Enhanced skeletal muscle contractile function and corticospinal excitability precede strength and architectural adaptations during lower-limb resistance training.

PURPOSE: Evolving investigative techniques are providing greater understanding about the early neuromuscular responses to resistance training among novice exercisers. The aim of this study was to investigate the time-course of changes in muscle contractile mechanics, architecture, neuromuscular, and strength adaptation during the first 6-weeks of lower-limb resistance training. METHODS: Forty participants: 22 intervention (10 males/12 females; 173.48 ± 5.20 cm; 74.01 ± 13.13 kg) completed 6-week resistance training, and 18 control (10 males/8 females; 175.52 ± 7.64 cm; 70.92 ± 12.73 kg) performed no resistance training and maintained their habitual activity. Radial muscle displacement (Dm) assessed via tensiomyography, knee extension maximal voluntary contraction (MVC), voluntary activation (VA), corticospinal excitability and inhibition via transcranial magnetic stimulation, motor unit (MU) firing rate, and muscle thickness and pennation angle via ultrasonography were assessed before and after 2, 4, and 6-weeks of dynamic lower-limb resistance training or control. RESULTS: After 2-weeks training, Dm reduced by 19-25% in the intervention group; this was before any changes in neural or morphological measures. After 4-weeks training, MVC increased by 15% along with corticospinal excitability by 16%; however, there was no change in VA, corticospinal inhibition, or MU firing rate. After 6-weeks training there was further MVC increase by 6% along with muscle thickness by 13-16% and pennation angle by 13-14%. CONCLUSION: Enhanced contractile properties and corticospinal excitability occurred before any muscle architecture, neural, and strength adaptation. Later increases in muscular strength can be accounted for by architectural adaptation.

Bayesian analysis of changes in standing horizontal and vertical jump after different modes of resistance training.

Training interventions often have small effects and are tested in small samples. We used a Bayesian approach to examine the change in jump distance after different resistance training programmes. Thirty-three 18- to 45-year-old males completed one of three lower limb resistance training programmes: deadlift (DL), hip thrust (HT) or back squat (BS). Horizontal and vertical jump performance was assessed over the training intervention. Examination of Bayesian posterior distributions for jump distance estimated that the probability of a change above a horizontal jump smallest worthwhile change (SWC) of 4.7 cm for the DL group was ~12%. For the HT and BS groups, the probability of a change above the SWC was ~87%. The probability of a change above a vertical jump SWC of 1.3 cm for the DL group was ~31%. For the HT and BS groups, the probability of a change above the vertical jump SWC was ~62% and ~67%, respectively. Our study illustrates that a Bayesian approach provides a rich inferential interpretation for small sample training studies with small effects. The extra information from such a Bayesian approach is useful to practitioners in Sport and Exercise Science where small effects are expected and sample size is often constrained.

Tensiomyography Derived Parameters Reflect Skeletal Muscle Architectural Adaptations Following 6-Weeks of Lower Body Resistance Training.

Measurement of muscle specific contractile properties in response to resistance training (RT) can provide practitioners valuable information regarding physiological status of individuals. Field based measurements of such contractile properties within specific muscle groups, could be beneficial when monitoring efficacy of training or rehabilitation interventions. Tensiomyography (TMG) quantifies contractile properties of individual muscles via an electrically stimulated twitch contraction and may serve as a viable option in the aforementioned applications. Thus, aims of this study were; (i) to investigate the potential use of TMG to quantify training adaptations and differences, in response to exercise specific lower limb RT; and (ii) investigate any associations between TMG parameters and accompanying muscle architectural measures. Non-resistance trained male participants (n = 33) were randomly assigned to 1 of 3 single-exercise intervention groups (n = 11 per group); back squat (BS), deadlift (DL), or hip thrust (HT). Participants completed a 6-week linearized training program (2× per week), where the assigned exercise was the sole method of lower body training. Pre- and post-intervention testing of maximal dynamic strength was assessed by one repetition maximum (1RM) of BS, DL, and HT. Radial muscle belly displacement (Dm) and contraction time (Tc) were obtained via TMG from the rectus femoris (RF) and vastus lateralis (VL) pre- and post-intervention, alongside muscle architectural measures (pennation angle and muscle thickness). All three groups displayed significant increases all 1RM strength tests (p < 0.001; pη2 = 0.677-0.753). Strength increases were accompanied by significant overall increases in RF muscle thickness (p < 0.001, pη2 = 0.969), and pennation angle (p = 0.007, pη2 = 0.220). Additionally, an overall reduction in RF Dm (p < 0.001, pη2 = 0.427) was observed. Significant negative relationships were observed between RF Dm and pennation angle (p = 0.003, r = -0.36), and with RF Dm and muscle thickness (p < 0.001, r = -0.50). These findings indicate that TMG is able to detect improved contractile properties, alongside improvements in muscle function within an untrained population. Furthermore, the observed associations between Dm and muscle architecture suggest that TMG contractile property assessments could be used to obtain information on muscle geometry.

