Midazolam Premedication Immediately Before Surgery Is Not Associated With Early Postoperative Delirium.

BACKGROUND: Postoperative delirium is common among older surgical patients and may be associated with anesthetic management during the perioperative period. The aim of this study is to assess whether intravenous midazolam, a short-acting benzodiazepine used frequently as premedication, increased the incidence of postoperative delirium. METHODS: Analyses of existing data were conducted using a database created from 3 prospective studies in patients aged 65 years or older who underwent elective major noncardiac surgery. Postoperative delirium occurring on the first postoperative day was measured using the confusion assessment method. We assessed the association between the use or nonuse of premedication with midazolam and postoperative delirium using a χ2 test, using propensity scores to match up with 3 midazolam patients for each control patient who did not receive midazolam. RESULTS: A total of 1266 patients were included in this study. Intravenous midazolam was administered as premedication in 909 patients (72%), and 357 patients did not receive midazolam. Those who did and did not receive midazolam significantly differed in age, Charlson comorbidity scores, preoperative cognitive status, preoperative use of benzodiazepines, type of surgery, and year of surgery. Propensity score matching for these variables and American Society of Anesthesiology physical status scores resulted in propensity score-matched samples with 1-3 patients who used midazolam (N = 749) for each patient who did not receive midazolam (N = 357). After propensity score matching, all standardized differences in preoperative patient characteristics ranged from -0.07 to 0.06, indicating good balance on baseline variables between the 2 exposure groups. No association was found between premedication with midazolam and incident delirium on the morning of the first postoperative day in the matched dataset, with odds ratio (95% confidence interval) of 0.91 (0.65-1.29), P = .67. CONCLUSIONS: Premedication using midazolam was not associated with higher incidence of delirium on the first postoperative day in older patients undergoing major noncardiac surgery.

Awake Sedation With Propofol Attenuates Intraoperative Stress of Carotid Endarterectomy in Regional Anesthesia.

BACKGROUND: Carotid endarterectomy in regional anesthesia is often associated with increased perioperative stress. We assumed that carotid endarterectomy performed under awake sedation with propofol is more beneficial to prevent such stress than alprazolam premedication only. METHODS: A total of 47 consecutive patients with significant carotid artery stenosis were enrolled into this investigation and followed up for 5 years to explore vascular complications. All operations were performed under regional anesthesia. As premedication, all patients took 0.5 mg of alprazolam 30 minutes before the procedure. After randomization, 22 patients had awake sedation with target controlled propofol infusion, and the other 25 had only premedication. Cortisol plasma levels were serially analyzed: before surgery (T1), before (T2) and after release of carotid clamp (T3), and at 2 (T4) and 24 postoperative hours (T5). Alprazolam levels were also measured before and after the surgery. RESULTS: The plasma concentration of cortisol was significantly lower in the propofol sedation group at T2 (P < 0.001), T3 (P = 0.001), and T4 (P < 0.001) than in the alprazolam-only group. Alprazolam levels did not correlate with cortisol levels at any time point. A significant positive correlation was found between the clamp time and plasma cortisol level at T3 (P = 0.018), similarly between the degree of contralateral carotid stenosis and plasma cortisol level at T3 (P = 0.03). Plasma cortisol concentration 2 hours after the operation (T4) proved to be an independent predictor of carotid restenosis during the 5-year follow-up (odds ratio: 1.67, 95% confidence interval: 1.02-2.73, P = 0.04). CONCLUSIONS: An additional intraoperative propofol sedation provides better stress relief than alprazolam-only premedication during awake carotid endarterectomy.

No Pain, More Gain: Reduced Postoperative Opioid Consumption with a Standardized Opioid-Sparing Multimodal Analgesia Protocol in Opioid-Tolerant Patients Undergoing Colorectal Surgery.

