Awareness With Paralysis in Mechanically Ventilated Patients in the Emergency Department and ICU: A Systematic Review and Meta-Analysis.

OBJECTIVE: Awareness with paralysis is a devastating complication for mechanically ventilated patients and can carry long-term psychologic sequelae. Hundreds of thousands of patients require mechanical ventilation in the emergency department and ICU annually, yet awareness has only been rigorously examined in the operating room (incidence ~0.1%). This report collates the global literature regarding the incidence of awareness with paralysis outside of the operating room. DATA SOURCES: We searched OvidMedline, Embase, Scopus, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, conference proceedings, and reference lists. STUDY SELECTION: Randomized or nonrandomized studies (except single case studies) reporting on awareness with paralysis in the emergency department or ICU were eligible. DATA EXTRACTION: Two independent reviewers screened abstracts for eligibility. DATA SYNTHESIS: The search identified 4,454 potentially eligible studies. Seven studies (n = 941 patients) were included for analysis. A random effects meta-analysis of proportions along with multiple subgroup analyses was performed. Significant between-study heterogeneity in reporting of awareness with paralysis was noted, and the quality of the evidence was low. Analyses stratified by: 1) good-quality studies and 2) use of the modified Brice questionnaire to detect awareness revealed estimates of 3.4% (95% CI, 0-10.2%) and 1.9% (95% CI, 1.0-3.0%), respectively. CONCLUSIONS: The incidence of awareness with paralysis in mechanically ventilated patients in the emergency department and ICU, as evaluated in a small number of qualifying studies from this comprehensive systematic review, appears much higher than that reported from the operating room. Given the clinical and statistical heterogeneity, caution is warranted in the interpretation of these findings. Further high-quality studies are needed to both define the true incidence and to target the prevention of awareness with paralysis in this vulnerable patient cohort.

Effects of Local Anesthetic Volume (Standard Versus Low) on Incidence of Hemidiaphragmatic Paralysis and Analgesic Quality for Ultrasound-Guided Superior Trunk Block After Arthroscopic Shoulder Surgery.

BACKGROUND: Relative to interscalene block, superior trunk block (STB) provides comparable analgesia and a reduced risk of hemidiaphragmatic paralysis. However, the incidence of hemidiaphragmatic paralysis remains high when a standard volume (15 mL) of local anesthetic is used. This study aimed to evaluate the effects of local anesthetic volume of STB on the incidence of phrenic nerve palsy, as well as its analgesic efficacy following arthroscopic shoulder surgery. METHODS: Patients scheduled for elective arthroscopic shoulder surgery were randomized to receive ultrasound-guided STB using either 5- or 15-mL 0.5% ropivacaine before general anesthesia. The primary outcome was the incidence of hemidiaphragmatic paralysis at 30 minutes after block. The secondary outcomes were pulmonary function, grade of sensory and motor blockade, pain score, opioid consumption, adverse effects, and satisfaction. RESULTS: Relative to standard-volume STB, low-volume STB was associated with a lower incidence of hemidiaphragmatic paralysis after block (14.3 [4.8%-30.3%] vs 65.7 [46.8%-80.9%]; difference 51.4% [95% confidence intervals {CIs}, 29.0%-67.1%]; P < .0001) and at the postanesthesia care unit (9.4% vs 50.0%; difference 40.6 [95% CI, 18.9%-57.7%]; P = .0004). Pulmonary function was also better preserved in the low-volume group than in the standard-volume group. The extent of the sensory and motor blocks was significantly different between the groups. Pain-related outcomes, satisfaction, and any adverse events were not significantly different between the groups. CONCLUSIONS: Low-volume STB provided a lower incidence of hemidiaphragmatic paralysis with no significant difference in analgesic efficacy relative to standard-volume STB for arthroscopic shoulder surgery.

Characteristics and outcomes of children with congenital heart disease needing diaphragm plication.

