Combined caudal retrocostal and lateral ultrasound-guided approach for transversus abdominis plane injection: A descriptive pilot study in pig cadavers.

Transversus abdominis plane (TAP) block is a regional anesthetic technique used to desensitize the abdominal wall in several species. This study aimed to describe the anatomical characteristics of the abdominal wall and to identify a feasible approach for an US-guided TAP injection that would result in adequate staining of the relevant nerves in the abdominal wall in pig cadavers. Fresh cadavers from five Landrace pigs (age, 12 weeks; body weight, 35.5 ± 1.6 kg) were used. One pig (n = 1) was anatomically dissected, and four pigs (n = 4; i.e., 8 hemiabdomens) were used for TAP injections and evaluation of dye spread. The volume of 0.3 mL/kg/injection point of methylene blue was injected bilaterally. In the caudal retrocostal approach, the injection was performed ventral to the most caudal part of the costal arch. In the lateral approach, the injection was performed between the last rib and iliac crest. A needle was inserted in plane for the caudal retrocostal and the lateral approach caudocranially and craniocaudally, respectively. Successful staining was defined as presence of dye on the nerve for a length of >1 cm in its entire circumference. The TAP was found between different muscle layers in the described anatomical regions. In the caudal retrocostal approach the TAP was found between the external abdominal oblique and transversus abdominis muscle bellies. In the lateral approach the TAP was found between the internal abdominal oblique and transversus abdominis muscles. The approach combining lateral and caudal retrocostal injections at the studied volume stained a median of 5 (3-6) target nerves from the fourth-last thoracic nerve to L2 (six nerves). Combined caudal retrocostal and lateral TAP injections of 0.3 mL/kg/injection point, resulted in staining of target nerve branches which supply the periumbilical and caudal abdominal wall in pig cadavers.

A therapeutic effect for males with spinal cord injury using abdominal functional electrical stimulation for sexual functioning.

INTRODUCTION: Sexual functioning is a high priority for people with a spinal cord injury (SCI) yet this area has received little attention. Two SCI case reports are presented which suggests there may be greater potential for the recovery of sexual functioning than previously recognised. CASE PRESENTATION: A 74-year-old SCI male (AIS D, C5/C6) and a 36-year-old SCI male (AIS A, T4/T5) were treated for neurogenic bowel using 6 weeks of abdominal FES (ABFES) (40 Hz, 300 µ pulse width (current typically 30-60 MA) simultaneously delivered (8 s contraction with 2 s ramps and 3 s off period) from both channels). The 74-year-old AIS D, C5/C6 participant reported improved strength and duration of erectile function after using ABFES for 3 weeks. The 36-year-old AIS A, T4/T5 participant reported improvements in ejaculatory function and urine flow. Both reported a reduction in time required for bowel management. DISCUSSION: The findings could be attributed to an improved vascularisation of the abdominal area, an improved body image and self-esteem, direct innervation of nerves involved in parasympathetic pathways or innervation of the T11/T1 area implicated in the alternative psychogenic pathway. Both participants reported they had not used ABFES during sexual activity suggesting a therapeutic effect from the treatment.

Transversus Abdominis Plane Block in Laparoscopic Colorectal Surgery: A Systematic Review.