The utility of opioid-sparing multimodal analgesia protocols (OSMMAPs) in opioid-tolerant (OT) patients is unknown. We sought to determine the impact of a standardized OSMMAP in OT versus opioid-naïve (ON) patients after major colorectal surgery. Consecutive patients undergoing surgery before (January 2015-March 2017) and after OSMMAP implementation (April 2017-March 2018) were identified from a single-institution prospective colorectal surgery registry. OT was defined by the presence of an opioid on the preadmission medication record. Opioid use (measured in oral morphine equivalents (OMEs)) and surgical outcomes were compared between OT and ON patients pre- and post-OSMMAP. The study cohort of 201 patients included 59 OT patients (25 pre- and 34 post-OSMMAP) and 142 ON controls (34 pre- and 108 post-OSMMAP). The median age was 47.5 years (IQR 32), and 50% were male. 185 patients (92%) had a laparoscopic/robotic resection and 16 (8%) open. There were statistically significant reductions in OME required post-OSMMAP on each postoperative day (days 1 to 4) and cumulative OME for both OT and ON patients. The reduction in opioid requirements was significantly larger in OT than ON patients. We present the first study highlighting a larger opioid usage reduction in OT than in ON patients after OSMMAP implementation.

Postinduction apnoea in dogs premedicated with acepromazine or dexmedetomidine and anaesthetized with alfaxalone or propofol.

OBJECTIVE: To compare incidence and duration of postinduction apnoea in dogs after premedication with methadone and acepromazine (MA) or methadone and dexmedetomidine (MD) followed by induction with propofol (P) or alfaxalone (A). STUDY DESIGN: Prospective, randomized clinical trial. ANIMALS: A total of 32 American Society of Anesthesiologists class I dogs (15 females, 17 males), aged between 4 months and 4 years, weighing between 3 and 46 kg. METHODS: Dogs were randomly allocated to be administered MA+P, MA+A, MD+P or MD+A (methadone 0.5 mg kg-1 and acepromazine 0.05 mg kg-1 or dexmedetomidine 5 µg kg-1). Induction agents were administered intravenously via syringe driver (P at 4 mg kg-1 minute-1 or A at 2 mg kg-1 minute-1) until successful endotracheal intubation and the endotracheal tube connected to a circle system with oxygen flow at 2 L minute-1. Oxygen saturation of haemoglobin (SpO2), end tidal partial pressure of carbon dioxide and respiratory rate were monitored continuously. If apnoea (≥ 30 seconds without breathing) occurred, the duration until first spontaneous breath was measured. If SpO2 decreased below 90% the experiment was stopped and manual ventilation initiated. Data were analysed with general linear models with significance set at p ≤ 0.05. RESULTS: There was no statistical difference in the incidence (11 of 16 dogs in A groups and 12 of 16 dogs in P groups), or mean ± standard deviation duration (A groups 125 ± 113 seconds, P groups 119 ± 109 seconds) of apnoea. The SpO2 of one dog in the MD+P group decreased below 90% during the apnoeic period. CONCLUSIONS AND CLINICAL RELEVANCE: Propofol and alfaxalone both cause postinduction apnoea and the incidence and duration of apnoea is not influenced by the use of acepromazine or dexmedetomidine in premedication. Monitoring of respiration is recommended when using these premedication and induction agent combinations.

¿La exposición a anestesia general en niños afecta el rendimiento académico y cognitivo a largo plazo? / Does the exposure to general anaesthesia in children affect long-term academic and cognitive performance?

Conclusiones de los autores del estudio: la exposición anestésica a edades menores de cuatro años tiene un efecto pequeño sobre el rendimiento académico o inteligencia en la adolescencia. Aunque pueden existir grupos vulnerables con un riesgo mayor, la baja diferencia global en el rendimiento académico en niños expuestos a cirugía es tranquilizadora. Comentario de los revisores: aunque se trata de un efecto mínimo y dudoso, es una información que debemos considerar cuando nos planteemos someter niños en edad preescolar a actos quirúrgicos programados que podrían ser aplazados (AU)

Authors’ conclusions: exposure to anaesthesia before the age of four years has a small association with academic or cognitive performance in adolescence. While more vulnerable groups of children may exist, the low overall difference in academic performance after childhood exposure to surgery is reassuring. Reviewers’ commentary: although this is a minimal and doubtful effect, this information should be taken into account when assessing toddlers for whom we are considering programmed surgery for indications that could be postponed (AU)

Incidence of bradycardia at arrival to the operating room after oral or intravenous premedication with clonidine in children.

