Chakib M. Ayoub

The Sedative and Analgesic Sparing Effect of Music

Background To determine whether music influences intraoperative sedative and analgesic requirements, two randomized controlled trials were performed. Methods In phase 1, 35 adults undergoing urologic procedures with spinal anesthesia and patient‐controlled intravenous propofol sedation were randomly assigned to hear favorable intraoperative music via headset or to have no music. In phase 2, 43 adults undergoing lithotripsy treatment of renal or ureteral calculi and receiving patient‐controlled intravenous opioid analgesia were randomly assigned to either a music or no‐music group. The effect of music on sedatives and analgesics requirements, recovery room duration, and adverse outcomes was assessed. Results In phase 1, patients in the music group required significantly less propofol for sedation than patients in the control group (0 [0–150] mg vs. 90 [0–240] mg, median[range]; P < 0.001). These findings persisted after adjusting for duration of surgery (0.3 +/‐ 0.1 mg/min vs. 1.6 +/‐ 0.4 mg/min; P < 0.001). Similarly, in phase 2, patients who listened to music had a significant reduction in alfentanil requirements (1,600 [0–4,250] [micro sign]g vs. 3,900 [0–7,200] [micro sign]g; P = 0.005). This persisted after adjusting for duration of surgery (52 +/‐ 9 [micro sign]g/min vs. 119 +/‐ 16 [micro sign]g/min, mean +/‐ SD, P < 0.001). Duration of stay in the postanesthesia care unit and the rate of adverse events was similar in both groups (P = NS). Conclusions Use of intraoperative music in awake patients decreases patient‐controlled sedative and analgesic requirements. It should be noted, however, that patients in the no‐music group did not use a headset during operation. Thus, the decrease in sedative and analgesic requirements could be caused by elimination of ambient operating room noise and not by the effects of music.

Attenuation of the preoperative stress response with midazolam: effects on postoperative outcomes.

Background. Previously, effects of preoperative sedatives were assessed mainly with respect to preoperative outcomes such as anxiety and compliance. The purpose of this investigation was to evaluate the effects of preoperative sedatives on postoperative psychological and clinical recovery. Methods Patients undergoing general anesthesia and outpatient surgery were enrolled in a double-blind, randomized, placebo-controlled trial. Subjects (n = 55) were randomly assigned to receive either 5 mg intramuscular midazolam (n = 26) or a placebo injection (n = 29) at least 30 min before surgery. The anesthetic technique was controlled. Postoperative anxiety, pain, analgesic consumption, clinical recovery parameters, and global health (SF-36) were evaluated up to 1 month after surgery. Results Surgery length did not differ significantly between the treatment and placebo groups (118 ± 45 min vs 129 ± 53 min;P = NS). Throughout the first postoperative week, subjects in the treatment group reported a greater reduction in postoperative pain compared with subjects in the placebo group (F1,50= 3.5;P = 0.035). Moreover, at 1 week, ibuprofen use was reported by less subjects in the treatment group than in the placebo group (0%vs 17.2%;P = 0.026). Subjects in the treatment group also reported a greater reduction in postoperative anxiety throughout the follow-up period (F1,53 = 9.2;P = 0.04). However, global health indexes (SF-36) did not detect any significant differences between the two experimental groups (multivariate F1,45 = 0.44;P = 0.51). Conclusion Subjects treated with midazolam preoperatively self-report improved postoperative psychological and pain recovery. However, the clinical significance of these findings is unclear at the present time.

Music and ambient operating room noise in patients undergoing spinal anesthesia.

