Propensity score matching comparison of laparoscopic versus open surgery for rectal cancer in a middle-income country: short-term outcomes and cost analysis.

BACKGROUND: Laparoscopic surgery for rectal cancer is associated with improved postoperative outcomes compared to open surgery; however, economic studies have yielded contradictory results. The aim of this study was to compare the clinical and economic outcomes of laparoscopic versus open surgery for patients with rectal cancer. METHODS: Propensity score matching analysis was performed in a retrospective cohort of patients who underwent elective low anterior resection for rectal cancer treatment by laparoscopic and open surgery in a single Brazilian cancer center. Matched covariates included age, gender, body mass index, pTNM stage, American Society of Anesthesiologists score, type of anesthesia, neoadjuvant chemoradiotherapy, and interval between neoadjuvant chemoradiotherapy and index surgery. The clinical and economic outcomes were evaluated. The follow-up period was within 30 days of the index procedure. The clinical outcomes were reoperation, postoperative complications, operative time, length of stay in the intensive care unit, and postoperative hospital stay. For economic outcomes, a cost analysis was used to compare the costs. RESULTS: Initially, 220 patients were evaluated. After propensity score matching, 100 patients were included in the analysis (50 patients in the open surgery group and 50 patients in the laparoscopic surgery group). There were no differences in patients' baseline characteristics. Operative time was longer for laparoscopic surgery (247 minutes vs 285 minutes, P=0.006). There were no significant differences in other clinical outcomes. The hospital costs were similar between the two groups (Brazilian reais 21,233.15 vs Brazilian reais 21,529.28, P=0.115), although the intraoperative costs were higher for laparoscopic surgery, mainly owing to the surgical devices and the theater-related costs. The postoperative costs were lower for laparoscopic surgery, owing to lower intensive care unit, ward, and reoperation costs. CONCLUSION: Laparoscopic surgery for rectal cancer is not costlier than open surgery from the health care provider's perspective, since the intraoperative costs were offset by lower postoperative costs. Open surgery tends to have a longer length of stay.

Liberal Versus Restrictive Transfusion Strategy in Critically Ill Oncologic Patients: The Transfusion Requirements in Critically Ill Oncologic Patients Randomized Controlled Trial.

OBJECTIVE: To assess whether a restrictive strategy of RBC transfusion reduces 28-day mortality when compared with a liberal strategy in cancer patients with septic shock. DESIGN: Single center, randomized, double-blind controlled trial. SETTING: Teaching hospital. PATIENTS: Adult cancer patients with septic shock in the first 6 hours of ICU admission. INTERVENTIONS: Patients were randomized to the liberal (hemoglobin threshold, < 9 g/dL) or to the restrictive strategy (hemoglobin threshold, < 7 g/dL) of RBC transfusion during ICU stay. MEASUREMENTS AND MAIN RESULTS: Patients were randomized to the liberal (n = 149) or to the restrictive transfusion strategy (n = 151) group. Patients in the liberal group received more RBC units than patients in the restrictive group (1 [0-3] vs 0 [0-2] unit; p < 0.001). At 28 days after randomization, mortality rate in the liberal group (primary endpoint of the study) was 45% (67 patients) versus 56% (84 patients) in the restrictive group (hazard ratio, 0.74; 95% CI, 0.53-1.04; p = 0.08) with no differences in ICU and hospital length of stay. At 90 days after randomization, mortality rate in the liberal group was lower (59% vs 70%) than in the restrictive group (hazard ratio, 0.72; 95% CI, 0.53-0.97; p = 0.03). CONCLUSIONS: We observed a survival trend favoring a liberal transfusion strategy in patients with septic shock when compared with the restrictive strategy. These results went in the opposite direction of the a priori hypothesis and of other trials in the field and need to be confirmed.

A comparison of the cardiopulmonary effects of pressure controlled ventilation and volume controlled ventilation in healthy anesthetized dogs.

