The effect of norepinephrine versus epinephrine in irrigation fluid on the incidence of hypotensive/bradycardic events during arthroscopic rotator cuff repair with interscalene block in the sitting position.

PURPOSE: To compare the occurrence rate of hypotensive and bradycardic events (HBEs) during arthroscopic rotator cuff repair performed with interscalene brachial plexus block anesthesia in the sitting position in 2 groups of patients who underwent the procedure with norepinephrine or epinephrine added to the irrigation fluid. The secondary objective was to evaluate the efficacy of norepinephrine in comparison with epinephrine in controlling intraoperative bleeding and maintaining adequate visualization of the arthroscopic field of view during the procedure. We hypothesized that norepinephrine added to the irrigation fluid during shoulder arthroscopy in the sitting position would reduce the occurrence of HBEs, allowing optimal intraoperative bleeding control. METHODS: One hundred twenty patients underwent an arthroscopic rotator cuff repair performed under peripheral anesthesia and in the beach-chair position. Patients were randomly divided into 2 groups of 60 cases each: Norepinephrine (0.66 mg/L) and epinephrine (0.33 mg/L) were added to irrigation bags in group N and group E, respectively. The primary outcome was the occurrence rate of HBEs during surgery. The secondary outcomes were timing of onset of HBEs, accompanying symptoms, and intraoperative bleeding that impaired arthroscopic visualization. The clarity of the visual field was rated postoperatively by the surgeon using a visual analog scale. Comparison between groups for all baseline variables and outcome measurements was performed with the χ(2) or Fisher exact test, as appropriate, for categorical variables and the Student t test or Mann-Whitney U test, as appropriate, for continuous variables. Significance was set at P < .05. RESULTS: One patient was excluded from group E because of block failure; therefore 119 patients were finally included in the study. Comparison between groups showed no significant differences in baseline characteristics. The occurrence rate of HBEs was significantly greater in group E (n = 15) than in group N (n = 5) (P = .02). No differences between groups were found in the average time of onset of HBEs, accompanying symptoms, and clarity of the visual field. CONCLUSIONS: Continuous administration of norepinephrine, 0.66 mg/L, diluted in irrigation fluid during arthroscopic rotator cuff repair with the patient in the beach-chair position reduces the incidence of HBEs and is as effective as epinephrine in controlling intraoperative bleeding and maintaining the visual clarity of the surgical field. LEVEL OF EVIDENCE: Level I, randomized clinical study.

Bilateral lumbar ultrasound-guided erector spinae plane block versus local anesthetic infiltration for perioperative analgesia in lumbar spine surgery: a randomized controlled trial.

BACKGROUND: Lumbar spinal surgery is associated with severe postoperative pain. We examined the analgesic efficacy of bilateral lumbar ultrasound-guided erector spinae plane block (ESPB) with ropivacaine compared with local infiltration. METHODS: Patients undergoing elective lumbar arthrodesis were randomly divided into two groups. Control group received 0.375% ropivacaine 40 mL through the wound, and ESPB group received preoperative bilateral ESPB with 0.375% ropivacaine 40 mL. Primary outcome was postoperative pain intensity at rest using a Numeric Rating Scale (NRS). Secondary outcomes included difference in pain intensity between preintervention and defined timepoints, total amount of opioid analgesic requested by the patients at the same timepoints, the incidence of any adverse event, and the length of hospital stay (LOS) after surgery. RESULTS: Sixty patients were enrolled in the study. After surgery we detected a NRS value of 1.9±1.5 in ESPB group and 5.9±1.6 in control group (P<0.001). About the opioid consumption we found a total sufentanil tablets consumption of 17±6 and 10±3 at 48 hours for control group and ESPB group, respectively (P<0.001). Concerning LOS, 30 (100%) patients in the control group and 22 (73.3%) in ESPB group were discharged after 72 hours (P=0.005). CONCLUSIONS: Bilateral ultrasound-guided ESPB offers improved postoperative analgesia compared with local infiltration in patients undergoing lumbar spinal surgery.

Erector spinae plane block in children: a narrative review.