BACKGROUND: Multimodal analgesia is important for postoperative recovery in laparoscopic colorectal surgery. Multiple randomized controlled trials have investigated the use of transversus abdominis plane local anesthetic infiltration as a method of decreasing postoperative pain and opioid consumption, with variable results. OBJECTIVE: This study aimed to examine the overall effect of transversus abdominis plane block in postoperative pain, opioid use, and speed of recovery in laparoscopic colorectal surgery. DATA SOURCES: A literature search was done with PubMed, EMBASE, Web of Knowledge, and Cochrane Library. Only randomized controlled trials were selected for review. INTERVENTIONS: Transversus abdominis plane local anesthetic infiltration versus no intervention, saline, or other techniques in laparoscopic colorectal surgeries was investigated. MAIN OUTCOME MEASURES: The primary outcome measured was postoperative pain on day 1, at rest or with activity. The secondary outcomes measured were postoperative pain beyond day 1, consumptions of opioid, and length of hospital stay. RESULTS: Eight clinical trials including 649 patients between 2013 and 2018 were included. Resting pain scores within 2 hours (standardized mean difference, -0.53; p = 0.01), 4 hours (standardized mean difference, -0.42; p = 0.004), and 6 hours (standardized mean difference, -0.47; p = 0.03) showed statistically significant reduction. Six studies including 413 patients demonstrated lower cumulative opioid consumption within 24 hours after surgery (standardized mean difference, -0.82; p = 0.01). Five studies including 357 patients did not show a significant difference in length of stay (standardized mean difference, -0.04; p = 0.82). LIMITATIONS: Local anesthetic used in block varied in type and quantity across different studies. There were heterogeneities in pain score measurements and opioid consumption. Patient populations may be different among studies. CONCLUSIONS: Transversus abdominis block can lead to a lower pain score at rest within the first 6 hours and reduce opioid consumption within the first 24 hours. See Video Abstract at http://links.lww.com/DCR/A997.

Robot-Assisted Transversus Abdominis Plane Block: Description of the Technique and Comparative Analysis.

BACKGROUND: Several randomized clinical trials have shown the efficacy of percutaneous transversus abdominis plane (TAP) block in decreasing pain after open and minimally invasive surgeries. We postulated that TAP block could be performed by a robot-assisted transperitoneal approach and provide postoperative pain control equivalent to local anesthetic port infiltration. OBJECTIVE: To compare different indicators of postoperative pain between robot-assisted TAP and local anesthetic port infiltration in patients who had undergone robot-assisted radical prostatectomy (RARP). METHODOLOGY: A retrospective comparison of 214 consecutive patients undergoing RARP over a 1-year period was conducted. Patient demographics, comorbidities, operative details, and outcomes, including time to ambulation, pain score, narcotic usage, and length of stay, were compared. RESULTS: In total, 206 patients were included: 101 received local anesthetic port infiltration and 105 robot-assisted TAP block. There were no differences in estimated blood loss, operative time, time to ambulation, and length of stay between the two groups. The robot-assisted TAP block cohort experienced lesser pain than the local anesthetic port infiltration cohort in the intervals of 6 to 12 hours (2.05 vs 3.21, p = 0.0016) and 12 to 18 hours (2.19 vs 2.97, p = 0.0495) postoperation. CONCLUSION: Robot-assisted TAP block is a safe alternative to local anesthetic port-site infiltration. Robot-assisted TAP is associated with lower postoperative pain scores and less narcotic use than local anesthetic port-site infiltration.

Comparison of Therapeutic Benefit of Bupivacaine HCl Transversus Abdominis Plane (TAP) Block as Part of an Enhanced Recovery Pathway versus Traditional Oral and Intravenous Pain Control after Minimally Invasive Colorectal Surgery: A Prospective, Randomized, Double-Blind Trial.

