Peter T.-L. Choi

How strong is the evidence for the use of perioperative β blockers in non-cardiac surgery? Systematic review and meta-analysis of randomised controlled trials

Abstract Objective To determine the effect of perioperative β blocker treatment in patients having non-cardiac surgery. Design Systematic review and meta-analysis. Data sources Seven search strategies, including searching two bibliographic databases and hand searching seven medical journals. Study selection and outcomes We included randomised controlled trials that evaluated β blocker treatment in patients having non-cardiac surgery. Perioperative outcomes within 30 days of surgery included total mortality, cardiovascular mortality, non-fatal myocardial infarction, non-fatal cardiac arrest, non-fatal stroke, congestive heart failure, hypotension needing treatment, bradycardia needing treatment, and bronchospasm. Results Twenty two trials that randomised a total of 2437 patients met the eligibility criteria. Perioperative β blockers did not show any statistically significant beneficial effects on any of the individual outcomes and the only nominally statistically significant beneficial relative risk was 0.44 (95% confidence interval 0.20 to 0.97, 99% confidence interval 0.16 to 1.24) for the composite outcome of cardiovascular mortality, non-fatal myocardial infarction, and non-fatal cardiac arrest. Methods adapted from formal interim monitoring boundaries applied to cumulative meta-analysis showed that the evidence failed, by a considerable degree, to meet standards for forgoing additional studies. The individual safety outcomes in patients treated with perioperative β blockers showed a relative risk for bradycardia needing treatment of 2.27 (95% CI 1.53 to 3.36, 99% CI 1.36 to 3.80) and a nominally statistically significant relative risk for hypotension needing treatment of 1.27 (95% CI 1.04 to 1.56, 99% CI 0.97 to 1.66). Conclusion The evidence that perioperative β blockers reduce major cardiovascular events is encouraging but too unreliable to allow definitive conclusions to be drawn.

Epidural analgesia reduces postoperative myocardial infarction: a meta-analysis.

Postoperative cardiac morbidity and mortality continue to pose considerable risks to surgical patients. Postoperative epidural analgesia is considered to have beneficial effects on cardiac outcomes. The use in high-risk cardiac patients remains controversial. No study has shown that postoperative epidural analgesia decreases postoperative myocardial infarction (PMI) or death. All studies are underpowered to show such a result, and the cost of conducting a large trial is prohibitive. We performed a metaanalysis to determine whether postoperative epidural analgesia continued for more than 24 h after surgery reduces PMI or in-hospital death. The available databases were searched for randomized controlled trials of epidural analgesia that was extended at least 24 h into the postoperative period. The search yielded 17 studies, of which 11 were randomized controlled trials comprising 1173 patients. Metaanalysis was conducted by using the fixed-effects model, calculating both an odds ratio and a rate difference. Postoperative epidural analgesia resulted in better analgesia for the first 24 h after surgery. The rate of PMI was 6.3%, with lower rates in the Epidural group (rate difference, −3.8%; 95% confidence interval [CI] −7.4%, −0.2%;P = 0.049). The frequency of in-hospital death was 3.3%, with no significant difference between Epidural and Nonepidural groups (rate difference, −1.3%; 95% CI, −3.8%, 1.2%, P = 0.091). Subgroup analysis of postoperative thoracic epidural analgesia showed a significant reduction in PMI in the Epidural group (rate difference, −5.3%; 95% CI, −9.9%, −0.7%;P = 0.04).

PDPH is a common complication of neuraxial blockade in parturients: a meta-analysis of obstetrical studies