BACKGROUND: Diaphragm dysfunction following surgery for congenital heart disease is a known complication leading to delays in recovery and increased post-operative morbidity and mortality. We aimed to determine the incidence of and risk factors associated with diaphragm plication in children undergoing cardiac surgery and evaluate timing to repair and effects on hospital cost and length of stay. METHODS: We conducted a multi-institutional retrospective observational cohort study. Forty-three hospitals from the Pediatric Health Information System database were included, and a total of 112,110 patients admitted between January 2004 and December 2014 were analysed. RESULTS: Patients less than 18 years of age who underwent cardiac surgery were included. Risk Adjustment for Congenital Heart Surgery was utilized to determine procedure complexity. The overall incidence of diaphragm dysfunction was 2.2% (n = 2513 out of 112,110). Of these, 24.0% (603 patients) underwent diaphragm plication. Higher complexity cardiac surgery (Risk Adjustment for Congenital Heart Surgery 5-6) and age less than 4 weeks were associated with a higher likelihood of diaphragm plication (p-value < 0.01). Diaphragmatic plication was associated with increased hospital length of stay (p-value < 0.01) and increased medical cost. CONCLUSIONS: Diaphragm plication after surgery for congenital heart disease is associated with longer hospital length of stay and increased cost. There is a strong correlation of prolonged time to plication with increased length of stay and medical cost. The likelihood of plication increases with younger age and higher procedure complexity. Methods to improve early recognition and treatment of diaphragm dysfunction should be developed.

Incidence of hemi-diaphragmatic paresis after ultrasound-guided intermediate cervical plexus block: a prospective observational study.

PURPOSE: An intermediate cervical plexus block (CPB) targets the posterior cervical space between the sternocleidomastoid muscle and the prevertebral fascia. The phrenic nerve descends obliquely on the surface of the anterior scalene muscle beneath the prevertebral fascia after originating from the C3-C5 ventral rami. Therefore, the phrenic nerve can be affected by a local anesthetic during an intermediate CPB, depending on the permeability characteristics of the prevertebral fascia. This study investigated whether an intermediate CPB affects the phrenic nerve, inducing hemidiaphragmatic paresis. METHODS: In this prospective observational study, 20 patients undergoing single-incision transaxillary robot-assisted right thyroidectomy were enrolled. The intermediate CPB (0.25% ropivacaine 0.2 ml/kg) was performed at the C4-5 intervertebral level carefully, without penetrating the prevertebral fascia, before the patient emerged from general anesthesia. Diaphragmatic motions of the block side were measured by M-mode ultrasonography at three time points: before anesthesia (baseline) and at 30 and 60 min after the intermediate CPB. Hemidiaphragmatic paresis was divided into three grades, depending on the percentage of diaphragm movement compared to the baseline: none (> 75%), partial paresis (25-75%), and complete paresis (< 25%). RESULTS: No patient showed any partial or complete ipsilateral hemidiaphragmatic paresis within 60 min after the intermediate CPB. CONCLUSION: Intermediate CPB using 0.2 ml/kg of 0.25% ropivacaine at the C4-5 intervertebral level did not cause ipsilateral hemidiaphragmatic paresis. This may imply that the effect of the intermediate CPB on the phrenic nerve is not significant.

Association Between Diaphragmatic Paralysis and Ipsilateral Cervical Spondylosis on MRI.

PURPOSE: Diaphragmatic paralysis (DP) is an important cause of dyspnea with many underlying etiologies; however, frequently no cause is identified despite extensive investigation. We hypothesized that cervical spondylosis (CS), as manifest by cervical neuroforaminal stenosis on magnetic resonance imaging (MRI), is an underrecognized cause of unilateral DP. METHODS: A retrospective study was performed assessing cervical spine imaging utilization in the investigation of unilateral DP, and the contribution of CS to its pathogenesis. To assess the relationship between CS and DP, comparison was made between severity of ipsilateral and contralateral foraminal stenosis on cervical spine MRI in individuals with idiopathic DP, and to controls with DP of known etiology. RESULTS: Record searches identified 334 individuals with DP who were classified as idiopathic (n = 101) or DP of known etiology (n = 233). Of those with idiopathic DP, only 37% had undergone cervical spine imaging. Cervical spine MRIs, available for 32 individuals from the total cohort identified (n = 15 idiopathic DP, n = 17 DP of known etiology), were reviewed and severity of CS graded (0-2). In idiopathic DP, CS was significantly more severe (grade 2 stenosis) on the side of DP at C3-C4 (73% affected vs 13% unaffected side; p = 0.031) and C4-C5 (60% affected vs 20% unaffected side; p = 0.0039), while no difference was observed in DP of known etiology. Overall severity of CS across all cervical spine levels was significantly worse in idiopathic DP versus those with DP of known etiology. CONCLUSIONS: In unilateral idiopathic DP, severity of CS is associated with DP laterality and is an underrecognized cause of diaphragmatic dysfunction. We propose that evaluation of 'idiopathic' DP should routinely include cervical spine imaging, preferably by MRI.