Enhanced recovery pathways (ERPs), when combined with transversus abdominis plane (TAP) blocks, have been proven to reduce the length of stay (LOS) and improve quality outcomes. Nonopioid pain management is an essential component of this pathway, leading to a reduction in immobility, postoperative ileus, and an increase in patient satisfaction. TAP block variations have been studied in general and gynecologic surgery. This study evaluates the effectiveness of laparoscopic TAP blocks in conjunction with the benefit of an ERP. One hundred thirty-seven consecutive laparoscopic and robotic-assisted Colorectal Surgery patients received TAP blocks under laparoscopic guidance while under anesthesia, randomized to a placebo, bupivacaine TAP block, or bupivacaine TAP block with an ERP arm of the trial. Patient demographics, operative techniques, and postoperative outcomes were analyzed using statistical analysis software. Our main objective was to determine short-term benefits of TAP blocks on reducing total narcotic consumption. Secondary objectives included effects of TAP blocks on time to ambulation, time to bowel function, and LOS. To isolate the effect of the TAP blocks, no efforts were made to control nursing or patient education in patients managed without an ERP. Of 137 patients, 14 were withdrawn. All cases were elective, with the main diagnosis colon cancer or dysplastic polyps (47.1%). The median age in each group was comparable (P = 0.12), with female majority in both groups (58.5%). Most procedures were segmental colon resections (74.7%). Thirty-one patients received a placebo, 41 bupivacaine TAP, and 51 bupivacaine TAP plus ERP. In terms of primary endpoints, the bupivacaine plus ERP arm used statistically significant less IV narcotics on postoperative day 1 and in total (P = 0.001, P = 0.008). All patients ambulated on average within the first 24 hours postoperatively, with the TAP plus ERP group approximately 0.5 days sooner (P = 0.001). The TAP plus ERP group also had a return of bowel function and LOS approximately 24 hours early (P = 0.001 and P = 0.001). This study shows that a laparoscopically placed bupivacaine TAP block when used as part of an ERP can reduce LOS, postoperative narcotics, time to ambulation and bowel function, and LOS. Defined pain regimens with auxiliary staff teaching can add to the improvement in quality outcomes in laparoscopic colorectal surgery and, with the addition of the TAP block, can add to patient satisfaction and lower hospital costs.

Local infiltration versus laparoscopic-guided transverse abdominis plane block in laparoscopic cholecystectomy: double-blinded randomized control trial.

BACKGROUND: Transverse abdominal plane block (TAP) is a new technique of regional block described to reduce postoperative pain in laparoscopic cholecystectomy (LC). Recent reports describe an easy technique to deliver local anesthetic agent under laparoscopic guidance. METHODS: This randomized control trial was designed to compare the effectiveness of additional laparoscopic-guided TAP block against the standard full thickness port site infiltration. 45 patients were randomized in to each arm after excluding emergency LC, conversions, ones with coagulopathy, pregnancy and allergy to local anesthetics. All cases were four ports LC. Interventions-Both groups received standard port site infiltration with 3-5 ml of 0.25% bupivacaine. The test group received additional laparoscopic-guided TAP block with 20 ml of 0.25% bupivacaine subcostally, between the anterior axillary and mid clavicular lines. As outcome measures the pain score, opioid requirement, episodes of nausea and vomiting and time to mobilize was measured at 6 hourly intervals. RESULTS: The two groups were comparable in the age, gender, body mass index, indication for cholecystectomy difficulty index and surgery duration. The pain score at 6 h (P = 0.043) and opioid requirement at 6 h (P = 0.026) was higher in the TAP group. These were similar in subsequent assessments. Other secondary outcomes were similar in the two groups. CONCLUSION: Laparoscopic-guided transverses abdominis plane block using plain bupivacaine does not give an additional pain relief or other favorable outcomes. It can worsen the pain scores. Pre registration: The trial was registered in Sri Lanka clinical trial registry-SLCTR/2016/011 ( http://www.slctr.lk/trials/357 ).

Stimulation of abdominal and upper thoracic muscles with surface electrodes for respiration and cough: Acute studies in adult canines.

OBJECTIVE: To optimize maximal respiratory responses with surface stimulation over abdominal and upper thorax muscles and using a 12-Channel Neuroprosthetic Platform. METHODS: Following instrumentation, six anesthetized adult canines were hyperventilated sufficiently to produce respiratory apnea. Six abdominal tests optimized electrode arrangements and stimulation parameters using bipolar sets of 4.5 cm square electrodes. Tests in the upper thorax optimized electrode locations, and forelimb moment was limited to slight-to-moderate. During combined muscle stimulation tests, the upper thoracic was followed immediately by abdominal stimulation. Finally, a model of glottal closure for cough was conducted with the goal of increased peak expiratory flow. RESULTS: Optimized stimulation of abdominal muscles included three sets of bilateral surface electrodes located 4.5 cm dorsal to the lateral line and from the 8th intercostal space to caudal to the 13th rib, 80 or 100 mA current, and 50 Hz stimulation frequency. The maximal expired volume was 343 ± 23 ml (n=3). Optimized upper thorax stimulation included a single bilateral set of electrodes located over the 2nd interspace, 60 to 80 mA, and 50 Hz. The maximal inspired volume was 304 ± 54 ml (n=4). Sequential stimulation of the two muscles increased the volume to 600 ± 152 ml (n=2), and the glottal closure maneuver increased the flow. CONCLUSIONS: Studies in an adult canine model identified optimal surface stimulation methods for upper thorax and abdominal muscles to induce sufficient volumes for ventilation and cough. Further study with this neuroprosthetic platform is warranted.