PurposePostdural puncture headache (PDPH) is an iatrogenic complication of neuraxial blockade. We systematically reviewed the literature on parturients to determine the frequency onset, and duration of PDPH.MethodsCitations on PDPH in the obstetrical population were identified by computerized searches, citation review, and hand searches of abstracts and conference proceedings. Citations were included if they contained extractable data on frequency, onset, or duration of PDPH. Using meta-analysis, we calculated pooled estimates of the frequency of accidental durai puncture for epidural needles and pooled estimates of the frequencies of PDPH for epidural and spinal needles.ResultsParturients have approximately a 1.5% [95% confidence interval (CI) 1.5% to 1.5%) risk of accidental durai puncture with epidural insertion. Of these, approximately half (52.1%; 95% CI, 51.4% to 52.8%) will result in PDPH. The risk of PDPH from spinal needles diminishes with small diameter, atraumatic needles, but is still appreciable (Whitacre 27-gauge needle 1.7%; 95% CI, 1.6% to 1.8%). PDPH occurs as early as one day and as late as seven days after durai puncture and lasts 12 hrto seven days.ConclusionPDPH is a common complication for parturients undergoing neuraxial blockade.RésuméObjectifLes céphalées post-ponction durale (CPPD) sont une complication iatrogène du bloc neuraxial. Une revue systématique des publications sur les parturientes a permis de déterminer la fréquence, le délai d’installation et la durée des CPPD.MéthodeLes citations sur les CPPD dans la population obstétricale ont été repérées par des recherches informatisées, la revue des références et des recherches manuelles de résumés et de comptes rendus de conférences. Les références retenues devaient comporter des données sur la fréquence, le délai d’installation et la durée des CPPD. Nous avons calculé, par méta-analyse, les estimations groupées de la fréquence de ponction durale accidentelle par aiguilles péridurales et celles de la fréquence de CPPD par aiguilles péridurales et rachidiennes.RésultatsChez les parturientes, le risque de subir une ponction durale accidentelle avec une aiguille péridurale est d’environ 1,5 % [intervalle de confiance de 95 % (IC) 1,5 % à 1,5 %]. Environ la moitié de ces ponctions (52,1 % ; IC de 95 %, 51,4 % à 52,8 %) va provoquer des CPPD. Le risque de CPPD avec les aiguilles rachidiennes diminue pour des aiguilles atraumatiques de petit diamètre, mais demeure appréciable (aiguille Whitacre 27 G 1,7 % ; IC de 95 %, 1,6% à 1,8 %). Les CPPD surviennent parfois aussi tôt qu’un jour, et aussi tard que sept jours, après la ponction durale et durent de 12 h à sept jours.ConclusionLes CPPD sont une complication courante chez les parturientes qui subissent un bloc neuraxial.

Are the recommendations to use perioperative β-blocker therapy in patients undergoing noncardiac surgery based on reliable evidence?

Of the approximately 26 million North Americans who undergo noncardiac surgical procedures every year,[1][1],[2][2] 1%–5% suffer a major perioperative cardiovascular event.[1][1],[3][3] Perioperative ischemic events prolong hospital stays by a mean of 11 days[4][4] and cost the US economy

Payments for care at private for-profit and private not-for-profit hospitals: a systematic review and meta-analysis

Background: It has been shown that patients cared for at private for-profit hospitals have higher risk-adjusted mortality rates than those cared for at private not-for-profit hospitals. Uncertainty remains, however, about the economic implications of these forms of health care delivery. Since some policy-makers might still consider for-profit health care if expenditure savings were sufficiently large, we undertook a systematic review and meta-analysis to compare payments for care at private for-profit and private not-for-profit hospitals. Methods: We used 6 search strategies to identify published and unpublished observational studies that directly compared the payments for care at private for-profit and private not-for-profit hospitals. We masked the study results before teams of 2 reviewers independently evaluated the eligibility of all studies. We confirmed data or obtained additional data from all but 1 author. For each study, we calculated the payments for care at private for-profit hospitals relative to private not-for-profit hospitals and pooled the results using a random effects model. Results: Eight observational studies, involving more than 350 000 patients altogether and a median of 324 hospitals each, fulfilled our eligibility criteria. In 5 of 6 studies showing higher payments for care at private for-profit hospitals, the difference was statistically significant; in 1 of 2 studies showing higher payments for care at private not-for-profit hospitals, the difference was statistically significant. The pooled estimate demonstrated that private for-profit hospitals were associated with higher payments for care (relative payments for care 1.19, 95% confidence interval 1.07–1.33, p = 0.001). Interpretation: Private for-profit hospitals result in higher payments for care than private not-for-profit hospitals. Evidence strongly supports a policy of not-for-profit health care delivery at the hospital level.