Interscalene versus supraclavicular plexus block for the prevention of postoperative pain after shoulder surgery: A systematic review and meta-analysis.

BACKGROUND: Interscalene brachial plexus blockade is the most common regional anaesthesia technique for alleviating pain after shoulder surgery, but complications occur, including ipsilateral hemidiaphragmatic paresis, Horner's syndrome and hoarseness. The supraclavicular approach might be an effective alternative with fewer adverse effects. OBJECTIVES: The aim of this study was to determine whether there is a difference in postoperative pain scores and morphine equivalents between interscalene and supraclavicular brachial plexus blocks. Secondary endpoints were serious adverse events. DESIGN: A systematic review and meta-analysis of randomised controlled trials. DATA SOURCES: A comprehensive literature search of Embase, CENTRAL, MEDLINE and Web of Science was performed from the earliest record to December 2018. ELIGIBILITY CRITERIA: Prospective randomised controlled trials that compare interscalene and supraclavicular brachial plexus blocks in patients undergoing shoulder surgery were eligible for inclusion. Only studies that reported their methods transparently and comprehensibly were included. Conference abstracts or meeting abstracts were not excluded a priori. Risk of bias was assessed using Cochrane methodology. RESULTS: Twelve studies were eligible for meta-analysis. The supraclavicular approach showed overall comparable 24-h pain scores (mean difference -0.34; 95% CI -0.75 to 0.07, P = 0.11) and comparable morphine equivalent consumption (mean difference 1.84 mg per 24 h; 95% CI -0.00 to 3.69, P = 0.05). Secondary endpoint analysis revealed a significantly lower rate of hemidiaphragmatic paresis (risk ratio 0.56; 95% CI 0.39 to 0.82, P = 0.003) and Horner's syndrome (risk ratio 0.29; 95% CI 0.19 to 0.44, P < 0.00001) for the supraclavicular approach. There was no significant difference in hoarseness (risk ratio 0.73; 95% CI 0.48 to 1.13, P = 0.16). CONCLUSION: After 24 postoperative hours, pain scores and consumption of morphine equivalents were comparable. Adverse effects were less common with the supraclavicular approach. The supraclavicular approach might be an efficient alternative to the interscalene approach for shoulder surgery. However, the available evidence is inadequate and prevents a firm conclusion.

Diaphragmatic paralysis in obese patients in arthroscopic shoulder surgery: consequences and causes.