Comparison between adenosine and magnesium sulphate as adjuvants for transversus abdominis plane block: a prospective randomized controlled trial.

BACKGROUND: Various adjuvants have been employed during different nerve blocks. We aimed to evaluate the effect of adding adenosine versus magnesium sulfate to bupivacaine on the quality and duration of transversus abdominis plane (TAP) block. METHODS: Participants were randomized to TAP block using either 20 mL of bupivacaine hydrochloride 0.375% + 12 mg adenosine in 2 mL of saline 0.9% (adenosine group), 20 mL of bupivacaine hydrochloride 0.375% + 500 mg magnesium sulphate in 2 mL saline 0.9% (magnesium group) or 20 mL of bupivacaine hydrochloride 0.375% + 2 mL saline 0.9% (control group). Primary outcome measure included postoperative pain as assessed by Visual Analog Scale (VAS) for pain scoring on movement and secondary outcomes included analgesia duration, postoperative morphine need and any adverse effects. RESULTS: VAS in adenosine and magnesium groups was significantly less than in control group at 6 and 12 hours postoperatively whereas it was comparable in adenosine and magnesium groups at all time points. Analgesia duration was significantly longer in adenosine and magnesium groups in comparison to the control group and it was relatively longer in the magnesium group when compared to adenosine group (401 vs. 447 vs. 320 minutes in adenosine, magnesium and control groups, respectively; P=0.003). CONCLUSIONS: Both adenosine and magnesium improved the quality and duration of TAP block, but the duration was relatively longer with magnesium.

Clinimetric properties of the pressure biofeedback unit method for estimating respiratory pressures.

OBJECTIVE: The Pressure Biofeedback Unit (PBU) is used to assess the transversus abdominis muscle activity in order to determine the effectiveness of segmental stabilization, but not to verify its accuracy for measuring the pressure values of breathing from transversus abdominis activation. The objective of this study was to cross-validate the PBU pressure evaluated in transversus abdominis muscle activation with the respiratory pressure assessed through manovacuometry in order to verify the extent to which the PBU can be used to indirectly evaluate the strength of the respiratory muscle in both men and women and verify the reliability of the methods. PARTICIPANTS: A total of 39 healthy subjects. METHODS: Manovacuometry and Pressure Biofeedback Unit tests were performed in three days each with three replications: 1) Maximal Inspiratory Pressure; 2) Maximal Expiratory Pressure; and 3) Pressure Biofeedback Unit. RESULTS: Both tests showed good reliability and low correlation between the Pressure Biofeedback Unit and Maximal Inspiratory Pressure (r = 0.40; p = 0.01) and Maximal Expiratory Pressure (r = 0.33; p = 0.04). High differences were observed between pressures and wide limits of agreement in Bland-Altman analysis. CONCLUSION: It seems that the Pressure Biofeedback Unit is not able to effectively predict the respiratory muscles' strength as routinely evaluated through the use of the manovacuometry presenting a low cross-validation and good reliability.

The acute effects of targeted abdominal muscle activation training on spine stability and neuromuscular control.