Ultrasound Imaging Accurately Identifies the Lateral Femoral Cutaneous Nerve

BACKGROUND:Anesthesia of the lateral femoral cutaneous nerve (LFCN) is useful in surgery involving the anterolateral thigh. We investigated the accuracy of ultrasound compared with anatomical landmarks in identifying the LFCN in human cadavers and volunteers. METHODS:Twenty cadavers were examined. A needle was inserted targeting the LFCN with ultrasound guidance and green dye was injected. A second needle was inserted using anatomical landmarks. The LFCN was identified by dissection, and coloring of the LFCN and needle positions were evaluated. A volunteer study with 10 individuals was performed. Transdermal nerve stimulation was used to identify the LFCN bilaterally. Its position was compared with marked positions identified in advance using ultrasound and anatomical landmarks. RESULTS:Sixteen of 19 needles inserted under ultrasound guidance in the cadavers were in contact with the LFCN. The median horizontal distance from the needle tip to the nerve was 0.0 mm (interquartile range [IQR], 0.0-0.0 mm). Only 1 of 19 needles inserted using anatomical landmarks was in contact with the LFCN. The median horizontal distance from the needle tip to the nerve was 18.0 mm (IQR, 11.0–23.0 mm). Sixteen of 20 marked positions made using ultrasound guidance corresponded to the identified LFCN in volunteers. The median horizontal distance from the pen-mark to the LFCN was 0.0 mm (IQR, 0.0-0.0 mm). None of the 20 marked positions made with anatomical landmarks corresponded to the LFCN. The median horizontal distance from the pen-mark to the LFCN was 15.0 mm (IQR, 10.8–20.0 mm). CONCLUSIONS:Identification of the LFCN by ultrasound is technically feasible and more accurate than anatomical landmarks.

The cricoid cartilage and the esophagus are not aligned in close to half of adult patients

PurposeTo determine the frequency and degree of lateral displacement of the esophagus relative to the cricoid cartilage (“cricoid”) using computed tomography (CT) images of normal necks.MethodsFifty-one cervical CT scans of clinically normal patients were reviewed retrospectively. Esophageal diameter, distance between the midline of the cricoid and the midline of the esophagus, and distance between the lateral border of the cricoid and the lateral border of the esophagus were measured.ResultsLateral esophageal displacement was observed in 49% (25/51) of CT images. When present, the mean length of displaced esophagus relative to the midline of the cricoid was 3.3 mm ± SD 1.3 mm. Of those with lateral displacement, 64% had esophageal displacement beyond the lateral border of the cricoid (mean 3.2 mm ± SD 1.2 mm). There is a relatively normal distribution of the grouped measures of percentage of esophageal diameter that is displaced. Of those with displacement, 48% had over 15% of the total width of the esophagus displaced laterally and 20% had over 20% of the esophageal width displaced laterally.ConclusionThere is a 49% frequency of some degree of lateral displacement of the esophagus relative to the cricoid.RésuméObjectifDéterminer la fréquence et le degré de déplacement latéral de l’œsophage relativement au cartilage cricoïde («cricoïde») en utilisant les Images tomodensltométriques cervicales normales.MéthodeCinquante et une Images de tomodensltométrle cervicale de patients diniquement normaux ont été revues rétrospectivement. Le diamètre œsophagien, la distance entre la ligne médiane du cricoïde et celle de l’œsophage et la distance entre le bord latéral du cricoïde et celui de l’œsophage ont été mesurées.RésultatsLe déplacement latéral de l’œsophage a été observé dans 49% (25/51) des Images. Lorsqu’il était présent, il était en moyenne de 3,3 mm ± 1,3 mm d’écart type par rapport à la ligne médiane du cricoïde. Soixantequatre pour cent des déplacements latéraux de l’œsophage allaient au delà du bord latéral du cricoïde (moyenne de 3,2 mm ± 1,2 mm d’écart type). Nous avons noté une distribution relativement normale des mesures groupées de pourcentage de diamètre œsophagien déplacés. De ces déplacements, 48% présentaient plus de 15% de la largeur totale de l’œsophage déplacé latéralement et 20% avaient plus de 20% de déplacement.ConclusionLa fréquence de déplacement latéral de l’œsophage d’un certain degré par rapport au cricoïde est de 49%.

Induction with sevoflurane-remifentanil is comparable to propofol-fentanyl-rocuronium in PONV after laparoscopic surgery