Lingual Nerve Microsurgery Outcomes Using 2 Different Conduits: A Retrospective Cohort Study.

PURPOSE: This study compared a type 1 collagen conduit (NeuraGen) with a porcine small intestinal submucosa conduit (AxoGuard) when used in lingual nerve microsurgery and any differences in achieving functional sensory recovery (FSR). PATIENTS AND METHODS: All patients who underwent lingual nerve microsurgery performed by 1 surgeon (V.B.Z.) from 2007 to 2014 had their surgical information obtained by a retrospective review of hospital records and office charts after institutional review board approval. Those patients whose surgery included the use of a nerve conduit were included in the study. Subjective neurosensory recovery was determined by neurosensory testing, including responses to hot, cold, wisp, brush, and pinprick. Objective recovery was determined by testing 2-point discrimination and fine touch threshold with von Frey fibers. The objective findings were correlated to a Medical Research Council System score, with grades S3, S3+, and S4 indicating FSR. RESULTS: The conduits were compared using a Student t test with a 2-tailed hypothesis. The von Frey fiber test had a preoperative mean of 6.29 (standard deviation [SD], 0.95), which improved to 3.97 (SD, 0.67) for the NeuraGen and 4.17 (SD, 0.56) for the AxoGuard. Two-point discrimination improved from a mean higher than 19.42 to 9.32 mm (SD, 2.96 mm) for the NeuraGen and 9.67 mm (SD, 2.13 mm) for the AxoGuard. The mean FSR was S3+. CONCLUSIONS: There were no meaningful differences in outcomes between the 2 conduits studied, and all patients achieved FSR according to the Medical Research Council Scale.

Treatment of chest wall implosion injuries without thoracotomy: technique and clinical outcomes.

BACKGROUND: Chest wall implosion injuries secondary to side impact are unusual but devastating injuries. The purpose of this series is to describe the clinical entity, present a surgical technique to reduce and repair the thoracic cage deformity without thoracotomy, and report outcomes in nine patients. STUDY: Institutional review board approved retrospective case series, surgical technique. SETTING: Level I Trauma Center. METHODS: Twenty-two patients were admitted during 7-year period with thoracic cage implosion injuries and multiple segmental rib fractures from a side impact mechanism. All patients' required mechanical ventilation and had an implosion deformity along the posterolateral thoracic cage, pulmonary contusion, and clavicular fractures. Nine patients underwent repair of rib fractures through a paramidline posterior approach without thoracotomy using standard 2.4-mm titanium plates. Seven patients with similar fracture pattern treated nonoperatively were used as a historical control. Total intubation time, intensive care unit (ICU) length of stay (LOS), and final shoulder function using the Constant Murley scoring system were compared between the two groups. RESULTS: Average age, male to female ratio, and injury severe score were comparable for both cohorts (p > 0.6). Average follow-up was 16 months versus 12 months for the operative and nonoperative groups, respectively, (p = 0.11). In the operative group, 8 of 9 (89%) patients were extubated within 24 hours of surgery; 3 of 9 (33%) were extubated in the operating room. In the operative group, seven patients underwent internal fixation of the clavicle and progressed to union with a mean Constant score of 93. Nine patients had nonoperative treatment of the clavicle with a mean Constant score of 75 (p = 0.04). Total intubation time (1.9 days) was significantly shorter in the operative group than the nonoperative controls at 13.3 days (p < 0.01) and length of ICU stay was also shortened at 5.7 (4-8) days versus 16.7 (10-26) days, respectively, (p < 0.01). CONCLUSION: Chest wall implosion injuries with fixed deformities of the thoracic cage, multiple segmental rib fractures, and clavicular injury are a distinct clinical entity, which can be effectively managed with a posterior paramidline approach without thoracotomy. Reduction of the deformity and repair of the rib fractures led to a dramatic reduction in time to extubation, ICU LOS, and in-hospital complications including pneumonia and sepsis. Repair of the clavicular fracture appeared to be beneficial.