OBJECTIVE: To compare the effects of pressure controlled ventilation (PCV) with volume-controlled ventilation (VCV) on lung compliance, gas exchange, and hemodynamics in isoflurane-anesthetized dogs. DESIGN: Prospective randomized study. SETTING: Veterinary teaching hospital. ANIMALS: Forty client-owned bitches undergoing elective ovariohysterectomy. INTERVENTIONS: Dogs were randomly assigned to be ventilated with 100% oxygen using PCV (n = 20) or VCV (n = 20). The respiratory rate was 20/min and positive end-expiratory pressure (PEEP) was 5 cm H2 O, with a tidal volume of 10 mL/kg. Cardiac output (CO) was measured using thermodilution. Cardiopulmonary and blood gas data were obtained during spontaneous ventilation and after 30 (T30) and 60 minutes (T60) of controlled ventilation. MEASUREMENTS AND MAIN RESULTS: In dogs ventilated with PCV, at T30 and T60, PIP was lower (11.4 ± 1.9 and 11.1 ± 1.5 cm H2 O, respectively) and static compliance (CST ) was higher (51 ± 7 and 56 ± 6 mL/cm H2 O, respectively) than in VCV group (PIP of 14.3 ± 1.3 and 15.5 ± 1.4 cm H2 O; CST of 34 ± 8 and 33 ± 9 mL/cm H2 O, P < 0.0001). Compared with spontaneous ventilation, both groups had decreased alveolar-arterial oxygen difference at T30 and T60 (PCV: 128 ± 32 mm Hg vs 108 ± 20 and 104 ± 16 mm Hg, respectively; VCV: 131 ± 38 mm Hg vs 109 ± 19 and 107 ± 14 mm Hg, respectively; P < 0.01), while CO was maintained at all time points. CONCLUSIONS: Compared to spontaneous ventilation, both ventilatory modes effectively improved gas exchange without hemodynamic impairment. PCV resulted in higher lung CST and lower PIP compared to VCV.

Changes in Purines Concentration in the Cerebrospinal Fluid of Pregnant Women Experiencing Pain During Active Labor.

Labor pain has been reported as a severe pain and can be considered as a model of acute visceral pain. It is well known that extracellular purines have an important role in pain signaling in the central nervous system. This study analyzes the relationship between extracellular purines and pain perception during active labor. A prospective observational study was performed. Cerebrospinal fluid (CSF) levels of the purines and their metabolites were compared between women at term pregnancy with labor pain (n = 49) and without labor pain (Caesarian section; n = 47). Control groups (healthy men and women without chronic or acute pain-n = 40 and 32, respectively) were also investigated. The CSF levels of adenosine were significantly lower in the labor pain group (P = 0.026) and negatively correlated with pain intensity measured by a visual analogue scale (r = -0.48, P = 0.0005). Interestingly, CSF levels of uric acid were significantly higher in healthy men as compared to women. Additionally, pregnant women showed increased CSF levels of ADP, GDP, adenosine and guanosine and reduced CSF levels of AMP, GTP, and uric acid as compared to non-pregnant women (P < 0.05). These findings suggest that purines, in special the nucleoside adenosine, are associated with pregnancy and labor pain.

Minimum alveolar concentrations and hemodynamic effects of two different preparations of sevoflurane in pigs.

BACKGROUND: Original sevoflurane (Sevo A) is made with water, while a generic sevoflurane (Sevocris) is produced with propylene glycol as a stabilizing additive. We investigated whether the original and generic sevoflurane preparations differed in terms of their minimum alveolar concentration (MAC) values and hemodynamic effects. METHODS: Sixteen pigs weighing 31.6+/-1.8 kg were randomly assigned to the Sevo A or Sevocris groups. After anesthesia induction via mask with the appropriate sevoflurane preparation (6% in 100% oxygen), the MAC was determined for each animal. Hemodynamic and oxygenation parameters were measured at 0.5 MAC, 1 MAC and 1.5 MAC. Histopathological analyses of lung parenchyma were performed. RESULTS: The MAC in the Sevo A group was 4.4+/-0.5%, and the MAC in the Sevocris group was 4.1+/-0.7%. Hemodynamic and metabolic parameters presented significant differences in a dose-dependent pattern as expected, but they did not differ between groups. Cardiac indices and arterial pressures decreased in both groups when the sevoflurane concentration increased from 0.5 to 1 and 1.5 MAC. The oxygen delivery index (DO(2)I) decreased significantly at 1.5 MAC. CONCLUSION: Propylene glycol as an additive for sevoflurane seems to be as safe as a water additive, at least in terms of hemodynamic and pulmonary effects.

Arterial pulse pressure variation predicting fluid responsiveness in critically ill patients.

In critically ill patients, it is important to predict which patients will have their systemic blood flow increased in response to volume expansion to avoid undesired hypovolemia and fluid overloading. Static parameters such as the central venous pressure, the pulmonary arterial occlusion pressure, and the left ventricular end-diastolic dimension cannot accurately discriminate between responders and nonresponders to a fluid challenge. In this regard, respiratory-induced changes in arterial pulse pressure have been demonstrated to accurately predict preload responsiveness in mechanically ventilated patients. Some experimental and clinical studies confirm the usefulness of arterial pulse pressure as a useful tool to guide fluid therapy in critically ill patients.