Previous studies have indicated that music decreases intraoperative sedative requirements in patients undergoing surgical procedures under regional anesthesia. In this study we sought to determine whether this decrease in sedative requirements results from music or from eliminating operating room (OR) noise. A secondary aim of the study was to examine the relationship of response to intraoperative music and participants’ culture (i.e., American versus Lebanese). Eighty adults (36 American and 54 Lebanese) undergoing urological procedures with spinal anesthesia and patient-controlled IV propofol sedation were randomly assigned to intraoperative music, white noise, or OR noise. We found that, controlling for ambient OR noise, intraoperative music decreases propofol requirements (0.004 ± 0.002 mg · kg−1 · min−1 versus 0.014 ± 0.004 mg · kg−1 · min−1 versus 0.012 ± 0.002 mg · kg−1 · min−1; P = 0.026). We also found that, regardless of group assignment, Lebanese patients used less propofol as compared with American patients (0.005 ± 0.001 mg · kg−1 · min−1 versus 0.017 ± 0.003 mg · kg−1 · min−1; P = 0.001) and that, in both sites, patients in the music group required less propofol (P < 0.05). We conclude that when controlling for ambient OR noise, intraoperative music decreases propofol requirements of both Lebanese and American patients who undergo urological surgery under spinal anesthesia.

Fertility drugs and the risk of breast cancer: a meta-analysis and review

The risk of breast cancer has been associated with reproductive history. The purpose of this study was to determine the relationship between fertility drugs used in assisted reproductive procedures and the risk of breast cancer. We performed a literature search using the MEDLINE, the COCHRANE Library, and Scopus to identify studies linking breast cancer to fertility drugs. We excluded case series, case reports, and review articles from our analysis. The study populations included women who were treated for infertility with clomiphene, gonadotropins, gonadotropin-releasing hormones, or other unspecified fertility agents. We extracted information on study design, sample size, type of fertility drugs and number of treatment cycles, breast cancer incidence, and follow-up time from these studies. Eight case–control studies and fifteen cohort studies were included in the quantitative analyses. The Newcastle–Ottawa Quality Assessment Scales were used. Two investigators independently extracted study methods, sources of bias, and outcomes. We found that the risk of breast cancer was not significantly associated with fertility drug treatment. The follow-up periods were short in some of the studies analyzed in our study; however, we proceeded to test the trend in risk estimates across different durations of follow-up and found a trend for association using the nonparametric test; this was interpreted with caution in view of the lack of adjustment with other confounding factors. The current published data do not suggest higher risk of breast cancer in women who receive fertility treatment, but the lack of long-term follow up and the inherent weaknesses in some of the published studies have to be cautiously taken into account.

Widespread application of topical steroids to decrease sore throat, hoarseness, and cough after tracheal intubation.

T racheal intubation for general anesthesia often leads to trauma of the airway mucosa, resulting in postoperative sore throat (ST), cough (C), and hoarseness (H), with reported incidences of 21%-65% (1,2). Although typically not incapacitating, these sequelae can be very uncomfortable and may be especially annoying to patients returning home after ambulatory procedures. The aforementioned effects are likely the consequences of local irritation and inflammation and hence may be amenable to locally administered steroids. However, relatively little research has been performed in this area. Topical application of 1% hydrocortisone near the endotracheal tube cuff was not beneficial (3), whereas one puff of a beclomethasone inhaler (50 pg) effectively reduced the incidence of ST from 55% to 10% (4). Neither of these studies evaluated the effect of the steroid on H and C. In light of the cost associated with pretreatment with inhalers, we sought to determine whether we could obtain a reduction of C and H as well as ST with a wider distribution of topical gel. We hypothesized that coating the endotracheal tube from the cuff to the 15-cm mark with betamethasone, a water-soluble steroid that has been used topically for the treatment of inflammatory lesions of the oral mucosa, would reduce these sequelae.

Laryngospasm: review of different prevention and treatment modalities

Laryngospasm is a common complication in pediatric anesthesia. In the majority of cases, laryngospasm is self‐limiting. However, sometimes laryngospasm persists and if not appropriately treated, it may result in serious complications that may be life‐threatening. The present review discusses laryngospasm with the emphasis on the different prevention and treatment modalities.