BACKGROUND: Clonidine has been advocated as a valid alternative for premedication in children but one of the few limitations is its association with reduced heart rate (HR), which thus raises the question of the safety of clonidine as premedication in children. The aim of this study was to investigate the incidence of bradycardia in children premedicated with oral or intravenous clonidine as compared to children not receiving pharmacologic premedication. METHODS: An open, nonrandomized, observational study design was used. During the preoperative assessment visit the children were prescribed no premedication, intravenous or oral clonidine. On arrival to the operating room (OR) HR was recorded by connecting the patient to standard monitoring with pulseoximetry and/or Electrocardiogram. The primary outcome measure was the number of patients with a HR below 85% of the lower limit of the normal range (1st centile), which was defined as bradycardia that might need clinical intervention. RESULTS: One thousand five hundred and seven patients were included in the analysis. 600 and 85 patients did not receive any premedication (Group 0), 305 patients received iv Clonidine (Group CIV), and 517 patients were given oral Clonidine (Group CPO). One patient in Group 0 (0.15%; 95% CI: 0-0.81%), none in Group CIV (0%; 95% CI: 0.00-0.98%), and 5 patients in Group CPO (0.97%; 95% CI: 0.31-2.24%) were observed to have a HR of <85% of the 1st centile. CONCLUSION: The incidence of bradycardia following oral or intravenous premedication with clonidine in a pediatric population scheduled for anesthesia is low. Thus, it does not appear rational to refrain from using clonidine as premedication in children only due to fear of bradycardia.

Efficacy of maropitant in preventing vomiting in dogs premedicated with hydromorphone.

OBJECTIVE: The goal of this study was to evaluate the effectiveness of maropitant (Cerenia(®)) in preventing vomiting after premedication with hydromorphone. STUDY DESIGN: Randomized, blinded, prospective clinical study. ANIMALS: Eighteen dogs ASA I/II admitted for elective orthopedic surgical procedures. The dogs were a mixed population of males and females, purebreds and mixed breeds, 1.0-10.2 years of age, weighing 3-49.5 kg. METHODS: Dogs were admitted to the study if they were greater than 1 year of age, healthy and scheduled to undergo elective orthopedic surgery. Dogs were randomly selected to receive one of two treatments administered by subcutaneous injection. Group M received 1.0 mg kg(-1) of maropitant, Group S received 0.1 mL kg(-1) of saline 1 hour prior to anesthesia premedication. Dogs were premedicated with 0.1 mg kg(-1) of hydromorphone intramuscularly. A blinded observer documented the presence of vomiting, retching and/or signs of nausea for 30 minutes after premedication. RESULTS: All dogs in S vomited (6/9), retched (1/9) or displayed signs of nausea (2/9). None (0/9) of the dogs in M vomited, retched or displayed signs of nausea. Dogs in M had significantly fewer incidences of vomiting (p=0.0090), vomiting and retching (p=0.0023) and vomiting, retching and nausea (p<0.0001) when compared to S. CONCLUSION AND CLINICAL RELEVANCE: Maropitant prevents vomiting, retching and nausea associated with intramuscular hydromorphone administration in dogs.

[Low-dose aspirin doesn't increase surgical bleeding nor transfusion rate in total knee arthroplasty]. / El tratamiento preoperatorio con aspirina a dosis bajas no aumenta la hemorragia quirúrgica ni la tasa transfusional en la prótesis total de rodilla.