The erector spinae plane block (ESPB) is a novel technique used in both adult and pediatric patients. Its use in children has mostly been described in terms of perioperative pain management for various types of surgery. After its introduction, anesthesiologists began using ESPBs in various surgical settings. As adequate analgesia along with a low complication rate were reported, interest in this technique dramatically increased. Many studies in adults and children, including randomized controlled trials, have been published, resulting in the emergence of different clinical indications, with various technical and pharmacological approaches currently evident in the literature. This narrative review aims to analyze the current evidence in order to guide practitioners towards a more homogeneous approach to ESPBs in children, with a major focus on clinical applications. The ESPB is an efficient, safe, and relatively easy technique to administer. It can be applied in a wide range of surgeries, includes thoracic, abdominal, hip, and femur surgery. Its usefulness is evident in the context of enhanced recovery after surgery protocols and multimodal analgesia. Single-shot, intermittent bolus, and continuous infusion techniques have been described, and non-inferiority has been observed when compared with other locoregional techniques. Even though both the efficacy and safety of the procedure are widely accepted, current evidence is predominantly based on case reports, with very few well-designed observational studies. Consequently, the level of evidence is still poor, and more well-designed double-blind, randomized, placebo-controlled trials are needed to refine the procedure for different clinical applications in the pediatric population.

Pain Management Optimisation by an Ultrasound-Guided Analgesic Technique in Outpatients with Plantar Fasciitis during High-Energy Extracorporeal Shock Wave Therapy.

OBJECTIVE: Several studies have demonstrated the efficacy of high-energy extracorporeal shock wave therapy (HESWT) for the treatment of painful foot diseases. A crucial complication of HESWT is the appearance of pain with the subsequent interruption of the procedure. The aim of this study was the evaluation of ultrasound (US)-guided posterior tibial nerve block (PTNB) efficacy in outpatients who discontinued the first application of HESWT due to surge of moderate-severe pain. METHODS: Twenty-one patients, scheduled for HESWT due to plantar fasciitis, who interrupted the treatment for surge of pain (numeric rating scale [NRS] 5), were enrolled. After interruption of the first treatment, the patients received US-guided PTNB for every subsequent HESWT session. The same skilled anaesthesiologist performed an US-guided PTNB all the times. Once the nerve was identified, the needle was inserted and 5ml mepivacaine 1% were injected. Intensity of pain during each procedure by NRS and evaluation of patient's adherence to the treatment were detected. RESULTS: The HESWT was split into only three applications giving in average about 0.25 mJ mm-2, and all patients completed the treatment sessions. US-guided PTNB showed a significant reduction of NRS (P < 0.01) between the first HEWST without anaesthesia and the three subsequent treatments under peripheral block. CONCLUSION: US-guided PTNB resulted a valid support for the HEWST in outpatients with plantar fasciitis because it reduced the pain during the procedure, allowing to minimise the patient discomfort and to give the therapeutic doses just in three sessions.

Hypobaric versus isobaric spinal levobupivacaine for total hip arthroplasty.

BACKGROUND: Spinal anesthesia (SA) in the lateral decubitus position is often used to perform total hip arthroplasty (THA). Hypobaric local anesthetic ensures enhanced and prolonged sensory and motor block in the involved side. The aim of this study was to compare the intraoperative anesthetic efficacy of hypobaric with isobaric levobupivacaine solutions for THA. METHODS: Forty patients scheduled to elective THA were allocated into two groups: isobaric levobupivacaine group (IL group) and hypobaric levobupivacaine group (HL group). All the patients were placed with the operative side uppermost on the surgical table and spinal anesthesia was performed with 4 mL (12.5 mg) of selected solution. The evolution of sensory and block on nondependent (operative) and dependent sides were checked. RESULTS: Regarding the nondependent side the onset times for maximal sensory block level in the in HL group was 17.8±1.1 minutes vs. 24.2±4.1 minutes in IL group. In HL group the onset time for motor block was 9.2±3.5 minutes vs. 15.6±5.4 minutes in IL group. The sensory regression time to L2 was significantly prolonged in HL group (192±30.3 minutes vs. 111±13.4 min). After surgery in HL group the residual motor block degree was 2.4±0.9 vs. 0.2±0.4 in IL group. CONCLUSIONS: In patients undergoing THA under spinal anesthesia 12.5 mg of hypobaric levobupivacaine, compared with the same dose of isobaric levobupivacaine, allow shorter onset time for sensory block and delayed regression of sensory and motor block in the nondependent side.