PurposeTo compare sevoflurane-remifentanil induction and propofol-fentanyl-rocuronium induction with regards to the frequency of moderate to severe postoperative nausea and vomiting (PONV) in the first 24 hr after laparoscopic day surgery.MethodsAfter informed consent, 156 ASA physical status class I to III patients undergoing laparoscopic cholecystectomy or tubal ligation were randomized to either induction with sevoflurane 8%, N2O 67% and iv remifentanil I to 1.5 βg · kg−1 or induction with iv fentanyl 2 to 3 μg · kg−1, propofol 2 mg · kg−1, and rocuronium 0.3 to 0.5 mg · kg−1. All patients received iv ketorolac 0.5 mg · kg−1 at induction and sevoflurane-N2O maintenance anesthesia with rocuronium as needed. PONV was treated with iv ondansetron, droperidol, or dimenhydrinate; postoperative pain was treated with opioid analgesics. Patients were followed for 24 hr with regards to PONV and pain. Intubating conditions, induction and emergence times, time to achieve fast-track discharge criteria, and drug costs were measured.ResultsNo differences were seen between the two groups in their frequencies of 24-hr moderate to severe PONV and postoperative pain, or in their intubating conditions, induction and emergence times, and time to achieve fast-track discharge criteria. Patients undergoing sevoflurane-remifentanil induction received more morphine (11 mg vs 8 mg; P < 0.001) in the postanesthetic care unit. Sevoflurane-remifentanil induction resulted in similar anesthetic and total drug costs for both procedures.ConclusionWe did not demonstrate any difference in PONV pain, or anesthetic/recovery times or costs between the sevoflurane and propofol groups. Sevoflurane-remifentanil induction is a feasible technique for anesthetic induction.RésuméObjectifComparer l’induction avec sévoflurane-rémifentanil ou propofol-fentanyl-rocuronium quant à la fréquence de nausées et vomissements postopératoires (NVPO) de modérés à sévères pendant les 24 premières heures après une opération en chirurgie d’un jour sous laparoscopie.MéthodeAprès avoir accordé leur consentement, 156 patients d’état physique ASA I à III devant subir une cholécystectomie laparoscopique ou une ligature des trompes ont été randomisés pour une induction avec du sévoflurane à 8%, N2O à 67 % et l à 1,5 μg · kg−1 de rémifentanil iv ou une induction iv avec 2 à 3 μg · kg−1 de fentanyl, 2 mg · kg−1 de propofol et 0,3 à 0,5 mg · kg−1 de rocuronium. Tous les patients ont reçu 0,5 mg · kg−1 de kétorolac iv à l’induction et un mélange de sévoflurane-N2O pour le maintien de l’anesthésie, avec rocuronium au besoin. Un traitement iv avec ondansétron, dropéridol ou dimenhydrinate a été donné pour les NVPO et la douleur postopératoire a été soulagée avec des analgésiques opioïdes. Les patients ont été suivis pendant 24 h pour les NVPO et la douleur. Ont été notés: les conditions d’intubation, les temps nécessaires à l’induction et au réveil, le temps d’atteindre les critères de congé de la chirurgie ambulatoire et le coût des médicaments.RésultatsAucune différence intergroupe n’a été enregistrée concernant la fréquence de NVPO de modérés à sévères et la douleur postopératoire pendant 24 h, ou les conditions d’intubation, les temps d’induction et de réveil, de même que le temps nécessaire à l’atteinte des critères de congé. Les patients soumis à une induction avec un mélange de sévoflurane-rémifentanil ont demandé plus de morphine (11 mg vs 8 mg; P < 0,001) en salle de réveil. L’induction avec sévoflurane-rémifentanil a conduit à un usage d’anesthésiques et à un coût total de médicaments similaires pour les deux types d’interventions chirurgicales.ConclusionNous n’avons trouvé aucune différence de NVPO, de douleur ou de temps liés à l’analgésie et à la récupération postopératoires entre les groupes sous sévoflurane ou propofol. Un mélange de sévoflurane-rémifentanil peut servir à l’induction de l’anesthésie.

The use of glycopyrrolate in a case of intermediate syndrome following acute organophosphate poisoning