Critical Care Clinicians’ Knowledge of Evidence-Based Guidelines for Preventing Ventilator-Associated Pneumonia

BACKGROUND Ventilator-associated pneumonia is the most common hospital-acquired infection among patients receiving mechanical ventilation in an intensive care unit. Different initiatives for the prevention of ventilator-associated pneumonia have been developed and recommended. OBJECTIVE To evaluate knowledge of critical care providers (physicians, nurses, and respiratory therapists in the intensive care unit) about evidence-based guidelines for preventing ventilator-associated pneumonia. METHODS Ten physicians, 41 nurses, and 18 respiratory therapists working in the intensive care unit of a major tertiary care university hospital center completed an anonymous questionnaire on 9 nonpharmacological guidelines for prevention of ventilator-associated pneumonia. RESULTS The mean (SD) total scores of physicians, nurses, and respiratory therapists were 80.2% (11.4%), 78.1% (10.6%), and 80.5% (6%), respectively, with no significant differences between them. Furthermore, within each category of health care professionals, the scores of professionals with less than 5 years of intensive care experience did not differ significantly from the scores of professionals with more than 5 years of intensive care experience. CONCLUSIONS A health care delivery model that includes physicians, nurses, and respiratory therapists in the intensive care unit can result in an adequate level of knowledge on evidence-based nonpharmacological guidelines for the prevention of ventilator-associated pneumonia.

Changes in resistances of endotracheal tubes with reductions in the cross-sectional area.

Background and objectives: Partial obstruction of endotracheal tubes due to accumulation of secretions and mucus plugs can increase the tube resistance and subsequently impose increased resistive load on the patient. This study was performed to determine the changes in the resistance of endotracheal tubes of sizes 7.5, 8.0 and 8.5 mm with different degrees and locations of endotracheal tube narrowing. Methods: Reductions of 10%, 25%, 50% and 75% in the endotracheal tubes cross‐sectional areas were created at different sites along the axes of the tube connected to an artificial lung. While ventilating with a constant inspiratory flow, a 1 s end‐inspiratory occlusion manoeuvre was applied and the resulting plateau pressure was determined. The resistance was calculated as (peak airway pressure ‐ plateau pressure)/peak inspiratory flow. Results: Significant increases in the endotracheal tubes resistances were observed as the tubes cross‐sectional area reduction was increased from 25% to 50% and from 50% to 75% for the 7.5 mm endotracheal tube, from 25% to 50% for the 8.0 mm endotracheal tube, and from 50% to 75% for the 8.5 mm endotracheal tube. Changes of the endotracheal tube resistances were not affected by the site of cross‐sectional area reductions along the axes of the tubes. Conclusions: For endotracheal tubes of sizes 7.5, 8.0 and 8.5 mm, significant changes in the tubes resistances are observed when the partial obstructions of the tubes exceed certain critical values. The location of the partial obstruction did not affect the changes in the endotracheal tube resistances.

Magnesium therapy for refractory ventricular fibrillation

THE MAGNESIUM ION has a distinct influence on cardiac activity.1 The value of magnesium in correcting lethal arrhythmias in hypomagnesemic patients has been well established.2,3 Its antiarrhythmic effect has also been reported in the absence of known magnesium (Mg++) deficiency, or hypomagnesemia.4 A search of the medical literature, however, revealed no controlled studies of the efficacy of magnesium in the treatment of sustained ventricular fibrillation (VF), and only a few cases of intractable ventricular tachyarrhythmias or refractory VF responsive to magnesium therapy have been reported.4–7 The VF algorithm suggested by the American Heart Association recommends the use of magnesium in hypomagnesemia, torsades de pointes, digitalis toxicity, and as a last resort when other antiarrhythmic drugs, such as lidocaine and bretylium, fail to control the fibrillation.8 The authors report five cardiac patients who developed refractory VF, secondary to different causes, who were successfully treated by a single countershock after the administration of a bolus of magnesium sulfate (Table 1). The rationale behind the use of magnesium for management of refractory VF is the well-known benefit of magnesium in the management of intractable tachyarrhythmias4–7 as well as its myocardial protective action in the setting of ischemia-reperfusion injury.9

Prophylactic methylene blue in a patient with congenital methemoglobinemia.