BACKGROUND: Targeted activation of the transversus abdominis (TrA) muscle through the abdominal drawing-in maneuver (ADIM) is a frequently prescribed exercise for the prevention and rehabilitation of low back pain. However, there is still debate over the role the ADIM plays in maintaining a stable spine during movement. Thus, a single cohort pre/post-intervention protocol was used to examine whether 5 min of ADIM training prior to a dynamic movement task alters dynamic spine stability and control. METHODS: Thirteen healthy participants performed a repetitive spine flexion task twice, once before and once after they received biofeedback training on how to correctly perform the ADIM in standing. Abdominal and back muscle activation (indwelling and surface electromyography, EMG) and 3D kinematic data were recorded during all trials. EMG activation (percent maximum) and local dynamic stability of spine movement [maximum finite-time Lyapunov exponent (λmax)] were compared before and after the training using Friedman's rank test and repeated-measures ANOVA, respectively. To assess the moderating effects of absolute changes in EMG (∆EMG) of each muscle after training on changes in stability, the ∆EMG (peak and mean) were added to the ANOVA as separate covariates (ANCOVA). RESULTS: Following ADIM training, there were greater peak and mean levels of activation in all tested abdominal muscles, including TrA, (p < 0.05), but not in the back muscles. The ANOVA showed no significant change in λmax following training (p = 0.633). However, after considering the moderating effects of the ∆EMG seen in each muscle with training, it was found that only changes in TrA EMG significantly influenced stability. The ANCOVA revealed a significant main effect of training on stability as well as a significant interaction effect between training and ∆EMG recorded from TrA (p < 0.05); those with larger increases in TrA activation demonstrated larger improvements in stability. CONCLUSION: As a group, 5 min of ADIM training did not change spine stability during dynamic movement. However, those who were most successful in improving TrA activation with a 5-min ADIM training session showed the greatest improvements in local dynamic spine stability after training. As such, dynamic spine stability in some individuals may benefit from ADIM training.

Abdominal functional electrical stimulation to enhance mechanical insufflation-exsufflation.

CONTEXT: Respiratory complications, attributed to the build-up of secretions in the airway, are a leading cause of rehospitalisation for the tetraplegic population. Previously, we observed that the application of Abdominal Functional Electrical Stimulation (AFES) improved cough function and increased demand for secretion removal, suggesting AFES may aid secretion clearance. Clinically, secretion clearance is commonly achieved by using Mechanical insufflation-exsufflation (MI-E) to simulate a cough. In this study the feasibility of combining AFES with MI-E is evaluated. FINDINGS: AFES was successfully combined with MI-E at eight fortnightly assessment sessions conducted with one sub-acute participant with tetraplegia. By using the signal from a pressure sensor, integrated with the MI-E device, AFES was correctly applied in synchrony with MI-E with an accuracy of 96.7%. Acute increases in exhaled volume and peak flow were observed during AFES assisted MI-E, compared to MI-E alone, at six of eight assessment sessions. CONCLUSION: The successful integration of AFES with MI-E at eight assessment sessions demonstrates the feasibility of this technique. The acute increases in respiratory function observed at the majority of assessment sessions generate the hypothesis that AFES assisted MI-E may be more effective for secretion clearance than MI-E alone.

Neuromuscular adaptations after a rehabilitation program in patients with chronic low back pain: case series (uncontrolled longitudinal study).

BACKGROUND: To investigate the impact of a short-term multimodal rehabilitation program for patients with low back pain (LBP) on trunk muscle reflex responses and feedforward activation induced by postural perturbations. METHODS: Case series (uncontrolled longitudinal study). Thirty chronic patients with LBP (21 women and 19 men, mean age 42.6 ± 8.6 years, mean weight 73 ± 14 kg, mean height 174 ± 10 cm) were included. The intervention consisted in a 5-day program including therapeutic education sessions (360 min), supervised abdominal and back muscle strength exercises (240 min), general aerobic training (150 min), stretching (150 min), postural education (150 min) and aqua therapy (150 min). Feedforward activation level and reflex amplitude determined by surface electromyographic activity triggered by postural perturbations were recorded from abdominal and paraspinal muscles in unexpected and expected conditions. Subjects were tested before, just after and again one month after the rehabilitation program. RESULTS: No main intervention effect was found on feedforward activation levels and reflex amplitudes underlining the absence of changes in the way patients with LBP reacted across perturbation conditions. However, we observed a shift in the behavioral strategy between conditions, in fact feedforward activation (similar in both conditions before the program) decreased in the unexpected condition after the program, whereas reflex amplitudes became similar in both conditions. CONCLUSIONS: The results suggest that a short-term rehabilitation program modifies trunk behavioral strategies during postural perturbations. These results can be useful to clinicians for explaining to patients how to adapt to daily life activities before and after rehabilitation.