PurposeThis report describes a case of organophosphate intoxication refractory to atropine in which glycopyrrolate was used to reduce cholinergic symptoms, and describes the development of intermediate syndrome, an uncommon subacute complication of organophosphate poisoning.Clinical featuresA 44-yr-old woman presented in cholinergic crisis following malathion ingestion. Treatment was initiated with atropine and pralidoxime. Despite clinical signs of adequate atropinisation, the patient continued to have profuse bronchorrhoea, which resolved with glycopyrrolate. During her course in the intensive care unit, she displayed a subacute deterioration in neuromuscular and mental status with decrement-increment phenomenon on electromyography consistent with intermediate syndrome. The patient eventually made a complete recovery.ConclusionThis case report describes the successful use of glycopyrrolate in organophosphate intoxication and the development of the intermediate syndrome, characterised by onset of weakness of neck flexors, proximal limb muscles, and respiratory muscles within one to four days after poisoning. Recognition of the syndrome is important in light of the potential for respiratory depression requiring ventilatory support.RésuméObjectifCette observation décrit un cas d’intoxication aux organophosphorés réfractaire à l’atropine où le glycopyrrolate a été utilisé pour diminuer les symptômes cholinergiques, et décrit aussi le développement d’un syndrome intermédiaire, une complication subaiguë non fréquente de l’empoisonnement aux organophosphorés. Éléments cliniques: Une femme de 44 ans se présente en crise cholinergique suite à l’ingestion de malathion. On débute le traitement à l’atropine et à la pralidoxime. Malgré des signes cliniques d’atropinisation adéquate, la patiente continue à présenter une bronchorrhée profuse, qui rentre dans l’ordre avec le glycopyrrolate. Durant son séjour aux soins intensifs, elle présente une détérioration subaiguë de la fonction neuromusculaire et mentale avec phénomène incrémentiel-décrémentiel à l’électromyographie, compatible avec un syndrome intermédiaire. Cette patiente va éventuellement récupérer complètement.ConclusionCette observation à propos d’un cas décrit l’utilisation avec succès du glycopyrrolate dans l’intoxication aux organophosphorés et la survenue d’un syndrome intermédiaire caractérisé par l’apparition de faiblesse au niveau des fléchisseurs du cou, des muscles proximaux des membres et des muscles respiratoires survenant dans un délai de un à quatre jours après l’intoxication, (Lidentification de ce syndrome est importante à cause de son potentiel d’insuffisance respiratoire nécessitant un support ventilatoire.

Concurrent subarachnoid haemorrhage and myocardial injury

PurposeSubarachnoid haemorrhage is frequently associated with myocardial injury and dysfunction. This report describes such a case, reviews the understanding of this phenomenon, and discusses the implications for timing of surgical clipping of intracranial aneurysm in patients with concurrent myocardial damage.Clinical FeaturesA 64-yr-old woman presented with syncope and congestive heart failure. A diagnosis of subarachnoid haemorrhage was made three days following the initial diagnosis of myocardial infarction. The patient presented for clipping of an intracranial aneurysm on day 36, after her cardiac status had stabilized. No new myocardial ischaemic events occurred, either intra-operatively or post-operatively. Ultimate neurological recovery was poor.ConclusionsThis case report demonstrates four important aspects of the clinical course of patients with concurrent subarachnoid haemorrhage and myocardial damage: 1) On presentation, cardiac features may predominate, and delay diagnosis and treatment of the underlying subarachnoid haemorrhage. 2) Left ventncular dysfunction, although dramatic, is usually transient. 3) There is confusion regarding the appropriate cardiac risk assessment and management in such patients when presenting for surgery. 4) Long-term morbidity is most often related to neurological, not medical, complications.RésuméObjectifL’hémorragie sous-arachnoïdienne s’accompagne souvent d’une lésion et d’un dysfonctionnement myocardiques. Ce compte rendu décnt un cas de cette affection, fait un survol de nos connaissances et discute de I’importance de ben planifier le moment de clamper I’anévrisme intracrânien chez des patients atteints d’une lésion myocardique.Éléments cliniquesUne femme de 64 ans se présente en état de syncope et d’insuffisance cardiaque. On constate qu’elle présente une hémorragie sous-arachnoïdienne trois jours après le diagnostic initial d’infarctus du myocarde. Trente-six jours plus tard, après stabilisation de la condition cardiaque, on insère un clip sur un col anévrismal. Elle ne présente pas de nouveaux épisodes d’ischémie myocardique peropératoires et postopératoires. La récupération neurologique définitive a été médiocre.ConclusionsCette observation illustre quatre aspect importants de I’évolution clinique de patients victimes d’hémorragie sous-arachnoïdienne et de lésion myocardique simultanées: 1) au départ, les éléments cardiaques peuvent prédominer et retarder le diagnostic et le traitement de l’hémorragie sous-arachnoïdienne sous-jacente. 2) L’insuffisance ventriculaire gauche tout en étant dramatique est transitoire. 3) L’évaluation du risque cardiaque et la prise en charge de ce type de patient pour la chirurgie prête à confusion. 4) la morbidité a long terme est plus souvent en rapport avec les complication neurologiques que cardiaques.