Predictors of anesthesia ready time: Analysis and benchmark data

Objective

Patients undergoing congenital cardiac surgery require induction of anesthesia. Our objective was to identify the median anesthesia ready time and the predictors of this time.

Methods

By using the Society of Thoracic Surgeons Congenital Heart Surgery Database, we identified patients who underwent cardiopulmonary bypass procedures from 2017 to 2021. Univariate and multivariable regression modeling to predict the anesthesia ready time was performed using mixed-effects linear regression.

Results

After exclusion of outliers, 44,418 cases were analyzed. The median anesthesia ready time was 51 minutes (interquartile range, 38-66). On multivariable analysis, independent predictors of a longer anesthesia ready time included decreasing weight (0.3 min/10 kg, 95% CI, 0.1-0.6; P = .011), prematurity (1.5 minutes, 95% CI, 0.8-2.2; P < .001), and presence of chromosomal abnormality (3.4 minutes, 95% CI, 1.5-5.2; P < .001). An increase in the duration in anesthesia ready time was seen with increasing Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery mortality category with an additional 7.8 minutes (95% CI, 5.2-10.4; P < .001) for a Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery 5 procedure compared with Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery 1. Emergency versus elective case designation was associated with an anesthesia ready time reduction of 3.6 minutes (95% CI, 1.1-6.1; P = .005), and an afternoon case start was associated with an anesthesia ready time reduction of 4.2 minutes (95% CI, 2.8-5.6; P < .001). The presence of an anesthesia trainee increased the anesthesia ready time by 3.8 minutes (95% CI, 2.6-5.0; P < .001). The presence of an airway in situ decreased the anesthesia ready time by 3.6 minutes (95% CI, 1.6-5.5; P < .001), whereas an in situ arterial line decreased the anesthesia ready time by 7.4 minutes (95% CI, 4.6-10.2; P < .001). Placement of a central venous line increased the anesthesia ready time by 8.5 minutes (95% CI, 5.9-11.1; P < .001).

Conclusions

The median anesthesia ready time was 51 minutes. For patients with characteristics associated with prolonged anesthesia ready time, consideration should be given to allocation of additional anesthesia staffing to improve efficiency.

Histopathology of resected tissue from repair of anomalous aortic origin of a coronary artery: Potential mechanism of coronary artery compression

Objective

This study aimed to describe the histomorphologic characteristics of resected (unroofed) common wall tissue from repair of anomalous aortic origin of a coronary artery and to determine whether the histologic features correlate with clinical and imaging findings.

Methods

The histology of resected tissue was analyzed and reviewed for the presence of fibrointimal hyperplasia, smooth muscle disarray, mucoid extracellular matrix accumulation, mural fibrosis, and elastic fiber disorganization and fragmentation using hematoxylin and eosin and special stains. Clinical, computed tomography imaging, and surgical data were correlated with the histopathologic findings.

Results

Twenty specimens from 20 patients (age range, 7-18 years; 14 males) were analyzed. Anomalous aortic origin of a coronary artery involved the right coronary in 16 (80%), and a slit-like ostium was noted in 18 (90%). By computed tomography imaging, the median proximal coronary artery eccentricity index was 0.4 (range, 0.20-0.90). The median length of intramural course was 8.2 mm (range, 2.6-15.2 mm). The anomalous vessel was determined to be interarterial in 14 patients (93%, 15 had evaluable images). The median distance from a commissure was 2.5 mm above the sinotubular junction (STJ) (range: 2 mm below the STJ-14 mm above the STJ). Prominent histopathologic findings included elastic fiber alterations, mural fibrosis, and smooth muscle disarray. The shared wall of the aorta and intramural coronary artery is more similar to the aorta histologically. Mural fibrosis and elastic fiber abnormalities tended to be more severe in patients >10 years of age at the time of surgery, but this did not reach statistical significance. The extent of vascular changes did not appear to have a clear relationship with the imaging features.

Conclusions

The findings confirm the aortic wall-like quality of the intramural segment of the coronary artery and the presence of pathologic alterations in the wall microstructure.

