title: Continuous interscalene brachial plexus nerve block prolongs unilateral diaphragmatic dysfunction.
abstract: OBJECTIVE
  Single interscalene blocks (ISB) impair pulmonary function (<24h). We hypothesized that continuous ISBs would prolong pulmonary dysfunction until h48 compared with a single ISB. We compared the time course of spirometric and diaphragmatic dysfunction following single or continuous ISBs.
  
  
  METHODS
  We prospectively included consecutive adult patients scheduled to undergo shoulder surgery under standard general anaesthesia with single (n=30) or continuous (n=31) ISB. Before ISB (baseline), spirometric tests were recorded and the diaphragm course was evaluated with a B-mode ultrasound technique every 12h until h48. ISBs were performed with 15mL 0.5% ropivacaine using an ultrasound technique approach. The continuous group received the same bolus followed by 0.2% ropivacaine 5mL·h-1(48h). The primary end point was the reduction (> 25% from baseline) of forced vital capacity (FVC) over the study period (48h).
  
  
  RESULTS
  Patient characteristics were similar in both groups. Thirty minutes after blocks in the PACU, all patients demonstrated a similar and significant unilateral diaphragm paralysis (< 25% from baseline). For the primary end point (FVC), no significant difference was observed between groups over the study period. A difference between single and continuous groups was observed at h24 for: FVC (-25%, P=0.038), FEV1s (-24%, P=0.036), diaphragmatic course (-26%, P=0.02), while no differences for other time points (h0-h48) were noted. Clinical respiratory evaluations (respiratory rate, SpO2, supplementary nasal O2), postoperative pain scores and additional opioid consumption were similar between groups.
  
  
  CONCLUSIONS
  Over infusion, continuous ISB did not significantly prolong unilateral phrenic paresis and demonstrated a limited pulmonary impact.
authors.affiliation: Department of Anaesthesiology and Pain Management, Centre Hospitalo-Universitaire (CHU) Carémeau, Nîmes, France; Université Montpellier 1, Montpellier, France. Electronic address: philippe.cuvillon@chu-nimes.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Cuvillon
authors.affiliation: Department of Anaesthesiology and Critical Care, Centre Hospitalo-Universitaire Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France.
authors.forename: Frederic
authors.initials: F
authors.lastname: Le Sache
authors.affiliation: Department of Biostatistics, Epidemiology, Public Health and Medical Information (BESPIM), University Hospital, Nîmes, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Demattei
authors.affiliation: Department of Anaesthesiology and Critical Care, Centre Hospitalo-Universitaire Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France.
authors.forename: Lionel
authors.initials: L
authors.lastname: Lidzborski
authors.affiliation: Department of Anaesthesiology and Pain Management, Centre Hospitalo-Universitaire (CHU) Carémeau, Nîmes, France; Université Montpellier 1, Montpellier, France.
authors.forename: Lana
authors.initials: L
authors.lastname: Zoric
authors.affiliation: AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles-Foix, Department of Emergency Medicine and Surgery, 75013 Paris, France; Sorbonne Universités, UPMC Université Paris 06, 75005 Paris, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Riou
authors.affiliation: Sorbonne Universités, UPMC Université Paris 06, 75005 Paris, France; AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles-Foix, Department of Anaesthesiology and Critical Care, 75013 Paris, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Langeron
authors.affiliation: AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles-Foix, Department of Anaesthesiology and Critical Care, 75013 Paris, France; Inserm, UMR_S 1158, Neurophysiologie Respiratoire Expérimentale et Clinique, 75005 Paris, France; Sorbonne Universités, UPMC Université Paris 06, UMR-S 1158, Neurophysiologie Respiratoire Expérimentale et Clinique, 75005 Paris, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Raux
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000577:Amides; D000762:Anesthesia Recovery Period; D000768:Anesthesia, General; D000779:Anesthetics, Local; D001917:Brachial Plexus; D003964:Diaphragm / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000009:adverse effects*; D010100:Oxygen / Q000097:blood; D010149:Postoperative Pain / Q000453:epidemiology; D012129:Respiratory Function Tests; D000077212:Ropivacaine; D012782:Shoulder / Q000601:surgery; D013147:Spirometry; D018084:Ultrasonography, Interventional; D014797:Vital Capacity; D055815:Young Adult
chemical_list: D000577:Amides; D000779:Anesthetics, Local; D000077212:Ropivacaine; D010100:Oxygen
keywords: Anaesthetic techniques; Anaesthetics techniques; Continuous interscalene; Evaluation; Regional; Spirometry