[Anaesthesia for shock wave therapy in orthopaedics]. / Anestesia nel trattamento con onde d'urto in patologia ortopedica.

Shock wave therapy (orthotripsy) is a non-invasive method to treat or ameliorate many musculoskeletal disorders. When higher energies are applied on bones pain is associated with treatment, and anaesthesia is necessary, but there is no need of analgesia after shock wave application. Patients usually receive treatments during a short hospital stay: therefore, short duration drugs and techniques should be preferred, avoiding those causing unpleasant postanaesthetic sequelae. Between February 2002 and October 2004, a series of 136 patients have been treated with orthotripsy requiring some kind of anaesthesia. Anaesthetic techniques and agents suitable for orthotripsy are discussed.

Attenuation of aortic banding-induced cardiac hypertrophy by propranolol is independent of beta-adrenoceptor blockade.

OBJECTIVE: Racemic propranolol attenuates cardiac hypertrophy secondary to abdominal aortic banding-induced pressure overload by a mechanism independent of its effect on cardiac work load. This was only observed, however, using doses of propranolol that were much higher than those needed to induce beta-adrenoceptor blockade. Thus, the question remains as to whether the antihypertrophic effect of propranolol depends on its ability to antagonize cardiac beta-adrenoceptor-mediated action (positive chronotropic effect, trophic effect) or on beta-adrenoceptor-independent action. METHODS: In a rat model of chronic pressure overload induced by abdominal aortic banding, we evaluated the effects on left ventricular hypertrophy (LVH) of the propranolol isomers, L-propranolol and D-propranolol, which compared to L-isomer is approximately 50-fold less potent as a beta-adrenoceptor antagonist, but is similarly potent as a membrane-stabilizer, as well as of timolol, a non-selective beta-adrenergic antagonist devoid of membrane stabilizing activity, and disopyramide, which is a membrane stabilizer, but not a beta-adrenoceptor blocker. RESULTS: Compared to sham-operated rats, banded rats had 30% greater left ventricular to body weight (LVW/BW) ratio (P < 0.01). The increase in LVW/BW ratio was significantly attenuated by treatment with 40 and 80 (but not 10) mg/kg per day of L-propranolol. Left ventricular hypertrophy was also prevented by D-propranolol, 40 and 80 mg/kg per day, and disopyramide, 50 mg/kg per day, whereas timolol, 30 and 60 mg/kg per day, showed no antihypertrophic effect. In separate groups of banded rats in which the reduction in heart rate induced by propranolol (80 mg/kg per day) was prevented by chronic cardiac pacing at 375 b.p.m., hypertrophy was again prevented, indicating that the effects of L-propranolol on LVH are not related to a reduction in cardiac work load. CONCLUSIONS: In the aortic banding-induced model of LVH: (i) the antihypertrophic effect of propranolol is independent of its beta-adrenergic blocking activity; and Iii) since disopyramide and D-propranolol also proved to be able to antagonize banding-induced LVH, the hypothesis is proposed that membrane-stabilizing activity, among the ancillary properties of propranolol, most likely accounts for the antihypertrophic effect of this drug.

Na+/H+ exchange inhibition attenuates left ventricular remodeling and preserves systolic function in pressure-overloaded hearts.