The Yasui operation: A single institutional experience over 30 years

Objective

The Yasui operation was introduced in 1987 for patients with 2 adequate ventricles, a ventricular septal defect, and aortic atresia or interrupted aortic arch. Despite promising early outcomes, left ventricular outflow tract obstruction (LVOTO) remains a long-term concern. The purpose of this study is to report our institutional experience with the Yasui operation.

Methods

We retrospectively reviewed all patients undergoing the Yasui operation between 1989 and 2021. Results are reported as median with interquartile range (IQR).

Results

Twenty-five patients underwent a Yasui operation (19 primary), at 11 days (IQR, 7-218 days) of life and weight of 3 kg (IQR, 2.8-4.1 days). Fundamental diagnosis was ventricular septal defect/interrupted aortic arch in 11 patients and ventricular septal defect/aortic atresia in 14. Follow-up was 96% (24 out of 25) at 5 years (IQR, 1.4-14.7) with 92% survival. Freedom from LVOTO reoperation was 91% at late follow-up with 2 patients requiring baffle revision at 6 and 9 years. Latest echocardiogram showed 100% of patients had normal biventricular function and 87% (20 out of 23) less than mild LVOTO at 5 years (IQR, 2.3-14.9). Diagnosis, aortic valve morphology, and material used were not predictors of LVOTO. Freedom from right ventricle-to-pulmonary artery conduit reoperation was 48% at a median of 5 years (IQR, 1.4-14.7). Conduit type was not a predictor of reintervention.

Conclusions

The Yasui operation can be performed with low morbidity and mortality in patients with 2 acceptable-size ventricles and aortic atresia or interrupted aortic arch with severe LVOTO. Despite some burden of reoperation, midterm reoperation for LVOTO is not common and ventricular function is preserved.

Patch augmentation of small ascending aorta during stage I procedure reduces the risk of morbidity and mortality

OBJECTIVES

Hypoplastic left heart syndrome (HLHS) with aortic atresia (AA) patients are prone to coronary insufficiency due to a small ascending aorta. Prophylactic patch augmentation of the small ascending aorta during the stage I procedure (S1P) may reduce the risk of coronary insufficiency as marked by ventricular dysfunction, need for extracorporeal membrane oxygenator (ECMO) support or mortality.

METHODS

Retrospective analysis of patients with HLHS with AA who underwent an S1P was completed. Baseline ascending aorta size, right ventricular (RV) function and outcome variables of transplant-free survival, ECMO support after the stage 1 operation and RV function at the time of the bidirectional Glenn and latest follow-up were collected.

RESULTS

Between January 2010 and April 2020, 11 patients underwent prophylactic ascending aorta augmentation at the time of the S1P as a planned portion of the procedure. A total of 125 patients underwent S1P during this period as a comparison. Overall survival was 100% for the augmented group and 74% for the control group (P = 0.66). A composite end point of transplant-free survival, no post-S1P ECMO and less than moderate RV dysfunction was created. At the time of BDG, this composite end point was 100% for the augmented group and 61.8% for the control group (P = 0.008) and at most recent follow-up was 100% for the augmented group and 59.3% for control (P = 0.007). Eight patients required a rescue procedure for the clinical evidence of coronary insufficiency following S1P that included ascending aorta patch augmentation or stent placement. When comparing these rescue versus prophylactic ascending aortic augmentations, there were also differences in the composite outcome 100% for augmented and 60% for rescue (P = 0.009) and at the time of most recent follow-up 100% for augmented and 50% for rescue (P = 0.029).

CONCLUSIONS

Prophylactic patch augmentation of the ascending aorta in HLHS patients with AA may reduce the risk of mortality, ECMO and reduced RV function. Patients not initially undergoing augmentation but then requiring a rescue procedure have particularly poor outcomes. Patch augmentation for smaller ascending aortic diameters should be considered and further clinical experience may help delineate aorta diameter threshold for augmentation.

