Br J Anaesth. 2004 Mar 19   [Epub ahead of print] 

Cerebral ischaemia during cardiac surgery in children detected by combined
monitoring of BIS and near-infrared spectroscopy.

Hayashida M, Kin N, Tomioka T, Orii R, Sekiyama H, Usui H, Chinzei M, Hanaoka K.

Department of Anesthesiology, Graduate School of Medicine, University of Tokyo,
7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan; Surgical Center Research
Hospital, Institute of Medical Science, University of Tokyo, 4-6-1 Shiroganedai,
Minato-ku, Tokyo 108-8639, Japan.

BACKGROUND: Children frequently suffer transient cerebral ischaemia during
cardiac surgery. We measured cerebral ischaemia in children during cardiac
surgery by combining two methods of monitoring. METHODS: We studied 65 children
aged between 5 months and 17 yr having surgery to correct non-cyanotic heart
disease using hypothermic cardiopulmonary bypass (CPB). During surgery, we
measured the Bispectral Index (BIS) and regional cerebral haemoglobin oxygen
saturation (SrO2) with near-infrared spectroscopy (NIRS). Cerebral ischaemia was
diagnosed if both SrO2 and BIS decreased abruptly when acute hypotension
occurred. In each patient, the relationship between SrO2 and arterial blood
pressure (AP) was indicated by a plot of mean SrO2 against simultaneous mean AP.
RESULTS: We noted 72 episodes of cerebral ischaemia in 38 patients. Sixty-three
ischaemic events were during CPB. Cerebral ischaemia was less frequent in older
patients. Cerebral ischaemia was more common and more frequent in children under
4 yr old. Haematocrit during CPB was lower and SrO2 was more dependent on AP in
children under 4 yr. CONCLUSIONS: Children less than 4 yr of age are more likely
to have cerebral ischaemia caused by hypotension during cardiac surgery.
Ineffective cerebral autoregulation and haemodilution during CPB may be
responsible.

Eur J Cardiothorac Surg.  2004 Mar;25(3):415-8.  

Cardioplegic arrest does not increase the risk of atrial fibrillation after
coronary artery bypass surgery.

Hakala T, Pitkanen O, Hartikainen J.

Department of Surgery, Kuopio University Hospital and Kuopio University, P.O.
Box 1777, FIN-70211 Kuopio, Finland. tapio.hakala@kuh.fi

OBJECTIVE: Atrial fibrillation (AF) is the most common arrhythmia after coronary
artery bypass grafting (CABG). It is a considerable source of morbidity,
prolongs hospital stay and increases costs of treatment. Atrial cannulation,
cardiopulmonary bypass and cardioplegic arrest have been suggested to play a
role in the development of AF after CABG. The aim of this case-control study was
to evaluate the role of cardiopulmonary bypass and cardioplegic arrest in the
development of postoperative AF. METHODS: Data from 114 patients undergoing CABG
without cardiopulmonary bypass and cardioplegic arrest (off-pump) between
October, 1998 and December, 2002 were evaluated for the occurrence of
postoperative AF. Each patient was individually matched by gender, age (+/-3
years), left ventricle ejection fraction (+/-5%), history of myocardial
infarction, unstable angina, and beta-blocker medication with patients
undergoing CABG with cardiopulmonary bypass and cardioplegic arrest (on-pump)
during the same period. The data from off-pump and on-pump groups were compared.
RESULTS: Off-pump and on-pump groups had similar preoperative characteristics.
The number of distal anastomoses was lower in the off-pump (2.3+/-0.9) than in
the on-pump (3.9+/-1.1, (P<0.001) group. However, the incidence of postoperative
AF in the off-pump (36.8%) and the on-pump groups (36.0%) did not differ from
each other. Old age was the only independent predictor of AF after CABG.
CONCLUSIONS: Neither cardiopulmonary bypass nor cardioplegic arrest increases
the risk of postoperative AF after CABG.

J Paediatr Child Health.  2004 Mar;40(3):144-148.  

Quality assurance of paediatric cardiac surgery: A prospective 6-year analysis.

Justo R, Janes E, Sargent P, Jalali H, Pohlner P.

The Queensland Centre for Congenital Heart Disease, The Prince Charles Hospital,
Brisbane, Queensland, Australia.