PURPOSE: Ambulatory process in arthroscopic shoulder surgery has boomed over past decades. Some anesthetic techniques such as interscalene block (ISB) and its surrogates are associated with diaphragmatic paralysis and might compromise outpatient procedure. HYPOTHESIS: This study aims to assess consequences of diaphragmatic paralysis in obese patients. METHODS: This prospective observational study screened patients with body mass index (BMI) ≥ 30 kg/m2 undergoing acromioplasty or supraspinatus tendon repair. Surgery was performed using brachial plexus block, and the method of brachial plexus block was left at the discretion of attending anesthesiologists. Post-operative hemidiaphragmatic paralysis was evaluated using M-mode ultrasonography and its consequences on patient ventilation were assessed: occurrence of hypoxic episode defined as oxygen saturation less than 90% (by pulse oximeter) in room air, dyspnea and failure of ambulatory procedure. Causes of diaphragmatic paralysis were also analyzed. RESULTS: Ninety-one patients were screened, 82 patients were included in this study and 37 patients (45%) presented diaphragmatic paralysis. Compared to patients without diaphragmatic paralysis, diaphragmatic paralysis was associated with dyspnea [10 (27%) versus 1 (2%); p = 0.0019], occurrence of patients presenting at least one hypoxic episode [6 (16%) versus 1 (2%); p = 0.02] and failure of ambulatory process [10 (27%) versus 1 (2%); p = 0.009]. The combination of axillary and suprascapular nerve blocks, but also low volume ISB, was found to be protective against diaphragmatic paralysis when compared to high volume ISB [Odds ratios 0.0019 (0.001-0.026) and 0.0482 (0.008-0.27), respectively; p < 0.001]. CONCLUSION: In patients with BMI ≥ 30 kg/m2 undergoing arthroscopic shoulder surgery, diaphragmatic paralysis is associated with dyspnea, occurrence of hypoxic episodes and failure of ambulatory procedure. High volume ISB and also, to a lesser extent, low volume ISB were found to be responsible for diaphragmatic paralysis. TRIAL REGISTRY NUMBER: Registration n° 2014-202.

Lessons Learned at the Epicenter of Brazil's Congenital Zika Epidemic: Evidence From 87 Confirmed Cases.

Congenital Zika virus infection has stimulated great international concern. A prospective case series of 87 infants with laboratory-confirmed congenital Zika syndrome (CZS) at the epicenter of the Brazilian Zika epidemic in Pernambuco state is presented. Mothers were interviewed for symptoms of possible Zika virus (ZIKV) infection during pregnancy, and fetal ultrasounds were obtained. Infant cerebrospinal fluid (CSF) samples were tested for ZIKV-specific antibodies, and sera were screened for other congenital infections. Neuroimaging and ophthalmologic evaluations were also performed. Sixty-six mothers (76%) reported symptoms of ZIKV infection during gestation. Fetal ultrasounds were available from 90% of the mothers, and all demonstrated brain structural abnormalities. All of the CSF samples tested positive for ZIKV immunoglobulin M. The majority of infants (89%) were term; the mean birth weight was 2577 ± 260 g, and the mean head circumference was 28.1 ± 1.8 cm. Severe microcephaly, defined as head circumference 3 SD below the mean for sex and gestational age, was found in 72 (82%) infants. All infants had an abnormal neurological exam, and 18 (20.7%) had arthrogryposis. The main abnormalities detected in computed tomography scans were calcifications (99%), followed by ventricular enlargement (94%), cortical hypogyration (81%), and less commonly, cerebellar hypoplasia (52%). Unilateral diaphragm paralysis was identified in 3 infants. Maternal young age, term infant, small for gestational age, and the presence of ophthalmologic abnormalities were significantly associated with a smaller head circumference Z score. Our findings, based on laboratory-confirmed ZIKV infection, add valuable evidence for the understanding of CZS.

Reduced hemidiaphragmatic paresis with extrafascial compared with conventional intrafascial tip placement for continuous interscalene brachial plexus block: a randomized, controlled, double-blind trial.

