Ghassan E. Kanazi

Effect of low‐dose dexmedetomidine or clonidine on the characteristics of bupivacaine spinal block

Background:  The purpose of this study was to compare the onset and duration of sensory and motor block, as well as the hemodynamic changes and level of sedation, following intrathecal bupivacaine supplemented with either dexmedetomidine or clonidine.

A single dose of propofol at the end of surgery for the prevention of emergence agitation in children undergoing strabismus surgery during sevoflurane anesthesia

Background:Emergence agitation in children after sevoflurane is common. Different drugs have been used to decrease its occurrence with variable efficacy. The authors compared the incidence and severity of emergence agitation in children who received a single dose of propofol at the end of strabismus surgery versus children who received saline. Methods:In this prospective, randomized, double-blind study, the authors enrolled 80 healthy children aged 2–6 yr. The children were randomly allocated to the propofol group (n = 41), which received 1 mg/kg propofol at the end of surgery, or to the saline group (n = 39), which received saline. Results:The mean scores on the Pediatric Anesthesia Emergence Delirium scale were significantly lower in the propofol group compared with the saline group (8.6 ± 3.9 vs. 11.5 ± 4.5; P = 0.004). Also, the incidence of agitation was significantly lower in the propofol group compared with the saline group (19.5% vs. 47.2%; P = 0.01). A threshold score greater than 10 on the Pediatric Anesthesia Emergence Delirium scale was the best discriminator between presence and absence of emergence agitation. Times to removal of the laryngeal mask airway (10.6 ± 1.5 vs. 9.4 ± 1.9 min; P = 0.004) and emergence times (23.4 ± 5.7 vs. 19.7 ± 5 min; P = 0.004) were significantly longer in the propofol group. However, discharge times were similar between the two groups (propofol: 34.1 ± 8.4 min; saline: 34.9 ± 8.6 min). More parents in the propofol group were satisfied. Conclusions:In children undergoing strabismus surgery, 1 mg/kg propofol at the end of surgery after discontinuation of sevoflurane decreases the incidence of agitation and improves parents’ satisfaction without delaying discharge from the postanesthesia care unit.

The Analgesic Efficacy of Subarachnoid Morphine in Comparison with Ultrasound-Guided Transversus Abdominis Plane Block After Cesarean Delivery: A Randomized Controlled Trial

BACKGROUND: Ultrasound-guided transversus abdominis plane block is an effective method of providing pain relief after cesarean delivery. Neuraxial morphine is currently the “gold standard” treatment for pain after cesarean delivery. In this study we tested the hypothesis that subarachnoid morphine would provide more prolonged and superior analgesia than would transversus abdominis plane block in patients undergoing elective cesarean delivery. METHODS: In this prospective, double-blind study, 57 patients were randomly assigned to receive either subarachnoid morphine (group SAM; n = 28) or transversus abdominis plane block (group TAP; n = 29). Patients received bupivacaine spinal anesthesia combined with morphine 0.2 mg in group SAM and received saline in group TAP. At the end of surgery, bilateral transversus abdominis plane block was performed using saline in group SAM or using bupivacaine 0.375% plus epinephrine 5 &mgr;g/mL in group TAP with 20 mL on each side. Postoperative analgesia for the first 24 hours consisted of scheduled rectal diclofenac and IV paracetamol; breakthrough pain was treated with IV tramadol. For the next 24 hours, scheduled rectal diclofenac was given; oral paracetamol and IV tramadol were administered upon patient request. Patients were assessed postoperatively in the postanesthesia care unit (time 0 hours) and at 2, 4, 6, 12, 24, 36, and 48 hours. The primary outcome measure was the time to first analgesic request. RESULTS: Median (range) time to first analgesic request was longer in group SAM than in group TAP [8 (2–36) hours versus 4 (0.5 to 29) hours (P = 0.005)]. Median (range) number of tramadol doses received between 0 and 12 hours was 0 (0–1) in group SAM versus 0 (0–2) in group TAP (P = 0.03). Postoperative visceral pain scores at rest and on movement during first the 4 hours were lower in group SAM than in group TAP, but were not different at any other time points. The incidence of moderate to severe nausea was higher in group SAM than in group TAP [13/28 (46%) versus 5/29 (17%) (P = 0.02)]. More patients developed pruritus requiring treatment in group SAM than in group TAP [(11/28 (39%) versus none (0%) (P < 0.001)]. CONCLUSION: As part of a multimodal analgesic regimen, subarachnoid morphine provided superior analgesia when compared with ultrasound-guided transversus abdominis plane block after cesarean delivery, yet at the cost of increased side effects.