Relationship of Preoperative Thyroid Dysfunction to Clinical Outcomes in Pediatric Cardiac Surgery

CONTEXT

Thyroid function may be assessed in children before cardiac surgery because of concerns that hypothyroidism or thyrotoxicosis might adversely affect cardiac function perioperatively. However, the relationship between preoperative thyroid dysfunction and surgical outcomes is unknown.

OBJECTIVE

Determine the relationship between preoperative thyroid dysfunction and outcomes of pediatric cardiac surgery.

METHODS

Retrospective cohort study (January 2005 to July 2019).

SETTING

Academic pediatric hospital.

PATIENTS

All patients <19 years old who underwent cardiac surgery with cardiopulmonary bypass and had thyrotropin (TSH) measured within 14 days preoperatively. Exclusion criteria included neonates (≤30 days), preoperative extracorporeal life support, salvage operations, or transplantation procedures.

MAIN OUTCOME MEASURES

Subjects were stratified by preoperative TSH concentration (mIU/L): low (<0.5), normal (0.5-5), mildly high (5.01-10), or moderately high (>10). Outcomes were compared among subjects with normal TSH (control) and each group with abnormal TSH concentrations. The primary outcome was 30-day mortality. Secondary outcomes included time to extubation, intensive care unit and hospital length of stay, and operative complications.

RESULTS

Among 592 patients analyzed, preoperative TSH was low in 15 (2.5%), normal in 347 (58.6%), mildly high in 177 (29.9%), and moderately high in 53 (9.0%). Free thyroxine was measured in 77.4% of patients and was low in 0 to 4.4% of subjects, with no differences among TSH groups. Thirty-day mortality was similar among TSH groups. There were no differences in any secondary outcome between patients with abnormal TSH and patients with normal TSH.

CONCLUSION

Preoperative mild to moderate subclinical hypothyroidism was not associated with adverse postoperative outcomes in children undergoing cardiopulmonary bypass procedures.

The Use of Regional Catheters in Children Undergoing Repair of Aortic Coarctation

OBJECTIVE

The objective was to assess the effectiveness and safety of peripheral regional anesthesia in congenital cardiac surgical patients undergoing thoracotomy for aortic coarctation.

DESIGN

A retrospective chart review of pediatric patients (<18 years) who underwent surgical repair of congenital heart diseases via thoracotomy between September 2013 and July 2018 was done. Among patients who underwent coarctation repair, a propensity score was used to match patients who received a regional catheter (C) versus traditional medical treatment only (M).

SETTING

A single center children's hospital.

PARTICIPANTS

The median age was 172 days (IQR 64-1315) in group C and 176 days (IQR 71-1146) in group M (SMD = 0.07). The median weight was 6.8 kg (IQR 4.8-13.6) in group C and 7.7 kg (4.6-17.4) in group M (SMD = 0.003).

MEASUREMENTS AND MAIN RESULT

Outcomes assessed were postoperative hospital length of stay, median pain scores in the first 24 and 48 hours, and total morphine equivalent use in the first 24 and 48 hours. Complications related to the catheters were reviewed. The median oral morphine equivalent dose administered in the first 24 hours was lower in group C than group M (0.8 mg/kg, IQR 0.5-1.1 vs. 1.4 mg/kg, IQR 0.9-1.7, p = 0.019). There were no major complications related to the catheters, including hematoma.

CONCLUSIONS

Peripheral regional catheters may be used to reduce opioid requirements in patients after CoA repair. Due to the low risk of these catheters, they should be considered as part of a pain management strategy for pediatric patients undergoing thoracotomy and should be incorporated into strategies to improve outcomes.

Impact of a Composite Valved RV-PA Graft After Stage 1 Palliation

BACKGROUND

The use of a valved right ventricular to pulmonary artery shunt (RVPAS) has been reported by some to improve pulmonary artery growth after stage 1 palliation (S1P).

METHODS

We retrospectively reviewed all patients undergoing an S1P with an RVPAS between January 2013 and May 2017, stratified by RVPAS type: a ring-reinforced polytetrafluoroethylene (PTFE) graft or a composite graft that included a distal valved femoral or saphenous vein homograft. We examined the association of RVPAS type on postoperative hemodynamics, time to reintervention, pulmonary artery growth, and survival.