BACKGROUND.: The incidence of hemidiaphragmatic paresis with continuous interscalene brachial plexus block (CISB) can approach 100%. We tested the hypothesis that extrafascial placement of the catheter tip reduces the rate of hemidiaphragmatic paresis compared with intrafascial tip placement for CISB while providing effective analgesia. METHODS.: Seventy patients undergoing elective major shoulder surgery under general anaesthesia were randomized to receive an ultrasound-guided CISB plexus block for analgesia with the catheter tip placed either within (intrafascial group) or immediately outside (extrafascial group) the brachial plexus sheath midway between the levels of C5 and C6. Catheters were bolus dosed with ropivacaine 0.5% 20 ml before surgery, followed by an infusion of ropivacaine 0.2% at 4 ml h -1 for the first 2 days after surgery. The primary outcome was hemidiaphragmatic paresis measured by M-mode ultrasonography on postoperative day (POD) 1. Secondary outcomes included forced vital capacity, forced expiratory volume in 1 s, and rest pain scores. RESULTS.: The incidence of hemidiaphragmatic paresis on POD 1 was significantly reduced in the extrafascial group {intrafascial, 41% [95% confidence interval (CI) 25-59%]; extrafascial, 15% (95% CI 5-32%); P =0.01}. We were unable to detect a difference between groups in any of the functional respiratory outcomes or in rest pain scores [numerical rating scale (1-10): intrafascial, 3 (95% CI 2-3); extrafascial, 3 (95% CI: 2-4); P =0.93] on POD 1. CONCLUSIONS.: Placement of the catheter tip immediately outside of the brachial plexus sheath reduced the incidence of hemidiaphragmatic paresis on POD 1 associated with ultrasound-guided CISB while providing effective analgesia after major shoulder surgery. Our results do not support the routine placement of the catheter tip within the brachial plexus sheath for CISB. CLINICAL TRIAL REGISTRATION.: NCT02433561.

A comparison of ultrasound-guided interscalene and supraclavicular blocks for post-operative analgesia after shoulder surgery.

BACKGROUND: In contrast to interscalene block, there was little information regarding the analgesic efficacy of supraclavicular block for shoulder surgery. This study aimed to compare the analgesic efficacy and side effects of interscalene and supraclavicular blocks for shoulder surgery. METHODS: Patients scheduled for shoulder surgery were assigned to receive either ultrasound-guided interscalene (n = 25) or supraclavicular block (n = 24) with 20 ml of 0.375% ropivacaine. We assessed the duration of post-operative analgesia as a primary outcome and pain scores, supplemental analgesia, diaphragmatic excursion, motor block, fingertip numbness, side effects, and patient satisfaction as secondary outcomes. RESULTS: The duration of post-operative analgesia was not statistically different between groups: 868 (800-1440) min for supraclavicular block vs. 800 (731-922) min for interscalene block (median difference -85 min, 95% CI, -283 to 3 min, P = 0.095). The incidence of diaphragmatic paresis was significantly lower in the supraclavicular block group compared with that in the interscalene block group, both at 30 min after the block (66.7% vs. 92%, P = 0.021) and in the post-anaesthesia care unit (62.5% vs. 92%, P = 0.024). Motor block was higher in the supraclavicular block group in the post-anaesthesia care unit, however, not at 24 h. Other secondary outcomes were similar for both groups. CONCLUSIONS: This study showed no statistically significant difference in the duration of post-operative analgesia between the supraclavicular and interscalene blocks. However, the supraclavicular block was associated with a lower incidence of diaphragmatic paresis compared with that of the interscalene block after shoulder surgery.

Extrafascial injection for interscalene brachial plexus block reduces respiratory complications compared with a conventional intrafascial injection: a randomized, controlled, double-blind trial.

BACKGROUND: Hemidiaphragmatic paresis after ultrasound-guided interscalene brachial plexus block is reported to occur in up to 100% of patients. We tested the hypothesis that an injection lateral to the brachial plexus sheath reduces the incidence of hemidiaphragmatic paresis compared with a conventional intrafascial injection, while providing similar analgesia. METHODS: Forty ASA I-III patients undergoing elective shoulder and clavicle surgery under general anaesthesia were randomized to receive an ultrasound-guided interscalene brachial plexus block for analgesia, using 20 ml bupivacaine 0.5% with epinephrine 1:200 000 injected either between C5 and C6 within the interscalene groove (conventional intrafascial injection), or 4 mm lateral to the brachial plexus sheath (extrafascial injection). The primary outcome was incidence of hemidiaphragmatic paresis (diaphragmatic excursion reduction >75%), measured by M-mode ultrasonography, before and 30 min after the procedure. Secondary outcomes were forced vital capacity, forced expiratory volume in 1 s, and peak expiratory flow. Additional outcomes included time to first opioid request and pain scores at 24 h postoperatively (numeric rating scale, 0-10). RESULTS: The incidences of hemidiaphragmatic paresis were 90% (95% CI: 68-99%) and 21% (95% CI: 6-46%) in the conventional and extrafascial injection groups, respectively (P<0.0001). Other respiratory outcomes were significantly better preserved in the extrafascial injection group. The mean time to first opioid request was similar between groups (conventional: 802 min [95% CI: 620-984 min]; extrafascial: 973 min [95% CI: 791-1155 min]; P=0.19) as were pain scores at 24 h postoperatively (conventional: 1.6 [95% CI: 0.9-2.2]; extrafascial: 1.6 [95% CI: 0.8-2.4]; P=0.97). CONCLUSIONS: Ultrasound-guided interscalene brachial plexus block with an extrafascial injection reduces the incidence of hemidiaphragmatic paresis and impact on respiratory function while providing similar analgesia, when compared with a conventional injection. CLINICAL TRIAL REGISTRATION: NCT02074397.

