Can haemodialysis-induced hypotension be predicted?

BACKGROUND: During haemodialysis (HD) ultrafiltration may affect the central blood volume to an extent that blood pressure decreases. Thoracic electrical impedance (TI) is applied to monitor the central blood volume and we evaluated if it can be used to predict HD-induced hypotension. METHODS: In 12 hypotensive prone (H) and 13 non-hypotensive prone (N) patients, blood pressure and heart rate were recorded during one dialysis session every 30 min, while TI, thoracic intracellular water (Th(ICW)) and total body impedance (TBI) were followed every 10 min. Hypotension was defined as a decrease in systolic blood pressure (SAP) >/=30 mm Hg or a SAP < 90 mm Hg. RESULTS: All 12 H patients developed hypotension after 190 +/- 10 min (mean +/- SE) as SAP decreased 35 +/- 5 mm Hg, while the 13 N patients maintained blood pressure. TBI increased in all patients and the increase was similar (60 +/- 5 and 56 +/- 6 Omega in H and N patients, respectively). In N patients TI did not change significantly for the first 2 h of HD, while it became elevated by 2.8 +/- 0.6 Omega (1.5 kHz) and 2.3 +/- 0.7 Omega (100 kHz) by the end of the dialysis. In H patients, the increase in TI took place at the onset of HD to reach higher values (by 7.0 +/- 0.5 Omega at 1.5 kHz and 5.9 +/- 0.5 Omega at 100 kHz). Th(ICW) was changed only in H patients (decreased by 7.9 +/- 2.1 Siemens (S) 10(-4), p < 0.05), while HR increased (9 +/- 2 beats/min) in 8 of 12 H patients, while it decreased in 1 patient (by 9 beats/min). CONCLUSIONS: The results suggest that in HD patients hypotension is elicited by a reduction in the central blood volume that affects heart rate and the distribution of red cells within the body. To prevent HD-induced hypotention, the ultrafiltration rate could be reduced when an increase in thoracic impedance approaches 5 Omega, or when an index of intracellular water decreases by 6 10(-4).     

Can parathyroid hyperplasia be predicted preoperatively?

Introduction

The purpose of this study was to determine if there are clinical features that raise suspicion for parathyroid hyperplasia.

Can ultrasound be useful for predicting the size of a left double-lumen bronchial tube? Tracheal width as measured by ultrasonography versus computed tomography

STUDY OBJECTIVE: To correlate tracheal width as measured by ultrasound with width measured by computed tomography (CT), and to evaluate the possible role of ultrasound in the selection of the proper size of left-sided double-lumen endotracheal tubes (LDLTs). DESIGN: Two independent, prospective, observational clinical studies (Study 1 and Study 2). SETTING: University hospital. PATIENTS: Study 1 included 25 patients and Study 2 included 20 adult thoracic surgery patients who required a LDLT during anesthesia. INTERVENTIONS AND MEASUREMENTS: In Study 1, CT measurements of tracheal width were made at the coronary plane 0.5 cm above the sternoclavicular joint; CT measurements of the left main bronchus diameter were made 1 cm below the carina. Ultrasound measurement of tracheal width was performed just above the sternoclavicular joint in the transversal section. In Study 2, patients' tracheas were intubated with a LDLT based on ultrasound measurements. The frequencies of incorrect selections of LDLT and unsatisfactory lung collapse were analyzed. MAIN RESULTS: There was a strong correlation between tracheal width as measured by ultrasound and tracheal width (r=0.882, P<0.001) and left main bronchus width (r=0.832, P<0.001) as measured by CT. In 5 cases (25%), the incorrect LDLT by ultrasound was selected; and one (5%) was found to have an unsatisfactory lung collapse. CONCLUSION: Measurement of the outer tracheal width by ultrasound can be a useful method for predicting the diameter of left main bronchus and for selecting a LDLT.     

Can postoperative nausea and vomiting be predicted?

BACKGROUND: Iletrospective studies fail to identify predictors of postoperative nausea and vomiting (PONV). The authors prospectively studied 17,638 consecutive outpatients who had surgery to identify predictors. METHODS: Data on medical conditions, anesthesia, surgery, and PONV were collected in the post-anesthesia care unit, in the ambulatory surgical unit, and in telephone interviews conducted 24 h after surgery. Multiple logistic regression with backward stepwise elimination was used to develop a predictive model An independent set of patients was used to validate the model RESULTS: Age (younger or older), sex (female or male), smoking status (nonsmokers or smokers), previous PONV, type of anesthesia (general or other), duration of anesthesia (longer or shorter), and type of surgery (plastic, orthopedic shoulder, or other) were independent predictors of PONV. A 10-yr increase in age decreased the likelihood of PONV by 13%. The risk for men was one third that for women. A 30-min increase in the duration of anesthesia increased the likelihood of PONV by 59%. General anesthesia increased the likelihood of PONV 11 times compared with other types of anesthesia. Patients with plastic and orthopedic shoulder surgery had a sixfold increase in the risk for PONV. The model predicted PONV accurately and yielded an area under the receiver operating characteristic curve of 0.785+/-0.011 using an independent validation set. CONCLUSIONS: A validated mathematical model is provided to calculate the risk of PONV in outpatients having surgery. Knowing the factors that predict PONV will help anesthesiologists determine which patients will need antiemetic therapy.     