OBJECTIVES: Surgical bleeding. transfusion rate and cardiovascular complications were analized in patients undergoing chronic treatment with low-doses aspirin and scheduled to unilateral primary knee arthroplasty. PATIENTS AND METHODS: We retrospectively studied 117 patients between 2005 and 2006 scheduled for elective knee replacement that received antiplatelet therapy with aspirin (100mg/day). Aspirin medication was maintained or discontinued preoperatively according to medical criteria. We analyzed the biological, clinical and anesthetic data, blood-saving techniques used, surgical bleeding, allogeneic blood transfusion rate, cardiocirculatory complications (myocardial, cerebral or peripheral ischemia), hospital stay and mortality. This population was compared with 190 patients (control group) who underwent the same operation at the same time interval but did not receive aspirin therapy. RESULTS: The aspirin-treated group was significantly older, with higher weight and poorer health state (higher incidence of ischemic heart disease, cerebral ischemia and diabetes). The hidden and external surgical bleeding and transfusion rate were similar if the aspirin were interrupted or not, preoperatively. Bleeding and transfusion rates were independent of time of interruption of the aspirin. Hospital mortality was zero in the 2 groups. A acute myocardial infarction and a transient stroke happened in two patients wich aspirin treatment was discontinued. CONCLUSIONS: Preoperative treatment with low doses of aspirin does not increase surgical bleeding and transfusion rate in total knee arthroplasty. Preoperative discontinuation can cause severe cardiocirculatory complications.

Risk of anaesthetic mortality in dogs and cats: an observational cohort study of 3546 cases.

OBJECTIVE: To evaluate the anaesthetic death risk for dogs and cats in a French private practice. STUDY DESIGN: Observational cohort study. ANIMAL POPULATION: All small animals anesthetized at the Centre Hospitalier Vétérinaire des Cordeliers between April 15th, 2008 and April 15th, 2010. METHODS: General anaesthesia was defined as a drug-induced unconsciousness characterised by a controlled and reversible depression of the central nervous system and analgesia, sufficient to allow endotracheal intubation. Patient outcome (alive or dead) was assessed at the end of anaesthesia defined as the meeting point of the return of consciousness, rectal temperature >36 °C and ability to maintain sternal recumbency. Death occurring during anaesthesia was recorded. Relationship between anaesthetic death and ASA status, species, age, nature of the procedure, anaesthetic protocol and occurrence of epidural administration of a combination of morphine and bupivacaine were analysed. RESULTS: During the study period 3546 animals underwent general anaesthesia. The overall death rate in the present study was 1.35% (48 in 3546, 95% CI 0.96-1.75). The death rate of healthy animals (ASA 1 and 2) was 0.12% (3 in 2602 95% CI 0.02-0.34). For sick animals (ASA status 3 and over), the overall death rate was 4.77% (45 in 944 95% CI 3.36-6.18). The death rates in the ASA 3, 4 and 5 categories were 2.90%, 7.58% and 17.33%, respectively. The main factor associated with increased odds of anaesthetic death in ASA categories 3 and over was poor health status (ASA physical status classification). The nature of the procedure the patient underwent and epidural administration of a combination of morphine and bupivacaine were not correlated with the occurrence of death during anaesthesia. Neither species nor age effects were detected. CONCLUSION AND CLINICAL RELEVANCE: Specific factors were associated with increased odds of anaesthetic death, especially poor health status. Efforts must be directed towards thorough preoperative patient evaluation and improvement of clinical conditions if possible. Identification of risk factors before anaesthesia should lead to increased surveillance by trained staff. This could result in better outcomes.

Effects of acepromazine maleate or morphine on tear production before, during, and after sevoflurane anesthesia in dogs.

OBJECTIVE: To investigate the effects of acepromazine maleate and morphine on aqueous tear production before, during, and after sevoflurane anesthesia in dogs. ANIMALS: 6 mixed-breed dogs. PROCEDURES: In a Latin square study design, dogs underwent i.m. administration of morphine (1 mg/kg), acepromazine (0.05 mg/kg), or saline (0.9% NaCl) solution (0.05 mL/kg), followed by induction and maintenance of anesthesia with sevoflurane for 30 minutes. The protocol was repeated until all dogs had received all treatments, with a minimum of 7 days between anesthetic episodes. Aqueous tear production was measured via Schirmer tear test I before treatment (baseline); before anesthetic induction; 5, 10, 20, and 30 minutes after anesthetic induction; immediately once dogs recovered from anesthesia; and 2 and 10 hours after recovery. RESULTS: Aqueous tear production for all treatments was significantly lower 10, 20, and 30 minutes (but not 5 minutes) after anesthetic induction than at baseline, before anesthetic induction, at recovery, and 2 and 10 hours after recovery. Aqueous tear production was significantly higher after saline solution administration than after morphine administration at the preinduction measurement point and 2 hours after recovery. No other differences were detected among the 3 treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Aqueous tear production after anesthesia did not differ significantly from baseline values after any treatment following 30 minutes of sevoflurane anesthesia, suggesting premedication with morphine or acepromazine does not contribute to a decrease in lacrimation in these circumstances.