Incidence and characteristics of phrenic nerve palsy following pulmonary vein isolation with the second-generation as compared with the first-generation cryoballoon in 360 consecutive patients.

AIMS: The second-generation cryoballoon (CB2) with increased surface cooling has recently become available. The aim was to investigate the incidence and characteristics of phrenic nerve palsy (PNP) during pulmonary vein isolation (PVI) using the CB2 as compared with the first-generation balloon (CB1). METHODS AND RESULTS: A total of 360 consecutive patients with atrial fibrillation underwent PVI with the CB1 (106 patients) or the CB2 (254 patients). Right PN function was monitored by continuous stimulation and palpation during septal PV ablation. Persistent PNP (present at discharge) occurred in 2.8 and 1.9% (P = 0.63) of patients, transient PNP (full recovery before discharge) in 5.9 and 3.8% (P = 0.41) of patients in the CB2 and CB1 group, respectively. Phrenic nerve palsy during ablation at the right inferior PV was observed in 0% (CB1) and 4.3% (CB2, P = 0.03) of patients. Using the CB2, a trend of reduced incidence of persistent PNP over quartiles of consecutive patients was observed [4.8% (Q1) vs. 0% (Q4); P = 0.077]. At the culprit PV, PNP occurred after 3.5 ± 2.1 (CB1) and 1.1 ± 0.4 applications (CB2; P = 0.036). Complete recovery of PN function occurred after 29 ± 11 (CB1) and 259 ± 137 days (CB2; P = 0.004). CONCLUSIONS: The rate of transient/persistent PNP associated with the use of the CB2 was 5.9 and 2.8%, respectively. Time to restitution of PN function was longer using the CB2.

Persistence of Phrenic Nerve Palsy Following 28-mm Cryoballoon Ablation: A Four-Year Single Center Experience.

BACKGROUND: Phrenic nerve palsy (PNP) is the most frequently observed complication in the setting of cryoballoon (CB) ablation (Arctic Front, Medtronic Inc., Minneapolis, MN, USA). Although, usually transient, resolving before the end of the procedure, persistent PNP (not resolving before the end of procedure) can occur. Literature on persistent PNP after second generation CB ablation is relatively sparse. METHODS: A total of 316 consecutive patients having undergone large 28-mm CB ablation as index procedure in the Heart Rhythm Management Center, UZ Brussels, Belgium, from January 2009 to December 2013 were retrospectively reviewed for the study. Of these 117 patients were treated with the first generation CB (CB1) and 199 patients with the second generation CB (CB2). RESULTS: PNP occurred in 10% of the total population. Persistent PNP was only observed following CB2 ablation which occurred in 4.5% of the group. At a mean follow-up of 11 months, diaphragmatic contraction in persistent PNP patients resumed in 78% (7/9) of the patients. In a final follow-up at 5 and 20 months, PNP persisted in two patients, respectively. PNP during ablation in the right inferior pulmonary vein was only observed in the CB2 group. No predictors of persistency of PNP were observed. CONCLUSION: Persistence of PNP only occurred in the CB2 group in 4.5% of patients. The majority of patients with persistent PNP were asymptomatic. In most of the patients having persistent PNP after ablation, complete phrenic nerve function resumed during follow-up (78%).

