (IQR) of 15 (4‐39) days. Survival was 97.6% at 1 month and 75.6% at 1 year. Renal recovery to RRT independence occurred in 100% of survivors by 1 year; however, the mean (standard deviation) estimated glomerular filtration rate (eGFR) was 54.7 (19.1) mL/minute/m2, with 62.1% having an eGFR < 60 mL/minute/m2. In conclusion, our data suggest that intraoperative CRRT during OLT is achievable and safe. Intraoperative CRRT may be a valuable adjuvant therapy for those with preoperative AKI. Additional investigations are warranted. Liver Transpl 15:73–78, 2009.

Neurodevelopmental outcome following exposure to sedative and analgesic drugs for complex cardiac surgery in infancy

Objectives/Aim:  To determine whether sedation/analgesia drugs used before, during, and after infant cardiac surgery are associated with neurodevelopmental outcome.

The incidence of laryngospasm with a "no touch" extubation technique after tonsillectomy and adenoidectomy.

In this case series, we evaluated the incidence of laryngospasm using a clearly defined awake tracheal extubation technique in 20 children undergoing elective tonsillectomy with or without adenoidectomy. This technique required patients to be turned to the recovery position at the end of the procedure before discontinuing the volatile anesthetics. No further stimulation, besides continuous oximetry monitoring, was allowed until the patients spontaneously woke up (“no touch” technique). The incidence of laryngospasm, oxygen saturation, and coughing was recorded. No cases of laryngospasm, oxygen desaturation, or severe coughing occurred in our patient population.

Prevalence of Laryngomalacia in Children Presenting with Sleep-Disordered Breathing

To determine the prevalence of laryngomalacia among children presenting with symptoms of sleep‐disordered breathing (SDB).

Combined propofol and remifentanil intravenous anesthesia for pediatric patients undergoing magnetic resonance imaging

Background : A prospective observational case series of children receiving light general anesthesia for magnetic resonance imaging (MRI) was performed. Our purpose was to examine the merit of anesthesia and recovery/discharge times of combined remifentanil and propofol total intravenous anesthesia (TIVA) in spontaneously breathing children.

Threshold Current for an Insulated Epidural Needle in Pediatric Patients

We designed this study to determine the threshold current for nerve stimulation of an insulated needle in the epidural space. The intended dermatome was identified using the bony landmarks of the spine. An 18-gauge insulated Tuohy needle was inserted perpendicularly to the skin and advanced until “loss of resistance” was felt. A nerve stimulator was then connected to the insulated needle. Twenty patients were studied using an insulated Tuohy needle and one patient was studied using a noninsulated Tuohy needle. Muscle twitch was elicited with a current of 11.1 ± 3.1 mA (mean ± sd) in all patients in which an insulated needle was used. Muscle twitches were within 2 myotomes of the intended level (based on bony landmarks). Muscle twitch was not elicited with a noninsulated needle. After catheter threading, positive stimulation tests were elicited via epidural catheters in all patients (4.9 ± 2.3 mA). Postoperative radiograph confirmed all catheter placements within 2 myotomes of the muscle twitches. Electrical stimulation may be a useful adjuvant tool to loss of resistance for confirming proper thoracic epidural needle placement. The threshold current criteria for an insulated needle (6–17 mA) would be higher than the original Tsui test criteria described for an epidural catheter (1–10 mA) in the epidural space.

Neurotoxicity of sedative and analgesia drugs in young infants with congenital heart disease: 4-year follow-up.

To determine whether sedation/analgesia drugs used before, during, and after infant cardiac surgery are associated with neurocognitive and functional outcomes.

An Evaluation of Intraoperative Renal Support during Liver Transplantation: A Matched Cohort Study

Background: Intraoperative continuous renal replacement therapy (CRRT) has been utilized during liver transplantation (LT). Our objective was to assess intraoperative CRRT for metabolic control, postoperative complications and outcomes. Methods: Retrospective matched cohort study. Cases were LT patients receiving intraoperative CRRT. Controls were matched for demographics and Model for End-Stage Liver Disease (MELD) score. Data were extracted on physiology, course and outcomes. Results: 72 patients were included. Despite effort to match by MELD, cases had higher scores (35.4 vs. 29.9, p = 0.01) compared to controls. Preoperatively, cases received more vasopressors (p = 0.006), and more RRT (94.4 vs. 25.7%, p < 0.0001). There was no difference in complications (p = 0.35) or ICU re-admission rate (p = 0.29). Cases were more likely to require postoperative RRT (p < 0.0001). There was no difference in hospital mortality (p = 0.61). Conclusions: LT patients selected for intraoperative CRRT more commonly have hemodynamic instability and preoperative acute kidney injury requiring RRT. Despite higher illness severity for cases, there were no differences in complications or mortality.

Specificity of Radionuclide Brain Blood Flow Testing in Brain Death: Case Report and Review

Brain blood flow tests with diffusible radiopharmaceuticals are often done as an ancillary test in brain death (BD). We report a case of an infant with absent brain blood flow on an anterior planar image despite persistent breathing and extensor posturing. We reviewed the literature from 1980 to 2008 using MEDLINE and PubMed to determine the sensitivity and specificity of these tests in the diagnosis of BD. Search terms were any combination of: brain death; and single photon emission computed tomography (SPECT), radiopharmaceuticals, technetium Tc 99m exametazime, or organotechnetium compounds. The sensitivity of absent brain blood flow on planar imaging for clinically confirmed BD is 119/153 = 77.8% [95% CI 70.5%—83.7%]; and the specificity is 41/41 (100%) [95% CI 92.6%—100%]. For clinically confirmed BD, the sensitivity of SPECT is 107/121 (88.4%) [95% CI 81.4%—93.1%], and specificity is 12/12 (100%) [95% CI 78.4%—100%]. For contrast angiography confirmed BD, the sensitivity of SPECT is 34/34 (100%) [95% CI 91.2%—100%]; the specificity could not be estimated as there were no patients without clinical BD having both tests. Case reports emphasized the possibility of isolated posterior-fossa blood flow, which would not be detectable using non-diffusible radiopharmaceuticals, or without a lateral view using diffusible agents. We conclude that patients having an ancillary radiopharmaceutical brain blood flow test for BD should have anterior and lateral views without exception. Larger numbers of patients both with and without BD (but with severe brain injury) must be studied to determine the sensitivity and specificity of these tests.