Severe traumatic brain injury: is there a gender difference in mortality?

BACKGROUND: Emerging evidence suggests that male and female nervous systems respond differently to traumatic brain injury (TBI). The objective of this study was to examine outcomes between the sexes after TBI. PATIENTS AND METHODS: A retrospective review of all severe TBI patients admitted between January and December 2005 was performed. Isolated severe TBI was defined as a head abbreviated injury score greater than 3 with an abbreviated injury score of 3 or less for other anatomic regions. The population was stratified into age subgroups (<14 y, 14-44 y, 45-54 y, and > or =55 y). Logistic regression was used to identify independent predictors of mortality. RESULTS: A total of 1,807 TBI patients were admitted. The mortality was significantly higher for women (43.2% vs 36.2%, P < .01) with an adjusted odds ratio of 1.4 (95% confidence interval, 1.1-1.9, P < .05). After stratification, only women age 55 and older had a significant difference in mortality (odds ratio, 1.71; 95% confidence interval, 1.11-2.62, P = .02). CONCLUSIONS: Female sex (particularly those age > or =55 y) is associated independently with higher mortality in isolated severe TBI. This increased mortality of postmenopausal women after isolated TBI may suggest a hormonal influence and warrants further investigation.

A promising new alternative for the rapid reversal of warfarin coagulopathy in traumatic intracranial hemorrhage.

BACKGROUND: Internationally, Factor IX complex (FIX complex) has been used to correct warfarin-induced coagulopathy. We present our experience with 28 patients using FIX complex. METHODS: A retrospective chart review was conducted between November 2002 and July 2006 on patients with warfarin-induced coagulopathy. We recorded the dose and timing of FIX complex, serial international normalized ratios (INRs), early adverse events, and patient outcome. RESULTS: Twenty-eight patients met criteria. The mean INR on admission was 5.1, and after FIX complex infusion was reduced significantly to 1.9 (P = .008). Eleven patients had a repeat INR drawn within 30 minutes after FIX complex infusion. The mean time to correction was 13.5 minutes. There were no early thrombotic events or allergic reactions. CONCLUSIONS: FIX complex results in an immediate reversal of coagulopathy within 15 minutes after administration. Its use should be considered as an alternative treatment to fresh-frozen plasma and recombinant Factor VIIa. Prospective randomized trials are needed to confirm these findings.

A 2-minute pre-extubation protocol for ventilated intensive care unit patients.

BACKGROUND: Clinicians often are challenged with safely predicting the optimal time of extubation for ventilated patients. Commonly used weaning parameters have poor positive predictive value for successful extubation. METHODS: A total of 213 intubated patients in our 20-bed surgical intensive care unit were enrolled in a trial to test a prospective, observational, 2-minute extubation protocol (TMEP). Daily measurements were obtained on all intubated patients who met criteria, which included adequate oxygenation, systolic blood pressure, heart rate, hemoglobin, Glasgow Coma Score greater than 10t, absence of significant metabolic/respiratory acidosis, and absence of therapeutic or neurologic paralysis. During TMEP, endotracheally intubated patients were physically disconnected from the ventilator for a 2-minute period of observation while spontaneously breathing room air. Patients were extubated if they tolerated the trial without clinically significant desaturation or alteration of vital signs or mental status. RESULTS: The TMEP reliably predicted successful extubations in 203 of 213 patients (95.3%). Patients who required reintubation had a longer intensive care unit stay and a longer hospital stay. CONCLUSIONS: TMEP is a simple and reliable method of predicting successful extubation.