Protocol for diaphragm pacing in patients with respiratory muscle weakness due to motor neurone disease (DiPALS): a randomised controlled trial.

BACKGROUND: Motor neurone disease (MND) is a devastating illness which leads to muscle weakness and death, usually within 2-3 years of symptom onset. Respiratory insufficiency is a common cause of morbidity, particularly in later stages of MND and respiratory complications are the leading cause of mortality in MND patients. Non Invasive Ventilation (NIV) is the current standard therapy to manage respiratory insufficiency. Some MND patients however do not tolerate NIV due to a number of issues including mask interface problems and claustrophobia. In those that do tolerate NIV, eventually respiratory muscle weakness will progress to a point at which intermittent/overnight NIV is ineffective. The NeuRx RA/4 Diaphragm Pacing System was originally developed for patients with respiratory insufficiency and diaphragm paralysis secondary to stable high spinal cord injuries. The DiPALS study will assess the effect of diaphragm pacing (DP) when used to treat patients with MND and respiratory insufficiency. METHOD/DESIGN: 108 patients will be recruited to the study at 5 sites in the UK. Patients will be randomised to either receive NIV (current standard care) or receive DP in addition to NIV. Study participants will be required to complete outcome measures at 5 follow up time points (2, 3, 6, 9 and 12 months) plus an additional surgery and 1 week post operative visit for those in the DP group. 12 patients (and their carers) from the DP group will also be asked to complete 2 qualitative interviews. DISCUSSION: The primary objective of this trial will be to evaluate the effect of Diaphragm Pacing (DP) on survival over the study duration in patients with MND with respiratory muscle weakness. The project is funded by the National Institute for Health Research, Health Technology Assessment (HTA) Programme (project number 09/55/33) and the Motor Neurone Disease Association and the Henry Smith Charity. TRIAL REGISTRATION: Current controlled trials ISRCTN53817913. The views and opinions expressed therein are those of the authors and do not necessarily reflect those of the HTA programme, NIHR, NHS or the Department of Health.

Effect of superior trunk block on diaphragm function and respiratory parameters after shoulder surgery.

BACKGROUND: The interscalene brachial plexus block has been used effectively for intraoperative and postoperative analgesia in patients undergoing shoulder surgery, but it is associated with high rates of diaphragmatic dysfunction. Performing the block more distally, at the level of the superior trunk, may reduce the incidence of phrenic nerve palsy. We hypothesized that superior trunk block would result in diaphragmatic paralysis rate of less than 20%. METHODS: 30 patients undergoing arthroscopic shoulder surgery received superior trunk block under ultrasound guidance. Measurements of diaphragm excursion were determined with ultrasound prior to the block, 15 min after the block, and postoperatively in phase II of postanesthesia care unit, in conjunction with clinical parameters of respiratory function. RESULTS: 10 patients (33.3%, 95% CI 17.3% to 52.8%) developed complete hemidiaphragmatic paralysis at the postoperative assessment. An additional eight patients (26.7%) developed paresis without paralysis. Of the 18 patients with diaphragm effects, seven (38.9%) reported dyspnea. 83.3% of patients with abnormal diaphragm motion (56.7% of the total sample) had audibly reduced breath sounds on auscultation. Oxygen saturation measurements did not correlate with diaphragm effect and were not significantly reduced by the postoperative assessment. CONCLUSION: Although injection of local anesthetic at the superior trunk level is associated with less diaphragmatic paralysis compared with traditional interscalene block, a significant portion of patients will continue to have ultrasonographic and clinical evidence of diaphragmatic weakness or paralysis.

Ropivacaine for ultrasound-guided interscalene block: 5 mL provides similar analgesia but less phrenic nerve paralysis than 10 mL.