RESULTS

Among 94 infants, 56 (60%) underwent PTFE-only shunt, 24 (25%) underwent femoral vein homograft, and 14 (15%) underwent saphenous vein homograft, and no relevant risk factor differences were found between the groups. Arterial saturation was 2.3% higher (p = 0.014) and serum lactic acid was 1.24 mg/dL lower (p = 0.03) in the femoral vein homograft group than in the PTFE-only group, although venous saturation was similar. By 60 days, 50% of patients with saphenous vein homograft had a reintervention compared with 5% with PTFE graft (p < 0.0001) and 12% with femoral vein homograft (p = 0.2 versus PTFE). At the time of stage 2 palliation, no differences were found in pulmonary artery size or growth over time by either echocardiogram or angiography or in the density of aortopulmonary collaterals or degree of tricuspid regurgitation. The 12-month survival was similar between the groups.

CONCLUSIONS

The use of an interposition femoral vein homograft into the RVPAS may enhance perioperative stability, but it does not substantially improve interstage growth of the pulmonary arteries. Use of saphenous vein homograft is associated with earlier time to reintervention after S1P.

Clinical Utility of Preimplantation Homograft Cultures in Patients Undergoing Congenital Cardiac Surgery

Institutional practice at our hospital (Boston Children's Hospital) is to culture homografts before implantation during congenital cardiac surgery. Over a 4-year period, 5% (73 of 1376) of these cultures were positive, but the results had minimal clinical impact. Our experience demonstrates that there is limited utility in preimplantation cultures of cardiac homografts.

Direct heart shunt placement for CSF diversion: technical note

The authors report a complex case of an 18-year-old male with a history of hydrocephalus secondary to intraventricular hemorrhage of prematurity, with more than 30 previous shunt revisions, who presented to the authors' institution with shunt malfunction. After exhausting his peritoneal cavity and pleural space as possible distal sites of shunt placement, he underwent a direct heart shunt placement when it was discovered he had thrombosis of his subclavian vein precluding a standard wire-guided atrial cannulation. His course was complicated by postoperative distal catheter migration and repeat surgery for reimplantation of the shunt directly into the atrium. At the 16-month follow-up visit, the patient showed no symptoms of shunt malfunction or pericardial effusion. Imaging studies demonstrated a functioning shunt system. This is the second reported successful ventricle to direct heart shunt placement in an adult. The authors report on the technical aspects of the case and review the relevant literature.

Phosphodiesterase Inhibitor-Based Vasodilation Improves Oxygen Delivery and Clinical Outcomes Following Stage 1 Palliation

BACKGROUND

Systemic vasodilation using α-receptor blockade has been shown to decrease the incidence of postoperative cardiac arrest following stage 1 palliation (S1P), primarily when utilizing the modified Blalock-Taussig shunt. We studied the effects of a protocol in which milrinone was primarily used to lower systemic vascular resistance (SVR) following S1P using the right ventricular to pulmonary artery shunt, measuring its effects on oxygen delivery (DO₂) profiles and clinical outcomes. We also correlated Fick-based assessments of DO₂ with commonly used surrogate measures.

METHODS AND RESULTS

Neonates undergoing S1P were treated according to best clinical judgment prior to (n=32) and following (n=24) implementation of a protocol that guided operative, anesthetic, and postoperative management, particularly as it related to SVR. A majority of the subjects (n=51) received a modified right ventricular to pulmonary artery shunt. In a subset of these patients (n=21), oxygen consumption (VO₂) was measured and used to calculate SVR, DO₂, and oxygen debt. Neonates treated with the protocol had significantly lower SVR (P=0.02), serum lactate (P<0.001), and Sa-vO₂ difference (P<0.001) and a lower incidence of CPR requiring extracorporeal membrane oxygenation (E-CPR, P=0.02) within the first 72 postoperative hours. DO₂ was closely associated with SVR (r²=0.78) but correlated poorly with arterial (SaO₂) and venous (SvO₂) oxyhemoglobin concentrations, the Sa-vO₂ difference, and blood pressure.