Goal-directed fluid management based on pulse pressure variation monitoring during high-risk surgery: a pilot randomized controlled trial.

INTRODUCTION: Several studies have shown that maximizing stroke volume (or increasing it until a plateau is reached) by volume loading during high-risk surgery may improve post-operative outcome. This goal could be achieved simply by minimizing the variation in arterial pulse pressure (deltaPP) induced by mechanical ventilation. We tested this hypothesis in a prospective, randomized, single-centre study. The primary endpoint was the length of postoperative stay in hospital. METHODS: Thirty-three patients undergoing high-risk surgery were randomized either to a control group (group C, n = 16) or to an intervention group (group I, n = 17). In group I, deltaPP was continuously monitored during surgery by a multiparameter bedside monitor and minimized to 10% or less by volume loading. RESULTS: Both groups were comparable in terms of demographic data, American Society of Anesthesiology score, type, and duration of surgery. During surgery, group I received more fluid than group C (4,618 +/- 1,557 versus 1,694 +/- 705 ml (mean +/- SD), P < 0.0001), and deltaPP decreased from 22 +/- 75 to 9 +/- 1% (P < 0.05) in group I. The median duration of postoperative stay in hospital (7 versus 17 days, P < 0.01) was lower in group I than in group C. The number of postoperative complications per patient (1.4 +/- 2.1 versus 3.9 +/- 2.8, P < 0.05), as well as the median duration of mechanical ventilation (1 versus 5 days, P < 0.05) and stay in the intensive care unit (3 versus 9 days, P < 0.01) was also lower in group I. CONCLUSION: Monitoring and minimizing deltaPP by volume loading during high-risk surgery improves postoperative outcome and decreases the length of stay in hospital. TRIAL REGISTRATION: NCT00479011.

Effects of preanesthetic administration of midazolam, clonidine, or dexmedetomidine on postoperative pain and anxiety in children.

BACKGROUND: A growing interest in the possible influences of pre- and postoperative anxiety and pain scores as outcomes of surgical treatment and benefits of anxiety or pain-reducing interventions has emerged. The aim of this study was to evaluate the influence of three different premedication regimens on postoperative pain and anxiety in children. METHODS: A prospective, randomized, open-label clinical trial enrolled 60 schoolchildren. They were randomized for premedication with oral midazolam 0.5 mgxkg(-1), oral clonidine 4 microgxkg(-1), or transmucosal dexmedetomidine (DEX) 1 mug.kg(-1), submitted to a pre- and postoperative evaluation of anxiety with the State-Trait Anxiety Inventory for Children and asked to report any pain in verbal and visual analog scales. We also evaluated secondary outcomes such as parents' anxiety, sedation, separation from parents, adverse effects and hemodynamic status. RESULTS: Dexmedetomidine and clonidine were related to lower scores of pain than midazolam. alpha(2)-agonists produced lower scores of peroperative mean arterial pressure and heart rate than midazolam. Both groups had similar levels of postoperative state-anxiety in children. There was no difference in preanesthesia levels of sedation and response to separation from parents between groups. CONCLUSIONS: These findings indicate that children receiving clonidine or DEX preoperatively have similar levels of anxiety and sedation postoperatively as those receiving midazolam. However, children given alpha(2)-agonists had less perioperative sympathetic stimulation and less postoperative pain than those given midazolam.

Pulse pressure variation: beyond the fluid management of patients with shock.

In anesthetized patients without cardiac arrhythmia the arterial pulse pressure variation (PPV) induced by mechanical ventilation has been shown the most accurate predictor of fluid responsiveness. In this respect, PPV has so far been used mainly in the decision-making process regarding volume expansion in patients with shock. As an indicator of the position on the Frank-Starling curve, PPV may actually be useful in many other clinical situations. In patients with acute lung injury or with acute respiratory distress syndrome, PPV can predict hemodynamic instability induced by positive end-expiratory pressure and recruitment maneuvers. PPV may also be useful to prevent excessive fluid restriction/depletion in patients with pulmonary edema, and to prevent excessive ultrafiltration in critically ill patients undergoing hemodialysis or hemofiltration. In the operating room, a goal-directed fluid therapy based on PPV monitoring has the potential to improve the outcome of patients undergoing high-risk surgery.

Pulmonary function is better preserved in pigs when acute normovolemic hemodilution is achieved with hydroxyethyl starch versus lactated Ringer's solution.