OBJECTIVE: To audit effective quality assurance methods to monitor outcomes
following paediatric cardiac surgery at a single institution. METHODS: All
patients undergoing cardiac surgery from January 1996 to December 2001 were
enrolled prospectively. Patients were stratified by complexity of surgical
procedure into four groups, with Category 4 being the most complex procedure.
Outcome measures included death, length of admission and morbidity from
complications. RESULTS: A total of 1815 patients underwent 1973 surgical
procedures. Of these, 1447 (73.3%) were cardiopulmonary bypass procedures, and
543 (27.5%) were more complex (Category 3 and 4) procedures. Median patient age
was 3.5 years (range, 1 day-20 years) and patient weight 15.0 kg (range, 900 g
to 90 kg). Sixty-six patients (3.6%) died during the study period. Of the
procedures in 1996, 22.7% were classified as complex compared with 29.2% of
procedures in 2001. The annual surgical mortality ranged from 1.9-4.7% (P =
0.20), and when mortality was adjusted for complexity of surgery, there was no
significant yearly variation in the mortality rate (P = 0.57). Analysis of
individual surgeon's results showed no significant difference in the mortality
rate by complexity of surgery performed (P = 0.90). Mean ventilation times did
not change significantly over time (P = 0.79). The yearly incidence of
significant neurological complications ranged from 0.6% to 4.5% and the
incidence of arrhythmias from 4.2% to 8.0%. No difference was detected between
the years. CONCLUSIONS: Stratifying complexity of surgery proved valuable in
monitoring surgical outcomes and detecting differences in performance over time
as large subgroups were created for analysis.

J Thorac Cardiovasc Surg.  2004 Mar;127(3):812-22.  

The Impella Recover microaxial left ventricular assist device reduces mortality
for postcardiotomy failure: a three-center experience.

Siegenthaler MP, Brehm K, Strecker T, Hanke T, Notzold A, Olschewski M, Weyand
M, Sievers H, Beyersdorf F.

Department of Cardiovascular Surgery, University of Freiburg, Hugstetterstrasse
55, 79106 Freiburg, Germany. siegenth@ch11.ukl.uni-freiburg.de

BACKGROUND: We evaluated patient outcomes and complications associated with the
microaxial Impella Recover left ventricular assist device (Impella Cardiosystems
AG, Aachen, Germany) for postcardiotomy low-output syndrome. This low-cost
device is inserted across the aortic valve through a 10-mm vascular graft sewn
to the ascending aorta. METHODS: Impella patients were compared with 198
patients treated with an intraoperative intra-aortic balloon pump between
January 2000 and December 2002. Three risk scores were used: the Hausmann score,
the Texas Heart Institute score, and the Cleveland intensive care unit score.
Between September 2001 and March 2003, 24 patients were treated with the Impella
Recover for low-output syndrome. Before device insertion, 21 could not be
separated from cardiopulmonary bypass, and 3 had postoperative hemodynamic
instability despite high-dose catecholamines. Sixteen were treated with the
Impella and intra-aortic balloon pump and 8 with the Impella alone (no
intra-aortic balloon pump because of peripheral vascular disease or because
deemed unnecessary). RESULTS: No technical problems with device insertion
occurred. Pump flow was 3.3 +/- 0.7 L/min at 28,000 +/- 4500 RPM. Support time
was 61 +/- 56 hours (range, 7-228 hours). Four devices required repositioning.
One device failed (leaking purge line) and was removed. Hemolysis was minimal
(lactate dehydrogenase levels of 540 +/- 260 U/dL for Impella survivors).
Mortality for Impella patients was 54% (13/24), similar to that for high-risk
intra-aortic balloon pump patients (Hausmann score > or =2 [57%], intensive care
unit score > or =2 [51%], Texas Heart Institute score > or =0.75 [55%], and
cardiac index < or =2.3 [45%]). Cardiac output data were available in 19 Impella
patients. Impella patients able to increase their cardiac output to 1 L/min or
more above the pump flow of the Impella Recover had a 10% (1/10) mortality,
versus 88% (8/9) in patients with a residual cardiac function of 1 L/min or less
(P =.001). Comparison of high-risk intra-aortic balloon pump patients with
Impella patients with residual cardiac function of 1 L/min or more showed a
significant reduction in mortality, regardless of the high-risk definition used.
Residual cardiac function was the strongest predictor of survival in Impella
patients. CONCLUSIONS: The Impella Recover device provides 3 to 4 L/min flow. It
improves survival in patients with low-output syndrome if the heart is able to
pump 1 L/min or more above device flow.