PurposeTo report the beneficial effect of prophylactic methylene blue administration before induction of anesthesia in a patient with congenital methemoglobinemia.Clinical featuresA 26-yr-old male patient known to have congenital methemoglobinemia was scheduled forturbinectomy under general anesthesia. The patient was clinically cyanotic with a pulse oximetry of 91 %. Arterial blood gas analysis showed a partial pressure of oxygen (PaO2) of 81.3 mmHg associated with a fractional oxyhemoglobin of 80.7%, and a methemoglobin fraction of 0.159. Preoperativeiv administration of 1 mg·kg-1 of methylene blue resulted, within five minutes, in a decrease of methemoglobin fraction down to 0.05 associated with an increase of the fractional oxyhemoglobin saturation up to 94.7%. After two hours, the methemoglobin fraction decreased to 0.01 and the fractional oxyhemoglobin concentration increased to 97.7%. Induction of anesthesia as well as intraoperative and postoperative course were uneventful without any episode of hypoxemia. Postoperatively, the methemoglobin fractions remained low for 24 hr, to be followed by a gradual increase up to 0.02 on the second day to reach 0.094 on the fifth day.ConclusionThe prophylactic preoperative methylene blue administration in a patient with congenital methemoglobinemia significantly decreased the methemoglobin level and increased the fractional oxygen saturation with a consequent increase of the safety margin against perioperative hypoxemia.RésuméObjectifSignaler l’effet bénéfique de l’administration prophylactique de bleu de méthylène avant l’induction de l’anesthésie chez un patient atteint de méthémoglobinémie congénitale.Éléments cliniquesUn homme de 26 ans atteint de méthémoglobinémie congénitale devait subir une turbinectomie sous anesthésie générale. Le patient était cyanosé et présentait une sphygmo- oxymétrie de 91 %. L’analyse des gaz artériels a montré une pression partielle d’oxygène (PaO2) de 81,3 mmHg associée à une oxyhémo- globine fractionnelle de 80,7 % et à une fraction de méthémoglobine de 0,159. L’administration iv préopératoire de 1 mg·kg-1 de bleu de méthylène a donné, en moins de cinq minutes, une baisse de la frac- tion de méthémoglobine jusqu’à 0,05, et une hausse de la saturation d’oxyhémoglobine fractionnelle jusqu’à 94,7 %. Après deux heures, la fraction de méthémoglobine a baissé à 0,01 et la concentration d’oxy- hémoglobine fractionnelle a augmenté à 97,7 %. L’induction de l’anesthésie et l’évolution peropératoire et postopératoire ont été sans incident et sans épisode d’hypoxémie. Après l’opération, les fractions de méthémoglobine sont demeurées basses pendant 24 h et ont été suivies d’une hausse graduelle jusqu’à 0,02 le deuxième jour et 0,094 le cinquième jour.Conclusion : L’administrationprophylactique préopératoire de bleu de méthylène chez un patient atteint de méthémoglobinémie con-génitale a significativement réduit le niveau de méthémoglobine et augmenté la saturation en oxygène fractionnée, ce qui a augmenté la marge de sécurité contre l’hypoxémie périopératoire.PURPOSE To report the beneficial effect of prophylactic methylene blue administration before induction of anesthesia in a patient with congenital methemoglobinemia. CLINICAL FEATURES A 26-yr-old male patient known to have congenital methemoglobinemia was scheduled for turbinectomy under general anesthesia. The patient was clinically cyanotic with a pulse oximetry of 91%. Arterial blood gas analysis showed a partial pressure of oxygen (PaO(2)) of 81.3 mmHg associated with a fractional oxyhemoglobin of 80.7%, and a methemoglobin fraction of 0.159. Preoperative iv administration of 1 mg.kg(-1) of methylene blue resulted, within five minutes, in a decrease of methemoglobin fraction down to 0.05 associated with an increase of the fractional oxyhemoglobin saturation up to 94.7%. After two hours, the methemoglobin fraction decreased to 0.01 and the fractional oxyhemoglobin concentration increased to 97.7%. Induction of anesthesia as well as intraoperative and postoperative course were uneventful without any episode of hypoxemia. Postoperatively, the methemoglobin fractions remained low for 24 hr, to be followed by a gradual increase up to 0.02 on the second day to reach 0.094 on the fifth day. CONCLUSION The prophylactic preoperative methylene blue administration in a patient with congenital methemoglobinemia significantly decreased the methemoglobin level and increased the fractional oxygen saturation with a consequent increase of the safety margin against perioperative hypoxemia.