Acute normovolemic hemodilution (ANH) has been proposed to decrease the need for allogenic blood transfusion. Consequently, great amounts of fluids are necessary to maintain hemodynamics during and after blood removal. The aim of this experiment was to evaluate the oxygenation, respiratory compliance, and lung structure during ANH performed with lactated Ringer's solution and hydroxyethyl starch (HES). Gas exchange, extravascular lung water, intrathoracic blood volume, serum osmolality, respiratory mechanics, and optical and electronic microscopy of lung biopsies were evaluated. Animals were randomized into three groups: CTL (control, n = 9), HES (HES 6% 200/0.5, n = 9), and LR (lactated Ringer's solution, n = 9). Animals in groups HES and LR underwent ANH to reach a preestablished hematocrit of around 15%. The removed blood was replaced with HES in a proportion of 1:1 and with lactated Ringer's solution 3:1. The LR group demonstrated a tendency for a marked time-dependence decrease in compliance (P = 0.013 in T2; P = 0.008 in T3) and in Pao2/fraction of inspired oxygen (Fio2) ratio (P = 0.033 in T2) as well as an increase in (A-a) Grad O2 (P = 0.037 in T2). Extravascular lung water and intrathoracic blood volume did not present any significant variation among the groups. In contrast, serum osmolality presented a significant decline in animals hemodiluted with lactated Ringer's solution. Optical and electronic microscopy of lungs biopsies revealed moderate to serious collapses and basement membrane enlargement in LR group. In this kind of experimental model, ANH with 6% HES (200/0.5) seems to preserve lung structure better as evidenced by maintenance of oxygenation indexes and respiratory compliance when compared with that in the Ringer's solution hemodiluted group.

Hypertonic saline solution increases cerebral perfusion pressure during clinical orthotopic liver transplantation for fulminant hepatic failure: preliminary results.

UNLABELLED: During orthotopic liver transplantation for fulminant hepatic failure, some patients may develop sudden deterioration of cerebral perfusion and oxygenation, mainly due to increased intracranial pressure and hypotension, which are likely responsible for postoperative neurological morbidity and mortality. In the present study, we hypothesized that the favorable effects of hypertonic saline solution (NaCl 7.5%, 4 mL/kg) infusion on both systemic and cerebral hemodynamics, demonstrated in laboratory and clinical settings of intracranial hypertension and hemorrhagic shock resuscitation, may attenuate the decrease in cerebral perfusion pressure that often occurs during orthotopic liver transplantation for fulminant hepatic failure. METHODS: 10 patients with fulminant hepatic failure in grade IV encephalopathy undergoing orthotopic liver transplantation with intracranial pressure monitoring were included in this study. The effect on cerebral and systemic hemodynamics in 3 patients who received hypertonic saline solution during anhepatic phase (HSS group) was examined, comparing their data with historical controls obtained from surgical procedure recordings in 7 patients (Control group). The maximal intracranial pressure and the corresponding mean arterial pressure values were collected in 4 time periods: (T1) the last 10 min of the dissection phase, (T2) the first 10 minutes at the beginning of anhepatic phase, (T3) at the end of the anhepatic phase, and (T4) the first 5 minutes after graft reperfusion. RESULTS: Immediately after hypertonic saline solution infusion, intracranial pressure decreased 50.4%. During the first 5 min of reperfusion, the intracranial pressure remained stable in the HSS group, and all these patients presented an intracranial pressure lower than 20 mm Hg, while in the Control group, the intracranial pressure increased 46.5% (P < 0.001). The HSS group was the most hemodynamically stable; the mean arterial pressure during the first 5 min of reperfusion increased 21.1% in the HSS group and decreased 11.1% in the Control group (P < 0.001). During the first 5 min of reperfusion, cerebral perfusion pressure increased 28.3% in the HSS group while in the Control group the cerebral perfusion pressure decreased 28.5% (P < 0.001). Serum sodium at the end of the anhepatic phase and 3 hours after reperfusion was significantly higher in the HSS group (153.00 +/- 2.66 and 149.00 +/- 1.73 mEq/L) than in the Control group (143.71 +/- 3.30 and 142.43 +/- 1.72 mEq/L), P = 0.003 and P < 0.001 respectively. CONCLUSION: Hypertonic saline solution can be successfully used as an adjunct in the neuroprotective strategy during orthotopic liver transplantation for fulminant hepatic failure, reducing intracranial pressure while restoring arterial blood pressure, promoting sustained increase in the cerebral perfusion pressure.

Guidelines for inspiratory flow setting when measuring the pressure-volume relationship.