Can persisting detrusor hyperreflexia be predicted after transurethral prostatectomy for benign prostatic hypertrophy?

Detrusor hyperreflexia (DH) is frequently found in patients with benign prostatic hypertrophy (BPH) and persists in 30-50% of patients after successful removal of bladder neck obstruction by transurethral prostatectomy (TUR-P) or surgical enucleation of the prostate. It would be beneficial for surgeons to be able to identify patients who are at risk of persistent post-operative urinary irritation symptoms and DH. Twenty-three patients who showed DH pre-operatively were included in this study. Of these 23 patients, four had neurogenic bladder because of previous cerebrovascular disease. The other 19 patients were considered to have DH because of BPH. These 19 patients were classified according to their cystometry chart patterns. Pattern 1 was the continual sporadic onset and offset of DH, pattern 2 was a single episode of DH at a bladder volume of <160 mL, and pattern 3 was a single DH episode at a bladder volume >160 mL. Preoperative single-photon emission computed tomography (SPECT) was performed on 14 patients. Cystometric findings at 3 to 6 months after surgery were compared with the pre-operative findings. Four of the six patients with pattern 2 (67%) and all patients with pattern 3 (100%) showed an absence of DH after surgery. In contrast, all five patients with pattern 1 and all four patients with neurogenic bladder showed persistent DH. Compared with pattern 3 patients, pattern 1 patients more frequently complained of urgency before surgery, and their symptoms and uroflowmetry parameters did not improve afterward. Among 14 patients who had pre-operative SPECT, all eight patients with low cerebral blood flow in the frontal region showed persisting DH. Conversely, all six patients with normal SPECT results showed no DH after surgery. When DH occurs repeatedly (pattern 1) or occurs at a bladder volume of <160 mL (pattern 2), there is a greater risk of post-operative irritation symptoms. Abnormal SPECT findings can also predict the post-operative persistence of DH. Combing these two pre-operative examinations allows us to predict better post-operative DH in patients with BPH.     

Can the outcome of carpal tunnel release be predicted?

Between 1994 and 1996 we performed a prospective study on the effect of carpal tunnel release on the health status of 96 patients. The Nottingham Health Profile, a validated global scoring system, was used to assess quality of life before, and at 4 months after surgery. Carpal tunnel syndrome had a significant impact on the health status of our patients. There were significant improvements in the scores for pain, energy and sleep. Patients who were dissatisfied following surgery had significantly higher pre-operative scores, indicating poor perceived health status. Our findings show that outcome assessment tools have predictive value in identifying patients who may not benefit from surgery, or in whom a poor result might be anticipated.     

Can progression of valvar aortic stenosis be predicted accurately?

BACKGROUND: It was the aim of the present study to elaborate criteria for the assessment of rapid hemodynamic progression of valvar aortic stenosis. These criteria are of special importance when cardiac surgery is indicated for other reasons but the established criteria for aortic valve replacement are not yet fulfilled. Such aspects of therapeutic planing were mostly disregarded in the past so that patients had to undergo cardiac reoperation within a few years. METHODS: Hemodynamic, echocardiographic, and clinical data of 169 men and 88 women with aortic stenosis, aged 55.2 +/- 15.7 years at their first and 63.4 +/- 15.6 years at their second cardiac catheterization, were analyzed. RESULTS: The progression rate of aortic valve obstruction was found to be dependent on the degree of valvar calcification ([VC] scoring 0 to III) and to be exponentially correlated with the aortic valve opening area (AVA) at initial catheterization. Neither age nor sex of the patient nor etiology of the valvar obstruction significantly influence the progression of aortic stenosis. If AVA decreases below 0.75 cm(2) with a present degree of VC = 0, or AVA of 0.8 with VC of I, AVA of 0.9 with VC of II, or AVA of 1.0 with VC of III, it is probable that aortic stenosis will have to be operated upon in the following years. CONCLUSIONS: The present data indicate that for clinical purposes and planning of valvar surgery the progression of asymptomatic aortic stenosis can be sufficiently predicted by the present aortic valve opening area and the degree of valvar calcification.     

Can initial tacrolimus trough levels be predicted from clinical variables?