Low-dose (1 microg/kg) clonidine premedication and hypotension after carotid artery surgery.

We investigated the role of low-dose clonidine intravenous (IV) premedication in arterial pressure variation during and after carotid endarterectomy (CEA). A total of 84 patients, American Society of Anesthesiologists (ASA) II-III, scheduled for elective CEA under general anesthesia participated in this study. The patients were divided into 2 groups: group P (n = 42) and group C (n = 42) and received N/S 0.9% (placebo) or clonidine 1 µg/kg IV, respectively, 15 minutes before induction of anesthesia. Recovery times, number of patients needed to be treated for circulatory events (hypertension, hypotension, and bradycardia), number of circulatory events per patient, and consumption of vasoactive drugs (nitroglycerine, phenylphrine, and atropine) intraoperatively and the first 6 hours postoperatively were recorded. Significantly less hypertensive episodes were observed intraoperatively, but more hypotensive episodes were observed postoperatively in patients receiving clonidine. Intravenous premedication with low-dose clonidine (1 µg/kg) seems to be effective in preventing hypertensive episodes during CEA under general anesthesia but seems to increase the incidence of hypotension postoperatively.

Perioperative effects of oral midazolam premedication in children undergoing skin laser treatment. A double-blinded randomized placebo-controlled trial.

PURPOSE: To investigate and compare the efficacy of oral midazolam with two different dosages in orange juice on perioperative hemodynamics and behavioral changes in children who underwent skin laser treatment in an academic educational Hospital. METHODS: Ninety children, candidates for skin laser treatment were randomly assigned to 1 of 3 groups of 30 each: the placebo group received 0.1 ml/kg orange flavored juice, group 2 and 3 receiving 0.5 and 1 mg/kg of injectable midazolam mixed with an equal volume of orange juice, respectively. The main outcome measures included the mask acceptance, patients' behavioral scales and postoperative events. RESULTS: There were no significant differences in heart rate, respiratory rate, and systolic blood pressure among the three groups. However, arterial oxygen saturation was significantly reduced in those given 1 mg.kg(-1) midazolam. The median scores of anxiety, separation from parent, preparing an intravenous line, acceptance of the oxygen mask, good sedation, crying reduction and consciousness level were better in midazolam group. Postoperative agitation and re-crying were also more frequent in placebo receivers. Those given 1 mg.kg(-1) midazolam were significantly more optimal for sedation, crying, consciousness, preparing an intravenous line, and postoperative re-crying compared with 0.5 mg.kg(-1) midazolam receivers. CONCLUSION: As a preanaesthetic medication, the 1 mg.kg(-1) dose of orally given midazolam especially in a volume of orange juice and can optimize the children's behavior during skin laser treatment with no serious adverse effects, enhancing their parents' satisfactions about the sedative protocol.

Perioperative effects of oral midazolam premedication in children undergoing skin laser treatment: a double-blinded randomized placebo-controlled trial / Efeitos peroperatórios da premedicação oral de midazolam em crianças submetidas a tratamento de pele por laser: estudo duplo-cego randomizado e controlado