CONCLUSIONS

A vasodilator protocol utilizing milrinone following S1P effectively decreased SVR, improved serum lactate, and decreased postoperative cardiac arrest. DO₂ correlated more closely with SVR than with Sa-vO₂ difference, highlighting the importance of measuring VO₂ in this population.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02184169.

Outcomes of surgery for young children with multivessel pulmonary vein stenosis

OBJECTIVE

We pursued a multimodality approach to the treatment of patients with pulmonary vein stenosis, incorporating sutureless surgical repair, catheter interventions, and adjunctive chemotherapy. We report our outcomes after surgery.

METHODS

Between January 2007 and August 2013, 49 patients with multivessel pulmonary vein stenosis underwent operations at our institution. We retrospectively reviewed data from a pulmonary vein stenosis registry and the medical records.

RESULTS

At the time of the index operation, the median patient age was 6 months (range, 32 days-48 months) and weight was 4.9 kg (range, 2.1-13.4 kg). Fourteen patients (28%) died during the follow-up period (median follow-up was 0.5 years [range, 0.04-4.9 years]). There were 2 deaths (4%) within 30 days. Age at repair <6 months, weight at repair <3 kg, and a preoperative right ventricular systolic pressure < ¾ systemic were found to be associated with mortality. One patient required repeat operation for recurrent stenosis. Thirty-nine patients (80%) underwent postoperative catheterizations. The median number of catheterizations per patient was 2 (range, 0-14). Twenty-nine patients (59%) underwent catheterizations with pulmonary vein intervention. The median number of catheterizations with intervention per patient was 1 (range, 0-14). There were no identifiable associations with need for or number of catheterizations with intervention. Ten patients were listed for lung transplantation: 4 patients were de-listed, 3 patients died waiting, and 3 patients underwent transplant.

CONCLUSIONS

Using a multimodality approach, we observed acceptable early survival after operation in patients with pulmonary vein stenosis, despite the need for catheter reinterventions. Lung transplantation remains a viable option.

Valve reconstruction for congenital mitral valve disease

The surgical treatment of mitral valve disease in children is a challenging problem. Mitral stenosis and regurgitation may occur in isolation or together. Mitral valve repair is almost always preferable to replacement. Mitral valve replacement is not an ideal alternative to repair due to limitations of size, growth, structural valve degeneration, anticoagulation and poor survival. Surgical repair of congenital mitral stenosis must address the multiple levels of obstruction, including resection of the supramitral ring, thinning of leaflets and mobilization of the subvalvular apparatus. Sometimes leaflet augmentation is required. Repair of mitral regurgitation in children may involve simple cleft closures, edge-to-edge repairs, triangular resections and annuloplasties. Techniques used in adults, such as annuloplasty bands or artificial chords, may not be appropriate for children. Overall, an imperfect mitral valve repair may be more acceptable than the negative consequences of a replacement in a child.

Risk factors for surgical site infection after delayed sternal closure

We examined the rates and risk factors for surgical site infections (SSIs) following delayed sternal closure after pediatric cardiac surgery by way of retrospective review of prospectively collected infection control data. Of 130 patients, 13.7% developed an SSI, and 6.9% developed mediastinitis following delayed sternal closure. There was a trend toward increased SSIs in patients undergoing delayed sternal closure in beds in the open bay of a pediatric intensive care unit.

β(3)-Adrenoceptor Antagonist SR59230A Attenuates the Imbalance of Systemic and Myocardial Oxygen Transport Induced by Dopamine in Newborn Lambs

Background

In neonates, the increase in O₂-delivery (DO₂) by dopamine is offset by a greater increase in O₂-consumption (VO₂). This has been attributed to β₃-adrenergic receptors in neonatal brown fat tissue. β₃ receptors in the heart have negative inotropic properties. We evaluated the effects of SR59230A, a β₃-antagonist, on the balance of systemic and myocardial O₂-transport in newborn lambs treated with dopamine.