J Thorac Cardiovasc Surg.  2004 Mar;127(3):738-45.  

Alteration of the critical arteriovenous oxygen saturation relationship by
sustained afterload reduction after the Norwood procedure.

Hoffman GM, Tweddell JS, Ghanayem NS, Mussatto KA, Stuth EA, Jaquis RD, Berger
S.

Department of Anesthesiology, Pediatric Anesthesiology and Critical Care
Medicine, Children's Hospital of Wisconsin, #735, 9000 West Wisconsin Avenue,
Milwaukee, WI 53226, USA. ghoffman@mcw.edu

OBJECTIVES: Hemodynamic vulnerability after the Norwood procedure for
hypoplastic left heart syndrome results from impaired myocardial function, and
critical inefficiency of parallel circulation. Traditional management strategies
have attempted to optimize circulatory efficiency by using arterial oxygen
saturation (SaO(2)) as an index of pulmonary/systemic flow balance, attempting
to maintain SaO(2) within a theoretically optimal critical range of 75% to 80%.
This optimal range of SaO(2) has not been verified clinically, and strategies
targeting SaO(2) may be limited by the fact that SaO(2) is a poor predictor of
systemic oxygen delivery. We have previously reported higher venous saturation
(SvO(2)), lower arteriovenous oxygen content difference, lower systemic vascular
resistance, lower pulmonary/systemic flow ratio, and improved survival with the
perioperative use of phenoxybenzamine and continuous monitoring of SvO(2). In
this investigation, we tested the hypothesis that intense afterload reduction
with phenoxybenzamine would modify the SvO(2)-SaO(2) relationship by preventing
deterioration of systemic oxygen delivery at high SaO(2). METHODS: Seventy-one
consecutive neonates undergoing the Norwood procedure with and without
phenoxybenzamine were studied. Perioperative hemodynamic management targeted
SvO(2) greater than 50%. Hemodynamic data were prospectively acquired for 48
hours postoperatively and analyzed to assess the effect of phenoxybenzamine on
the relationship between SaO(2) and SvO(2) and other hemodynamic indices.
Sixty-two patients received phenoxybenzamine 0.25 mg/kg on cardiopulmonary
bypass; 9 who did not served as controls. RESULTS: In control patients, SvO(2)
peaked at an SaO(2) of 77%, with reduced SvO(2) at SaO(2) > 85% and SaO(2) < 70%
(P <.01), while arteriovenous oxygen content difference increased with SaO(2)
greater than 80% (P <.001). In patients receiving phenoxybenzamine, the SvO(2)
increased linearly with SaO(2) greater than 65% (P <.001), and arteriovenous
oxygen content difference was constant at all SaO(2) (P = ns). The SvO(2) was
higher, and the arteriovenous oxygen content difference lower, across the whole
SaO(2) range with phenoxybenzamine (P <.0001). CONCLUSIONS: A critical range of
SaO(2) for optimizing systemic oxygen delivery was confirmed in control
patients, and was effectively eliminated by phenoxybenzamine, specifically by
eliminating the systemic hypoperfusion associated with high SaO(2). This effect
allows higher SaO(2) to be included in a rational hemodynamic strategy to
improve systemic oxygen delivery in the early postoperative management of
patients receiving intense afterload reduction with phenoxybenzamine. The
predictability of SvO(2) from SaO(2) is low in both groups, emphasizing the
importance of SvO(2) measurement in these patients.

Ann Thorac Surg.  2004 Mar;77(3):988-93.  

New technique of right heart bypass in congenital heart surgery with autologous
lung as oxygenator.

Shivaprakasha K, Rameshkumar I, Kumar RK, Nair SG, Koshy S, Sunil GS, Rao SG.