UNLABELLED: Acquisition of pressure-volume (PV) curves to improve ventilation strategy is time consuming when using static methods. Low-flow techniques use less time, but compliance values can be decreased by the resistance to flow in airways and tracheal tube (P-t). In this study, we determined the impact of three flows on the resistive component of airway pressure during anesthesia. We studied 10 ASA status P1/P2 patients with normal respiratory function. Airway and esophageal pressures were measured while volume-control ventilated with 6, 12, and 30 L/min continuous flows. PV curves, lower inflection point, respiratory system, and chest wall compliances at 250, 500, 750, and 1000 mL tidal volume were established before and after removing P-t. Data were submitted to analysis of variance. The inflection point was lower for the lower flow when comparing 6 and 12 with 30 L/min (P < 0.001). No difference was found between 6 and 12 L/min. Removal of P-t showed a difference only for 30 L/min (P = 0.004). Higher flows generated lower compliances. P-t subtraction reduced compliances only for 30 L/min. Chest wall compliances showed no difference between flows. We concluded that flows < or =12 L/min minimize P-t during intraoperative PV curves acquisition. Compliances suggest 6 L/min as the most adequate flow. IMPLICATIONS: We suggest guidelines for inspiratory flow setting when measuring the pressure-volume relationship during anesthesia based on the comparison among three different continuous flow values, aiming at better intraoperative respiratory settings in patients with normal respiratory function.

Transplante cardíaco no neonato e na infância: resultados a médio prazo / Heart transplantation in neonates and children: intermediate-term results

OBJECTIVE: To assess intermediate-term outcome in children who have undergone orthotopic heart transplantation. METHODS: We carried out a longitudinal and prospective study between October '92 and June '99 comprising 20 patients with ages ranging from 12 days to 7 years (mean of 2.8 years). We employed a double immunosuppression protocol with cyclosporine and azathioprine and induction therapy with polyclonal antithymocyte serum. Survival and complications resulting from the immunosuppression protocol were analyzed. RESULTS: The double immunosuppression protocol and the induction therapy with polyclonal antithymocyte serum resulted in an actuarial survival curve of 90 per cent and 78.2 per cent at 1 and 6 years, respectively, with a mean follow-up period of 3.6 years. One patient died due to acute rejection 40 days after transplantation; another patient died 2 years after transplantation due to lymphoproliferative disorder; a third patient died because of primary failure of the graft; and a fourth patient died due to bronchopneumonia. The major complications were as follows: acute rejection, infection, nephrotoxicity, and systemic hypertension. The means of rejection and infection episodes per patient were 2.9 and 3.4, respectively. After one year of transplantation, a slight reduction in the creatinine clearance and systemic hypertension were observed in 7 (38.9 per cent) patients. CONCLUSION: Heart transplantation made life possible for those patients with complex congenital heart diseases and cardiomyopathies in refractory congestive heart failure constituting a therapeutical option for this group of patients in the terminal phase.

Avaliaçäo hemodinâmica e evoluçäo clínica de crianças portadoras de cardiomiopatia dilatada grave candidatas a transplante cardíaco / Hemodynamic evaluation and clinical outcome of children candidates for heart transplantation with severe dilated cardiomyipathy

Objetivo - Estudar o perfil dos parâmetros hemodinâmicos e a evolução clínica de crianças candidatas a transplante cardíaco, portadoras de cardiomiopatia grave. Métodos - Foram 24 crianças, com idade entre 4 meses e 10 anos e 8 meses (média de 3,7+2,5 anos), no período de fevereiro/92 a maio/96, submetidas a estudo hemodinâmico e medidos os seguintes parâmetros: débito cardíaco, pressão média de artéria pulmonar (PMAP) e pressão capilar pulmonar. Foram calculados o índice de resistência vascular pulmonar (IRVP) e gradiente de pressão transpulmonar (GPT). Resultados - Do ponto de vista evolutivo, 10 (41,6 por cento) crianças foram transplantadas (grupo A), 5 (20,8 por cento) aguardam o transplante (grupo B) e 9 (37,6 por cento) faleceram (grupo C). Observou-se que a média das idades dos pacientes do grupo B foi significativamente menor que do grupo C. Dos dados hemodinâmicos, a PMAP, GTP e IRVP apresentaram médias significativamente menores no grupo A em relação ao grupo C. Conclusão - O perfil hemodinâmico de crianças candidatas ao transplante cardíaco mostrou-se compatível ao quadro clínico de insuficiência cardíaca grave. A idade foi o único fator que diferenciou o grupo B e C (p=0,036). O IRVP, PMAP e o GTP foram fatores que diferenciam de modo significativo o grupo A e o grupo C (p=0,010; p=0,044 e p=0,023, respectivamente). Quanto maior a idade no momento da indicação do transplante na criança, pior foi seu prognóstico.