Methods

Lambs (2–5 days old, n = 12) were anesthetized and mechanically ventilated. Heart rate (HR) and rectal temperature were monitored. VO₂ was measured by respiratory mass spectrometry and cardiac output (CO) by a pulmonary artery transonic flowmeter. Arterial, jugular bulb venous and coronary sinus blood gases and lactate were measured to calculate DO₂, O₂ extraction ratio (ERO₂), myocardial O₂ and lactate extraction ratios (mERO₂, mERlac). After baseline measurements, lambs were randomized to receive SR59230A at 5 mg/kg iv (SRG) or placebo. Both groups received incremental doses of a dopamine infusion (0–5–10–15–20 mcg/kg/min) every 15 min. Measurements were repeated at the end of each dose.

Results

After SR59230A infusion, CO and HR trended to decrease (P = 0.06), but no significant changes occurred in other parameters. Over the incremental doses of dopamine, temperature increased in both groups (P < 0.0001) but to a lesser degree in SRG (P = 0.004). CO and HR increased (P = 0.005 and 0.04) and similarly in both groups (P > 0.1). DO₂ trended to a small increase (P = 0.08). VO₂ increased in both groups (P < 0.0001) but to a lesser degree in SRG (P < 0.0001). As a result, ERO₂ increased in both groups (P < 0.0001), but to a lesser degree in SRG (P < 0.0001). mERO₂ was lower in SRG (P = 0.01) with a faster increase (P < 0.0001). mERlac was higher in SRG (P = 0.06) with a faster decrease (P = 0.04).

Conclusion

Although SR59230A tends to induce an initial drop in CO, it significantly attenuates the rise in VO₂ and hence the imbalance of systemic and myocardial O₂ transport induced by dopamine at higher doses. Studies are warranted to examine the effect of SR59230A in cases of cardiac dysfunction and increased VO₂, observed after cardiac surgery.

Aberrant right subclavian artery from an aneurysmal diverticulum of Kommerell in an 84-year-old man

The investigators describe an unusual case of tracheal and esophageal compression by atherosclerotic dilatation of the diverticulum of Kommerell associated with a congenital aberrant right subclavian artery, illustrating how aging-related vascular degenerative disease can modify the clinical manifestations of congenital anomalies in an 84-year-old man. In conclusion, the potential interactions between congenital and acquired cardiovascular disease should be considered in the evaluation of cardiovascular symptoms in the elderly population.

Results of the 1.5-ventricle repair for Ebstein anomaly and the failing right ventricle

OBJECTIVE

Repair of Ebstein anomaly and impaired right ventricular function pose challenges for the cardiac surgeon. The bidirectional cavopulmonary shunt may improve early outcomes. We reviewed our experience with the 1.5-ventricle repair in this patient population.

METHODS

Between July 1999 and March 2006, 169 patients underwent operations to repair Ebstein anomaly. Fourteen patients had a bidirectional cavopulmonary shunt constructed. The median age at operation was 6 years (17 months-57.8 years). All of the patients had severe Ebstein anomaly with dilated right-sided chambers and/or right ventricular dysfunction. The mean left ventricular ejection fraction was 54.5% (range 35%-72%). Three patients were initially referred for heart transplantation, and the bidirectional cavopulmonary shunt allowed a conventional repair.

RESULTS

Procedures included bidirectional cavopulmonary shunting (14), tricuspid valve replacement (11), tricuspid valve repair (2), and right ventricular resection (3). Shunting was planned preoperatively in 9 patients; the indication in 5 other patients was hemodynamic instability after separation from cardiopulmonary bypass. One patient died of multiple organ failure. Median follow-up in 10 patients was 18 months (3 months-6.5 years). The preoperative left ventricular ejection fraction of less than 50% improved in 3 patients to greater than 50% postoperatively.