Treatment of postherpetic neuralgia: an update.

Postherpetic neuralgia (PHN) is a chronic pain syndrome that is often refractory to treatment and can last for years, causing physical and social disability, psychological distress, and increased use of the healthcare system. In this paper we provide an update on recent developments in the treatment of PHN. We emphasise the results of recent studies that provide an evidence-based approach for treating PHN that was not available until very recently. In randomised, controlled clinical trials, the topical lidocaine patch, gabapentin, and controlled release oxycodone have been shown to provide superior pain relief in patients with PHN when compared with placebo. It has also recently been demonstrated that the tricyclic antidepressant nortriptyline provides equivalent analgesic benefit when compared with amitriptyline, but is better tolerated. Based on these results, nortriptyline can now be considered the preferred antidepressant for the treatment of PHN, although desipramine may be used if the patient experiences unacceptable sedation from nortriptyline. The topical lidocaine patch, gabapentin and controlled release oxycodone all appear to be as effective as tricyclic antidepressants in the treatment of patients with PHN, and the results of these recent studies suggest that each of these treatments should be considered early in the course of treatment. Additional controlled trials are needed to compare the efficacy and tolerability of these 4 treatments — tricyclic antidepressants, gabapentin, the topical lidocaine patch and controlled release opioid analgesics — used singly and in various combinations in the treatment of patients with PHN.

Preoperative caudal block prevents emergence agitation in children following sevoflurane anesthesia

Background:  The frequency of emergence agitation in children is increased following sevoflurane anesthesia. However, controversies still exist concerning the exact etiology of this postanesthetic problem. Although this phenomenon is present with adequate pain relief or even following pain‐free procedures, pain is still regarded as a major contributing factor.

Femoral vein cannulation performed by residents: a comparison between ultrasound-guided and landmark technique in infants and children undergoing cardiac surgery.

BACKGROUND: Percutaneous cannulation of the femoral vein, in the pediatric age group, can be technically challenging, especially when performed by residents in training. We examined whether the use of real-time ultrasound guidance is superior to a landmark technique for femoral vein catheterization in children undergoing heart surgery. METHODS: Patients were prospectively randomized into 2 groups. In group LM, the femoral vein was cannulated using the traditional method of palpation of arterial pulse. In group US, cannulation was guided by real-time scanning with an ultrasound probe. The time to complete cannulation (primary outcome), success rate, number of needle passes, number of successful cannulations on first needle pass, and incidence of complications were compared between the 2 groups. RESULTS: Forty-eight pediatric patients were studied. The time to complete cannulation was significantly shorter (155 [46–690] vs 370 [45–1620] seconds; P = 0.02) in group US versus group LM. The success rate was similar in both groups (95.8%). The number of needle passes was smaller (1 [1–8] vs 3 [1–21]; P = 0.001) and the number of successful cannulations on first needle pass higher (18 vs 6; P = 0.001) in group US compared with group LM. The incidence of femoral artery puncture was comparable between the 2 groups. CONCLUSIONS: Ultrasound-guided cannulation of the femoral vein, in pediatric patients, when performed by senior anesthesia residents, is superior to the landmark technique in terms of speed and number of needle passes, with remarkable improvement in first attempt success.

Addition of ketamine to propofol for initiation of procedural anesthesia in children reduces propofol consumption and preserves hemodynamic stability

Background: There is no ideal anesthesia protocol to perform short invasive procedures in pediatric oncology. The combination of propofol and ketamine may offer advantages over propofol alone.

Noninvasive bilevel positive airway pressure for preoxygenation of the critically ill morbidly obese patient.