In eligible patients, cardiac transplantation has become the definitive treatment for end-stage heart failure. The initial posttransplantation course is marked by many potential difficulties, including renal insufficiency, hemodynamic instability, and perioperative bleeding. It is important to prevent early rejection; calcineurin inhibitors, such as tacrolimus or cyclosporine, are integral parts of such management. However, these drugs are associated with renal toxicity in some patients. Previous work suggests that limiting the increase in tacrolimus levels is associated with less renal insufficiency. The hypothesis of the current study was that a combination of clinical or laboratory variables could identify patients at risk for rapid changes in tacrolimus target levels. No single variable was strongly associated with high resultant trough levels following a standard 1-mg oral "test dose" of tacrolimus. However, the combination of 2 indices of liver metabolism (alanine aminotransferase and total bilirubin) along with serum creatinine did identify patients who tended toward elevated levels of tacrolimus (> or =4.5 ng/dL). Other variables, such as demographics, and even functional variables, such as right ventricular function by echocardiography, did not enhance the predictive value of this simple scoring system.     

Can biliary-cyst communication be predicted before surgery for hepatic hydatid disease: does size matter?

Background

The aim of this study was to determine if there is any predictive factor indicating the risk of bile leakage before surgery for hepatic hydatid disease in clinically asymptomatic patients.

Methods

The data of 116 patients who underwent surgery for hepatic hydatid disease were reviewed retrospectively. There were 43 men (37%) and 73 women (63%) with a mean age of 45 ± 15 years. Because of high preoperative serum bilirubin and liver function test levels, 12 patients were excluded from the study. These patients underwent preoperative endoscopic retrograde cholangiopancreatography. In addition, 2 medically treated patients were excluded from the study. The following variables were analyzed as potential predictors of biliary-cyst communication: age, sex, physical examination findings, leukocyte count, liver function test results, and ultrasonographic cyst features (type, diameter, number, and localization).

Results

Bile leakage was detected in 24 out of 102 patients. There were no differences in age, sex, cyst type, alkaline phosphatase level, γ-glutamyl transpeptidase level, alanine aminotransferase level, aspartate aminotransferase level, bilirubin level, and number of cysts and cyst locations between the patients with and without bile leakage. The mean cyst size in patients with biliary leakage was 10.2 cm as compared with 6.1 cm in patients with no biliary leakage (P < .05). When the cut-off value of cyst diameter was accepted as 7.5 cm, the specificity and sensitivity for biliary-cyst communication were 73% and 79%, respectively.

Conclusions

These data suggest that cyst diameter is an independent factor that is associated with a high risk of biliary-cyst communication in clinically asymptomatic patients. Preoperative endoscopic retrograde cholangiopancreatography should be performed in these asymptomatic patients to reduce the incidence of postoperative complications.     

Can fecal continence be predicted in patients born with anorectal malformations?

PurposeThe purpose of this study was to identify factors associated with attaining fecal continence in children with anorectal malformations (ARM).MethodsWe performed a multi-institutional cohort study of children born with ARM in 2007–2011 who had spinal and sacral imaging. Questions from the Baylor Social Continence Scale were used to assess fecal continence at the age of ≥ 4 years. Factors present at birth that predicted continence were identified using multivariable logistic regression.ResultsAmong 144 ARM patients with a median age of 7 years (IQR 6–8), 58 (40%) were continent. The rate of fecal continence varied by ARM subtype (p = 0.002) with the highest rate of continence in patients with perineal fistula (60%). Spinal anomalies and the lateral sacral ratio were not associated with continence. On multivariable analysis, patients with less severe ARM subtypes (perineal fistula, recto-bulbar fistula, recto-vestibular fistula, no fistula, rectal stenosis) were more likely to be continent (OR = 7.4, p = 0.001).ConclusionType of ARM was the only factor that predicted fecal continence in children with ARM. The high degree of incontinence, even in the least severe subtypes, highlights that predicting fecal continence is difficult at birth and supports the need for long-term follow-up and bowel management programs for children with ARM.Type of StudyProspective Cohort Study.Level of EvidenceII.     

Can failure of percutaneous drainage of postoperative abdominal abscesses be predicted?

BACKGROUND: Percutaneous drainage (PD) of complex postoperative abscesses associated with a variety of factors such as multiple location or enteric fistula remains a matter of debate. Accordingly, this retrospective study was designed to determine the predictive factors for failure of PD of postoperative abscess, in order to better select the patients who may benefit from PD. METHODS: From 1992 to 2000, the data of 73 patients who underwent computed tomography (CT)-guided PD for postoperative intra-abdominal abscess, were reviewed. PD was considered as failure when clinical sepsis persisted or subsequent surgery was needed. The possible association between failure of PD and 27 patient-, abscess-, surgical-, and drainage-related variables were assessed using univariate and multivariate analysis. RESULTS: Successful PD was achieved in 59 of 73 (81%) patients. The overall mortality was 3% but no patient died after salvage surgery. Multivariate analysis showed that only an abscess diameter of less than 5 cm (P = 0.042) and absence of antibiotic therapy (P = 0.01) were significant predictive variables for failure of PD. CONCLUSIONS: CT-guided PD associated with antibiotic therapy could be attempted as the initial treatment of postoperative abdominal abscesses even in complex cases such as loculated abscess or abscess associated with enteric fistula.