CONCLUSIONS

The 1.5-ventricle repair can be utilized in patients with severe Ebstein anomaly and impaired right ventricular function who are at high risk for surgical treatment. We believe the bidirectional cavopulmonary shunt may be considered as a planned procedure, as an intraoperative salvage maneuver, or as an alternative to cardiac transplantation in selected patients.

Crystalloids vs. colloids in fluid resuscitation: a systematic review

OBJECTIVE

To systematically review the effects of isotonic crystalloids compared with colloids in fluid resuscitation.

DATA SOURCES

Computerized bibliographic search of published research and citation review of relevant articles.

STUDY SELECTION

All randomized clinical trials of adult patients requiring fluid resuscitation comparing isotonic crystalloids vs. colloids were included. Pulmonary edema, mortality, and length of stay were evaluated. Independent review of 105 articles identified 17 relevant primary studies of 814 patients. Weighted c about article inclusion was high (0.76).

DATA EXTRACTION

Data on population, interventions, outcomes, and methodologic quality of the studies were obtained by duplicate independent review with differences resolved by consensus. Weighted ic on the validity assessment was moderate (0.54).

DATA SYNTHESIS

No difference was observed overall between crystalloid and colloid resuscitation with respect to mortality and pulmonary edema; however, the power of the aggregated data was insufficient to detect small but potentially clinically important differences. Subgroup analysis suggested a statistically significant difference in mortality in trauma in favor of crystalloid resuscitation (relative risk 0.39, 95% confidence intervals: 0.17 to 0.89). Several methodologic issues are noteworthy regarding the primary studies, including lack of blinding (except in three studies). The type, dose, and duration of fluid administration and outcomes measured were different across these trials.

CONCLUSIONS

Overall, there is no apparent difference in pulmonary edema, mortality, or length of stay between isotonic crystalloid and colloid resuscitation. Crystalloid resuscitation is associated with a lower mortality in trauma patients. Methodologic limitations preclude any evidence-based clinical recommendations. Larger well-designed randomized trials are needed to achieve sufficient power to detect potentially small differences in treatment effects if they truly exist.

The use of glycopyrrolate in a case of intermediate syndrome following acute organophosphate poisoning

PURPOSE

This report describes a case of organophosphate intoxication refractory to atropine in which glycopyrrolate was used to reduce cholinergic symptoms, and describes the development of intermediate syndrome, an uncommon subacute complication of organophosphate poisoning.

CLINICAL FEATURES

A 44-yr-old woman presented in cholinergic crisis following malathion ingestion. Treatment was initiated with atropine and pralidoxime. Despite clinical signs of adequate atropinisation, the patient continued to have profuse bronchorrhoea, which resolved with glycopyrrolate. During her course in the intensive care unit, she displayed a subacute deterioration in neuromuscular and mental status with decrement-increment phenomenon on electromyography consistent with intermediate syndrome. The patient eventually made a complete recovery.

CONCLUSION

This case report describes the successful use of glycopyrrolate in organophosphate intoxication and the development of the intermediate syndrome, characterised by onset of weakness of neck flexors, proximal limb muscles, and respiratory muscles within one to four days after poisoning. Recognition of the syndrome is important in light of the potential for respiratory depression requiring ventilatory support.

Contribution of transmission electron microscopy to fine-needle aspiration biopsy diagnosis: comparison of cytology and combined cytology and transmission electron microscopy with final histological diagnosis

This report evaluates 74 fine-needle aspiration biopsies processed for transmission electron microscopy with subsequent surgical procedure. The specificity of diagnosis obtained by cytology alone was compared to that obtained by cytology and electro microscopy, using histologic diagnosis as the gold standard. When cytology gave a diagnosis of malignancy but could not give tumor category or type, electron microscopy could correctly give both. When cytology could give tumor category but not type, electron microscopy correctly identified type in the majority of cases. When cytology gave tumor category and type, electron microscopy confirmed the diagnosis. Transmission electron microscopy is very helpful when the cytopathologist can diagnose malignancy but cannot give tumor category and/or type. When the cytopathologist is specific in his/her diagnosis, TEM is not as helpful.