PURPOSE: To investigate and compare the efficacy of oral midazolam with two different dosages in orange juice on perioperative hemodynamics and behavioral changes in children who underwent skin laser treatment in an academic educational Hospital. METHODS: Ninety children, candidates for skin laser treatment were randomly assigned to 1 of 3 groups of 30 each: the placebo group received 0.1 ml/kg orange flavored juice, group 2 and 3 receiving 0.5 and 1 mg/kg of injectable midazolam mixed with an equal volume of orange juice, respectively. The main outcome measures included the mask acceptance, patients' behavioral scales and postoperative events. RESULTS: There were no significant differences in heart rate, respiratory rate, and systolic blood pressure among the three groups. However, arterial oxygen saturation was significantly reduced in those given 1 mg.kg-1 midazolam. The median scores of anxiety, separation from parent, preparing an intravenous line, acceptance of the oxygen mask, good sedation, crying reduction and consciousness level were better in midazolam group. Postoperative agitation and re-crying were also more frequent in placebo receivers. Those given 1 mg.kg-1 midazolam were significantly more optimal for sedation, crying, consciousness, preparing an intravenous line, and postoperative re-crying compared with 0.5 mg.kg-1 midazolam receivers. CONCLUSION: As a preanaesthetic medication, the 1 mg.kg-1 dose of orally given midazolam especially in a volume of orange juice and can optimize the children's behavior during skin laser treatment with no serious adverse effects, enhancing their parents' satisfactions about the sedative protocol.

OBJETIVO:Investigar e comparar a eficácia do uso oral de midazolam com duas diferentes doses de suco de laranja na hemodinâmica peropeatória e mudanças de desempenho em crianças submetidas tratamento de pele por laser em Hospital educacional e acadêmico. MÉTODOS:Noventa crianças candidatas a tratamento de pele por laser foram distribuídas aleatóriamente em três grupos de 30 cada: o grupo placebo recebeu 0.1mg/kg de suco de laranja, grupos dois e três receberam 0.5 e 1mg/kg de midazolam injetável misturado em igual volume de suco de laranja respectivamente. Os principais registros incluíam a aceitação da máscara, escalas de comportamento e eventos pós-operatórios. RESULTADOS:Não houve diferenças significantes cardíacas, respiratórias e pressão sanguinea sistólica nos três grupos. Contudo, o nível de saturação de oxigênio foi reduzido significantemente nos que receberam 1mg.kg-1 de midazolam. Os níveis médios de ansiedade, separação dos pais, preparo intravenoso, aceitação da máscara de oxigênio, boa sedação, redução do choro e nível de consciência, foram melhores no grupo midazolam. Agitação pós-operatória e retorno do chora foi mais freqüente nos que receberam placebo. Observou-se que o grupo que recebeu 1mg.kg-1 foi melhor comparado ao que recebeu 0.5mg.kg-1. CONCLUSÃO:Como medicação pré-anestésica na dose de 1mg.kg-1 de midazolam, fornecida em igual volume de suco de laranja, é satisfatória no comportamento de crianças durante tratamento de pele por laser, proporcionando satisfação dos pais.

A comparison of anesthetic complications between diabetic and nondiabetic dogs undergoing phacoemulsification cataract surgery: a retrospective study.

OBJECTIVE: To compare the incidence of anesthetic complications in diabetic and nondiabetic dogs undergoing general anesthesia and phacoemulsification cataract surgery. PROCEDURE: The medical and anesthetic records of all dogs undergoing phacoemulsification cataract surgery at Davies Veterinary Specialists between 2005 and 2008 were reviewed. Anesthetic records were evaluated by an ECVAA Diplomate. Dogs for which records were incomplete were excluded. The anesthetic technique, including all drugs administered in the perioperative period, was recorded. The anesthetic complications investigated included hypotension (MAP (mmHg): >or=55 none/mild; 13.75 mmol/L (250 mg/dL)) in the diabetic group was also assessed. RESULTS: 66 diabetic and 64 nondiabetic dogs were included in the study. Diabetic dogs were more likely to develop moderate and severe intraoperative hypotension than nondiabetic dogs. Forty-four percent of diabetic dogs had at least one episode of severe hyperglycemia whilst anesthetized. CONCLUSIONS: Diabetic dogs undergoing phacoemulsification are more likely to suffer the anesthetic complications of moderate and severe hypotension than nondiabetic dogs. The increased incidence and severity of hypotension in diabetic dogs may be explained by hypovolemia secondary to hyperglycemia and resultant osmotic diuresis.