Noninvasive Doppler ultrasonography for assessing cardiac function: can it replace the Swan-Ganz catheter?

BACKGROUND: Cardiac function, including cardiac index (CI), traditionally has been measured by a pulmonary artery catheter (PAC). A noninvasive alternative for measuring cardiac function would offer obvious advantages. METHODS: A prospective study of trauma and nontrauma patients was performed in a surgical intensive care unit over a 3-month period. CI was determined using both a standard PAC and a continuous-wave Doppler ultrasound (UTS). The study had 2 phases: phase I was nonblinded and phase II was blinded; the correlation between UTS- and PAC-derived CI was assessed. RESULTS: A total of 120 paired measurements of CI were observed in 31 patients. The UTS-derived CI measurements showed agreement with PAC measurements in both phase I and phase II of the study with a bias of .06 L/min/m(2) +/- .4 L/min/m(2). Paired measurements correlated well in both phase I (r = .97, R2 = .95, P < .0001) and phase II (r = .93, R2 = .86, P < .0001) of the study. CONCLUSIONS: Doppler UTS correlates well with PAC measurements of CI. This noninvasive modality is an accurate and safe alternative to PAC.

Percutaneous tracheostomy in neurosurgical patients with intracranial pressure monitoring is safe.

BACKGROUND: Percutaneous tracheostomy (PT) is performed routinely on neurosurgical patients in many critical care units. Some of these patients suffer from severe brain injury and require intracranial pressure (ICP) monitoring. It remains uncertain whether this procedure causes an increase in ICP or jeopardizes the cerebral perfusion pressure (CPP) in these patients. We studied the effects of PT on ICP and CPP in this group of patients. METHODS: Our study group consisted of 52 neurosurgical patients in the surgical intensive care unit of an urban, Level I Trauma Center who had ICP monitoring and underwent PT between 2001 and 2005. Data were collected from 24 hours before to 24 hours after PT. ICP, CPP, and Glasgow Coma Score (GCS) scale were measured hourly during the study period. RESULTS: There was no statistically significant change in the mean ICP over the 48-hour study period or after the procedure. There was a temporary increase in ICP during the procedure (1.60 mm Hg) which was statistically not significant. There was statistically significant increase in the mean CPP after the procedure, although this increase was clinically not significant. The risk of having a critically high ICP (>20 mm Hg) or low CPP (<60 mm Hg) values did not increase after the procedure. There was no significant change in GCS after the procedure. CONCLUSION: PT in neurosurgical patients with ICP monitor does not cause clinically significant or hazardous changes in ICP, CPP, and GCS. We therefore consider PT to be safe in neurosurgical patients.

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Percutaneous endoscopic-guided gastrostomy (PEG) is done routinely on patients who suffer from inability to feed by mouth. PEG is generally considered a safe procedure with a low complication rate. A commonly underreported complication of PEG is malposition. This manuscript is a guideline to diagnosis and management of PEG malposition. We describe the different types of malposition, their diagnosis and management.

Adapting to the changing paradigm of management of colon injuries.

BACKGROUND: Based on the evolution that the management of colonic trauma has undergone since the early 1990s, we hypothesized that the use of diversion has decreased at our institution over the last decade. METHODS: A retrospective review was performed of all patients who presented to our trauma center with colon injuries between 1995 and 2006. RESULTS: A total of 81 patients were analyzed. Twenty-five patients (31%) were treated with diversion and 56 patients (69%) underwent primary repair or resection with anastomosis. The rate of diversion in the first half of the study period as well as the second half of the study period was 31%. There was no difference in the complication rates. CONCLUSIONS: The usage of diversion remains higher than current literature would indicate. As a result, we are implementing a program that will actively encourage our trauma surgeons to improve the quality of patient care by incorporating evidence-based medicine into clinical practice.