Outpatient inguinal hernia repair under local anaesthesia: feasibility and efficacy of ultrasound-guided transversus abdominis plane block.

BACKGROUND: The aim of this prospective randomized study was to determine the utility of transversus abdominis plane (TAP) block to improve the efficacy of conventional local anaesthesia for hernia repair in order to achieve an adequate anaesthesia and to evaluate its post-operative analgesic effectiveness. METHOD: Hundred and fifty consecutive male patients undergoing outpatient hernia repair (Lichtenstein technique) were enrolled in this study. Patients were randomly allocated to undergo a combined TAP block and local anaesthesia (case group) or single conventional local anaesthesia (control group). The study was designed to obtain a 1:2 case-control ratio. The primary outcome was the evaluation of the proportion of patients achieving an adequate anaesthesia. The secondary outcome was the evaluation of pain on movement, pain at rest, rescue analgesia need, nausea and satisfaction. RESULTS: An adequate anaesthesia was achieved in 8 % case and in 36 % control subjects (p = 0.001). At the 6 and 12 h post-operative evaluations, patients enrolled in the case group reported significantly less pain (evaluated by VAS score) both at rest and on movement (p always = 0.001). Moreover, the need of rescue analgesia resulted significantly higher in the control group (14 vs. 32 %, p = 0.01). CONCLUSION: Our results demonstrated that, as compared with conventional local anaesthesia, the combination of TAP block with local anaesthesia showed a higher efficacy in the obtainment of an adequate anaesthesia and in the post-operative pain control for hernia repair.

Open transversus abdominis plane block and analgesic requirements in patients following right hemicolectomy.

INTRODUCTION: Reducing exogenously administered opioids in the post-operative period is associated with early return of bowel function and decreased post-operative complication rates. We evaluated the effectiveness of a surgeon-delivered open transversus abdominis plane (TAP) block as a method to reduce post-operative opioid requirements, sedation and inpatient stay. METHODS: The patient cohort was identified from those who had undergone a right hemicolectomy for colonic cancer. Patients received either an open TAP block and post-operative patient controlled anaesthesia (PCA) ( n =20) or were part of a control group who received subcutaneous local anaesthetic infiltration and PCA ( n =16). RESULTS: PCA morphine use was reduced within the first 24 hours post-operatively in the TAP block group compared with controls (42.1mg vs 72.3mg, p =0.002). Sedation was also reduced significantly in the early post-operative period (p <0.04). There was a non-significant trend towards reduced length of stay in the intervention group (8.2 vs 8.73 days). There were no recorded complications attributable to the open TAP block. CONCLUSIONS: Open TAP blocks are safe and reduce post-operative opioid requirements and sedation after right hemicolectomies. They should be considered as part of a multimodal enhanced recovery approach to patients undergoing abdominal surgery via a transverse incision.

[Myofascial dysfunction of the lumboinguinal muscle and the experience with the diagnostic and therapeutic work in a cabinet of reflexotherapy].

The authors present a detailed description of the following diagnostic and therapeutic modalities: palpation techniques for the detection of myofascial trigger points, the dynamic ischemic compression maneuver that makes it possible to identify the pathomorphological substrate of the trigger point lying deep in the muscular tissue, and the methods of musculofascial meridional reflexotherapy for the alleviation ofmyofascial pains. The importance of the correction of structural disproportions in the musculoskeletal apparatus potentiating inactivation of myofscial trigger points (MfTP) is emphasized.

On the conscious control of the human heart.