Department of Pediatric Cardiac Sciences, Kerala, India.
shivaprakashak@aimshospital.org

BACKGROUND: Modifications have been made in cardiopulmonary circuit to reduce
the inflammatory deleterious effects and cost. We present our experience of one
such right heart bypass (RHB) circuit utilizing autologus lung as oxygenator.
METHODS: From September 2001 to December 2002, 15 patients underwent congenital
heart surgery with this technique. Bypass circuit consisted of a reservoir and a
roller pump along with a cardiotomy sucker. The left pulmonary artery and main
pulmonary artery were used for arterial return, and venous drainage was achieved
with innominate vein cannulation. Inferior vena cava cannulation was performed
when needed. Thirteen patients underwent bidirectional Glenn shunt surgery (12
to 24 months, 6 to 10 kg). One patient (26 years old) underwent central shunt
with enlargement of confluence and left pulmonary artery. Another patient (18
months old) underwent 1.5 ventricle repair. RESULTS: There were no hospital
deaths. Mean flow achieved on RHB was 0.57 +/- 0.3 L/min/m(2), central venous
pressure was 3.3 +/- 1.8 mm Hg (0 to 7 mm Hg), and mean arterial pressure could
be maintained satisfactorily in all patients (54 +/- 14 mm Hg). Mean RHB time
was 54 +/- 14 min. Mean central venous pressure was 10.1 +/- 2.4 mm Hg after
procedure and saturation was similar to that on (RHB 88% +/- 8%). The mean
amount of drainage was 9.1 +/- 4.2 mL/kg per 24 hours. Avoiding an oxygenator
and reducing the number of tubings achieved a combined cost savings of 40% for
all procedures. CONCLUSIONS: Right heart bypass is a simple, safer, and less
expensive alternative to conventional cardiopulmonary bypass. This technique
allows effective decompression of superior vena cava, adequate oxygenation, and
predicts saturation after Glenn shunt. It can also be applied for central shunts
and pulmonary artery reconstructions with cost containment.

Ann Thorac Surg.  2004 Mar;77(3):983-7; discussion 987.  

Fresh frozen plasma in the pediatric pump prime: a prospective, randomized
trial.

McCall MM, Blackwell MM, Smyre JT, Sistino JJ, Acsell JR, Dorman BH, Bradley SM.

Cardiovascular Perfusion Program, Department of Anesthesia, Charleston, South
Carolina, USA.

BACKGROUND: The aim of this study was to determine whether the use of fresh
frozen plasma (FFP) in the infant pump prime can avoid dilution of fibrinogen,
decrease the need for blood product transfusion after bypass, and decrease
exposure to donor blood products. METHODS: Twenty infants weighing less than 8
kg were prospectively randomized to receive either 1 U of FFP (10 patients) or
no FFP (10 patients) in the pump prime. Mean age (4.2 +/- 2.8 months), weight
(4.3 +/- 1.1 kg), total prime volume (641 +/- 96 ml), cardiopulmonary bypass
time, cross-clamp time, lowest temperature on bypass, and preoperative
coagulation parameters did not differ between the two groups. RESULTS: At the
end of bypass, the mean fibrinogen level was significantly higher in the FFP
than the no FFP group (123 +/- 20 versus 58 +/- 17 mg/dL; p < 0.0001), whereas
the mean platelet count did not differ (60 +/- 25 versus 52 +/- 26 K/mm(3); p =
0.5). Patients in the FFP group received significantly fewer units of
cryoprecipitate (0.4 +/- 0.8 versus 2.0 +/- 0.9 U/patient; p < 0.001), and had a
mean total donor exposure of 4.1 +/- 1.5 U/patient versus 5.4 +/- 1.4 U/patient
in the no FFP group (p = 0.06). The mean chest tube output over the first 24
hours did not differ between groups. CONCLUSIONS: The use of FFP in the pump
prime significantly limited dilutional hypofibrinogenemia, decreased the
transfusion of cryoprecipitate after bypass, and tended to decrease the overall
mean patient exposure to blood products.

Ann Thorac Surg.  2004 Mar;77(3):956-61.  

Neutrophil depletion reduces myocardial reperfusion morbidity.

Palatianos GM, Balentine G, Papadakis EG, Triantafillou CD, Vassili MI, Lidoriki
A, Dinopoulos A, Astras GM.