PURPOSE: Interscalene brachial plexus block (interscalene block) complications usually depend on the dose administered. The objective of this study was to determine whether ultrasound-guided interscalene block with a 5-mL dose of 0.75% ropivacaine would have sufficient analgesic efficacy after shoulder arthroscopic surgery when compared with a 10-mL dose. METHODS: Patients undergoing arthroscopic rotator cuff repair surgery (n = 60) were assigned randomly to one of two groups receiving 5 mL (Group 5) or 10 mL (Group 10) of 0.75% ropivacaine. Ultrasound-guided interscalene block was performed using the in-plane technique, and general anesthesia was administered. Time to first analgesic request was recorded, and the following issues were assessed in the postanesthesia care unit at six, 12, 24, and 48 hr postoperatively: postoperative pain as determined by a visual analogue scale (VAS), patient satisfaction, hemidiaphragmatic paralysis, other block-related complications, and postoperative nausea and vomiting (PONV). RESULTS: There was no significant difference between groups in time to first analgesic requirement (median [interquartile range] for Group 5: 16 [12-48] hr, Group 10: 18 [12-48] hr; P = 0.907). The postoperative pain VAS score was similar in both groups. The incidence of hemidiaphragmatic paralysis on postoperative chest x-ray was 33% in Group 5 and 60% in Group 10 (P = 0.035). However, the incidences of other block-related complications, PONV, and patient satisfaction were not significantly different between groups. CONCLUSION: Interscalene block performed under ultrasound guidance with 0.75% ropivacaine 5 mL showed analgesic efficacy similar to that with 0.75% ropivacaine 10 mL, but with a lower incidence of hemidiaphragmatic paralysis.

A classification and regression tree to assist clinical decision making in airway management for patients with cervical spinal cord injury.

STUDY DESIGN: This was a prospective observational study. OBJECTIVES: To review airway management of patients with acute cervical spinal cord injury (CSCI) who are admitted to the intensive care unit (ICU) and to develop a classification and regression tree (CART) to direct clinical decision making in airway management. SETTING: This study was carried out in Australia. METHODS: All patients with CSCI who required intubation and mechanical ventilation and who were admitted to ICU in three tertiary hospitals in Melbourne between October 2004 and May 2009 and two other interstate hospitals between December 2004 and December 2005 were included. Airway management was recorded. RESULTS: A total of 114 patients were included. Tracheostomy insertion occurred in 68 patients (59.7%). Using CART analysis, it was found that the variables forced vital capacity, the volume of pulmonary secretion and gas exchange were predictive of airway management on 82.3% occasions with an 8.7% extubation failure rate. CONCLUSION: A CART can be useful in clinical decision making regarding airway management in CSCI.

Diaphragm Paralysis After Pediatric Cardiac Surgery: An STS Congenital Heart Surgery Database Study.

BACKGROUND: Previous single-center studies of diaphragm paralysis (DP) after pediatric cardiac surgery report incidence of 0.3% to 12.8% and associate DP with respiratory complications, prolonged ventilation and length of stay, and mortality. To better define incidence and associations between DP and various procedures and outcomes, we performed a multicenter study. METHODS: The Society of Thoracic Surgeons Congenital Heart Surgery Database was queried to identify children who experienced DP after cardiac surgery (2010-2018; 126 centers). Baseline characteristics and postoperative outcomes were compared between patients with and without DP as well as between patients who underwent plication and those who did not. Associations between center volume and center rates of DP and use of plication were also explored. RESULTS: A total of 2214 of 191,463 (1.2%) patients experienced DP. Postoperative DP portended worse outcomes, including mortality (5.6% vs 3.5%; P < .001), major morbidity (37.2% vs 10.7%; P < .001), tracheostomy (7.1% vs 0.9%; P < .001), prolonged mechanical ventilation (38.0% vs 7.8%; P < .001), and 30-day readmission (22.0% vs 10.6%; P < .001). A total of 1105 of 2214 (49.9%) patients with DP underwent plication. Patients who underwent plication were younger, were smaller, had more risk factors, and underwent more complex surgeries. Plication rates varied widely across centers. There was no correlation between center volume and center risk-adjusted rates of DP (r = .05, P = .5), nor frequency of plication (r = .08, P = .4). CONCLUSIONS: DP complicating pediatric heart surgery is rare but portends significantly worse outcomes. One-half of patients underwent plication. Center-level risk-adjusted rates of DP and plication are not associated with case volume. Significant variability in plication practices suggests a target for quality improvement.