This study describes methods of volitional management of heart rhythms and proves that it is possible by means of management of its operations, subject to arbitrary control, which also has a strong functional connection to the center of the heart rhythm formation in the brain. Experiments demonstrate that it is possible for arbitrary changes in the heart rhythm to be made through conscious control of the breathing rhythm, and even a short-term cardiac arrest by means of contracting abdominal muscles. We postulate that the management of human heart rhythm is indirectly regulated through arbitrary controlled operations. The present article describes and analyzes ways that enable a human to consciously and purposefully manage the frequency of heart contractions. Common principles of arbitrary management of the heart rhythm in humans are uncovered through analysis.

Posterolateral surface electrical stimulation of abdominal expiratory muscles to enhance cough in spinal cord injury.

BACKGROUND: Spinal cord injury (SCI) patients have respiratory complications because of abdominal muscle weakness and paralysis, which impair the ability to cough. OBJECTIVE: This study aims to enhance cough in high-level SCI subjects (n = 11, SCI at or above T6) using surface electrical stimulation of the abdominal muscles via 2 pairs of posterolaterally placed electrodes. METHODS: From total lung capacity, subjects performed maximum expiratory pressure (MEP) efforts against a closed airway and voluntary cough efforts. Both efforts were performed with and without superimposed trains of electrical stimulation (50 Hz, 1 second) at a submaximal intensity set to evoke a gastric pressure (P(ga)) of 40 cm H(2)O at functional residual capacity. RESULTS: In the MEP effort, stimulation increased the maximal P(ga) (from 21.4 ± 7.0 to 59.0 ± 5.7 cm H(2)O) and esophageal pressure (P(es); 47.2 ± 11.7 to 65.6 ± 13.6 cm H(2)O). During the cough efforts, stimulation increased P(ga) (19.5 ± 6.0 to 57.9 ± 7.0 cm H(2)O) and P(es) (31.2 ± 8.7 to 56.6 ± 10.5 cm H(2)O). The increased expiratory pressures during cough efforts with stimulation increased peak expiratory flow (PEF, by 36% ± 5%), mean expiratory flow (by 80% ± 8%), and expired lung volume (by 41% ± 16%). In every subject, superimposed electrical stimulation improved peak expiratory flow during cough efforts (by 0.99 ± 0.12 L/s; range, 0.41-1.80 L/s). Wearing an abdominal binder did not improve stimulated cough flows or pressures. CONCLUSIONS: The increases in P(ga) and PEF with electrical stimulation using the novel posterolateral electrode placement are 2 to 3 times greater than improvements reported in other studies. This suggests that posterolateral electrical stimulation of abdominal muscles is a simple noninvasive way to enhance cough in individuals with SCI.

A control system for automatic electrical stimulation of abdominal muscles to assist respiratory function in tetraplegia.

This letter refers to a paper published by Gollee et al. [Gollee H, Hunt KJ, Allan DB, Fraser MH, McLean AN. A control system for automatic electrical stimulation of abdominal muscles to assist respiratory function in tetraplegia. Med Eng Phys 2007;29:799-807]. We address here the consequences of continuous use and suggest a refinement that may improve the cough peak flow under more chronic conditions.

A control system for automatic electrical stimulation of abdominal muscles to assist respiratory function in tetraplegia.

People with tetraplegia have poor respiratory function leading to limited tidal volume (V(T)) and reduced cough peak flow (CPF). These problems may cause respiratory failure during the initial admission or subsequent intercurrent illness. Electrical stimulation of the abdominal muscles during expiration can improve respiratory function by increasing V(T) and CPF. We developed a novel control system to automatically trigger muscle stimulation, synchronised with the subject's voluntary respiratory activity. The system was tested in four subjects with a functionally complete lesion at level C4 to C6, aged between 16 and 46 years, 3 months to 5 years post injury, who were breathing spontaneously. The algorithm delivered automatic stimulation patterns, detecting cough and quiet breathing while suppressing stimulation during other activities such as speaking. Marked increases in V(T) (between 9% and 71% of baseline) and CPF (between 31% and 54% of baseline) were observed, suggesting that the technique may have potential use in both acute and established tetraplegia to increase minute ventilation and to improve cough clearance of secretions.