Third Department of Cardiac Surgery, Onassis Cardiac Surgery Center, Athens,
Greece. palantianos@otenet.gr

BACKGROUND: We tested the hypothesis that depletion of neutrophil leukocytes
from the cardioplegic and the initial myocardial reperfusion perfusates reduces
clinical indices of reperfusion injury in patients undergoing elective coronary
artery bypass. METHODS: We studied 160 consecutive patients who underwent
standard coronary revascularization with cardiopulmonary bypass. Patients with
recent myocardial infarction or coronary angioplasty were excluded. Cold blood
cardioplegia was used. Just before aortic unclamping, the hearts were perfused
retrograde with 250 mL of normothermic cardioplegic solution and 750 mL of blood
(pump perfusate). Patients were randomly assigned to two groups. In 80 patients
(treated), neutrophils and platelets were removed from all cardiac perfusate
during aortic crossclamping with leukocyte filtration. In the remaining 80
patients (control group), leukocyte filtration was not used. RESULTS: There was
no significant difference between groups in age, sex, severity of disease, and
number of bypass grafts implanted. Treated patients showed lower prevalence of
low cardiac index and reperfusion ventricular fibrillation and lower levels of
creatinine kinase MB isoenzyme and troponin I early postoperatively (p < 0.05).
CONCLUSIONS: Neutrophil-filtered blood cardioplegia/reperfusion significantly
reduced clinical and biochemical indices of myocardial reperfusion injury after
elective coronary revascularization with cardiopulmonary bypass.

Pediatr Crit Care Med.  2004 Mar;5(2):157-62.  

Inhaled nitric oxide results in deteriorating hemodynamics when administered
during cardiopulmonary bypass in neonatal swine.

Hubble CL, Cheifetz IM, Craig DM, Quick G, Meliones JN, Clark RH.

Department of Pediatrics, Division of Pediatric Critical Care Medicine (CLH,
IMC, JNM), Department of Surgery, Division of Cardiovascular Surgery (DMC, GQ),
and Department of Pediatrics, Division of Neonatology, Duke University Medical
Center, Durham, NC.

OBJECTIVE: To evaluate if inhaled nitric oxide (iNO) has a lung-protective
effect when it is delivered during the ischemic phase of neonatal
cardiopulmonary bypass (CPB). DESIGN: Prospective, randomized, controlled study.
SETTING: Surgical research laboratory in a university hospital. SUBJECTS:
Thirty-five neonatal swine. INTERVENTIONS: One-week-old swine (2.1-3.4 kg) were
exposed to cool, low-flow CPB bypass designed to mimic the bypass used during
neonatal congenital heart repair. Animals were randomized to four groups: a) CPB
without exposure to iNO (n = 9); b) iNO delivery only during CPB with
discontinuation of iNO at the start of reperfusion (n = 7); c) iNO delivery both
during CPB and during the 90-min post-CPB observation period (n = 7); and d) iNO
delivery only after separation from CPB (n = 7). Each animal was placed on
nonpulsatile CPB and cooled to a nasopharyngeal temperature of 18 degrees C (64
degrees F). Low-flow CPB (35 mL.kg(-1).min(-1)) was instituted for 90 mins. The
blood flow then was returned to 100 mL.kg(-1).min(-1), and the animals were
warmed to 36 degrees C (96.8 degrees F) before separation from CPB. Animals were
followed 90 mins post-CPB. Lung tissue was harvested and evaluated for
myeloperoxidase activity, wet/dry weight, and lung pathology. Five animals
underwent sham protocol, receiving instrumentation but not exposure to CPB or
iNO. MEASUREMENTS AND MAIN RESULTS: We measured pulmonary vascular resistance,
right ventricular output, and pulmonary artery pressure in all animals at 30,
60, and 90 mins following separation from CPB. Study animals that received iNO
during the ischemic period of CPB were not protected against CPB-induced lung
injury. Those animals treated with iNO both during and after CPB trended worse
than those receiving iNO only after CPB. Inhaled nitric oxide delivered only
after separation from CPB improved the hemodynamic variables compared with all
other groups. Differences in lung wet/dry weight, myeloperoxidase, and pathology
were not significantly different among groups. CONCLUSIONS: The delivery of iNO
during the ischemic period of CPB does not protect against CPB-induced lung
injury in a neonatal piglet CPB model. Delivery of iNO during this phase of CPB
may, in fact, worsen the post-CPB hemodynamic condition. Inhaled nitric oxide
should be used with caution during periods of low pulmonary blood flow CPB.
Inhaled nitric oxide remains effective for reducing pulmonary vascular
resistance after CPB.