PurposeWe describe the use of noninvasive bilevel positive airway pressure (BiPAP) in a critically ill, hypoxemic and morbidly obese patient for preoxygenation prior to rapid sequence induction of anesthesia.Clinical featuresA critically ill morbidly obese patient (body mass index: 49 kg·m-2) was scheduled for urgent laparoscopic cholecystectomy. Preoxygenation with 5 L·min-1 oxygen flow resulted in a moderate increase in oxygen saturation (SPO2) from 79% to 90%. Prior to rapid sequence induction of anesthesia, a trial of noninvasive BiPAP with oxygen delivery at 5 L·min-1 increased his SPO2to 95% initially, with full saturation of 99% achieved when oxygen flow was increased to 10 L·min-1. Bilevel positive airway pressure with an inspiratory and expiratory pressures of 17 cm H2O and 7 cm H2O, respectively, was applied using a full face mask to achieve a tidal volume of 8 mL·kg-1. Rapid sequence induction proceeded uneventfully.ConclusionsPrior to rapid sequence induction of anesthesia in patients with respiratory compromise secondary to factors which reduce FRC, noninvasive BiPAP in combination with supplemental oxygen may be indicated whenever traditional preoxygenation does not provide adequate oxyhemoglobin saturation. Improved oxygenation is most likely attributable to improved ventilation and alveolar recruitment.RésuméObjectifNous décrivons l’utilisation de la ventilation en pression positive non invasive à bi-niveau (BiPAP) chez un patient sévèrement malade, hypoxémique et obèse morbide, pour la préoxygénation précédant l’induction de l’anesthésie en séquence rapide.Éléments cliniquesUn patient sévèrement malade et obèse morbide (indice de masse corporelle: 49 kg·m-2) s’est présenté pour une cholécystectomie laparoscopique urgente. La préoxygénation avec un débit d’oxygène de 5 L·min-1 a eu pour résultat une augmentation modérée de la saturation d’oxygène (SPO2) de 79 % à 90 %. Avant l’induction de l’anesthésie à séquence rapide, un essai de BiPAP non invasive avec un débit d’oxygène à 5 L·min-1 a accru sa SPO2 à 95% initialement, avec une saturation complète achevée à 99 % lorsque le débit d’oxygène a été accru à 10 L·min-1. La ventilation en pression positive bi-niveau avec des pressions inspiratoire et expiratoire de 17 cm H2O et 7 cm H2O respectivement a été appliquée à l’aide d’un masque facial total afin d’obtenir un volume courant de 8 mL·kg-1. L’induction à séquence rapide s’est déroulée sans incident.ConclusionAvant l’induction de l’anesthésie à séquence rapide chez les patients présentant des difficultés respiratoires secondaires à des facteurs réduisant la capacité fonctionnelle résiduelle, la BiPAP non invasive combinée à de l’oxygène supplémentaire pourrait être indiquée lorsque la préoxygénation traditionnelle ne fournit pas une saturation de l’oxyhémoglobine appropriée. Une meilleure oxygénation est sans doute attribuable à une meilleure ventilation et à un meilleur recrutement alvéolaire.

A randomized controlled trial of variable rate phenylephrine infusion with rescue phenylephrine boluses versus rescue boluses alone on physician interventions during spinal anesthesia for elective cesarean delivery.

BACKGROUND:Phenylephrine infusion is used to reduce hypotension during spinal anesthesia for cesarean delivery. A prophylactic fixed rate infusion regimen may not improve hemodynamic control; a variable rate regimen adjusted in response to changes in arterial blood pressure and heart rate may allow more accurate maintenance of baseline blood pressure. We hypothesized that a combination of crystalloid solution coload with a variable rate phenylephrine infusion and phenylephrine rescue boluses may be associated with fewer physician interventions needed to maintain maternal systolic blood pressure within 20% of baseline and greater hemodynamic stability than crystalloid solution coload with phenylephrine rescue boluses alone. METHODS:In this prospective, double-blind study, 80 patients received a coload with 15 mL/kg lactated Ringer’s solution immediately after the initiation of spinal anesthesia. Patients were randomized to receive a prophylactic variable rate phenylephrine infusion starting at 0.75 &mgr;g/kg/min (group P) or infusion of normal saline (group S). Maternal systolic blood pressure was maintained within 20% of baseline with rescue phenylephrine boluses using a preset algorithm. During the predelivery period, the number of physician interventions (primary outcome), hemodynamic performance, nausea/vomiting, and umbilical cord blood gas values were compared between the groups. RESULTS:One patient from group S was excluded due to protocol violation. Therefore, group P included 40 patients and group S 39 patients. The median (range) number of physician interventions needed to maintain maternal hemodynamics within the target range (0 [0–6] vs 3 [0–9], difference in median: 3, 95% confidence interval of difference: 2–4) and incidence of hypotension (8/40 [20%] vs 35/39 [90%]) were lower in group P compared with group S (P < 0.001). Group P had a higher incidence of hypertension compared with group S (6/40 [15%] vs 0/39 [0%], P = 0.026). The median performance error was closer to baseline (P < 0.001) with a smaller median absolute performance error (P = 0.001) in group P versus group S. In group P, 4/40 (10%) patients had nausea/vomiting compared with 17/39 (44%) in group S (P = 0.001). The number needed to treat was 1.4 women to prevent 1 case of hypotension, and 3 women to prevent 1 case of nausea/vomiting; the rate of hypertension was 1 case per 6.7 women treated. Neonatal outcomes were not different between the 2 groups. CONCLUSION:Prophylactic variable rate phenylephrine infusion and rescue phenylephrine bolus dosing is more effective than relying on rescue phenylephrine bolus dosing with respect to limiting clinician workload and maternal symptoms during spinal anesthesia for cesarean delivery.