CT angiography in penetrating neck trauma reduces the need for operative neck exploration.

The evaluation of penetrating neck injury has evolved dramatically from mandatory operative exploration of Zone II injuries that penetrate the platysma to selective management based on physical examination and adjunctive studies. More recently, CT angiography has emerged as an efficient, noninvasive method of evaluating penetrating neck injury. We retrospectively reviewed our experience over 10 years with the management of penetrating neck injury. One hundred thirty cases were reviewed with 34 undergoing CT angiogram (Group CTA) and 96 with no CT angiogram (Group nCTA). Group CTA had significantly fewer neck explorations, 1 (3%) versus 32 (33%), P < 0.001. Negative explorations were significantly higher in nCTA as well, with a rate of 22 per cent versus 0 in CTA (P < 0.01). The use of angiogram and esophagram was also significantly lower in CTA versus nCTA (P = 0.02 and P = 0.04). Of the 34 patients in CTA, 4 (12%) also underwent angiography and 4 (12%) received a contrast esophagram. Of the 64 patients in nCTA who did not undergo a neck exploration, 19 (29%) underwent angiography, and 17 (26%) received a contrast esophagram. The use of CT angiogram increased over time with a concomitant decrease in the rate of neck explorations.

Objective indications for early tracheostomy after blunt head trauma.

BACKGROUND: Early tracheostomy has been shown to be beneficial after trauma; however, there are few objective data to identify early in the recovery period which patients will ultimately require tracheostomy after blunt head trauma. METHODS: The charts of all patients admitted to the surgical intensive care unit intubated at a level 1 urban trauma center, over a 5-year period with a primary admission diagnosis of blunt head trauma were retrospectively reviewed. RESULTS: Sixty-four patients met inclusion and exclusion criteria and were divided into two groups: those extubated and those that required tracheostomy. By day 3 the Glasgow Coma Scores for the two groups were significantly different and on day 4 the Simplified Acute Physiology (SAPS) Scores were significantly different. CONCLUSIONS: Calculating objective scores such as GCS and SAPS can aid in identifying those patients who will ultimately require a tracheostomy for prolonged airway protection after blunt head trauma with high positive predictive value.

Analysis of causes and prevention of early readmission to surgical intensive care.

The purpose of this study was to analyze causes of early readmission to the surgical intensive care unit (SICU), to determine whether readmission can be predicted or prevented, and to compare outcomes of patients readmitted to the SICU with patients not requiring readmission. All patients admitted to the Cedars-Sinai SICU from January 1, 1996, to December 31, 2001, were included. Clinical data was prospectively collected in an on-line computer system. The charts of all early readmission patients were retrospectively reviewed. SICU and hospital outcomes were abstracted from a computerized data warehouse. During the study period, 10,840 patients were admitted to the SICU including 97 (0.89%) early readmissions. SICU admission APACHE II and SAPS I scores, SICU and hospital length of stay, and mortality were significantly higher in readmitted patients compared to patients not requiring readmission. The majority of early SICU readmissions were due to respiratory and neurologic deterioration. Upon review, 62 per cent of all readmissions met appropriate SICU discharge criteria and were not predictable while only 5 per cent of SICU discharge were felt to have been premature. Patient outcomes are adversely affected by early readmission to the SICU. Careful neurologic assessment, meticulous attention to respiratory care transfer orders, and prompt respiratory therapy on floor care may significantly decrease the need for early readmission to the SICU.

Tension pyopneumothorax in a child: a case report.

Pneumonia is an infection of the lung parenchyma that may result in pleural thickening, effusion, or an empyema. When there is air or gas in association with purulent exudate in the pleural cavity, a pyopneumothorax exists. The progression to pyopneumothorax under tension is extremely rare. We present a case of tension pyopneumothorax in a child.