Cardiac hypertrophy is a homeostatic response to elevated afterload. Na+/H+ exchanger (NHE) inhibition reduces the hypertrophic response in animal models of left ventricular hypertrophy (LVH) and myocardial infarction. We examined the effect of chronic treatment with cariporide, a selective inhibitor of Na+/H+ exchanger isoform 1 (NHE-1), on left ventricular (LV) systolic and diastolic function under pressure overload conditions. Male CD-1 mice were randomized to receive either a control diet or an identical diet supplemented with 6000 p.p.m. of cariporide. Cardiac pressure overload was induced by thoracic aortic banding. LV dimension and systolic and diastolic function were assessed in sham and banded mice by echocardiography and cardiac catheterization 2 and 5 weeks after surgery. Histological analysis was also performed. After 2 weeks of pressure overload, the vehicle-treated banded mice (Veh-Bd) had enhanced normalized LV weight (about +50%) and normal chamber size and function, whereas cariporide-treated banded mice (Car-Bd) showed a preserved contractility and systolic function despite a marked attenuation of LVH. Diastolic function did not differ significantly among groups. After 5 weeks, the Veh-Bd developed LV chamber enlargement and systolic dysfunction as evidenced by a 16% increase in LV end-diastolic diameter, a 36% decrease in myocardial contractility, and a 26% reduction in percent fractional shortening. In contrast, Car-Bd showed an attenuated increase in LV mass, normal chamber size, and a maintained systolic function. A distinct histological feature was that in banded mice, cariporide attenuated the development of cardiomyocyte hypertrophy but not the attendant myocardial fibrosis. In conclusion, the results of the present study indicate that (i) the hypertrophic response to pressure overload is dependent on NHE-1 activity, and (ii) at the 5-week stage, banding-induced deterioration of LV performance is prevented by NHE-1 inhibition.British Journal of Pharmacology (2004) 141, 526-532. doi:10.1038/sj.bjp.0705631

Video-assisted orotracheal intubation in mice.

Orotracheal intubation in mice is a complicated technique because of the peculiar oropharyngeal anatomy and the difficulty in visualizing the laryngis aditus. Here we report a new and simple method for rapid endotracheal intubation by using a small bore, straight fibre-optic arthroscope. Under endoscope-assisted visualization of the laryngis aditus, a polyethylene cannula, inserted on a guide-wire in order to facilitate the introduction of the tip across the vocal cords, was advanced in the trachea. The success rate of intubation was 100%. We were also able to re-intubate the mice 4 and 8 weeks later without any major complications. We conclude that this method can be easily and safely used for studies where controlled pulmonary ventilation is necessary.

Inhibition of left ventricular remodelling preserves chamber systolic function in pressure-overloaded mice.

Controversy exists whether the development of left-ventricular hypertrophy (LVH) is a mechanism able to prevent cardiac dysfunction under conditions of pressure overload. In the present study we re-assessed the long-term effects of attenuating LVH by using L- and D-propranolol, which are equally able to inhibit the development of LVH induced by aortic banding. The aortic arch was banded proximal to the left common carotid artery in 71 CD-1 mice that were then assigned randomly to receive L-propranolol, D-propranolol (both 80 mg/kg per day) or vehicle. Concurrently, sham-operated mice were given L-propranolol, D-propranolol or vehicle. LV dimension and performance were evaluated under isoflurane anaesthesia by cine-magnetic resonance imaging, echocardiography and cardiac catheterization up to 8 weeks after surgery. After 2 weeks of pressure overload, the vehicle-treated banded mice had enhanced LV weight, normal chamber size and increased relative wall thickness (concentric hypertrophy), whereas L-propranolol- or D-propranolol-banded mice showed a markedly blunted hypertrophic response, i.e. normal chamber size and normal relative wall thickness, as well as preserved systolic LV chamber function. After 4 weeks, the vehicle-treated banded mice showed LV enlargement with a reduced relative wall thickness (eccentric remodelling) and a clear-cut deterioration in LV systolic function. In contrast, L-propranolol- or D-propranolol-treated banded mice showed normal chamber size with a normal relative wall thickness and preserved systolic function. A distinct histological feature was that in banded mice, L-or D-propranolol attenuated the development of cardiomyocyte hypertrophy but not the attendant myocardial fibrosis. At the 8-week stage, LV dysfunction was present in propranolol-treated banded mice although it was much less severe than in vehicle-treated banded mice. It is concluded that (i) deterioration of LV systolic performance is delayed if LV hypertrophy is inhibited, (ii) banding-induced deterioration of LV systolic function is associated with LV eccentric remodelling and (iii) the antihypertrophic effect of propranolol is due to a selective action on cardiomyocytes rather than on collagen accumulation