Noninvasive bilevel positive airway pressure for preoxygenation of the critically ill morbidly obese patient

PurposeWe describe the use of noninvasive bilevel positive airway pressure (BiPAP) in a critically ill, hypoxemic and morbidly obese patient for preoxygenation prior to rapid sequence induction of anesthesia.Clinical featuresA critically ill morbidly obese patient (body mass index: 49 kg·m-2) was scheduled for urgent laparoscopic cholecystectomy. Preoxygenation with 5 L·min-1 oxygen flow resulted in a moderate increase in oxygen saturation (SPO2) from 79% to 90%. Prior to rapid sequence induction of anesthesia, a trial of noninvasive BiPAP with oxygen delivery at 5 L·min-1 increased his SPO2to 95% initially, with full saturation of 99% achieved when oxygen flow was increased to 10 L·min-1. Bilevel positive airway pressure with an inspiratory and expiratory pressures of 17 cm H2O and 7 cm H2O, respectively, was applied using a full face mask to achieve a tidal volume of 8 mL·kg-1. Rapid sequence induction proceeded uneventfully.ConclusionsPrior to rapid sequence induction of anesthesia in patients with respiratory compromise secondary to factors which reduce FRC, noninvasive BiPAP in combination with supplemental oxygen may be indicated whenever traditional preoxygenation does not provide adequate oxyhemoglobin saturation. Improved oxygenation is most likely attributable to improved ventilation and alveolar recruitment.RésuméObjectifNous décrivons l’utilisation de la ventilation en pression positive non invasive à bi-niveau (BiPAP) chez un patient sévèrement malade, hypoxémique et obèse morbide, pour la préoxygénation précédant l’induction de l’anesthésie en séquence rapide.Éléments cliniquesUn patient sévèrement malade et obèse morbide (indice de masse corporelle: 49 kg·m-2) s’est présenté pour une cholécystectomie laparoscopique urgente. La préoxygénation avec un débit d’oxygène de 5 L·min-1 a eu pour résultat une augmentation modérée de la saturation d’oxygène (SPO2) de 79 % à 90 %. Avant l’induction de l’anesthésie à séquence rapide, un essai de BiPAP non invasive avec un débit d’oxygène à 5 L·min-1 a accru sa SPO2 à 95% initialement, avec une saturation complète achevée à 99 % lorsque le débit d’oxygène a été accru à 10 L·min-1. La ventilation en pression positive bi-niveau avec des pressions inspiratoire et expiratoire de 17 cm H2O et 7 cm H2O respectivement a été appliquée à l’aide d’un masque facial total afin d’obtenir un volume courant de 8 mL·kg-1. L’induction à séquence rapide s’est déroulée sans incident.ConclusionAvant l’induction de l’anesthésie à séquence rapide chez les patients présentant des difficultés respiratoires secondaires à des facteurs réduisant la capacité fonctionnelle résiduelle, la BiPAP non invasive combinée à de l’oxygène supplémentaire pourrait être indiquée lorsque la préoxygénation traditionnelle ne fournit pas une saturation de l’oxyhémoglobine appropriée. Une meilleure oxygénation est sans doute attribuable à une meilleure ventilation et à un meilleur recrutement alvéolaire.